thiopental and Gastroesophageal-Reflux

Topics: Anesthesia; Anesthesia, Inhalation; Anesthesia, Intravenous; Child; Consciousness; Eating; Gastric Juice; Gastroesophageal Reflux; Gastrostomy; Humans; Hydrogen-Ion Concentration; Hyperventilation; Infant; Infant, Newborn; Inhalation; Intubation, Intratracheal; Methods; Posture; Preanesthetic Medication; Preoperative Care; Stomach; Succinylcholine; Thiopental; Wakefulness

Topics: Anesthesia; Barbiturates; Blood Circulation; Gastroesophageal Reflux; Humans; Hypotension; Intubation, Intratracheal; Neuromuscular Depolarizing Agents; Neuromuscular Nondepolarizing Agents; Reflex, Abnormal; Succinylcholine; Thiopental; Time Factors; Vomiting

To compare the cardiorespiratory effects and incidence of gastroesophageal reflux with the use of a laryngeal mask airway (LMA) or endotracheal tube (ET) in anesthetized cats during spontaneous (SV) or controlled ventilation (CV).. Prospective randomized experimental trial.. Thirty-two adult crossbred cats, weighing 2.7 +/- 0.4 kg.. The cats were sedated with intramuscular (IM) methotrimeprazine (0.5 mg kg(-1)) and buprenorphine (0.005 mg kg(-1)), followed 30 minutes later by induction of anesthesia with intravenous (IV) thiopental (12.5-20 mg kg(-1)). An ET was used in 16 cats and an LMA in the remaining 16 animals. Anesthesia was maintained with 0.5 minimum alveolar concentration (0.6%) of halothane in oxygen using a Mapleson D breathing system. Cats in both groups were further divided into two equal groups (n = 8), undergoing either SV or CV. Neuromuscular blockade with pancuronium (0.06 mg kg(-1)) was used to facilitate CV. Heart and respiratory rates, direct arterial blood pressure, capnometry (PE'CO2) and arterial blood gases were measured. Gastric reflux and possible aspiration was investigated by intragastric administration of 5 mL of radiographic contrast immediately after induction of anesthesia. Cervical and thoracic radiographs were taken at the end of anesthesia. Data were analyzed using anova followed by Student-Newman-Keuls, Kruskal-Wallis or Friedman test where appropriate.. Values for PaCO2 and PE'CO2 were higher in spontaneously breathing cats with the LMA when compared with other groups. Values of PaO2 and hemoglobin oxygen saturation did not differ between groups. Gastroesophageal reflux occurred in four of eight and two of eight cats undergoing CV with ET or LMA, respectively. There was no tracheal or pulmonary aspiration in any cases.. The use of an LMA may be used as an alternative to endotracheal intubation in anesthetized cats. Although aspiration was not observed, gastric reflux may occur in mechanically ventilated animals.

Topics: Anesthetics, Intravenous; Animals; Carbon Dioxide; Cats; Female; Gastroesophageal Reflux; Hydrogen-Ion Concentration; Intubation, Intratracheal; Laryngeal Masks; Male; Prospective Studies; Respiration; Thiopental

The aim of this study was to investigate whether an increased frequency of gastro-oesophageal reflux (GOR) is more common in large-sized, deep-chested dogs undergoing spinal surgery in sternal recumbency than in small-sized, barrelchested dogs.. Prospective, cohort study.. Nineteen small-sized, barrel-chested dogs (group B) and 26 large-sized, deep-chested dogs (group D).. The frequency of GOR during anaesthesia was significantly higher in group D (6/26 dogs; 23.07%) than in group B (0/19 dogs; 0%) (p = 0.032). Signs indicative of aspiration pneumonia, oesophagitis or oesophageal stricture were not reported in any of the GOR cases.. In large-sized, deep-chested dogs undergoing spinal surgery in sternal recumbency, it would seem prudent to consider measures aimed at preventing GOR and its potentially devastating consequences (oesophagitis/oesophageal stricture, aspiration pneumonia).

Topics: Anesthesia; Animals; Body Size; Dog Diseases; Dogs; Female; Gastroesophageal Reflux; Halothane; Hydrogen-Ion Concentration; Male; Patient Positioning; Postoperative Complications; Prospective Studies; Thiopental

