Hemodynamic Changes During Laparoscopic Gastric Bypass Procedures

Abstract

Significant detrimental intra-operative hemodynamic and respiratory changes occur in the morbidly obese during laparoscopic gastric bypass. Design: Case series. Setting: Tertiary care university hospital. Patients: Thirteen patients, 10 women and 3 men, undergoing uncomplicated laparoscopic gastric bypass for morbid obesity. Interventions: Using a pulmonary artery catheter and an arterial line, we intraoperatively monitored hemodynamic and respiratory parameters. Parameter values were recorded at set points of the procedure, and the changes were statistically analyzed. Results: Significant hemodynamic and respiratory changes, mostly unfavorable, occur in the morbidly obese

Response to Dr. Bernstein’s Review: Pressure Pulse Contour-Derived Stroke Volume and Cardiac Output in the Morbidly Obese Patient

“…Stroke volume (SV) of our patients [1], calculated from stroke volume index (SVI), according to the formula SV= SVI×BSA (Mosteller-derived), is similar to the data of Dumont et al [4] until MAP and HR do not diverge from ours, while the data of Nguyen et al [5] and Artuso et al [3] are different from ours [1] and similar between themselves, as shown on Table 1 (we prefer to analyze stroke volume instead of cardiac index because the latter is directly related to heart rate). Our systemic vascular resistance (SVR), calculated from systemic vascular resistance index (SVRI) according to the formula SVR=SVRI/BSA, is very different from Nguyen et al [5] and Artuso et al [3] and slightly different from Dumont et al [4] ( Table 1).…”

“…From an analysis of MAP and HR in reviewed studies, we can observe how [3][4][5] these values present different trends compared with our results (Table 1).…”

“…It is important to discuss the data presented in the review, considering that caution is necessary to accept his conclusion on pressure recording analytical method (PRAM) [2]. We wonder how it is possible to draw similar conclusions based on the small number of studies considered and patients enrolled [3][4][5]. We may also highlight some discrepancies not only between the studies considered but also within each study [3][4][5].…”

“…We wonder how it is possible to draw similar conclusions based on the small number of studies considered and patients enrolled [3][4][5]. We may also highlight some discrepancies not only between the studies considered but also within each study [3][4][5]. It is important to distinguish between hemodynamic data measured directly, such as mean arterial pressure (MAP) or heart rate (HR), and hemodynamic data calculated by the PRAM [6][7][8][9][10][11] or other methods [12].…”

Reply to Letter: Agreed: “PRAM May be Useful to Assess the Cardiovascular Changes in Obese Patients During Laparoscopy”

“…Other methods, if to be accepted as an equivalent or replacement for TDCO, must provide a small bias and reproducibility error, and limits of agreement within ±30%. In the face of this, Forfori et al trivialize the studies of Nguyen et al [3] and Artuso et al [4], which both used TDCO as their test method to determine CO and the derived indices of cardiac index (CI) stroke volume SV, stroke index (SI) and systemic vascular resistance (SVR) and SVRI. Alleging equivalence to TDCO, the authors emphasize that their results for SV are similar to those of Dumont et al [5], which are, on the mean, 64 and 72 mL, respectively.…”