Pre-operative neutralization of gastric acidity.

Area of Science:

• Anesthesiology
• Gastroenterology
• Pharmacology

Background:

• Mendelson's syndrome, a severe form of aspiration pneumonitis, poses a significant risk to surgical patients.
• High gastric acidity (pH < 2.5) is a primary risk factor for developing Mendelson's syndrome.
• Effective methods to reduce gastric acidity pre-operatively are crucial for patient safety.

Purpose of the Study:

• To evaluate the efficacy of magnesium trisilicate mixture in reducing gastric acidity prior to elective surgery.
• To assess the impact of magnesium trisilicate administration timing on its effectiveness.
• To determine the effect of this intervention on the incidence of Mendelson's syndrome.

Main Methods:

• A review of Mendelson's syndrome incidence across four Auckland hospitals.
• A prospective trial in a third hospital involving pre-operative administration of magnesium trisilicate mixture.
• Gastric pH measurements were taken in patients prepared for elective surgery, with interventions timed at premedication and within 30 minutes of anesthesia induction.

Main Results:

• The incidence of Mendelson's syndrome decreased in hospitals using pre-operative magnesium trisilicate.
• In a trial, 52% of patients had highly acidic gastric juice (pH < 2.5) before intervention.
• Administering magnesium trisilicate at premedication reduced highly acidic gastric juice. When given within 30 minutes of anesthesia induction, only 1% of patients had highly acidic gastric content.

Conclusions:

• Pre-operative administration of magnesium trisilicate mixture is effective in reducing gastric acidity.
• Timing of administration is critical, with maximal efficacy observed when given shortly before anesthesia induction.
• Magnesium trisilicate mixture represents a valuable tool for preventing Mendelson's syndrome in surgical settings.