To investigate the potential effect of increased blood progesterone (P(4)) and oestradiol-17beta (E(2)) concentrations on the barrier pressure (BrP) and the incidence of gastro-oesophageal reflux (GOR) in female dogs under general anaesthesia.. Prospective, blinded experimental trial.. Seven female, adult, healthy dogs weighing 14-21 kg and aged 1-7 years.. Each of the animals was studied under the influence of high blood E(2) and basal P(4) (study O), basal E(2) and high P(4) (study P) and basal E(2) and P(4) (study C) concentrations. Animals were premedicated with acepromazine and anaesthesia was induced with thiopental and maintained with halothane. Lower oesophageal pH was monitored continuously for 1 hour after induction. GOR was defined as oesophageal pH >7.5 or <4. Manometry of the posterior oesophageal sphincter (POS) was then performed using the slow pull-through technique.. Acid GOR was detected in only one animal of study O. The three studies did not differ significantly in GOR. Mean BrP was 11.2 (study O), 9.1 (study P) and 11.6 mmHg (study C). No significant differences were detected with respect to mean BrP, intra-gastric pressure and POS pressure.. It is unlikely that the increased concentrations of E(2) or P(4) during the normal ovarian cycle influence the functional efficiency of the POS as a major barrier to GOR in healthy, female dogs under general anaesthesia.. The fact that female dogs undergoing obstetrical surgery represented a substantial sub-group of the animals which developed postoperative benign oesophageal stricture, should probably not be attributed to the effects of increased concentrations of female sex steroid hormones.

Topics: Anesthesia, General; Animals; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Esophagogastric Junction; Estradiol; Estrous Cycle; Female; Gastroesophageal Reflux; Pressure; Progesterone; Thiopental

Lower oesophageal pH was monitored in 50 cats anaesthetized with either thiopentone or propofol. Gastro-oesophageal reflux, as evidenced by a decrease in lower oesophageal pH to less than 4.0 or an increase to more than 7.5, occurred in 16% (4/25) and 12% (3/25) of the cats anaesthetized with thiopentone and propofol, respectively, the difference between the two groups being non-significant. Reflux usually occurred shortly after the induction of anaesthesia and had a mean duration of about 23 min. The refluxate was always acidic (pH < 4.0). Gastric contents of pH below 2.5 were refluxed on three occasions, two in the thiopentone group and one in the propofol group. Regurgitation and flow of gastric contents from the mouth occurred in only one cat anaesthetized with propofol. None of the cats that exhibited reflux developed any signs of postanaesthetic oesophagitis or stricture formation.

Topics: Anesthesia, Intravenous; Anesthetics, Intravenous; Animals; Cat Diseases; Cats; Female; Gastroesophageal Reflux; Hydrogen-Ion Concentration; Male; Propofol; Thiopental

A case of intraoperative convulsions occurring in a child with arthrogryposis multiplex congenita is presented. Arthrogryposis and the anaesthetic management of children with this condition is discussed. Factors which may have contributed to the convulsions are considered.

Topics: Anesthetics, Inhalation; Anesthetics, Intravenous; Arthrogryposis; Fever; Fundoplication; Gastroesophageal Reflux; Humans; Infant; Intraoperative Complications; Intubation, Intratracheal; Male; Neuromuscular Nondepolarizing Agents; Nitrous Oxide; Seizures; Tachycardia, Sinus; Thiopental; Vecuronium Bromide

Topics: Adult; Anesthesia, General; Esophageal Achalasia; Gastroesophageal Reflux; Humans; Male; Thiopental; Zenker Diverticulum

Gastric contents regurgitation into the oesophagus during induction of anaesthesia may easily fail to be recognized. The incidence of this complication was investigated in 59 consecutive patients. They were scheduled for elective thoracic surgery. Anaesthesia was induced with thiopentone (6 mg.kg-1), fentanyl (3 micrograms.kg-1), and either atracurium (0.4 mg.kg-1), vecuronium (0.1 mg.kg-1) or suxamethonium (1.5 mg.kg-1). Oesophageal pH was monitored with an oesophageal pH probe, connected to a portable computer. The pH probe had a virtually instantaneous response time and was positioned in the lower oesophagus. Acid reflux was defined as a decrease in pH to less than 4.0. During the course of induction, three patients (5%) presented an episode of acid reflux. No patient presented any clinical or radiological signs of pulmonary aspiration. This study suggests that monitoring oesophageal pH is a simple method of detecting gastric reflux during the period of induction.

Topics: Adult; Aged; Anesthesia, Intravenous; Esophagus; Female; Fentanyl; Gastroesophageal Reflux; Humans; Hydrogen-Ion Concentration; Male; Middle Aged; Monitoring, Intraoperative; Thiopental

The upper oesophageal sphincter can prevent regurgitation of oesophageal contents into the pharynx following gastrooesophageal reflux in the awake patient. Upper oesophageal sphincter pressure was recorded with a Dent sleeve after hypnosis with midazolam (n = 7) and also during the rapid intravenous induction of anaesthesia with thiopentone (n = 16) or ketamine (n = 7). Thiopentone decreased mean (SD) sphincter pressure from an awake value of 43 (19) to 9 (7) mmHg (p less than 0.001) and midazolam from 38 (25) to 7 (3) mmHg (p less than 0.02). Mean (SD) sphincter pressures before and after ketamine were not significantly different at 29 (15) and 32 (21) mmHg respectively. After suxamethonium mean (SD) sphincter pressure in all patients (n = 30) was 7 (4) mmHg. Laryngoscopy (n = 30) caused a small increase in mean (SD) sphincter pressure to 13 (10) mmHg (p less than 0.001). Thiopentone caused a rapid fall in upper oesophageal sphincter pressure which usually started before loss of consciousness. These findings have implications for the timing of cricoid pressure application.

