An increased body mass index is no risk factor for postoperative nausea and vomiting. A systematic review and results of original data.

BACKGROUND An increased Body Mass Index (BMI) is almost always mentioned as a fundamental risk factor for postoperative nausea (PN), vomiting (PV) or both (PONV). However, multivariate analyses were unable to detect any correlation. Therefore, we asked whether an increased BMI is really a risk factor for PONV. METHODS For the systematic review, a search of electronic databases and a detailed manual search of reviews were carried out. For the analysis of the original data, 587 adult patients from a randomised controlled antiemetic trial (RCT) who underwent general anaesthesia were allocated to four weight groups: Underweight (BMI < 20), Normal Weight (BMI 20-25), Overweight (BMI 25-30) and Obesity (BMI > or = 30). RESULTS Four publications with original data were found. Two described a positive relationship, although not clearly supported by the data. Despite this, most narrative reviews claimed a positive correlation between obesity and PONV by quoting again narrative reviews or misquoting originals. In the RCT, the calculated underlying risk profile for PONV was comparable between all groups. Incidences (95% confidence intervals) of PONV were 45.8% (34.0; 57.6), 41.7 (36.5; 46.9), 47.8 (38.4; 57.1) and 44.1 (31.0; 57.1), for the groups Underweight, Normal Weight, Overweight and Obesity, respectively (P=0.69). The incidences of PN and PV also did not differ with P=0.76 and P=0.36, respectively. CONCLUSION Systematic search of the literature provides no evidence for a positive relationship. Furthermore, our data confirm that an increased BMI is not a risk factor for PONV. This negative finding is important as focussing on the relevant risk factors is needed to allow for an objective risk assessment of PONV.

[1]  A. M. Morin,et al.  Menstruationszyklus in der postoperativen Phase Der Einfluss auf die Inzidenz von Übelkeit und Erbrechen , 2000, Der Anaesthesist.

[2]  T. Cole,et al.  Establishing a standard definition for child overweight and obesity worldwide: international survey , 2000, BMJ : British Medical Journal.

[3]  David Moher,et al.  The Medical Review Article Revisited: Has the Science Improved? , 1999, Annals of Internal Medicine.

[4]  A. Hechler1,et al.  Die Inzidenz an postoperativer Übelkeit und Erbrechen ist unabhängig von der routinemäßigen Maskenvorbeatmung während der Narkoseeinleitung , 1999 .

[5]  N Roewer,et al.  A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers. , 1999, Anesthesiology.

[6]  E. Perez,et al.  ASHP Therapeutic Guidelines on the Pharmacologic Management of Nausea and Vomiting in Adult and Pediatric Patients Receiving Chemotherapy or Radiation Therapy or Undergoing Surgery. , 1999, American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists.

[7]  A. M. Morin,et al.  Ergebnisse einer Umfrage unter Anästhesisten zum Thema Übelkeit und Erbrechen in der postoperativen Phase , 1998 .

[8]  C. Greim,et al.  The discriminating power of a risk score for postoperative vomiting in adults undergoing various types of surgery , 1998, Acta anaesthesiologica Scandinavica.

[9]  C. Greim,et al.  A risk score to predict the probability of postoperative vomiting in adults , 1998, Acta anaesthesiologica Scandinavica.

[10]  S. Alahuhta,et al.  A survey of postoperative nausea and vomiting , 1997, Anaesthesia.

[11]  Andrew F. Smith.  An analysis of review articles published in four anaesthesia journals , 1997, Canadian journal of anaesthesia = Journal canadien d'anesthesie.

[12]  A. Dabbous.  Postoperative nausea and vomiting--its pathophysiology and management. , 1996, Middle East journal of anaesthesiology.

[13]  G. Kenny.  Risk factors for postoperative nausea and vomiting , 1994, Anaesthesia.

[14]  M M Cohen,et al.  The Postoperative Interview: Assessing Risk Factors for Nausea and Vomiting , 1994, Anesthesia and analgesia.

[15]  G. Kenny,et al.  Nausea and vomiting after gynaecological surgery: a meta-analysis of factors affecting their incidence. , 1993, British journal of anaesthesia.

[16]  M. Palazzo,et al.  Logistic regression analysis of fixed patient factors for postoperative sickness: a model for risk assessment. , 1993, British journal of anaesthesia.

[17]  S. Kallar.  New modalities in postoperative nausea and vomiting. , 1992, Journal of clinical anesthesia.

[18]  J. Schramm,et al.  SOMATOSENSORY EVOKED POTENTIAL-MONITORING DURING INTRACRANIAL ANEURYSM-SURGERY, WHICH ANESTHETIC SHOULD WE USE? , 1992 .

[19]  P. White,et al.  Postoperative Nausea and Vomiting: Its Etiology, Treatment, and Prevention , 1992, Anesthesiology.

[20]  J. Hovorka,et al.  Gastric Aspiration at the End of Anaesthesia Does Not Decrease Postoperative Nausea and Vomiting , 1990 .

[21]  J. Millar.  NAUSEA AND VOMITING AFTER GENERAL ANAESTHESIA , 1989, The Lancet.

[22]  S. McKenzie,et al.  An investigation into post-anesthesia nausea and vomiting in a community hospital-based anesthesiology practice. , 1987, AANA journal.

[23]  K. Offord,et al.  Role of nitrous oxide and other factors in postoperative nausea and vomiting: a randomized and blinded prospective study. , 1987 .

[24]  C. Mulrow.  The medical review article: state of the science. , 1987, Annals of internal medicine.

[25]  L Strunin,et al.  Anaesthesia and emesis. I: Etiology , 1984, Canadian Anaesthetists' Society journal.

[26]  J. Stein.  Factors affecting nausea and vomiting in the plastic surgery patient. , 1982, Plastic and reconstructive surgery.

[27]  F. Taylor,et al.  Antiemetic Effectiveness of Intramuscular Hydroxyzine Compared with Intramuscular Droperidol , 1981, Anesthesia and analgesia.

[28]  B. Mckie.  Postoperative nausea and vomiting: A review of their incidence, causes and effects. , 1970, The Australian and New Zealand journal of surgery.

[29]  I. Purkis.  Factors that influence postoperative vomiting , 1964, Canadian Anaesthetists' Society journal.

[30]  Morris Jv.  MAN'S PLACE IN NATURE. , 1964, Lancet.

[31]  I. Bross,et al.  POSTOPERATIVE NAUSEA AND VOMITING IV: FACTORS RELATED TO POSTOPERATIVE NAUSEA AND VOMITING , 1960, Anesthesiology.

[32]  J. F. Artusio,et al.  Nausea and vomiting in the immediate postanesthetic period. , 1959, Journal of the American Medical Association.

[33]  C. R. Stephen,et al.  POSTOPERATIVE VOMITING: INCIDENCE, ANALYSIS, AND THERAPEUTIC MEASURES IN 3,000 PATIENTS , 1955, Anesthesiology.

[34]  Broomhead Cj.  Reducing the incidence of postoperative nausea and vomiting. , 1995, British journal of hospital medicine.

[35]  J. Lerman,et al.  Surgical and patient factors involved in postoperative nausea and vomiting. , 1992, British journal of anaesthesia.

[36]  P. White,et al.  Nausea and vomiting: causes and prophylaxis , 1987 .