The acid perfusion test. A study in patients with symptomatic hiatus hernia, and of the effect of a modified Belsey MK IV repair on the test.

Acid perfusion with 0.1 n HC1 (5 ml/min for max. 30 min) and simultaneous intragastric instillation of equimolar amounts of sodium bicarbonate were performed in 55 patients with sliding hiatus hernia and symptoms attributable to gastro-oesophageal reflux. Acid perfusion reproduced the patient's spontaneous symptoms, and was thus positive, in 44 per cent of the cases. A positive acid perfusion test means that the patient's spontaneous symptoms may be of oesophageal origin, whereas a negative test does not allow any conclusions. The acid perfusion test was likewise performed before and three months after a modified Belsey MK IV repair in 37 patients with hiatal hernia and symptoms indicating surgical repair. The operation was followed by a reduction in oesophageal acid sensitivity (p less than 0.01).