piperidines and Apnea

Multiple analgesic strategies for pain relief during labour are available. Recently remifentanil, a short-acting opioid, has recently been used as an alternative analgesic due to its unique pharmacological properties.. To systematically assess the effectiveness of remifentanil intravenous patient-controlled analgesia (PCA) for labour pain, along with any potential harms to the mother and the newborn.. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (9 December 2015), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), handsearched congress abstracts (November 2015), and reference lists of retrieved studies.. Randomised controlled trials (RCTs) and cluster-randomised trials comparing remifentanil (PCA) with another opioid (intravenous (IV)/intramuscular (IM)), or with another opioid (PCA), or with epidural analgesia, or with remifentanil (continuous IV), or with remifentanil (PCA, different regimen), or with inhalational analgesia, or with placebo/no treatment in all women in labour including high-risk groups with planned vaginal delivery.. Two review authors independently assessed trials for inclusion, extracted data, and appraised study quality.We contacted study authors for additional information other than incomplete outcome data. We performed random-effects meta-analysis.To reduce the risk of random error in meta-analysis we performed trial sequential analysis. We included total zero event trials and used a constant continuity correction of 0.01 (ccc 0.01) for meta-analysis. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach to assess the quality of evidence.. Twenty RCTs with 3569 women were included. Of those, 10 trials (2983 participants) compared remifentanil (PCA) to an epidural, four trials (216 participants) to another opioid (IV/IM), three trials (215 participants) to another opioid (PCA), two trials (135 participants) to remifentanil (continuous IV), and one trial (20 participants) to remifentanil (PCA, different regimen). No trials were identified for the remaining comparisons.Methodological quality of studies was moderate to poor. We assessed risk of bias as high for blinding issues and incomplete outcome data in 65% and 45% of the included studies, respectively.There is evidence of effect that women in the remifentanil (PCA) group were more satisfied with pain relief than women in the other opioids (IV/IM) group (standardised mean difference (SMD) 2.11, 95% confidence interval (CI) 0.72 to 3.49, four trials, very low-quality evidence), and that women were less satisfied compared to women in the epidural group (SMD -0.22, 95% CI -0.40 to -0.04, seven trials, very low-quality evidence).There is evidence of effect that remifentanil (PCA) provided stronger pain relief at one hour than other opioids administered IV/IM (SMD -1.58, 95% CI -2.69 to -0.48, three trials, very low-quality evidence) or via PCA (SMD -0.51, 95% CI -1.01 to -0.00, three trials, very low-quality evidence). Pain intensity was higher in the remifentanil (PCA) group compared to the epidural group (SMD 0.57, 95% CI 0.31 to 0.84, six trials, low-quality evidence).Data were limited on safety aspects for both the women and the newborns. Only one study analysed maternal apnoea in a comparison of remifentanil (PCA) versus epidural and reported that half of the women in the remifentanil and none in the epidural group had an apnoea (very low-quality evidence). There is no evidence of effect that remifentanil (PCA) was associated with an increased risk for maternal respiratory depression when compared to epidural analgesia (RR 0.91, 95% CI 0.51 to 1.62, ccc 0.01, three trials, low-quality evidence) and no reliable conclusion might be reached compared to remifentanil (continuous IV) (all study arms included zero events, two trials, low-quality evidence). In one trial of remifentanil (PCA) versus another opioid (IM) three out of 18 women in the remifentanil and none out of 18 in the control group had a respiratory depression (very low-quality evidence).There is no evidence of effect that remifentanil (PCA) was associated with an increased risk f. Based on the current systematic review, there is mostly low-quality evidence to inform practice and future research may significantly alter the current situation. The quality of evidence is mainly limited by poor quality of the studies, inconsistency, and imprecision. More research is needed on maternal and neonatal safety outcomes (maternal apnoea and respiratory depression, Apgar score) and on the optimal mode and regimen of remifentanil administration to provide highest efficacy with reasonable adverse effects for mothers and their newborns.

Topics: Analgesia, Epidural; Analgesia, Obstetrical; Analgesia, Patient-Controlled; Analgesics, Opioid; Apnea; Cesarean Section; Female; Humans; Infant, Newborn; Labor Pain; Pain Measurement; Patient Satisfaction; Piperidines; Pregnancy; Randomized Controlled Trials as Topic; Remifentanil

Electrical cardioversion is an effective procedure for restoring normal sinus rhythm in the hearts of patients with irregular heart rhythms. It is important that the patient is not fully conscious during the procedure, as it can be painful and distressing. The drug used to make patients unaware of the procedure should rapidly achieve the desired level of sedation, should wear off quickly and should not cause cardiovascular or respiratory side effects.. We aimed to compare the safety, effectiveness and adverse events associated with various anaesthetic or sedative agents used in direct current cardioversion for cardiac arrhythmia in both elective and emergency settings.We sought answers to the following specific questions.• Which drugs deliver the best outcomes for patients undergoing electrical cardioversion?• Does using a particular agent confer advantages or disadvantages?• Is additional analgesic necessary to prevent pain?. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) on 27 March 2014. Our search terms were relevant to the review question and were not limited by outcomes. We also carried out searches of clinical trials registers and forward and backward citation tracking.. We considered all randomized controlled trials and quasi-randomized and cluster-randomized studies with adult participants undergoing electrical cardioversion procedures in the elective or emergency setting.. Two review authors independently assessed trial quality and extracted data, consulting with a third review author for disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias for all studies.. We included 23 studies with 1250 participants that compared one drug with one or more other drugs. Of these comparisons, 19 studies compared propofol with another drug. Seven of these compared propofol with etomidate (four of which combined the drugs with remifentanil or fentanyl), five midazolam, six thiopentone and two sevoflurane. Three studies compared etomidate with thiopentone, and three etomidate with midazolam. Two studies compared thiopentone with midazolam, one thiopentone with diazepam and one midazolam with diazepam. Drug doses and the time over which the drugs were given varied between studies. Although all studies were described as randomized, limited information was provided about the methods used for selection and group allocation. A high level of performance bias was observed across studies, as study authors had not attempted to blind the anaesthetist to group allocation. Similarly, study authors had rarely provided sufficient information on whether outcome assessors had been blinded.Included studies presented outcome data for hypotension, apnoea, participant recall, success of cardioversion, minor adverse events of nausea and vomiting, pain at injection site and myoclonus, additional analgesia and participant satisfaction. We did not pool the data from different studies in view of the multiple drug comparisons, differences in definitions and reporting of outcomes, variability of endpoints and high or unclear risk of bias across studies.. Few studies reported statistically significant results for our relevant outcomes, and most study authors concluded that both, or all, agents compared in individual studies were adequate for cardioversion procedures. It is our opinion that at present, there is no evidence to suggest that current anaesthetic practice for cardioversion should change.

