thiopental and Apnea

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

Topics: Anesthesia, Conduction; Anesthetics, Local; Animals; Apnea; Arrhythmias, Cardiac; Barbiturates; Central Nervous System; Critical Care; Diazepam; Drug Hypersensitivity; Epinephrine; Female; Humans; Infusions, Parenteral; Intubation, Intratracheal; Male; Monitoring, Physiologic; Oxygen Inhalation Therapy; Pregnancy; Procaine; Seizures; Succinylcholine; Thiopental

Topics: Anesthesia, Epidural; Anesthesia, General; Anesthesia, Intravenous; Anesthesia, Spinal; Anesthetics; Apnea; Cardiovascular System; Cesarean Section; Chlordiazepoxide; Diazepam; Female; Humans; Hydroxyzine; Inhalation; Neuromuscular Blocking Agents; Nitrous Oxide; Pregnancy; Succinylcholine; Thiopental

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

Airway irritation is a major drawback of desflurane anesthesia. This study was designed to evaluate the effect of intravenous fentanyl given before thiopental induction on airway irritation caused by a stepwise increase in desflurane in children.. Eighty children (2-8 years) were enrolled in a randomized, double-blind study. Forty received saline and 40 received 2 microg/kg of fentanyl intravenously; this was followed by thiopental sodium 5 mg/kg in both groups. Patients were assistant-ventilated with desflurane 1%, which was then increased by 1% every six breaths up to 10%. During this period, cough, secretion, excitation and apnea were graded and the desflurane concentration at which airway irritation symptoms first occurred was recorded. The results were analyzed using Pearson's chi-squared test.. The incidence of typical airway irritation events was lower with fentanyl than with saline (cough, 2.5% vs. 42.5%; secretion, 27.5% vs. 82.5%; excitation, 10% vs. 82.5%; apnea, 20% vs. 65%; P < 0.05). The mean expired desflurane concentration at which the first airway irritation symptom occurred was greater with fentanyl than with saline (7.3% vs. 5.5%, P < 0.05).. Intravenous fentanyl in children reduces airway complications caused by desflurane.

Topics: Analgesics, Opioid; Anesthesia, General; Anesthetics, Inhalation; Apnea; Blood Pressure; Child; Child, Preschool; Cough; Desflurane; Double-Blind Method; Electrocardiography; Female; Fentanyl; Heart Rate; Humans; Hypnotics and Sedatives; Injections, Intravenous; Irritants; Isoflurane; Male; Mucus; Thiopental

In a randomized, double-blind clinical trial, we studied the effect of different i.v. induction drugs on tracheal intubation conditions and apnoea time after small-dose (0.6 mg kg(-1)) succinylcholine used to facilitate orotracheal intubation at an urban, university-affiliated community medical centre.. One hundred and seventy-five ASA I and II adult patients scheduled to undergo surgical procedures requiring general anaesthesia and tracheal intubation were allocated to one of five groups according to i.v. anaesthetic induction drug used. General anaesthesia was induced by i.v. administration of lidocaine 30 mg and propofol 2.5 mg kg(-1) (Group 1), thiopental 5 mg kg(-1) (Group 2), lidocaine 30 mg and thiopental 5 mg kg(-1) (Group 3), etomidate 0.3 mg kg(-1) (Group 4), or lidocaine 30 mg and etomidate 0.3 mg kg(-1) (Group 5). After loss of consciousness, succinylcholine 0.6 mg kg(-1) was given i.v. followed by direct laryngoscopy and tracheal intubation after 60 s. Measurements included intubation conditions recorded during laryngoscopy 60 s after succinylcholine administration, and apnoea time.. Overall, clinically acceptable intubation conditions were met in 168 out of the 175 patients studied (96%). They were met in 35/35 patients in Group 1, 33/35 patients in Group 2, 34/35 patients in Group 3, 33/35 patients in Group 4, and 33/35 patients in Group 5. Mean (SD) apnoea time was 4.0 (0.4), 4.2 (0.3), 4.2 (0.6), 4.1 (0.2) and 4.1 (0.2) min respectively in Groups 1-5. There were no differences in the intubation conditions or apnoea times between the groups.. The use of succinylcholine 0.6 mg kg(-1) produced the same favourable intubation conditions and a short apnoea time regardless of the induction drug used.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anesthesia, General; Apnea; Dose-Response Relationship, Drug; Double-Blind Method; Etomidate; Female; Humans; Intubation, Intratracheal; Laryngoscopy; Lidocaine; Male; Middle Aged; Neuromuscular Depolarizing Agents; Propofol; Succinylcholine; Thiopental

