Comparison of the Effects of Magnesium Sulfate and Remifentanil on Hemodynamic Responses During Tracheal Extubation After Laparotomy: A Randomized Double-blinded Trial

BACKGROUND

Because blood pressure and heart rate (HR) elevations during tracheal extubation are common, different medications have been studied to prevent such complications.

OBJECTIVES

To compare magnesium sulfate, remifentanil, and placebo regarding mean arterial pressure (MAP) and HR changes during/after tracheal extubation, in patients who underwent laparotomy.

MATERIALS AND METHODS

In this randomized double-blinded trial, 120 patients undergoing laparotomy were evenly divided into three groups, including remifentanil (1 mcg/kg), magnesium sulfate (50 mg/kg), or normal saline, as placebo. Hemodynamic responses (MAP and HR) were documented at different times (before operation, during medication administration, immediately before extubation, immediately after extubation, and also 3, 5, and 10 minutes after extubation). The double burst time (DBT) was determined using neuromuscular monitoring, as time interval, between administration of reverse medication and DBT of 100%.

RESULTS

The HR was significantly lower, immediately after extubation and 3, 5, and 10 minutes after extubation, in both magnesium and remifentanil groups, compared to normal saline (P < 0.001). The MAP was also lower in magnesium and remifentanil groups, immediately after extubation and 3 minutes after extubation, in comparison to the normal saline group (P < 0.001). Mean (± SD) DBT 100% was significantly higher in magnesium group (30.2 ± 15.3) vs. remifenatnil (13.6 ± 6.8) and normal saline (13.5 ± 8.2) groups (P < 0.001).

CONCLUSIONS

Both remifentanil and magnesium had favorable outcomes in preventing HR and MAP elevation after tracheal extubation. However, remifentanil was associated with more rapid regaining of consciousness and reversal of muscular relaxation.

Efficacy of the valsalva maneuver on needle projection pain and hemodynamic responses during spinal puncture

This study evaluated the efficacy of the valsalva maneuver that can induce baroreceptor activation and nociception, on needle projection pain and hemodynamic responses associated with spinal puncture. Ninety adults, ASA physical status I and II undergoing elective surgeries were included. Patients were randomized into three equal groups. Group I (C): control; Group II (B): ball; pressed a rubber ball (attention-diverting method); Group III (V): valsalva; blew into sphygmomanometer tubing and hold the mercury column up to 30 mm Hg for a period of at least 20s. Spinal needle projection pain was graded using numeric rating scale (NRS): 1-10, where scales of 1-3 were rated as mild, 4-6 as moderate, and >6 as severe. Blood pressure and heart rate, five minutes before the procedure, during the spinal puncture and first and third minutes after that, were also recorded. Significant reduction in NRS was observed in the valsalva group compared with the control and the ball groups (p=0.001). There were statistical but no significant clinical differences in mean arterial blood pressure and heart rates between the study groups (P=0.008 and P=0.016 respectively). In conclusion valsalva maneuver can decrease the skin puncture pain associated with spinal needle projection while observing hemodynamic changes.

Effect of scalp infiltration with Bupivacaine on early hemodynamic responses during craniotomy under general anesthesia

The present study was conducted to evaluate the effect of scalp infiltration with Bupivacaine on hemodynamic responses during early stimulation in craniotomy under general anesthesia. Thirty six patients were prospectively randomized to receive Bupivacaine scalp infiltration (B group) or a saline control (S group) as an adjuvant to general anesthesia using isoflurane in 50% N2O-O2. Mean Arterial Blood Pressure (MAP) and Heart Rate (HR) were recorded as base line, after scalp incision or pin insertion and then every 3 min until 12 min. The measurements were repeated every 5 min till dura was opened. The mean difference between the two groups for HR during scalp incision or pin insertion was significant (p = 0.03). The mean MAP throughout the time intervals of preincision or pin insertion to 12 min postincision and then to dural opening were statistically different between the two groups (p = 0.001). No complications related to the technique of block or drugs were recorded. Scalp infiltration with Bupivacaine as an adjuvant to general anesthesia can provide more stable hemodynamics, as measured by HR and MAP changes during early stimulation in craniotomy.