Topics: Anesthetics; Apnea; Diazepam; Electric Countershock; Etomidate; Fentanyl; Humans; Hypnotics and Sedatives; Hypotension; Mental Recall; Methyl Ethers; Midazolam; Piperidines; Propofol; Randomized Controlled Trials as Topic; Remifentanil; Sevoflurane; Thiopental

The unique features of remifentanil are its rapid clearance and rapid ke0, resulting in a rapid onset and offset of drug effect. It is tempting to speculate that these characteristics will make remifentanil an easy drug to titrate, and that clinicians will not need to consider patient covariates such as advanced age when choosing a dosing regimen. However, the rapid onset of drug effect may be accompanied by rapid onset of adverse events such as apnea and muscle rigidity. The rapid offset of drug effect can result in patients who are in severe pain at a time when the anesthesiologist is ill equipped to deal the problem, for example when the patient is in transit to the recovery room. It is thus important that when treating elderly patients anesthesiologists understand the proper dose adjustment required for the elderly. By adjusting the bolus and infusion doses, the anesthesiologist can hope to avoid the peaks and valleys that might expose these patients to risk. When the proper adjustment is made, the variability in remifentanil pharmacokinetics is considerably less than for any other intravenous opioid. This makes remifentanil the most predictable opioid for treatment of the elderly.

Topics: Adult; Aged; Aged, 80 and over; Aging; Analgesics, Opioid; Anesthesia Recovery Period; Anesthetics, Intravenous; Apnea; Female; Forecasting; Half-Life; Humans; Infusions, Intravenous; Male; Metabolic Clearance Rate; Middle Aged; Muscle Rigidity; Pain, Postoperative; Piperidines; Remifentanil; Risk Factors; Titrimetry

Remifentanil is an ultrashort-acting synthetic opioid, and the metabolism of which is not influenced by hepatic or renal function. This study aims to compare the efficacy of two remifentanil doses during procedures in ventilated preterm infants.. Prospective, randomized, double-blind, noninferiority trial.. Neonatal ICU.. Preterm infants who were supported by a mechanical ventilator with tracheal tube and requiring central venous access.. Two remifentanil dosages were administered in mechanically ventilated preterm infants during peripherally inserted central catheter insertion. Fourteen preterm infants were randomly assigned to low-dose (0.1 μg/kg/min) or high-dose (0.25 μg/kg/min) remifentanil infusion. The Premature Infant Pain Profile was used to score pain during the procedure, and changes in the Premature Infant Pain Profile score between needle puncture and baseline were analyzed to investigate the noninferiority of low-dose to high-dose remifentanil. Occurrence of cardiorespiratory complications was also recorded.. The median gestational age (minimum, maximum) was 26 weeks (24, 31), and the median birth weight was 825 g (610, 1,280). Changes in Premature Infant Pain Profile in the high-dose and low-dose groups were 1.43 ± 3.10 and -0.60 ± 5.32, respectively. The difference in changes in the Premature Infant Pain Profile score between the high-dose and low-dose groups was -2.03 ± 4.13. The corresponding lower limit of one-tailed 97.5% CI was -7.24, below the noninferiority margin. Apneic events and bradycardia did not occur in the low-dose group; however, there were three episodes of apnea (42.9%) and one of bradycardia (14.3%) in the high-dose group (p = 0.683 and 0.366, respectively).. For mechanically ventilated preterm infants, the use of remifentanil at 0.25 μg/kg/min as an analgesic for short procedures represents a therapeutic option. Our pilot study suggests the need for larger randomized trials.

Topics: Analgesics, Opioid; Apnea; Birth Weight; Bradycardia; Catheterization, Central Venous; Double-Blind Method; Female; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Male; Pain; Pain Measurement; Piperidines; Prospective Studies; Remifentanil; Respiration, Artificial

Muscle relaxants used to facilitate tracheal intubation have disadvantages.. This study was designed to evaluate the dose requirements for remifentanil combined with thiopental for optimal lightwand intubation without muscle relaxants.. Prospective randomised controlled study.. A tertiary care teaching hospital.. Ninety-six patients requiring general anaesthesia for elective surgery.. Patients received remifentanil 1, 2, or 3 μg kg(-1) (group R1, R2, R3, each n = 32) as a slow bolus infusion over 60 s, followed by thiopental 5 mg kg(-1). Ninety seconds after remifentanil administration, lightwand intubation was attempted and intubation time was recorded. Intubating conditions were considered excellent if there was no patient movement or cough, good if coughing occurred once or twice after intubation and poor if persistent movement or cough occurred after intubation. Excellent or good intubating conditions were regarded as clinically acceptable. The duration of apnoea was recorded.. Intubating conditions and the duration of apnoea.. Lightwand intubation was successful at the first attempt in all patients except for two in group R1. The intubating conditions were more acceptable in groups R2 and R3 than in group R1 (97 and 100 vs. 63%, P < 0.01). Intubation time was shorter in group R3 than in group R1 (22 ± 8 vs. 33 ± 18 s, P < 0.01). There was no significant difference in intubation time and conditions between groups R2 and R3. The mean duration of apnoea was prolonged in group R3 compared with group R2 (10.2 ± 2.1 vs. 4.6 ± 1.6 min, P < 0.01).. Our results suggest that remifentanil 2 or 3 μg kg(-1) combined with thiopental 5 mg kg provides acceptable conditions for lightwand intubation without muscle relaxants. Spontaneous ventilation returns more rapidly following remifentanil 2 μg kg(-1) than with remifentanil 3 μg kg(-1).

Topics: Adult; Anesthetics, Intravenous; Apnea; Dose-Response Relationship, Drug; Drug Therapy, Combination; Female; Hospitals, Teaching; Humans; Intubation, Intratracheal; Male; Middle Aged; Piperidines; Prospective Studies; Remifentanil; Thiopental; Time Factors

This randomized, double-blind study investigated the suitable target effect-site concentration of remifentanil for laryngeal mask airway (LMA) insertion during inhalation induction with sevoflurane.. Patients aged 18 - 60 years were randomly assigned to one of three groups receiving infusions of normal saline (control group), or infusions with target effect-site remifentanil concentrations of either 1 ng/ml (R1 group) or 2 ng/ml (R2 group), 1 min after the induction of anaesthesia with sevoflurane. LMA insertion was attempted 2 min after induction. Insertion conditions were graded using a six-variable, three-point scale (excellent, intermediate or poor).. A total of 102 patients were included. The proportion of patients ranked as excellent for the LMA insertion was significantly higher in groups R1 and R2 compared with the control group. The incidence of apnoea was significantly more frequent in the R2 group than in the control or R1 groups.. Compared with 1 ng/ml remifentanil or normal saline, target-controlled infusion of 2 ng/ml remifentanil significantly improved the LMA insertion conditions during sevoflurane inhalational induction, although apnoeic episodes were more frequently observed.

Topics: Adolescent; Adult; Analgesics, Opioid; Anesthesia, Inhalation; Anesthetics, Inhalation; Apnea; Blood Pressure; Double-Blind Method; Elective Surgical Procedures; Female; Heart Rate; Humans; Infusion Pumps; Laryngeal Masks; Male; Methyl Ethers; Middle Aged; Piperidines; Remifentanil; Sevoflurane; Young Adult

