The effects of pneumoperitoneum and head-up position on heart rate variability and QT interval dispersion during...

The aim of the study was to evaluate the effects of pneumoperitoneum and head-up position on autonomic cardiac function changes during inhalational or total intravenous anesthesia by using the analysis of QT dispersion and heart rate variability (HRV).

In this prospective, single-blind study, 30 patients scheduled for elective laparoscopic cholecystectomy were randomly divided in two groups: a sevoflurane-based inhalational anesthesia group (N=15) and an intravenous anesthesia group with propofol (N=15). Propofol 2.0 mg/kg-1 and cisatracurium 0.15 mg/kg-1 during induction of anesthesia and Remifentanil as titrated infusion for analgesia were used in both groups. Pneumoperitoneum was established at 12 mmHg with patients in the supine position. ECG was recorded before the induction of anesthesia; 1 and 3 min after pneumoperitoneum (supine position); 1 and 3 min after shifting the patient to a head-up position (HUP) of 60 degrees; after abdominal deflation; and after awakening. RR interval, QT interval, corrected QT interval (QTc), QT interval dispersion (QTD), corrected QT interval dispersion (QTcD), low-frequency power (LF), high-frequency power (HF) and LF/HF ratio were recorded.

The LF/HF ratio increased significantly after 3 min HUP in the SEVO group (P<0.05). QTD and QTcD increased significantly at 3 min after abdominal insufflation and at 1 and 3 min after HUP in both groups (P<0.05).

Statistically significant increases of QTD and QTcD occurred during pneumoperitoneum and HUP, regardless of the anesthetic techniques used. In patients receiving inhalational anesthesia, the LF/HF ratio increased significantly after HUP.