RESUMO
BACKGROUND/AIMS: Swallowing of cold liquids decreases amplitude and velocity of peristalsis in healthy subjects, using standard manometry. Patients with achalasia and non obstructive dysphagia may have degeneration of sensory neural pathways, affecting motor response to cooling. To elucidate this point, we used high-resolution manometry. METHODS: Fifteen healthy subjects, 15 non-obstructive dysphagia and 15 achalasia patients, after pneumatic dilation, were studied. The 3 groups underwent eight 5 mL single swallows, two 20 mL multiple rapid swallows and 50 mL intraesophageal water infusion (1 mL/sec), using both water at room temperature and cold water, in a randomized order. RESULTS: In healthy subjects, cold water reduced distal contractile integral in comparison with water at room temperature during single swallows, multiple rapid swallows and intraesophageal infusion (ratio cold/room temperature being 0.67 [95% CI, 0.48-0.85], 0.56 [95% CI, 0.19-0.92] and 0.24 [95% CI, 0.12-0.37], respectively). A similar effect was seen in non-obstructive dysphagia patients (0.68 [95% CI, 0.51-0.84], 0.69 [95% CI, 0.40-0.97] and 0.48 [95% CI, 0.20-0.76], respectively), whereas no changes occurred in achalasia patients (1.06 [95% CI, 0.83-1.29], 1.05 [95% CI, 0.77-1.33] and 1.41 [95% CI, 0.84-2.00], respectively). CONCLUSIONS: Our data suggest impairment of esophageal reflexes induced by cold water in patients with achalasia, but not in those with non obstructive dysphagia.