This study aimed to determine the age-specific bolus dose of remifentanil (ED(50)) to facilitate tracheal intubation without the use of neuromuscular blocking agents.. ASA 1-2 subjects were recruited into three groups of 0-3 months (group I), 4-12 months (group II), and 1-3 years (group III) of age. A sequential up-and-down design determined the remifentanil bolus dose, which was initially started at 3 mcg x kg(-1) and adjusted in 1 mcg x kg(-1) increments (range 1-6 mcg x kg(-1)). Following pretreatment with glycopyrrolate 10 microg x kg(-1) and an induction dose of propofol 5 mg x kg(-1), remifentanil was administered with a blinded study investigator commencing tracheal intubation after 60 s. After tracheal intubation, the time to return of spontaneous ventilation was measured. Logistic regression was used to predict the ED(50) and ED(95) of remifentanil.. Sixty-four subjects were recruited. Tracheal intubation was successful at first attempt in over 90% of subjects in each age group. Satisfactory intubating conditions were achieved in 85%, 63%, and 75% of subjects in groups I, II, and III, respectively. The logistic regression results for ED(50) (95% CI) were 3.1 (2.5-3.8), 3.7 (2.0-5.4), and 3.0 (2.1-3.9) mcg x kg(-1), and ED(95) (95% CI) were 5.0 (3.0-7.0), 9.4 (1.5-17.4), and 5.6 (2.9-8.4) mcg x kg(-1) in groups I, II, and III, respectively. Infants aged 4-12 months (group II) showed a marked variability in dose response; however, the mean ED(50) and ED(95) were not different to groups I and III. Older children had a longer duration of apnea than infants, 331 vs 180 s (P < 0.05).. The ED(50) of remifentanil for tracheal intubation was higher in all age groups than previously reported. Ideal intubating conditions were achieved in 50% of subjects with remifentanil doses of 3.1-3.7 mcg x kg(-1). Higher doses will be required for higher success rates and with anticholinergic pretreatment, doses of up to 6 mcg x kg(-1) were tolerated, without adverse effects, in two patients. Further investigation of the variability in dose response in infants and assessment of the safety this technique is warranted.

Topics: Adjuvants, Anesthesia; Aging; Anesthetics, Intravenous; Apnea; Blood Gas Analysis; Child, Preschool; Cross-Over Studies; Glycopyrrolate; Hemodynamics; Humans; Infant; Infant, Newborn; Intubation, Intratracheal; Monitoring, Intraoperative; Piperidines; Remifentanil; Respiration, Artificial; Sample Size

Few studies address the dynamic effect of opioids on respiration. Models with intact feedback control of carbon dioxide on ventilation (non-steady-state models) that correctly incorporate the complex interaction among drug concentration, end-tidal partial pressure of carbon dioxide concentration, and ventilation yield reliable descriptions and predictions of the behavior of opioids. The authors measured the effect of remifentanil on respiration and developed a model of remifentanil-induced respiratory depression.. Ten male healthy volunteers received remifentanil infusions with different infusion speeds (target concentrations: 4-9 ng/ml; at infusion rates: 0.17-9 ng x ml x min) while awake and at the background of low-dose propofol. The data were analyzed with a nonlinear model consisting of two additive linear parts, one describing the depressant effect of remifentanil and the other describing the stimulatory effect of carbon dioxide on ventilation.. The model adequately described the data including the occurrence of apnea. Most important model parameters were as follows: C50 for respiratory depression 1.6 +/- 0.03 ng/ml, gain of the respiratory controller (G) 0.42 - 0.1 l x min x Torr, and remifentanil blood effect site equilibration half-life (t(1/2)ke0) 0.53 +/- 0.2 min. Propofol caused a 20-50% reduction of C50 and G but had no effect on t(1/2)ke0. Apnea occurred during propofol infusion only. A simulation study revealed an increase in apnea duration at infusion speeds of 2.5-0.5 ng x ml x min followed by a reduction. At an infusion speed of < or = 0.31 ng x ml x min, no apnea was seen.. The effect of varying remifentanil infusions with and without a background of low-dose propofol on ventilation and end-tidal partial pressure of carbon dioxide concentration was described successfully using a non-steady-state model of the ventilatory control system. The model allows meaningful simulations and predictions.

Topics: Adolescent; Adult; Apnea; Humans; Hypnotics and Sedatives; Infusion Pumps; Male; Models, Biological; Piperidines; Propofol; Remifentanil; Respiratory Mechanics; Wakefulness; Young Adult

We compared sedation by propofol combined with either fentanyl or remifentanil in pediatric outpatients undergoing diagnostic esophagogastroduodenoscopy.. Forty-two children scheduled for esophagogastroduodenoscopy in our institution were randomly assigned to receive 2 mg/kg propofol plus either 1 μg/kg bolus of fentanyl (group F; n = 20) or 0.5 μg/kg bolus of remifentanil (group R; n = 22). Cardiorespiratory parameters, sedation level, adverse effects related to the drugs and/or to the procedure, ease of performance for the endoscopist, and time to awakening were analyzed.. There were no clinically significant changes in hemodynamics. Apnea periods >20 seconds and decreases in SaO2 <90% occurred more frequently in group R (31.8% vs 0%, P < 0.01, and 27.3% vs 5.0%, P > 0.05, respectively). Children in group R had significantly shorter average time to awakening: 9.5 ± 5.6 vs 16.5 ± 10.5 minutes (P = 0.01), and received a significantly lower total dose of propofol (P = 0.034). Adverse effects within the first 24 hours postprocedure occurred less frequently in group R (P = 0.03).. Remifentanil in combination with propofol provides good analgesic and sedative effects, which were shorter lasting compared with fentanyl-based sedation, and caused fewer delayed adverse effects. The use of remifentanil was associated with respiratory depression, emphasizing the need for experienced anesthesiologists.

Topics: Analgesics, Opioid; Apnea; Child; Endoscopy, Digestive System; Female; Fentanyl; Hemodynamics; Humans; Hypnotics and Sedatives; Male; Piperidines; Postoperative Complications; Propofol; Remifentanil; Wakefulness

The study compared sevoflurane or propofol as anaesthesia supplements to remifentanil infusion and topical local anaesthesia for insertion of a rigid bronchoscope for bronchial foreign body removal in children aged one to three years. Seventy children were randomly allocated to two groups to receive remifentanil infusion at 0.2 microg x kg(-1) x min(-1) with either sevoflurane or propofol supplements for insertion of the rigid bronchoscope. Heart rate and systolic blood pressure before anaesthesia, prior to and on insertion of the bronchoscope and one, three, five, seven and ten minutes after insertion were measured. Incidence of cough and apnoea were recorded. The haemodynamic changes during bronchoscopy were moderate and did not differ between groups. The sevoflurane group had a lower incidence of cough than the propofol group. No significant difference was detected in the incidence of apnoea between groups. It can be concluded that remifentanil infusion with modest use of general anaesthetic agents facilitates rigid bronchoscopy successfully in children.

