Pre-operative Neutralization of Gastric Acidity

Abstract

The incidence of Iv! endelson' s syndrome in the four major A uckland hospitals is reviewed. The frec;uency. ~! this c~nditio,,! was redu~ed followinfJ the pre-operative administration of magnestum tnstltcate mtxture m two hospttals. A tnal was conducted in a third hospital ll:nd th.is showed that a 52 per cent incidence of highly acid gastric juice (PH less than 2•5) m .pattents prepa~ed for electwe surgery was reduced by administration of magnesium trisilicate m~xture at the t~me of p~emedtcatwn: When the magnesium trisilicate mixture was given wtthm the 30 mmutes pnor to mductwn of anaesthes1a, the number of patients with highlv acid gastric content fell to onc per cent.

Pulmonary Acid Aspiration Syndrome: Should Prophylaxis Be Routine?

“…The pH values show good agreement with those of Taylor and Pryse-Davies (1966) and Hutchinson and Newson (1975). Patients undergoing emergency obstetric procedures are at greater risk because of the larger volumes involved.…”

“…The present in vitro study shows that Mist, magnesium trisilicate has a superior neutralizing effect compared with sodium citrate. In contrast, the in vitro model chosen by Lahiri, Thomas and Hodgson (1973) failed to show an increase in pH beyond 2.50, although the clinical studies of Taylor and Pryse-Davies (1966) and Hutchinson and Newson (1975) prove its efficiency in clinical practice.…”

“…Dinnick (1964), analysing 400 deaths in which anaesthesia was causally related, found 31 non-obstetric patients and 12 obstetric patients in whom regurgitation or vomiting of fluid matter was the principal factor. In a recent paper from Auckland the rate of mortality from pulmonary acid aspiration over all hospitals between 1967 and 1969 was 1 in 11,000 of non-obstetric patients (Hutchinson and Newson, 1975). Statistics on morbidity are difficult to ascertain: six cases of inhalation are known to have occurred in Lewisham Hospital during the year of study without serious outcome.…”

Acid Aspiration during Laparoscopy

“…The prophylactic value of antacids in reducing pulmonary acid aspiration syndrome in obstetric practice is well established (Taylor and Pryse-Davies 1966, Crawford 1970, Peskett 1973, Roberts and Shirley 1974. Recent investigations have revealed that surgical patients were also at risk of developing acid aspiration syndrome and that pre-operative use of antacids was highly effective in reducing this anaesthetic hazard (Hutchinson andNewson 1975, Hester andHeath 1977).…”

Ranitidine and single‐dose antacid therapy as prophylaxis against acid aspiration syndrome in obstetric practice

“…It was originally hoped that keeping the volume of gastric contents to a minimum would reduce the amount of antacid required to elevate the intragastric pH above the quoted thresholds of safety for Mendelson's ~y n d r o m e .~-~ Oral magnesium trisilicate mixture BPC had been used for many years for pcophylaxis against acid aspiration in labouring women. 5 Owing to the disappointing figures for Mendelson's syndrome in recent reports from confidential enquiries into maternal deaths, and swayed by reports in both animals6 and humans' that particulate antacids may themselves be harmful if aspirated into the lungs, we began to use 0.3 M sodium citrate in all obstetric patients as G.B. Gillett.…”