CONTINUOUS GASTRIC SUCTIONING DECREASES MEASURED ESOPHAGEAL TEMPERATURE DURING GENERAL-ANESTHESIA

Objective. This study sought to determine whether continuous gastric s uctioning influences esophageal temperature measurements. Methods. Thi s study evaluated 21 patients scheduled for extremity or lower abdomin al surgery. After induction of general endotracheal anesthesia, an oro gastric tube, and esophageal and nasopharyngeal temperature probes wer e placed in functional positions. Baseline esophageal (Tes) and nasoph aryngeal (Tnas) temperatures were recorded and the orogastric tube was placed on continuous suction. After the first 11 patients (Group I) w ere studied, 10 additional patients (Group II) were studied with more frequent data collection to improve the time resolution of temperature changes. Temperatures were recorded for patients in Group I at 2 and 10 min with suctioning and 10 min after cessation of suctioning. In Gr oup II, temperatures were recorded at 1, 2, 5 and 10 min with suctioni ng and 10 min after cessation of suctioning. Analysis of data was perf ormed using repeated measures analysis of variance and paired t-tests with the Bonferroni correction. Results. In Group I, Tes decreased sig nificantly from 35.9 +/- 0.2 degrees C (mean +/- SE) to 35.1 +/- 0.4 d egrees C at 2 min and 34.8 +/- 0.3 degrees C at 10 min of suctioning ( p < 0.01). Ten minutes after cessation of suctioning, Tes was not sign ificantly different from the baseline measurement. Tnas did not change significantly over the 20 min observation period. In Group II, Tes co ntinually decreased from 36.2 +/- 0.1 degrees C to 34.8 +/- 0.3 degree s C after 10 min of suctioning (p < 0.006) and returned to near baseli ne 10 min after cessation of suctioning. There was no significant chan ge in Tnas over the 20 min observation period. Conclusion. We conclude that continuous gastric suctioning decreases esophageal temperature m easurements. This phenomenon should be recognized as an artifactual ch ange in esophageal temperature and not a reflection of core temperatur e.