title: Decreased cardiac output in humans during laparoscopic antireflux surgery: direct measurements.
abstract: OBJECTIVE
  In a porcine model, we demonstrated that laparoscopic Nissen fundoplication causes a significant drop in cardiac output (30%) because it exposes both the peritoneal cavity and the mediastinum to CO(2) under pressure. To determine if this occurs in humans, we examined cardiovascular physiology during laparoscopic Nissen fundoplication. Because of invasiveness required in this pilot trial, only six patients were studied.
  
  
  METHODS
  The arterial blood pressure (via radial arterial catheter) and the pulmonary artery diastolic pressure and cardiac index (via pulmonary artery thermodilution catheter) were measured at seven points in time during each laparoscopic Nissen fundoplication.
  
  
  RESULTS
  The systolic blood pressure decreased in all patients, and the cardiac index decreased in all but one patient. The exception was a patient with Huntington disease, in whom the cardiac output did not decrease. In four of the five patients, the cardiac output was lowest during hiatal dissection, and in the fifth, it was lowest after reverse Trendelenburg positioning. No significant change in the pulmonary artery diastolic pressure was noted. All patients received adequate intravenous fluid replacement (average, 58 +/- 16 mL/kg) to support blood pressure. In one patient, with a particularly large paraesophageal hernia, profound hypotension (40/25 mm Hg) developed during the mediastinal phase of the procedure, and this patient required alpha-adrenergic support followed by laparotomy to eliminate a surgical cause (none found).
  
  
  CONCLUSIONS
  Although it is a tremendous advance for patients, laparoscopic Nissen fundoplication can be associated with a significant reduction in cardiac output and blood pressure. Surgeons and anesthesiologists must be alert to changes reflecting these decreases during procedures, which violate both the peritoneal cavity and the mediastinum. We propose careful hemodynamic monitoring during these procedures, especially in patients with coronary artery disease or significant left ventricular dysfunction.
authors.affiliation: Department of Surgery, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.
authors.forename: Chandrakanth
authors.initials: C
authors.lastname: Are
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hardacre
authors.forename: Mark A
authors.initials: MA
authors.lastname: Talamini
authors.forename: Kazunori
authors.initials: K
authors.lastname: Murata
authors.forename: Steve
authors.initials: S
authors.lastname: Frank
mesh_terms: D000368:Aged; D002302:Cardiac Output; D005260:Female; D018662:Fundoplication; D005764:Gastroesophageal Reflux / Q000503:physiopathology* / Q000601:surgery; D006439:Hemodynamics; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged