The Induction of Anaesthesia in Patients Likely to Vomit With Special Reference to Intestinal Obstruction

Abstract

Vomiting or regurgitation during the induction of anaesthesia is a special hazard and the type of patient at risk is detailed. The preparation of such patients for operation is described and the care that must be taken over aspiration of the stomach contents is emphasized. The use of cricoid pressure during induction is considered to be valuable. The induction of anaesthesia using intravenous agents is described for cases in whom the advantages outweigh the risk of regurgitation, but the method preferred by the author is a purely inhalational technique. This method is described in detail and is based on a nitrous-oxide, oxygen, ether sequence using carbon dioxide as a respiratory stimulant. The disadvantages of a thiopentone-relaxant technique are considered and some of the reasons for believing that an inhalational technique is safer are given. Aspects of the recommended technique examined include the efiFects of hyperventilation on the vomiting mechanism, the carbon dioxide levels used, and the subsequent course of anaesthesia. Other techniques which may be used in special circumstances, with special reference to intubation whilst the patient is conscious, are considered.

The Anaesthetist and the Early Management of Acute Head Injuries

“…If suxamethonium is used, the problem of regurgitation is introduced. The variety of methods (Wylie, 1963;Inkster, 1963) employed to avoid this complication illustrates how unsatisfactory they are. Many anaesthetists omit this drug altogether when there is a danger of aspiration of stomach contents.…”

Science, pseudoscience and Sellick

“…Recommended anesthetic techniques for the 'full stomach' patient in the 1950s, before the days of succinylcholine, halothane and cricoid pressure, now sound bizarre. 4 Nevertheless, they were based on physiological principles and appeared to prevent pulmonary aspiration. The Newcastle technique was based on the premise that a patient cannot hyperventilate and vomit at the same time.…”

“…The 40° head-up tilt position raised the larynx 19 cm above the lower esophageal sphincter. 4 This strategy was based on O'Mullane's clinical studies, 5 which showed that, even with 500-1,000 mL saline in the stomach, the intragastric pressure did not exceed 18 cm water. The head-up tilt would therefore prevent passive reflux into the phar-ynx, but would unfortunately increase the likelihood of aspiration if active vomiting occurred.…”

“…Les techniques anesthésiques recommandées dans les années 1950 dans les cas "d'estomac plein", avant l'arrivée de la succinylcholine, de l'halothane et de la compression cricoïdienne, nous semblent maintenant étranges. 4 Elles étaient néanmoins fondées sur des principes physiologiques et ont semblé prévenir l'aspiration pulmonaire. Le fondement de la technique Newcastle était que l'hyperventilation et les vomissements ne peuvent être simultanés chez un même patient.…”

“…On a aussi expérimenté une position de Trendelenburg à 20° ou Trendelenburg en décubitus latéral pour faciliter le drainage du liquide hors de la glotte, ce qui complique la laryngoscopie, et une position de Fowler à 40°, ce qui élève le larynx de 19 cm au-dessus du sphincter inférieur de l'oesophage. 4 Cette position a été adoptée à la suite des études cliniques de O'Mullane 5 qui ont montré que, même avec 500 -1 000 mL de solution saline dans l'estomac, la pression intragastrique ne dépasse pas 18 cm d'eau. La tête vers le haut peut donc prévenir le reflux passif dans le pharynx, mais accroître la probabilité d'aspiration en cas de vomissement.…”