Topics: Adult; Anesthesia, Intravenous; Cricoid Cartilage; Esophagus; Female; Gastroesophageal Reflux; Humans; Intraoperative Complications; Ketamine; Male; Midazolam; Middle Aged; Pressure; Succinylcholine; Thiopental

In an attempt to explain the discrepancy between the high number of patients said to be at risk of aspiration pneumonitis and the low reported incidence of this anaesthetic complication, 100 ASA physical status I-II elective surgical patients were studied. The volume of fluid present in the stomach at the time of induction of anaesthesia was correlated with gastroesophageal reflux (GER) detected by visual inspection of the pharynx and by continuous measurement of upper oesophageal pH. Mean gastric volume was 30 +/- 28 ml (range 0-210 ml). Gastric fluid volume greater than or equal to 0.4 ml.kg-1 at pH less than or equal to 2.5 was present in 46 patients. No GER was detected during induction of anaesthesia in our sample of 100 patients. Furthermore, patient age, duration of preoperative fasting, body mass index, cigarette smoking, alcohol consumption, preoperative anxiety, and a history of preoperative GER were not correlated with significant modifications of gastric volume or pH. We conclude that the low incidence of aspiration pneumonitis in elective surgical patients may be explained in part by the very low risk of GER, despite gastric fluid volumes of more than 0.4 ml.kg-1 in a high proportion of this patient population.

Topics: Adult; Female; Gastroesophageal Reflux; Gastrointestinal Contents; Humans; Male; Middle Aged; Pneumonia, Aspiration; Risk Factors; Thiopental

The rationale of "crash induction" in patients with full stomach is reviewed. The technique does not precipitate regurgitation in normal patients having competent cardia, provided respiratory obstruction and IPPV are avoided during induction. On the other hand, in patients with incompetent cardia such as intestinal obstruction or hiatus hernia, excessive material may accumulate in the lower oesophagus. The accumulation will be suddenly released with the cricopharyngeal relaxation subsequent to "crash induction". The stomach and oesophagus should be adequately decompressed pre-operatively, and precautionary measures such as backward cricoid pressure must be taken during induction.

Topics: Anesthesia; Esophagogastric Junction; Gastroesophageal Reflux; Hernia, Hiatal; Humans; Intestinal Obstruction; Stomach; Succinylcholine; Thiopental

A method of 'crash induction' using pancuronium and thiopentone was studied in 100 patients at risk from vomiting or regurgitation. The technique was inferior to thiopentone/suxamethonium in terms of time to intubation, activity of vocal cords and responses to stimuli during induction. Six cases gave difficulty with intubation due to poor relaxation. Only two patients had a fall in systolic blood pressure of more than 20% following induction. No regurgitation occurred. The technique may be suitable for skilled anaesthetists in cases when suxamethonium is relatively contraindicated, when large doses of pancuronium can be used or when hypotension is likely to follow induction.

Topics: Adolescent; Adult; Aged; Anesthesia, General; Anesthesia, Intravenous; Female; Gastroesophageal Reflux; Humans; Intubation, Intratracheal; Male; Middle Aged; Pancuronium; Succinylcholine; Thiopental; Time Factors

The effects of some drugs generally used in premedication for and induction of anaesthesia on the lower oesophageal sphincter (LOS) pressure were investigated in 30 dogs, using the modern oesophageal manometric technique. In thiopental-induced anaesthesia, a distinct pressure gradient was noted between the LOS and gastric pressure. Atropine eliminated this pressure gradient almost completely. Metoclopramide increased the LOS pressure significantly, and subsequent atropine administration was unable to bring it down. Metoclopramide administered after atropine was unable to elevate the LOS pressure reduced by atropine. Succinylcholine had no observable lasting effect on the LOS pressure. The present findings seem to indicate that of the drugs generally used in premedication for and induction of anaesthesia, atropine significantly reduces the LOS competence, thereby creating favourable conditions for gastro-oesophageal reflux (GOR) and consequent postoperative pulmonary complications. Use of metoclopramide in premedication for or induction of anaesthesia to eliminate the depressant effect of atropine on the LOS pressure appears to be indicated.

Topics: Anesthesia, General; Anesthetics; Animals; Atropine; Dogs; Drug Evaluation, Preclinical; Drug Interactions; Esophagogastric Junction; Female; Gastroesophageal Reflux; Male; Metoclopramide; Preanesthetic Medication; Pressure; Succinylcholine; Thiopental

Topics: Anesthesia, General; Gastroesophageal Reflux; Humans; Inhalation; Injections, Intravenous; Intubation, Intratracheal; Laryngoscopy; Methods; Methohexital; Relaxation; Succinylcholine; Thiopental; Time Factors; Tubocurarine

Topics: Adult; Anesthesia, General; Anesthesia, Intravenous; Gastroesophageal Reflux; Humans; Intubation, Intratracheal; Methods; Succinylcholine; Thiopental; Time Factors