Topics: Anesthetics, Inhalation; Anesthetics, Intravenous; Apnea; Blood Pressure; Bronchoscopy; Child, Preschool; Cough; Female; Foreign Bodies; Heart Rate; Humans; Infant; Male; Methyl Ethers; Piperidines; Propofol; Remifentanil; Sevoflurane

The use of remifentanil before propofol administration facilitates the insertion of the Laryngeal Mask Airway. We designed the present study to determine whether remifentanil would also create more suitable conditions for providing Cobra Perilaryngeal airway (CobraPLA) insertion when administered with propofol.. Both remifentanil and propofol were given as effect-site target-controlled infusions. There were four groups of 25 patients each. The propofol effect-site concentration was set at 6 microg/mL in all groups. Group R1 received a target effect-site remifentanil concentration of 1 ng/mL, Group R2 received remifentanil at 2 ng/mL, Group R3 received remifentanil at 3 ng/mL, and Group R4 received remifentanil at 4 ng/mL before the induction of anesthesia with propofol. The ease of insertion of CobraPLA was graded by the following 3-point scale: Grade 1, excellent, no response to CobraPLA insertion; Grade 2, acceptable, gagging or swallowing with insertion of CobraPLA; Grade 3, poor, unable to open mouth or biting upon insertion of CobraPLA.. The most patients ranked as excellent for the first CobraPLA insertion (Grade 1) were found in Group R4, which was significantly higher than Groups R1 and R2 (P < 0.01), whereas no significant difference was found when compared with Group R3. The duration of apnea showed a significant dose-related increase (P < 0.01), especially between Group R2 (median 2.95 min) and R3 (median 7.9 min), but there was no significant difference between Groups R3 and R4. The incidence of hypotension in Group R4 within 1 min after insertion of CobraPLA was significantly more than for Groups R1 and R2 (P < 0.01). No significant differences could be found between the incidence of hypotension between Group R3 and the other groups. The incidence of hypertension at 1 min postinsertion was significantly more common in Groups R1 and R2 than Groups R3 and R4 (P < 0.01).. An effect-site concentration of remifentanil of 2 ng/mL provides excellent conditions for insertion of the CobraPLA on the first attempt with minimal hemodynamic perturbations and a shorter duration of apnea.

Topics: Adult; Anesthesia, General; Anesthetics, Combined; Anesthetics, Intravenous; Apnea; Blood Pressure; Equipment Design; Female; Heart Rate; Humans; Infusions, Intravenous; Laryngeal Masks; Male; Middle Aged; Piperidines; Propofol; Remifentanil; Respiration, Artificial; Time Factors

To evaluate the efficiency and safety of intravenous (i.v.) remifentanil and propofol for gastroscopy in healthy adults.. Randomized, double-blinded study.. Endoscopy Center, West China Hospital, Sichuan University (Chengdu, People's Republic of China).. 199 adult ASA physical status I and II patients.. Patients were randomly allocated to either the fentanyl group (n = 99) or the remifentanil group (n = 100). Patients received either fentanyl 0.5 microg/kg or remifentanil 0.5 microg/kg, followed by a bolus injection of one mg/kg of propofol. The subsequent doses of propofol were 0.5 mg/kg when the patient was conscious or body movement appeared.. Noninvasive blood pressure, heart rate, arterial pulse oxygen saturation, and respiratory rate were recorded before gastroscopy and at two-minute intervals until the end of the gastroscopy procedure. Patients were asked to evaluate their level of cognition using the Digit-Symbol Substitution Test score before gastroscopy and at 10 minutes after discontinuation of the drug injection.. Recovery time was significantly shorter in the remifentanil group than in the fentanyl group (P < 0.05). Postoperative Digit-Symbol Substitution Test scores were significantly higher in the remifentanil group than in the fentanyl group (P < 0.01). Total dosage of propofol given in the remifentanil group was significantly less than it was in the fentanyl group (P < 0.01). Frequency of apnea was significantly higher in the remifentanil group (P < 0.05). There were no significant differences in frequency of hypoxemia, bag ventilation, or body movement between the two groups (P > 0.05).. Intravenous remifentanil and propofol were more efficient for gastroscopy than i.v. fentanyl and propofol.

Topics: Adult; Anesthesia Recovery Period; Anesthetics, Combined; Anesthetics, Intravenous; Apnea; Cognition; Dose-Response Relationship, Drug; Double-Blind Method; Fentanyl; Gastroscopy; Humans; Hypoxia; Piperidines; Propofol; Remifentanil; Respiration, Artificial

A randomized and prospective study was performed to compare anaesthetic characteristics and stress hormone responses of two anaesthetic techniques.. Forty-two patients undergoing day case excisional biopsy of breast mass were randomly assigned to receive propofol-remifentanil or sevoflurane-N2O. Anaesthesia was induced and maintained either with sevoflurane and 50% N2O in oxygen or with target-controlled remifentanil and propofol in 50% oxygen and air. Anaesthetic depth was monitored by the bispectral index.. The times for induction (2.9 vs. 1.7 min) and for laryngeal mask insertion (5.7 vs. 3.3 min) were longer in the sevoflurane-N2O group than in the propofol-remifentanil group. However, apnoea (57.1% vs. 9.5%) and bradycardia (23.8% vs. 0%) were more prevalent with propofol-remifentanil. In the sevoflurane-N2O group, the emergence times to a verbal response (10.6 vs. 3.7 min), to extubation (11.8 vs. 4.0 min) and to orientation (14.7 vs. 4.8 min) were longer than in the propofol-remifentanil group. There were significantly more nausea (38.1% vs. 4.8%) and vomiting (19.2% vs. 0%) in the sevoflurane-N2O group than in the propofol-remifentanil group. The time to discharge was similar although there was less postoperative pain in the sevoflurane-N2O group. There were no differences in the perioperative cortisol responses in the two groups.. Smoother induction of anaesthesia was seen with sevoflurane-N2O. Propofol-remifentanil showed a quicker emergence with less nausea/vomiting. There were similar perioperative cortisol responses in the two anaesthetic techniques.

Topics: Adult; Ambulatory Surgical Procedures; Anesthesia Recovery Period; Anesthesia, General; Anesthetics, Intravenous; Apnea; Biopsy; Bradycardia; Breast; Electroencephalography; Female; Humans; Hydrocortisone; Methyl Ethers; Nitrous Oxide; Piperidines; Propofol; Prospective Studies; Remifentanil; Sevoflurane; Time Factors

Remifentanil is a short-acting drug that allows us to study the specific respiratory effects of potent opioid analgesics. The purpose of this study is to describe the effects of a remifentanil infusion during spontaneous ventilation in children. Pharmacokinetic studies provide useful information on the time course of opioid blood concentrations; however, they cannot be easily translated into infusion administration guidelines for pediatric clinical practice.. A total of 32 children, aged 2-7 years, undergoing restorative dentistry, spontaneously breathing under sevoflurane anesthesia were enrolled in the study. After an initial bolus dose of remifentanil, an infusion was administered in ascending logarithmic increments at 10 min intervals. Increments were discontinued when endtidal carbon dioxide exceeded 9 kPa (70 mmHg), desaturation occurred (SpO2 < 94%) or with the onset of apnea (>5 s). The maximum tolerated dose was determined for each subject. Endtidal carbon dioxide, minute ventilation and respiratory rate were continuously recorded.. The median tolerated dose of remifentanil was 0.127 microg.kg(-1).min(-1) (range: 0.053-0.3 microg.kg(-1).min(-1)). When comparing the last four incremental increases in each subject, 35% change in respiratory rate occurred in the last 10 min period while changes in endtidal carbon dioxide and minute ventilation were gradual and of less magnitude. There was no correlation between age and respiratory rate.. There is a large variation in the dose of remifentanil tolerated by children while breathing spontaneously under anesthesia. A respiratory rate of <10 b.min(-1) appears to be the best predictor of the maximum tolerated dose.

