The effect of intravenous lidocaine infusion on bispectral index during major abdominal surgery.

Intraoperative lidocaine infusion has become widely accepted as an adjunct to general anesthesia where its use has been associated with opioid-sparing and enhanced recovery. The aims of this study were to determine whether or not intravenous (IV) lidocaine infusion (a) has an anesthetic sparing effect during major colorectal procedures and (b) if it also affects level of hypnosis as measured by bispectral index (BIS). Twenty-five patients undergoing laparotomy for resection of colorectal tumours were randomized to receive either IV lidocaine (1.5 mg kg-1 bolus then 1 mg kg-1 per hour) or an equivalent volume of normal saline commenced after intravenous induction of general anesthesia. Anesthesia was maintained with volatile anesthetic agent combined with intermittent IV fentanyl titrated to hemodynamic stability. Minimum alveolar concentration (MAC) of volatile was calculated using an age-adjusted algorithm (corrected MAC). BIS values were recorded throughout; however, treating anesthesiologists were blinded to BIS values and hence they were not used to guide depth of anesthesia. No other regional anesthesia techniques were used. During the maintenance phase of anesthesia, corrected MAC of volatile agent was lower (1.0 versus 1.1, p = 0.003); whereas BIS values were higher (45 versus 39, p < 0.001) in patients who received lidocaine versus placebo. No differences in mean arterial pressure (80 versus 80 mmHg, p = 0.796) or total fentanyl dose (538 versus 444 mcg, p = 0.24) were observed between the two groups. Heart rate was slightly higher in patients who received lidocaine versus placebo (67 versus 64 bpm, p = 0.001). Lidocaine infusion resulted in mean plasma levels of 1.7 mcg ml-1 (1.3-2.0 mcg ml-1, 95% CI). Our results support an anesthetic sparing effect of lidocaine infusion indicated by lower MAC requirements. Higher BIS values in the lidocaine versus placebo group may indicate that levels of hypnosis were not equivalent. Alternatively, BIS may not be a sensitive indicator of synergistic interactions between local anesthetic and volatile agent. Our results advocate a cautious approach to titration of general anesthesia when combined with lidocaine infusion.

A randomized trial of long-term remote monitoring of pacemaker recipients (the COMPAS trial).

AIMS: Professional practice guidelines recommend that pacemaker recipients be followed regularly. However, the majority of scheduled ambulatory visits is unproductive and imposes a heavy burden on the health-care system. METHODS AND RESULTS: The COMPAS randomized, multicentre, non-inferiority trial examined the safety of long-term remote monitoring of pacemakers. Between December 2005 and January 2008, 538 patients were randomly assigned to remote monitoring follow-up (active group) vs. standard care (control group). The primary objective was to confirm that the proportion of patients who experienced at least one major adverse event (MAE), including all-cause death and hospitalizations for device-related or cardiovascular adverse events, was not >7% higher in the active than in the control group. MAE-free survivals and quality of life were compared in both groups. The characteristics of the study groups were similar. Over a follow-up of 18.3 months, 17.3% of patients in the active and 19.1% in the control group experienced at least one MAE (P < 0.01 for non-inferiority). Hospitalizations for atrial arrhythmias (6 vs. 18) and strokes (2 vs. 8) were fewer (P < 0.05), and the number of interim ambulatory visits was 56% lower (P < 0.001) in the active than the control group. Changes in pacemaker programming or drug regimens were made in 62% of visits in the active vs. 29% in the control group (P < 0.001). Quality of life remained unchanged in both groups. CONCLUSION: Remote monitoring was a safe alternative to conventional care and significantly lowered the number of ambulatory visits during long-term follow-up of permanently paced patients. ClinicalTrials.gov identifier: NCT00989326.