Arterial Hypotension During Induction of Anesthesia May Not Be a Risk Factor for Postoperative Nausea and Vomiting

Abstract

In Response: Unfortunately, Kranke et al. misinterpreted the aim of our study and stated erroneously in consequence that ”Table 1 demonstrates that there is consistent bias with respect to proven risk factors for PONV between the “hypotensive group” and “non-hypotensive” patients”… and “unfortunately the authors did not correct for these risk factors in their analysis.” Our research group is not interested in the detection of independent risk factors or the construction of some risk models. We try to find pathophysiological interactions between the occurrence of PONV, hemodynamic variables, the vestibular, and the autonomic nervous system. Results of our study should help to improve our daily anesthesia practice. Proven independent risk factors like female gender or historical PONV does not influence us by changing our anesthesiologic approach in gynecological surgery. Between group differences in our Table 1 should demonstrate that a systolic blood pressure decrease of >35% is not an independent risk factor. Furthermore, in our introduction, we reported that the aim of our study was to determine the association between a marked decrease in systolic blood pressure from the preanesthetic baseline during the introduction as well as during the maintenance of general anesthesia and the incidence of risk factors of PONV. We concluded: “Whether the blood pressure decrease triggers PONV or PONV symptoms influence hemodynamic variables is not clear.” We never suggested that a systolic blood pressure decrease during any phase of anesthesia is a proven independent risk factor for PONV. We agree with Kranke et al. that between the occurrence of PONV and a systolic blood pressure decrease of >35% during anesthesia induction only a weak association was found by us. I hope that a rereading of our publication will clear up misunderstandings. Franz Pusch, MD Eckart Wildling, MD