In our nonsuperiority analyses, we rejected the null hypotheses that intraoperative NG tube use was more beneficial (i.e., superior) compared with non-NG tube use for two of the three outcomes of interest, PONV (multivariable P = 0.033) and nausea (multivariable P = 0.037), assuming that an OR between 0.95 and 1.0 represents equivalence of the two methods of care (Table 3). From these one-tailed results, we infer that the adjusted OR for perioperative NG tube use is ≥0.95 for PONV and nausea. Nonsuperiority was not demonstrated for perioperative NG tube use (Table 4).
This analysis of a large case-matched dataset with more than 1000 patients evaluating the effect of a NG tube on PONV shows no evidence of a reduction in incidence of PONV. This result seems surprising given that mechanistically every effort that reduces intragastric volume should decrease the incidence of vomiting.
Our analysis includes a significantly larger sample size than any other previous randomized controlled trial and should thus be able to detect even small effects present. The main limitation of this analysis is that the original study was not randomized for the use of a gastric tube; however, to address this drawback patients were matched using a propensity score to yield groups balanced on potential baseline confounders.7,8
In conclusion, these results provide strong evidence that the routine use of a NG tube during surgical procedures does not reduce PONV.
The authors thank Dr. Anuj Malhotra for his careful editorial assistance.
The IMPACT investigators are as follows:
- Steering Committee—C. C. Apfel, A. Biedler, and K. Korttila.
- Data Management and Monitoring—C. C. Apfel, E. Kaufmann, M. Kredel, A. Schmelzer, and J. Wermelt.
- and Data Analyses—C. C. Apfel, K.-H. Kerger, and E. Mascha.
Site Investigators—C. C. Apfel, S. Alahuhta, F. Bach, A. Bacher, H. Bartsch, H. Bause, A. Biedler, B. Book, H. Bordon, D. Buschmann, K. Danner, O. Danzeisen, D. Detzel, L. H. J. Eberhart, H. Feierfeil, H. Forst, C. Frenkel, G. Frings, B. Fritz, G. Fritz, A. Goebel, M. Hergert, C. Heringhaus, M. Hinojosa, C. Hoehne, W. Hoeltermann, H.-B. Hopf, C. Isselhorst, R. M. Jokela, E. Kaufmann, H. Kerger, T. Kangas-Saarela, P. Karjaleinen, A. Kimmich, M. Koivuranta, K. Korttila, U. Koschel, P. Kranke, M. Kredel, M. Lange, F. Liebenow, W. Leidinger, M. Lucas, C. Madler, J. N. Meierhofer, F. Mertzlufft, J. Motsch, S. Muñoz, E. Palencikova, A. Paura, S. Pohl, C. Prause, R. Rincon, N. Roewer, U. Ruppert, A. Schmelzer, I. E. Schneider, R. Sneyd, Schramm, A. Soikkeli, S. Spieth, B. Steinbrecher, K. Stoecklein, M. Trick, A. Turan, S. Trenkler, I. Vedder, P. Vila, J. Wermelt, K. Werthwein, W. Wilhelm, and C. Zernak.
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