An admixture of thiopentone and propofol was evaluated against propofol for laryngeal mask airway (LMA) insertion. Eighty-one ASA 1 and 2 18- to 65-year-old patients, premedicated with 7.5 mg midazolam orally were assigned randomly to receive either propofol 1% or an admixture of thiopentone and propofol (1.25% and 0.5% respectively), both at a dose of 0.25 ml x kg(-1). Satisfactory conditions for insertion were achieved with the admixture, which was comparable to propofol (73% vs 85%, P>0.05). There was no statistical difference in the incidence or severity of gagging, coughing, inadequate jaw relaxation and laryngospasm. The incidence of hypotension was lower in the admixture group (51% vs 78%, P=0.02). The duration of apnoea was not different between the admixture and propofol group (mean 103s vs 109s respectively, P>0.05). We conclude that thiopentone/propofol admixture can be a suitable alternative to propofol for LMA insertion, producing less hypotension while allowing cost savings of up to 45%. An admixture of thiopentone and propofol (1.25% and 0.5% respectively) can produce suitable conditions compared to propofol 1%, for laryngeal mask insertion. In addition to cost containment, the admixture also produces less hypotension.

Topics: Adult; Aged; Anesthesia, Intravenous; Anesthetics, Combined; Anesthetics, Intravenous; Apnea; Double-Blind Method; Drug Costs; Female; Gagging; Humans; Laryngeal Masks; Male; Middle Aged; Propofol; Thiopental

We recorded the ventilatory effects of eltanolone 0.75 mg kg-1, propofol 2.5 mg kg-1 and thiopentone 4 mg kg-1 at induction of anaesthesia in 76 unpremedicated patients, aged 18-65 yr. Measurements were made using a pneumotachograph incorporated between a close-fitting face mask and a T-piece delivering 35% oxygen. Eltanolone caused significantly less apnoea than propofol (incidence 57% vs 100%) and less reduction in ventilation than propofol (median maximum decrease 4.8 vs 7.8 litre min-1), but the differences between eltanolone and thiopentone were smaller and generally not significant. Ventilatory frequency was maintained well in the eltanolone group.

Topics: Adolescent; Adult; Anesthetics, Intravenous; Apnea; Female; Humans; Male; Middle Aged; Postoperative Complications; Propofol; Respiration; Respiratory Insufficiency; Steroids; Thiopental

(1) To investigate changes in arterial oxygen saturation via pulse oximeter (SpO2) during apnea and after reinstitution of manual ventilation at SpO2 of 95% or 90% following rapid sequence induction of anesthesia in children after 2-minute preoxygenation; (2) to determine whether the setting of a safe threshold of apneic period to an SpO2 of 95% is appropriate in children during anesthetic induction; and (3) to evaluate the influences of age, body weight, and height on the time from the start of apnea to SpO2 of 95%.. A clinical study of random design and comparison among groups.. Operating room of a plastic surgery hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College.. 152 infants and children, ASA physical status 1, aged 3 months to 12 years, scheduled for elective plastic surgery.. Patients were divided into three age groups: Group 1-infants 3 months to 1 year (n = 39); Group 2 children 1 to 3 years (n = 41); and Group 3-children 3 to 12 years (n = 72). Patients in each age group were randomly allocated again to Subgroups A and B. After a 2-minute preoxygenation, anesthesia was induced with thiopental 5 mg/kg, fentanyl 5 micrograms/kg and suxamethonium 1.5 mg/kg. Patients were manually ventilated when SpO2 decreased to 90% in Subgroups A and 95% in Subgroups B, respectively, during apnea.. SpO2 was measured continuously with a Datex pulse oximeter applied to the right index finger. During apnea, the times for SpO2 to decrease to 09% (T99) and 95% (T99) in all children, and 90% (T90) in Subgroups A were recorded. The time for SpO2 to decrease from 95% to 90% (T95-90) in Subgroups A was also measured. After reinstitution of manual ventilation, the time when SpO2 continued to decrease (T1) and the time from the end of apnea to recovery of SpO2 baseline (T2) were determined. In addition, the lowest value of SpO2 after apnea was also recorded. The results showed that younger children were more susceptible than older children to the risk of hypoxemia during apnea. There were significant differences in T99, T95, T90, and T95-90 between the three age groups T1 and T2 were significantly longer in Group 3 than in Groups 1 and 2. There were significant differences in the lowest values of SpO2 following apnea among the three Subgroups A and between Subgroups A and B of each age group. During apnea, heart rate decreased gradually as SpO2 decreased, showing a significant decrease at SpO2 of 95%. Bradycardia was found in three children in Subgroups A. The apnea time to SpO2 of 95% correlated well with age, weight, and height by linear regression analysis.. The safe threshold of an apneic period setting to an SpO2 of 95% was appropriate in children during anesthesia induction. Despite the same duration of preoxygenation, younger children were more susceptible than elder ones to the risk of hypoxemia during apnea. The apnea time to SpO2 of 95% correlated with age, body weight, and height using linear regression analysis.