Topics: Analgesics, Opioid; Apnea; Carbon Dioxide; Child; Child, Preschool; Dentistry, Operative; Dose-Response Relationship, Drug; Female; Humans; Male; Piperidines; Remifentanil; Respiration; Sex Factors; Time Factors

Although former preterm birth infants are at risk for postoperative apnea after surgery, it is unclear whether the same is true of full-term birth infants. We evaluated the incidence of apnea in 60 full-term neonates and infants undergoing pyloromyotomy both before and after anesthesia. All subjects were randomized to a remifentanil- or halothane-based anesthetic. Apnea was defined by the presence of prolonged apnea (>15 s) or frequent brief apnea, as observed on the pneumocardiogram. Apnea occurred before surgery in 27% of subjects and after surgery in 16% of subjects, with no significant difference between subjects randomized to remifentanil or halothane anesthesia. This apnea was primarily central in origin, occurred throughout the recording epochs, and was associated with severe desaturation in some instances. Of the subjects with normal preoperative pneumocardiograms, new onset postoperative apnea occurred in 3 (23%) of 13 subjects who received halothane-based anesthetics versus 0 (0%) of 22 subjects who received remifentanil-based anesthetics (P = 0.04). Thus, postoperative apnea can follow anesthesia in otherwise healthy full-term infants after pyloromyotomy and is occasionally severe with desaturation. New-onset postoperative apnea was not seen with a remifentanil-based anesthetic.. Abnormal breathing patterns can follow anesthesia in infants after surgical repair of pyloric stenosis. Occasionally, these patterns can be associated with desaturation. New-onset postoperative apnea was not seen with a remifentanil-based anesthetic.

Topics: Anesthetics, Inhalation; Anesthetics, Intravenous; Apnea; Halothane; Heart Rate; Humans; Infant; Infant, Newborn; Piperidines; Postoperative Complications; Pyloric Stenosis; Pylorus; Remifentanil; Respiration

We have studied the apnoea time after induction with two successful drug intubating regimes, both containing remifentanil. Group 1 (n = 20); propofol 2 mg kg-1 and remifentanil 2 micrograms kg-1 and group 2 (n = 20); propofol 2 mg kg-1, remifentanil 1 microgram kg-1 and lignocaine 1 mg kg-1. Intubation was possible in all 40 patients, and regarded as acceptable in 90% and 85% of patients, respectively. The median time to the return of spontaneous respiration was 487 s in group 1 and 270 s in group 2 (P < 0.05). Median end-tidal CO2 concentration at the time of the first spontaneous respiration was 7.37 kPa in group 1 and 6.3 kPa in group 2 (P < 0.05). Both groups had a decrease in heart rate after induction, but this failed to reach either clinical or statistical significance, and no patient required atropine. Similarly, there was a decrease in arterial pressure after induction in both groups (P < 0.05), but this was not deemed to be clinically significant. Only two patients in each group required ephedrine 6 mg before arterial pressure was restored to within 25% of the base-line. Intubating conditions were similar in both groups, but group 2 provided a significantly shorter apnoea time.

Topics: Adolescent; Adult; Aged; Anesthetics, Intravenous; Anesthetics, Local; Apnea; Blood Pressure; Carbon Dioxide; Double-Blind Method; Female; Heart Rate; Humans; Intubation, Intratracheal; Lidocaine; Male; Middle Aged; Piperidines; Prospective Studies; Remifentanil; Time Factors

We evaluated the use of an infusion of remifentanil to provide postoperative analgesia during recovery from total intravenous anesthesia (TIVA) with remifentanil and propofol. One hundred fifty-seven patients from seven medical centers underwent abdominal, spine, joint replacement, or thoracic surgery. Remifentanil was titrated in an effort to limit pain to 0 or 1 on a 0-3 scale. At the end of the 30-min titration period, 78% of infusion rates were in the range of 0.05 to < or = 0.15 microgram.kg-1.min-1, 5% were < 0.05 microgram.kg-1.min-1, and 17% were > 0.15 microgram.kg-1.min-1. Pain scores were 0 or 1 in 64% of patients. Nausea occurred in 35% and emesis in 8% of patients; the peak incidence of nausea followed discontinuation of the remifentanil infusion at the time of administering morphine. Respiratory adverse events (oxygen saturation by pulse oximetry [Spo2] < 90% or respiratory rate < 12) affected 29% of patients. Apnea occurred in 11 patients (7.0%). There was a large variation in the incidence of respiratory depression between the centers, ranging from 0 to 75%. The explanation for the large variability in respiratory outcome was not evident.

Topics: Abdomen; Adult; Aged; Analgesics, Opioid; Anesthesia Recovery Period; Anesthesia, Intravenous; Anesthetics, Intravenous; Apnea; Female; Humans; Incidence; Infusions, Intravenous; Joint Prosthesis; Male; Middle Aged; Morphine; Nausea; Oxygen; Pain Measurement; Pain, Postoperative; Piperidines; Propofol; Remifentanil; Respiration; Spine; Thoracic Surgery; Vomiting

1. Electroencephalographic activity was registered in healthy subjects before, during and 90 minutes after intravenous injections of sufentanil and fentanyl. 2. With a dosage of ratio of 1:10, i.e., 0.025 mg/70 kg body weight sufentanil: 0.25 mg/70 kg body weight fentanyl as well as 0.015 mg/70 kg body weight sufentanil: 0.15 mg/70 kg body weight fentanyl, sufentanil was hypnotically more potent from fentanyl. 3. Sufentanil acts more powerfully on the respiratory regulation than does fentanyl. Periods of apnoea occur more frequently but can be interrupted by external psychophysiological stimulation. 4. The evaluation of indices of certain EEG-waves, characterizing well defined electroencephalographic stages corresponding to the waking-sleeping-behaviour confirmed the visual over-all analysis of the EEG-stages. 5. Physiological observations on heartrate, systemic blood pressure, rapid eye movements during wakefulness, and slow eye movements during sleepiness showed no reliable differences between sufentanil and fentanil. The systematically documented symptoms and vegetative signs of subjects also showed neither differences nor side-effects.

Topics: Adult; Anilides; Apnea; Blood Pressure; Dose-Response Relationship, Drug; Electroencephalography; Fentanyl; Heart Rate; Humans; Male; Piperidines; Respiration; Sleep; Sleep, REM

Magnetic resonance (MRI) scanning of the heart is an established part of the investigation of cardiovascular conditions in children. In young children, sedation is likely to be needed, and multiple controlled periods of apnea are often required to allow image acquisition. Suppression of spontaneous ventilation is possible with remifentanil; however, the dose required is uncertain.. To establish the dose of remifentanil, by infusion, required to suppress ventilation sufficiently to allow a 30-s apnea during MRI imaging of the heart.. Patients aged 1-6 years were exposed to different doses of remifentanil, and the success in achieving a 30-s apnea was recorded. A dose recommendation was made for each patient, informed by responses of previous patients using an adaptive Bayesian dose-escalation design. Other aspects of anesthesia were standardized. A final estimate of the dose needed to achieve a successful outcome in 80% of patients (ED80) was made using logistic regression.. 38 patients were recruited, and apnea achieved in 31 patients. The estimate of the ED80 was 0.184 µg/kg/min (95% CI 0.178-0.190). Post hoc analysis revealed that higher doses were required in younger patients.. The ED80 for this indication was 0.184 µg/kg/min (95% CI 0.178-0.190). This is different from optimal dosing identified for other indications and dosing of remifentanil should be specific to the clinical context in which it is used.

