End-expiratory pressure best approximates intrinsic lower esophageal sphincter pressure. Report of a patient with Cheyne-Stokes respiration.

Recent studies have shown that the respiratory oscillation inherent in the station pull-through technique of measuring lower esophageal sphincter (LES) pressure is the result of active diaphragmatic contraction. A recent study in cats suggested that intrinsic LES tone is best reflected by end-expiratory pressure during spontaneous respiration. This finding is confirmed in a patient we report with achalasia and Waldenstrom's macroglobulinemia who had Cheyne-Stokes breathing. LES pressure during periods of central apnea approximated end-expiratory pressure during periods of hyperpnea.