Topics: Age Factors; Anesthesia, Intravenous; Anesthetics, Intravenous; Apnea; Body Height; Body Weight; Bradycardia; Child; Child, Preschool; Disease Susceptibility; Elective Surgical Procedures; Fentanyl; Heart Rate; Humans; Hypoxia; Infant; Linear Models; Neuromuscular Depolarizing Agents; Oximetry; Oxygen; Respiration, Artificial; Risk Factors; Safety; Succinylcholine; Surgery, Plastic; Thiopental; Time Factors

The induction characteristics of propofol 2.0-2.5 mg kg-1 were compared with those of thiopentone 4-5 mg kg-1 in 60 fit children aged between 3 and 16 yr. All patients received i.m. premedication with papaveretum 0.4 mg kg-1 (maximum dose 15 mg) and hyoscine 0.008 mg kg-1 (maximum dose 0.3 mg). Seven children (24%) complained of pain after injection with propofol, compared with three (10%) after thiopentone. No child in either group complained of severe pain. Excitatory effects were observed in 10 children (33%) receiving propofol as opposed to five children (16%) after thiopentone, but these were transient and minor and all occurred after completion of injection. Apnoea lasting longer than 30 s occurred in only four children (13%) in each group despite the use of opioid premedication. The mean duration of apnoea was similar in both groups. Propofol caused greater decreases in arterial pressures (systolic, diastolic, mean) than thiopentone, but only the difference in systolic arterial pressure achieved significance. There was a significant difference in heart rate, which did not change after propofol, but increased with thiopentone. The overall quality of induction was assessed as being good in all children receiving thiopentone compared with 20 (66%) of those receiving propofol.

Topics: Adolescent; Anesthesia, Intravenous; Anesthetics; Apnea; Blood Pressure; Child; Child, Preschool; Depression, Chemical; Female; Heart Rate; Humans; Intraoperative Complications; Male; Pain; Phenols; Propofol; Thiopental

Hemodynamic changes and side effects of anesthesia induction with etomidate or thiopental were evaluated in 83 ASA class I or II patients. Patients were randomly assigned to one of 12 groups according to pretreatment drug (fentanyl, 100 micrograms, or normal saline intravenously), induction agent (etomidate, 0.4 mg/kg, or thiopental, 4 mg/kg), and maintenance anesthetic technique (isoflurane-oxygen, isoflurane-nitrous oxide-oxygen, or fentanyl-nitrous oxide-oxygen). The purpose of this experiment, of factorial design, was to evaluate the combined effects of two or more experimental variables used simultaneously and to observe interaction effects. There were significant increases in heart rate in all groups, especially after tracheal intubation. These increases were attenuated but not eliminated by fentanyl pretreatment. Systolic arterial blood pressure increased significantly after intubation and was not affected either by fentanyl pretreatment or by the induction agent. Patients in whom anesthesia was induced with etomidate had a greater incidence of pain on injection and myoclonus and a lesser incidence of apnea than patients in whom anesthesia was induced with thiopental. Fentanyl pretreatment significantly decreased the incidence of pain on injection and myoclonus, but it increased the incidence of apnea when anesthesia was induced with etomidate. The incidence of postoperative nausea and vomiting was similar after thiopental and etomidate and was unaffected by fentanyl pretreatment. (ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adolescent; Adult; Aged; Analysis of Variance; Anesthesia, General; Anesthesia, Inhalation; Anesthesia, Intravenous; Apnea; Blood Pressure; Etomidate; Female; Fentanyl; Heart Rate; Humans; Imidazoles; Male; Middle Aged; Myoclonus; Nausea; Nitrous Oxide; Pain; Preanesthetic Medication; Random Allocation; Thiopental

The authors performed a bioassay of midazolam maleate, an investigational, water-soluble benzodiazepine; to determine the duration of sleep after a single intravenous dose. Sodium thiopental was the standard against which the midazolam maleate was assayed. Prior to operation 60 surgical patients were randomly given one of five doses of drugs, either thiopental, 180 or 270 mg, or midazolam maleate, 6.6, 10, or 15 mg. The designated drug was infused intravenously over 20 sec in a double-blind fashion. Sleep was defined as commencing when the patients stopped counting, and ending when they could respond appropriately to verbal commands. Midazolam maleate, 10 mg (9--12 mg represents 95 per cent confidence limits), was found to be equivalent to thiopental, 200 mg, in the duration of sleep induced. Apnea following the infusion was less frequent and of shorter duration after midazolam maleate than after thiopental. It is concluded that midazolam maleate is a satisfactory agent for the induction of anesthesia, and that it is about 20 times as potent as thiopental.