Topics: Anesthesia, General; Anesthetics, Intravenous; Apnea; Bayes Theorem; Child; Child, Preschool; Humans; Infant; Magnetic Resonance Imaging; Piperidines; Propofol; Remifentanil

Topics: Airway Extubation; Anesthetics, Intravenous; Apnea; Arthroplasty, Replacement, Hip; Humans; Infusions, Intravenous; Male; Medical Errors; Middle Aged; Piperidines; Remifentanil

Remifentanil may be used by laboring women for analgesia, despite controversy because of potential apneas. We evaluated candidate variables as early warning alerts for apnea, based on prevalence, positive predictive rate, sensitivity for apnea event detection, and early warning alert time intervals (lead time) for apnea.. We performed a secondary analysis of respiratory physiological data that had been collected during a prospective IRB-approved study of laboring women receiving IV patient-controlled boluses of remifentanil 20 to 60 μg every 1 to 2 minutes. Analyzed data included the respiratory rate (RR), end-tidal CO2 (EtCO2), pulse oximetry (SpO2), heart rate (HR), and the Integrated Pulmonary Index (IPI; Capnostream 20; Medtronic, Boulder, CO) that had been recorded continuously throughout labor. We defined immediate early warning alerts as any drop in a variable value below a prespecified threshold for 15 seconds: RR < 8 breaths per minute (bpm), EtCO2 < 15 mm Hg, and SpO2 < 92%. We defined alerts as "sustained" when the value remained below the threshold for ≥ 10 further seconds. The IPI value (1 to 10; 10 = healthy patient, ≤4 = immediate attention required, 1 = dire condition) was generated from a proprietary algorithm using RR, EtCO2, SpO2, and HR parameters. Apnea was defined as maximal CO2 < 5 mm Hg for at least 30 consecutive seconds.. We counted 62 apneas, among 10 of 19 (52.6%) women who received remifentanil (total dose 1725 ± 1392 μg, administered over 160 ± 132 minutes). We counted 331 immediate early warning alerts for the variables; 271 (82%) alerts were sustained for ≥10 seconds. The positive predictive value of alerts for apnea was 35.8% (99% confidence interval [CI]: 27.1-45.6), 28.9% (99% CI: 20.8-38.7), 4.3% (99% CI: 1.9-9.6), and 24.6% (99% CI: 18.3-32.2) for RR, EtCO2, SpO2, and IPI, respectively. The sensitivity for apnea event detection was 100% (99% CI: 90.3-100) for RR (<8 bpm) and IPI (≤4); 75.8% (99% CI: 59.8-86.9) for EtCO2 <15 mm Hg; and 14.5% (99% CI: 6.5-29.4) for SpO2 <92%. We found a statistically significant difference in the timing of RR, EtCO2, SpO2, and IPI alerts for apnea; Friedman's Q = 33.53; P < .0001. The EtCO2 had a median (interquartile range) lead time of -0.2 (-12.2 to 0.7) seconds, and SpO2 had a median (interquartile range) lead time of 40.0 (40.0 to 40.0) seconds.. The majority of women receiving IV remifentanil for labor analgesia experienced apneas. Alerts for EtCO2 (<15 mm Hg), RR (<8 bpm), and IPI (≤4) detected most apneas, whereas SpO2 alerts missed the majority of apneas. All variables had a low positive predictive rate, demonstrating the limitations of the respiratory monitors utilized as early warning surveillance for apneas in this setting.

Topics: Analgesia, Patient-Controlled; Analgesics, Opioid; Apnea; Capnography; Clinical Alarms; Female; Humans; Infusions, Intravenous; Labor, Obstetric; Piperidines; Pregnancy; Prospective Studies; Remifentanil; Respiratory Physiological Phenomena

Topics: Aged; Anesthesia; Anesthetics, Intravenous; Apnea; Humans; Male; Naloxone; Narcotic Antagonists; Piperidines; Remifentanil; Ventriculoperitoneal Shunt

Cannabis is one of the most commonly used recreational drugs at ages highly correlated with potential pregnancy. Endocannabinoid signalling regulates important stages of neuronal development. When cannabinoid receptors, which are widely distributed through the nervous system, are activated by exogenous cannabinoids, breathing in adult rats is depressed. Here, we show that, in newborn mice, endocannabinoids, through the activation of cannabinoid receptor type 1 (CB1 R), participate in the modulation of respiration and its control. Blocking CB1 Rs at birth suppressed the brake exerted by endocannabinoids on ventilation in basal and in hypoxic conditions. The number of apnoeas and their duration were also minimized by activation of CB1 Rs in normoxic and in hypoxic conditions. However, prenatal cannabis intoxication, caused by a daily injection of WIN55,212-2, in pregnant mice durably modified respiration of the offspring, as shown by hyperventilation in basal conditions, an altered chemoreflex in response to hypoxia, and longer apnoeas. When CB1 Rs were blocked in WIN55,212-2 treated newborns, persistent hyperventilation was still observed, which could partly be explained by a perturbation of the central respiratory network. In fact, in vitro medullary preparations from WIN55,212-2 treated pups, free of peripheral or of supramedullary structures, showed an altered fictive breathing frequency. In conclusion, the endocannabinoid pathway at birth seems to modulate breathing and protect the newborn against apnoeas. However, when exposed prenatally to an excess of cannabinoid, the breathing neuronal network in development seems to be modified, probably rendering the newborn more vulnerable in the face of an unstable environment.

Topics: Animals; Animals, Newborn; Apnea; Benzoxazines; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Female; Hypoxia; Immunohistochemistry; Medulla Oblongata; Mice, Inbred C57BL; Morpholines; Naphthalenes; Periodicity; Piperidines; Plethysmography; Pregnancy; Prenatal Exposure Delayed Effects; Pyrazoles; Receptor, Cannabinoid, CB1; Respiration; Tyrosine 3-Monooxygenase

Undetected apnea can lead to severe hypoxia, bradycardia, and cardiac arrest. Tracheal sounds entropy has been proved to be a robust method for estimating respiratory flow, thus maybe a more reliable way to detect obstructive and central apnea during sedation.. A secondary analysis of a previous pharmacodynamics study was conducted. Twenty volunteers received propofol and remifentinal until they became unresponsive to the insertion of a bougie into the esophagus. Respiratory flow rate and tracheal sounds were recorded using a pneumotachometer and a microphone. The logarithm of the tracheal sound Shannon entropy (Log-E) was calculated to estimate flow rate. An adaptive Log-E threshold was used to distinguish between the presence of normal breath and apnea. Apnea detected from tracheal sounds was compared to the apnea detected from respiratory flow rate.. The volunteers stopped breathing for 15 s or longer (apnea) 322 times during the 12.9-h study. Apnea was correctly detected 310 times from both the tracheal sounds and the respiratory flow. Periods of apnea were not detected by the tracheal sounds 12 times. The absence of tracheal sounds was falsely detected as apnea 89 times. Normal breathing was detected correctly 1,196 times. The acoustic method detected obstructive and central apnea in sedated volunteers with 95% sensitivity and 92% specificity.. We found that the entropy of the acoustic signal from a microphone placed over the trachea may reliably provide an early warning of the onset of obstructive and central apnea in volunteers under sedation.

