Ascites characterizes perioperative clinical indices better than preoperative body mass index. A study in orthotopic liver transplant candidates

Background. Preoperative body mass index (pre-BMI) affecting patients' recovery from orthotropic liver transplantation (OLT) is controversial. Pre-BMI measurements may be exaggerated by ascites. Aim of the study was the assessment of early outcome associated with pre-BMI and ascites. Methods. Postoperative BMI values and ascites volumes of 206 patients undergoing OLT (2006-2007) were reviewed. Results. There were 141 preoperatively "non-obese" patients (pre-BMI ≤30 kg/m²) and 65 "obese" patients (pre-BMI >30 kg/m²). Demographics and model for end-stage liver disease scores were similar for both groups. Te mean volume of ascites removed from the "non-obese" patients was significantly larger compared to the "obese" ones (P=0.018). Seventeen "obese" patients became "non-obese" postoperatively. Te duration of anesthesia, ischemia, surgery, hemodynamic parameters, estimated blood loss and transfused products were similar for both groups. Ascites volumes correlated significantly (P<0.05) with various intraoperative indices but not pre-BMI. At 24 h postoperatively, the extubation rate was better for the "obese" group (99%) versus the "non-obese" group (93%, P=0.03). However, "non-obese" patients were extubated earlier than the "obese" both by 6 h (45% versus 22%, respectively, P<0.01) and by 12 h (88% versus 74%, respectively, P=0.012). Te postoperative, but not the preoperative BMI, correlated with extubation rate ≤6 h (r=0.924, P=0.0001). No "obese" patients died <1 month postoperatively, compared to 9 "non-obese" patients (P<0.01). Intensive Care Unit and hospital stay were ~25% longer for the "obese" group. Conclusion. Pre-OLT BMI does not correlate with ascites or postoperative BMI, nor does it afect duration of ventilation, especially <6 h after surgery. These results dissociate ascites from pre- and post-OLT.