Topics: Adolescent; Adult; Aged; Apnea; Benzodiazepines; Dose-Response Relationship, Drug; Female; Humans; Male; Middle Aged; Sleep; Solubility; Thiopental; Water

Three groups of 50 patients were anaesthetized with diazepam 0.32 mg/kg or thiopentone 3.7 mg/kg or propanidid 4.6 mg/kg for elective carfioversion. Propanidid caused more hypotension than diazepam or thiopentone. Apnoea was most frequent following thipentone and excitatory side-effects were most prominent following propanidid; the electric countershock worsened the excitatory phenomena. The success rate of conversion was higher in the diazepam group than in the other groups, but the difference was not statistically significant. Diazepam failed to produce amnesia in about 33% of the patients. Thiopentone is suitable and pleasant for cardioversion. Diazepam is recommended in poor-risk patients and in emergency situations.

Topics: Adult; Aged; Amnesia; Anesthesia, General; Apnea; Arrhythmias, Cardiac; Blood Pressure; Cardiac Complexes, Premature; Diazepam; Electric Countershock; Female; Heart Rate; Humans; Male; Middle Aged; Propanidid; Thiopental

Topics: Adult; Age Factors; Aged; Anesthesia, General; Apnea; Bronchoscopy; Cognition; Dreams; Female; Humans; Laryngoscopy; Male; Middle Aged; Oxygen; Preanesthetic Medication; Reflex; Scopolamine; Thiopental

Topics: Adult; Age Factors; Apnea; Female; Humans; Male; Middle Aged; Muscular Diseases; Pain; Propanidid; Sex Factors; Succinylcholine; Thiopental

Topics: Adolescent; Adult; Aged; Anesthesia, Intravenous; Apnea; Child; Child, Preschool; Chlordiazepoxide; Computers; Drug Synergism; Female; Humans; Imipramine; Male; Middle Aged; Preanesthetic Medication; Reserpine; Thiopental

The possibility of restoration of the natural rhythmic activity of the respiratory system by transcutaneous electrical stimulation of the respiratory center after termination of spontaneous respiratory movements caused by narcosis was shown in experiments on mongrel cats of both sexes under nembutal anesthesia. Natural rhythmic activity of respiratory center was stopped by additional administration of sodium thiopental. The proposed method of electrical stimulation of the respiratory center allows maintaining the rhythmic respiratory movements and their recovery after narcotic apnea up to complete recovery of spontaneous respiration.

Topics: Animals; Apnea; Cats; Electric Stimulation; Female; Male; Respiration; Respiratory Center; Thiopental

Topics: Abnormalities, Multiple; Amides; Analgesia, Epidural; Analgesics; Anesthetics, Inhalation; Anesthetics, Intravenous; Anesthetics, Local; Apnea; Child, Preschool; Clonidine; Facies; Fingers; Growth Disorders; Humans; Intellectual Disability; Male; Methyl Ethers; Nerve Block; Nitrous Oxide; Orchiectomy; Ropivacaine; Sevoflurane; Syndrome; Thiopental

Topics: Abnormalities, Multiple; Anticonvulsants; Apnea; Child; Chromosome Deletion; Chromosomes, Human, Pair 4; Craniofacial Abnormalities; Diazepam; Dose-Response Relationship, Drug; Drug Therapy, Combination; Emergency Medical Services; Epilepsy, Tonic-Clonic; Female; Humans; Infusions, Intravenous; Phenobarbital; Status Epilepticus; Syndrome; Thiopental; Valproic Acid

Ventilatory effects at induction of anaesthesia were studied following intubation in 66 dogs anaesthetised using thiopentone (10 mg/kg) or propofol (4 mg/kg, injected rapidly or 4 mg/kg, injected slowly). Acepromazine and morphine preanaesthetic medication was administered, and anaesthesia was maintained with halothane in nitrous oxide and oxygen. The time from connection of the breathing system to the first breath was measured. Apnoea was defined as cessation of spontaneous respiration for 15 seconds or longer. Respiratory rate and minute volume were measured for the first five minutes of anaesthesia. Propofol was associated with a greater incidence of apnoea than thiopentone (59 per cent and 64 per cent compared with 32 per cent), but this difference was not statistically significant. Time to first breath was significantly longer with propofol than thiopentone and longest with the slower injection of propofol (P<0.05) (median of four seconds for thiopentone, 19.5 seconds for the propofol rapid injection, and 28.8 seconds for the propofol slow injection). In conclusion, the induction agent and speed of injection affect the incidence and duration of post-intubation apnoea.