Topics: Adult; Anesthetics, Intravenous; Apnea; Entropy; Female; Humans; Male; Piperidines; Propofol; Reference Values; Remifentanil; Reproducibility of Results; Respiration; Respiratory Sounds; Sensitivity and Specificity; Trachea

Rett syndrome is a neurological disorder caused by loss of function mutations in the gene that encodes the DNA binding protein methyl-CpG-binding protein 2 (Mecp2). A prominent feature of the syndrome is disturbances in respiration characterized by frequent apnea and an irregular interbreath cycle. 8-Hydroxy-2-dipropylaminotetralin has been shown to positively modulate these disturbances (Abdala AP, Dutschmann M, Bissonnette JM, Paton JF, Proc Natl Acad Sci U S A 107: 18208-18213, 2010), but the mode of action is not understood. Here we show that the selective 5-HT1a biased agonist 3-chloro-4-fluorophenyl-(4-fluoro-4-{[(5-methylpyrimidin-2-ylmethyl)-amino]-methyl}-piperidin-1-yl)-methanone (F15599) decreases apnea and corrects irregularity in both heterozygous Mecp2-deficient female and in Mecp2 null male mice. In whole cell voltage-clamp recordings from dorsal raphe neurons, F15599 potently induced an outward current, which was blocked by barium, reversed at the potassium equilibrium potential, and was antagonized by the 5-HT1a antagonist WAY100135. This is consistent with somatodendritic 5-HT1a receptor-mediated activation of G protein-coupled inwardly rectifying potassium channels (GIRK). In contrast, F15599 did not activate 5-HT1b/d receptors that mediate inhibition of glutamate release from terminals in the nucleus accumbens by a presynaptic mechanism. Thus F15599 activated somatodendritic 5-HT1a autoreceptors, but not axonal 5-HT1b/d receptors. In unanesthetized Mecp2-deficient heterozygous female mice, F15599 reduced apnea in a dose-dependent manner with maximal effect of 74.5 ± 6.9% at 0.1 mg/kg and improved breath irrregularity. Similarly, in Mecp2 null male mice, apnea was reduced by 62 ± 6.6% at 0.25 mg/kg, and breathing became regular. The results indicate respiration is improved with a 5-HT1a agonist that activates GIRK channels without affecting neurotransmitter release.

Topics: Action Potentials; Animals; Apnea; Brain; Disease Models, Animal; Female; G Protein-Coupled Inwardly-Rectifying Potassium Channels; Glutamic Acid; Male; Methyl-CpG-Binding Protein 2; Mice; Mice, Inbred C57BL; Piperidines; Potassium; Pyrimidines; Raphe Nuclei; Receptor, Serotonin, 5-HT1A; Respiration; Rett Syndrome; Serotonin; Serotonin 5-HT1 Receptor Agonists; Serotonin 5-HT1 Receptor Antagonists; Synaptic Transmission

To characterize respiratory dynamics during emergence from propofol-remifentanil anesthesia using noninvasive respiratory inductance plethysmography (RIP).. Observational pilot study.. Operating room in a university-affiliated teaching hospital.. 50 ASA physical status 1, 2, and 3 patients scheduled for microdirect laryngoscopy or bronchoscopy using total intravenous anesthesia (TIVA) with high-frequency jet ventilation.. Patients were fitted with plethysmography bands around the chest and abdomen prior to induction. Following completion of surgery in patients undergoing brief airway procedures using propofol-remifentanil general anesthesia, the anesthetic infusions were stopped and ventilation suspended until resumption of spontaneous ventilation or desaturation below 90%. During this period of apnea, abdominal and thoracic girth was assessed with noninvasive RIP.. Cross-sectional area of the thorax and abdomen during emergence were measured.. Useful data were obtained from 41 patients, with stable apnea lasting 404 ± 193.1 seconds; of these, 34 exhibited a slow and significant decrease in abdominal girth over a period of 267.8 ± 128.5 seconds. Resumption of spontaneous ventilation generally coincided with the end of this abdominal relaxation.. Slow expiration is the initial step in the resumption of spontaneous ventilation during apnea induced with TIVA using propofol-remifentanil.

Topics: Abdominal Muscles; Anesthesia Recovery Period; Anesthesia, Intravenous; Anesthetics, Combined; Anesthetics, Intravenous; Apnea; Bronchoscopy; Exhalation; High-Frequency Jet Ventilation; Humans; Laryngoscopy; Monitoring, Physiologic; Muscle Relaxation; Pilot Projects; Piperidines; Plethysmography; Postoperative Care; Propofol; Remifentanil; Respiratory Mechanics

To give new insights into how an infant responded to naloxone, given after acquiring a maternal opiate by recording the breathing pattern directly after birth.. A respiratory recording is presented of an infant during resuscitation in the delivery room after receiving naloxone for respiratory depression, resulting from maternal remifentanyl use.. The infant was born apneic and bradycardic. Normal resuscitation manoeuvres had no effect on the respiratory drive. Directly after administration of naloxone, a tachypneic breathing pattern with sporadic expiratory breaking manoeuvres was observed.. The immediate tachypnoea is most likely a direct effect of the naloxone causing an immediate 'rebound response' after the release of the opiate-induced inhibition of the respiratory drive.

Topics: Analgesics, Opioid; Anesthetics, Intravenous; Apnea; Female; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Naloxone; Narcotic Antagonists; Piperidines; Pregnancy; Remifentanil; Respiratory Rate

In an earlier study investigating the "can't ventilate/can't intubate" clinical scenario, induction of anesthesia with thiopental 5 mg/kg and succinylcholine 1.0 mg/kg was associated with a significant risk of hemoglobin desaturation. It appeared that succinylcholine-induced apnea was responsible for the prolonged apnea. Our hypothesis was that using propofol and remifentanil for tracheal intubation might avoid prolonged apnea and subsequent desaturation attributable to muscle relaxation.. Twenty-four healthy volunteers ages 18 to 45 years participated. After oxygen administration to end-tidal oxygen >90%, volunteers received 2 mg/kg propofol and remifentanil either 2 mcg/kg (group 1; n = 12) or 1.5 mcg/kg (group 2; n = 12). Oxygen saturation (SpO(2)) was measured at a finger, an ear lobe, and the forehead. If SpO(2) decreased below 80%, volunteers received chin lift and, if persistent, assisted ventilation.. Desaturation (SpO(2) < 80%) occurred in 5 volunteers: 4 in the higher remifentanil dose (2 mcg/kg) group and 1 in the lower dose (1.5 mcg/kg) group. Chin lift and assisted ventilation was necessary in 3 volunteers. The lowest SpO(2) was 82.4 ± 10.5 (mean ± SD) in the higher-dose group vs. 92.4 ± 8.6 with the lower dose of remifentanil (P = 0.019). Apnea time was shorter (P = 0.0093) with the lower dose (4.7 ± 1.5) than with the higher dose of remifentanil (6.1 ± 1.0). Conditions for intubation were excellent or acceptable in 11 volunteers (92%; 95% confidence interval [CI], 65%-99%) in the higher-dose group, and in 8 (67%; 95% CI, 39%-86%) with the lower dose.. Administered with propofol 2 mg/kg, the remifentanil dose necessary to produce acceptable intubating conditions, 2 mcg/kg, produces apnea that carries a significant risk of desaturation, whereas a remifentanil dose of 1.5 mcg/kg does not reliably produce acceptable intubating conditions and does not eliminate the risk of desaturation.

