Continuous hemodynamic monitoring during laparoscopic gastric bypass in superobese patients by pressure recording analytical method

Background Morbid obesity, compromising cardiovascular and respiratory function, may increase the risk of anesthesia and was initially considered a contraindication to laparoscopy. The aim of this study was to investigate hemodynamic effects induced by pneumoperitoneum in superobese patients, assessed by arterial pulse contour method. Methods We prospectively studied 10 obese patients (BMI 53 +/- 9 kg/m(2)), scheduled for laparoscopic gastric bypass. After anesthesia induction, patients were intubated and mechanically ventilated. A radial artery was cannulated to obtain hemodynamic data implemented by means of a new pulse contour analysis method-the pressure recording analytical method (PRAM). Data were recorded after anesthesia induction (Tbas), at peritoneal insufflation (T0), at 1, 3, 5, 10, 30, and 60 min after pneumoperitoneurn induction (T1, T3, T5, T10, T15, T30, T60), at abdominal desufflation (Tdef) and 5 min after desufflation (T5def). Results MAP increased after pneumoperitoneum, returning to its baseline after deflation (79 +/- 7 Tbas, 81 +/- 6 mmHg T5def). HR remained unchanged. Systemic vascular resistance index (SVRI) increased after pneumoperitoneum induction and progressively returned to baseline (3,903 +/- 330 Tbas, 4,596 +/- 148 T1, and 3,786 +/- 202 dyn s m(2) cm(-5) T5def). Stroke volume index (SVI) and cardiac index (CI) increased after pneumoperitoneurn and remained elevated. Stroke volume variation (SVV) decreased after insufflation remaining lower than the basal value (28 +/- 4% Tbas, 15 +/- 5% T5des). Cardiac Cycle Efficiency (CCE) transient decreased after insufflation and subsequently increased (0.029 +/- 0.146 Tbas, 0.008 +/- 0.178 T5def). Aortic dP/dt max increased after insufflation, returning to baseline only after desufflation (0.68 +/- 0.07 Tbas, 0.94 +/- 0.08 T30 and 0.86 +/- 0.06 mmHg s(-1) T5def). Conclusion As assessed by PRAM, this study showed no deterioration in hemodynamic indices or ventricular performance during laparoscopic gastric bypass.