Topics: Anesthetics, Intravenous; Animals; Apnea; Dog Diseases; Dogs; Female; Incidence; Intubation, Intratracheal; Male; Propofol; Random Allocation; Respiration; Thiopental; Time Factors

Topics: Anesthesia, General; Anesthetics, General; Apnea; Bradycardia; Epilepsy, Generalized; Epilepsy, Tonic-Clonic; Hernia, Inguinal; Humans; Hyponatremia; Infant, Newborn; Isoflurane; Male; Seizures; Thiopental

Although pulmonary function is minimally changed by neuraxial blockade in most cases, ventilatory arrest may ensue in rare cases. The authors examined the mechanism of apnea in a rabbit model of sudden ventilatory arrest during the combination of epidural anesthesia and hypoxia.. Rabbits were studied during alpha-chloralose sedation and spontaneous ventilation through a tracheostomy tube. Heart rate and mean arterial pressure were monitored by intraarterial cannulation. Respiratory rate and tidal volume were measured by pneumotachograph. Responses were recorded during administration of oxygen at inspired oxygen concentrations of 11% for 2.5 min and 0% for 40 s, before and after either thoracolumbar epidural blockade (0.4 ml/kg lidocaine, 1.5%) or intramuscular lidocaine (15 mg/kg). In a third group of animals, epinephrine was given intravenously during epidural blockade to return mean arterial pressure to baseline values before hypoxia. In a fourth group of animals, which did not get lidocaine, sympathetic blockade and hypotension were produced with intravenously administered trimethaphan rather than epidural blockade.. Thoracolumbar epidural anesthesia decreased mean arterial pressure from 76 +/- 4 mmHg (mean +/- SE) to 42 +/- 2 mmHg. Apnea during hypoxia occurred in 90% of these animals (nine of ten) but in only 11% of animals (one of nine) after intramuscularly administered lidocaine (P < 0.01). Treatment of epidural hypotension with epinephrine prevented apnea (zero of nine animals). Apnea during hypoxia occurred in 50% (three of six) of animals given trimethaphan. Apnea in all groups was sudden in onset, with no preceding decreases in respiratory rate or tidal volume.. Epidural anesthesia results in a narrowed margin of safety for oxygen delivery to the brain and predisposes subjects to ventilatory arrest during hypoxia. This results from the combined effects of decreased blood oxygen content, which is due to decreased inspired oxygen concentration superimposed on circulatory depression due to neural blockade.

Topics: Anesthesia, Epidural; Anesthetics, Local; Animals; Apnea; Atropine; Blood Pressure; Epinephrine; Ganglionic Blockers; Heart Rate; Hypoxia; Lidocaine; Male; Rabbits; Thiopental; Trimethaphan

In this study, our induction methods of endotracheal anesthesia was evaluated with reference to electrocardiogram, hemodynamic status and arterial blood gas analysis on 153 patients. From the beginning of induction, electrocardiogram was recorded continuously to the completion of intubation. The blood pressure and heart rate were also measured. Arterial blood samples were taken at 40 seconds of apneic period after the mask was removed from the patient's face (CONT group), at 40 seconds of apnea with intratracheal spray (LIDO group), and after intubation following intratracheal spray (INT group). In the electrocardiographic survey, arrhythmias during intubation were rare (1/113, 0.9%). PaCO2 values in INT group showed a significant elevation (+ 14.0 mmHg; p < 0.01) compared to these in CONT group. As a result of careful and gentle induction techniques, the incidence of arrhythmias during intubation was very low. However, an elevation of PaCO2 was not avoidable, even in smooth and successful intubation. In conclusion, the importance of more adequate ventilation coupled with skillful intubation in a shorter period to avoid hypercapnia and arrhythmias is appreciated again in the endotracheal anesthesia for the maxillofacial surgical patients with anatomical airway problems.

Topics: Adult; Anesthesia, Dental; Anesthesia, General; Anesthetics, Inhalation; Anesthetics, Intravenous; Apnea; Arrhythmias, Cardiac; Blood Pressure; Carbon Dioxide; Ethers; Female; Heart Rate; Humans; Intubation, Intratracheal; Isoflurane; Male; Methyl Ethers; Middle Aged; Oxygen; Partial Pressure; Sevoflurane; Thiopental; Time Factors

We have examined the use of continuous positive airway pressure (CPAP) and apnoeic oxygenation for restoration of spontaneous breathing at the end of anaesthesia after controlled ventilation. We studied 45 adult patients without a history of acute or chronic respiratory disturbances. Anaesthesia was induced with thiopentone or propofol and maintained with nitrous oxide and enflurane in oxygen. The patients were normocapnic during artificial ventilation. At the end of surgery, the lungs were ventilated for 5 min with oxygen and then given a CPAP of 8 cm H2O. Spontaneous ventilation was regained after a mean of 5 min and an arterial blood sample was obtained at the third breath. All patients were well oxygenated (PO2 mean 43.5 kPa, range 21-76 kPa) when spontaneous ventilation started. The pH was close to 7.28 in most cases (mean 7.28, range 7.21-7.32), and PCO2 varied in the range 6.6-9.9 kPa (mean 7.9 kPa). It is concluded that the method is safe with regard to oxygenation and acid-base balance.

Topics: Adolescent; Adult; Aged; Anesthesia, General; Apnea; Carbon Dioxide; Enflurane; Female; Humans; Hydrogen-Ion Concentration; Male; Middle Aged; Oxygen; Partial Pressure; Positive-Pressure Respiration; Propofol; Random Allocation; Respiration; Thiopental; Time Factors

Obese patients have a decreased functional residual capacity and, hence, a reduced oxygen supply during periods of apnea. To determine whether obese patients are at greater risk of developing hypoxemia during induction of anesthesia than patients of normal weight, 24 patients undergoing elective surgical procedures were studied. Group 1 (normal) were within 20% of their ideal body weight. Group 2 (obese) were more than 20% but less than 45.5 kg over ideal body weight. Group 3 (morbidly obese) were more than 45.5 kg over ideal body weight. Patients were preoxygenated for 5 min or until expired nitrogen was less than 5%. After induction of anesthesia and muscle relaxation the patients were allowed to remain apneic until arterial saturation as measured by pulse oximetry reached 90%. The time taken for oxygen saturation to decrease to 90% was 364 +/- 24 s in group 1, 247 +/- 21 s in group 2, and 163 +/- 15 s in group 3; these times are significantly different at P less than 0.05 between groups. Regression analysis of the data demonstrated a significant negative linear correlation (r = -0.83) between time to desaturation and increasing obesity. These results show that obese patients are at an increased risk of developing hypoxemia when apneic.

Topics: Adult; Anesthesia; Apnea; Humans; Hypoxia; Middle Aged; Obesity; Obesity, Morbid; Risk; Thiopental

Topics: Adult; Anesthesia; Apnea; Humans; Huntington Disease; Male; Thiopental

Changes in Paco2 and Paco2 during the induction of anaesthesia with thiopental suxamethonium, and intubation were investigated in 20 patients who received preoxygenation for 2 min, but no ventilation before intubation. Both in fit patients below the age of 60 years (Group I) and in patients above the age-several suffering from cardiopulmonary disease - (group II), Pao2 increased to about 40 kPa during preoxygenation and remained at the level during apnoea. Mean Paco2 increased to 6.3 and 5.7 kPa in Groups I and II, respectively. No complications were seen, and it is concluded that the apnoea involved in the "crash induction" technique is sage. Pulmonary aspiration of acid gastric fluid may also occur in fasting patients, and it is suggested that even in elective cases ventilation might advantageously be replaced by preoxygenation when anaesthesia is induced with thiopental and suxamethonium.

Topics: Anesthesia, General; Apnea; Humans; Intubation, Intratracheal; Middle Aged; Oxygen Inhalation Therapy; Preoperative Care; Respiration, Artificial; Risk; Succinylcholine; Thiopental

In patients premedicated with scopolamine + morphine (+5 mg nitrazepam the evening before surgery), the sleep-inducing effect of midazolam 0.15 mg/kg i.v. was clearly slower in onset than that of thiopentone 4.67 mg/kg i.v. Somewhat fewer cardiovascular and local sequelae were found in the midazolam group, but, although apnoea occurred less often in the midazolam group it lasted longer. On the whole, the differences between midazolam and thiopentone had no apparent clinical consequences. Midazolam is a new alternative agent for induction in combination anaesthesia.