Topics: Adult; Anesthesia, Intravenous; Anesthetics, Intravenous; Apnea; Body Mass Index; Dose-Response Relationship, Drug; Female; Hemodynamics; Hemoglobins; Humans; Intubation, Intratracheal; Male; Oximetry; Oxygen; Oxyhemoglobins; Piperidines; Propofol; Remifentanil; Respiration; Respiration, Artificial; Sample Size; Supine Position; Unconsciousness; Young Adult

Topics: Anesthesia, Intravenous; Anesthetics, Intravenous; Apnea; Female; Hemoglobins; Humans; Male; Piperidines; Propofol; Remifentanil; Respiration

Topics: Anesthesia, Inhalation; Anesthesia, Intravenous; Anesthetics, Inhalation; Anesthetics, Intravenous; Apnea; Child; Conscious Sedation; Diagnostic Imaging; Humans; Methyl Ethers; Piperidines; Remifentanil; Respiration, Artificial; Sevoflurane

Topics: Analgesics, Opioid; Apnea; Bile Ducts; Humans; Infant; Lung; Magnetic Resonance Imaging; Male; Naloxone; Narcotic Antagonists; Piperidines; Remifentanil; Tomography, X-Ray Computed

A young, healthy adult man exhibited naloxone-reversible, prolonged apnea after a 4-hour infusion of remifentanil, which was used as the opioid component of a general endotracheal anesthetic. Clinical experience and pharmacokinetic simulations indicate that the apnea was clearly atypical.

Topics: Adult; Analgesics, Opioid; Anesthesia, General; Apnea; Craniotomy; Humans; Male; Naloxone; Narcotic Antagonists; Piperidines; Postoperative Complications; Remifentanil; Time Factors

Topics: Adult; Analgesia, Obstetrical; Apnea; Female; Humans; Labor Pain; Labor, Obstetric; Piperidines; Pregnancy; Remifentanil

Topics: Anesthetics, Intravenous; Apnea; Bradycardia; Child, Preschool; Coronary Angiography; Female; Humans; Piperidines; Remifentanil

A parturient presented for elective caesarean section with a history of multiple spinal operations and scoliosis and a biochemical diagnosis of suxamethonium apnoea. She declined any attempt at regional anaesthesia. We describe the use of a thiopental/remifentanil technique to relax the larynx and provide rapid and excellent conditions for laryngoscopy and tracheal intubation. The parturient awoke following an uneventful caesarean section with excellent pain relief and no recall. The baby had normal Apgar scores and umbilical blood gas measurements.

Topics: Adult; Analgesics, Opioid; Anesthesia, General; Anesthesia, Obstetrical; Apnea; Cesarean Section; Contraindications; Female; Humans; Intubation, Intratracheal; Neuromuscular Depolarizing Agents; Piperidines; Pregnancy; Pregnancy Outcome; Remifentanil; Succinylcholine

Remifentanil, a recently introduced ultra-short acting opioid, was used as a component of a conscious sedation technique in 30 patients for 40 painful medical procedures. In 31 of these procedures, remifentanil provided sufficient analgesia. However, 25 of those 31 patients developed apnea that required constant verbal stimulation at doses equal to or less than the dose required for analgesia. Ten of these apneic patients developed hypoxemia (oxyhemoglobin saturation less than 90%). Nine patients required abandonment of remifentanil and addition of either ketamine or propofol to achieve an analgesic state without respiratory depression. Although discharge times with remifentanil were considerably shorter, most patients, parents, and practitioners were not satisfied with the technique because of the prolonged time to reach an analgesic state, and their fear of persistent apnea. Therefore, remifentanil is generally not a useful agent as part of a conscious sedation technique during brief painful procedures. Although discharge times are rapid, it is accompanied by a high incidence of life-threatening respiratory depression at subtherapeutic levels.

Topics: Adolescent; Adult; Apnea; Child; Child, Preschool; Clinical Medicine; Conscious Sedation; Female; Humans; Hypnotics and Sedatives; Infant; Male; Pain; Piperidines; Remifentanil; Retrospective Studies

We report a case of postoperative apnoea in the recovery room, 25 minutes after tracheal extubation, in a fully awake patient. This event occurred after flushing of an obstructed IV line into which remifentanil had been injected through a 3-way stopcock during anaesthesia. The means for prevention of such an adverse event are discussed.

Topics: Adult; Anesthesia, General; Anesthetics, Intravenous; Apnea; Female; Humans; Intubation, Intratracheal; Piperidines; Postoperative Complications; Recovery Room; Remifentanil

Apnea in the neonatal period frequently is associated with prematurity. Full-term infants who develop apnea usually have associated clinical conditions such as infection, shock, metabolic disorders, neonatal abstinence syndrome, intracranial pathology, and gastroesophageal reflux. Gastric ulcer also is a rare phenomenon in the neonatal period. We describe a full-term infant presenting with apnea. Upon investigation, a 6-channel pneumocardiogram revealed central apnea and multiple episodes of low esophageal pH (< 4), which is suggestive of gastroesophageal reflux. This was confirmed by an upper gastrointestinal series. A small antral ulcer crater also was demonstrated. When assessing the etiology of apnea in a full-term infant, gastroesophageal reflux and gastric ulcer should be considered.

Topics: Anti-Ulcer Agents; Apnea; Cisapride; Esophagus; Gastroesophageal Reflux; Humans; Hydrogen-Ion Concentration; Infant, Newborn; Male; Nose; Oxygen; Piperidines; Pulmonary Ventilation; Pulse; Ranitidine; Respiration; Stomach Ulcer

The laryngeal chemoresponse (LCR), comprising laryngeal adductor spasm, central apnea, and subsequent cardiovascular instability, is thought to be a factor in sudden infant death syndrome. A muscarinic subtype receptor, M3, appears to be involved in central respiratory drive and control. Both the duration of the LCR apnea and levels of M3 receptor messenger RNA in the brain stem change according to postnatal age. This study examined the effect of central nervous system antagonism at M3 receptors on the LCR with respect to animal age and dose of antagonist. Ten piglets in each of three age groups (group 1, 5 to 8 days; group 2, 18 to 21 days; and group 3, 40 to 43 days) received a series of four increasing doses of an M3 antagonist (p-fluoro-hexahydro-sila-diphenidol) by intracerebral ventricle injection. The LCR was evoked at baseline and after each dose of antagonist. An effect on susceptible animals (groups 1 and 2) was evident by the second antagonist dose, and persisted for the remainder of the experiment (2 hours). At completion of the experiment, mean apnea duration had decreased in group 1 (61%, p < .05), and group 2 (57%, p < .05), but was unchanged in group 3 (<10%, p not significant). Length of mean baseline apneas correlated directly with degree of apnea shortening. The reduction is not attributable to changes in arterial PO2 or PCO2 or baseline respiratory rate. These results support an age-related influence on the LCR by M3 receptors in younger animals that decreases with maturation.

Topics: Age Factors; Animals; Animals, Newborn; Apnea; Chemoreceptor Cells; Disease Models, Animal; Dose-Response Relationship, Drug; Hemodynamics; Humans; Infant, Newborn; Laryngismus; Larynx; Muscarinic Antagonists; Piperidines; Receptor, Muscarinic M3; Receptors, Muscarinic; Sudden Infant Death; Swine; Time Factors

Topics: Aged; Apnea; Brain; Cisapride; Fatal Outcome; Humans; Hyperventilation; Male; Metoclopramide; Neuroleptic Malignant Syndrome; Piperidines

Topics: Aged; Androstanes; Apnea; Drug Interactions; Humans; Kanamycin; Male; Neuromuscular Nondepolarizing Agents; Piperidines

Topics: Adult; Androstanes; Apnea; Humans; Male; Neurofibromatosis 1; Neuromuscular Nondepolarizing Agents; Piperidines; Succinylcholine