Topics: Adolescent; Adult; Aged; Apnea; Benzodiazepines; Female; Humans; Male; Midazolam; Middle Aged; Preanesthetic Medication; Thiopental

To determine which part of the parasympathetic bronchoconstrictor pathway is most sensitive to depression by general anesthetics, we stimulated different parts of the pathway in dogs after initial anesthesia with chloralose and urethan and then after additional anesthetic drugs. We stimulated the entire reflex pathway by producing apnea or hypoventilation, the sensory pathway by electrically stimulating the proximal end of cut superior laryngeal nerves, and the motor pathway by stimulating the distal end of a cut cervical vagus nerve. Bronchoconstrictor responses to all stimuli were assessed with a bypassed tracheal segment. When no additional anesthetic was administered, responses to all stimuli increased with time. Small additional doses of anesthetics (thiopental, 1-5 mg/kg; pentobarbital, 1-2 mg/kg; amobarbital, 1-2 mg/kg; or chloralose, 10 mg/kg) decreased responses to reflex and sensory stimulation markedly and reversibly, but they did not affect responses to motor stimulation. Increased doses decreased responses to motor stimulation as well. Our previous study (Skoogh et al., Am. Rev. Respir. Dis. 123: 202, 1981) showed that barbiturates depress parasympathetic ganglionic synapses; the present study suggests that central nervous system synapses may be even more sensitive to depression by general anesthetics.

Topics: Amobarbital; Anesthesia, General; Anesthetics; Animals; Apnea; Bronchi; Chloralose; Dogs; Hypoventilation; Laryngeal Nerves; Parasympathetic Nervous System; Pentobarbital; Reflex; Thiopental; Vagus Nerve

Topics: Adult; Anesthesia, Intravenous; Apnea; Atropine; Electroconvulsive Therapy; Female; Humans; Male; Oxygen Inhalation Therapy; Succinylcholine; Thiopental; Time Factors

Topics: Adult; Aged; Anesthesia, Intravenous; Apnea; Atropine; Blood Pressure; Dose-Response Relationship, Drug; Drug Combinations; Female; Heart Rate; Humans; Hydroxysteroids; Ketosteroids; Male; Meperidine; Middle Aged; Pregnanes; Promethazine; Sleep; Thiopental

Topics: Anesthesia, Intravenous; Apnea; Arrhythmia, Sinus; Atropine; Blood Pressure; Drug Combinations; Electric Countershock; Electrocardiography; Female; Heart Rate; Humans; Hydroxysteroids; Ketosteroids; Male; Middle Aged; Preanesthetic Medication; Pregnanes; Steroids; Thiopental

Topics: Anesthesia, Intravenous; Apnea; Cholinesterases; Humans; Male; Middle Aged; Succinylcholine; Thiopental; Time Factors

Topics: Anesthesia, Intravenous; Apnea; Carbon Dioxide; Humans; Hydrogen-Ion Concentration; Laryngoscopy; Larynx; Microsurgery; Obesity; Oxygen; Succinylcholine; Thiopental

Topics: Air; Anesthesia, General; Apnea; Body Weight; Carbon Dioxide; Chemoreceptor Cells; Hemoglobins; Humans; Oxygen; Partial Pressure; Reflex; Thiopental; Time Factors

Topics: Adolescent; Adult; Aged; Amnesia; Anesthesia, General; Apnea; Bronchoscopy; Cognition; Consciousness; Diazepam; Humans; Laryngoscopy; Male; Middle Aged; Preanesthetic Medication; Thiopental

Topics: Anesthesia, Obstetrical; Apnea; Cesarean Section; Cholinesterases; Female; Humans; Infant, Newborn; Nitrous Oxide; Pregnancy; Succinylcholine; Thiopental; Tubocurarine

Topics: Adolescent; Adult; Aged; Anesthesia, General; Apnea; Body Weight; Female; Halothane; Humans; Intubation; Intubation, Intratracheal; Larynx; Liver Function Tests; Male; Meperidine; Methoxyflurane; Middle Aged; Neuromuscular Depolarizing Agents; Nitrous Oxide; Obesity; Oxygen; Pharynx; Succinylcholine; Thiopental; Time Factors

Topics: Action Potentials; Adolescent; Adult; Anesthesia, General; Apnea; Biopsy; Central Nervous System; Child; Creatine Kinase; Electromyography; Female; Fever; Follow-Up Studies; Heart Rate; Humans; Male; Middle Aged; Muscles; Nerve Degeneration; Reflex, Abnormal; Succinylcholine; Thiopental

Topics: Anesthetics, Local; Animals; Apnea; Atropine; Cats; Laryngismus; Larynx; Lidocaine; Respiration; Succinylcholine; Thiopental

Topics: Adolescent; Apnea; Female; Humans; Intubation, Intratracheal; Isoniazid; Middle Aged; Peritoneal Dialysis; Phenytoin; Poisoning; Renal Dialysis; Respiration, Artificial; Seizures; Shock, Septic; Thiopental

Topics: Adult; Apnea; Female; Halothane; Helium; Humans; Lung; Male; Middle Aged; Oxygen; Respiration; Rest; Spirometry; Succinylcholine; Thiopental; Wakefulness

Topics: Adolescent; Adult; Aged; Anesthetics; Apnea; Electroconvulsive Therapy; Female; Headache; Humans; Male; Middle Aged; Phenylacetates; Psychological Tests; Thiopental

Topics: Accidents; Amnesia; Anesthesia; Apnea; Central Nervous System; Convulsive Therapy; Depression; Electroconvulsive Therapy; Fear; History, 20th Century; Humans; Injections, Intravenous; Methods; Pentylenetetrazole; Thiopental; Thrombophlebitis

Topics: Analysis of Variance; Anesthesia, General; Apnea; Arrhythmias, Cardiac; Blood Specimen Collection; Bronchoscopy; Carbon Dioxide; Catheterization; Cyanosis; Female; Humans; Hypercapnia; Hyperventilation; Lidocaine; Male; Middle Aged; Oxygen; Oxygen Consumption; Positive-Pressure Respiration; Succinylcholine; Thiopental; Vocal Cords

Topics: Anesthesia, Inhalation; Apnea; Brain Neoplasms; Cerebral Angiography; Cerebrovascular Disorders; Halothane; Hypotension, Controlled; Nitrous Oxide; Oxygen; Punctures; Respiration, Artificial; Thiopental

Topics: Adjuvants, Anesthesia; Adult; Aged; Anesthesia, Endotracheal; Apnea; Carbon Dioxide; Female; Humans; Hypoxia; Injections, Intravenous; Male; Middle Aged; Oxygen; Preanesthetic Medication; Succinylcholine; Thiopental

Topics: Adult; Anesthesia; Apnea; Humans; Huntington Disease; Male; Thiopental

Topics: Adult; Anesthesia, General; Apnea; Bicarbonates; Decamethonium Compounds; Fever; Heart Massage; Humans; Isoproterenol; Male; Metaraminol; Methamphetamine; Pulmonary Atelectasis; Pulmonary Edema; Spasm; Succinylcholine; Thiopental

Topics: Adolescent; Adult; Aged; Anesthetics; Apnea; Blood Pressure; Child; Female; Halothane; Humans; Hyperventilation; Hypotension; Male; Middle Aged; Postoperative Complications; Pulse; Tachycardia; Thiopental

Topics: Acidosis, Respiratory; Adult; Aged; Anesthesia, General; Apnea; Bronchiectasis; Bronchoscopy; Carbon Dioxide; Female; Humans; Male; Methods; Middle Aged; Pressure; Succinylcholine; Thiopental

Topics: Anesthesia, General; Anesthesia, Inhalation; Anesthesiology; Apnea; Bronchoscopy; Carbon Dioxide; Humans; Intubation; Intubation, Intratracheal; Nitrous Oxide; Oxygen; Succinylcholine; Thiopental

Topics: Anesthesia; Anesthesia, General; Animals; Apnea; Blood Gas Analysis; Blood Pressure; Blood Pressure Determination; Carbon Dioxide; Dogs; Intubation; Intubation, Intratracheal; Neurons; Oxygen; Physiology; Research; Sympathetic Nervous System; Thiopental

Topics: Apnea; Electroconvulsive Therapy; Heart Arrest; Humans; Muscle Relaxants, Central; Succinylcholine; Thiopental; Toxicology

Topics: Acidosis; Apnea; Atropine; Bicarbonates; Bis-Trimethylammonium Compounds; Gallamine Triethiodide; Humans; Infusions, Parenteral; Laparotomy; Meperidine; Neostigmine; Nitrous Oxide; Obesity; Peritonitis; Postoperative Complications; Sodium Bicarbonate; Thiopental; Toxicology

Topics: Anesthesia; Anesthesia, Intravenous; Anesthetics; Anesthetics, Intravenous; Apnea; Barbiturates; Hyperventilation; Methohexital; Pharmacology; Preanesthetic Medication; Spirometry; Succinylcholine; Thiopental; Toxicology

Topics: Administration, Intravenous; Anesthesia; Anesthesia, Intravenous; Anesthesiology; Apnea; Humans; Incidence; Methohexital; Methotrexate; Thiopental