A randomized controlled study between fentanyl and Butorphanol with low dose intrathecal bupivacaine to facilitate early postoperative ambulation in urological procedures

Comparison of intrathecal bupivacaine-fentanyl and bupivacaine-butorphanol combinations for joint replacement surgeries

Background and Aims:

The objective of the study was to compare duration of analgesia of fentanyl versus butorphanol as adjuvants to bupivacaine in spinal anesthesia.

Material and Methods:

A prospective, randomized, double-blinded study conducted in 80 patients of 18–75 years age group and American Society of Anesthesiologists Grades I and II undergoing joint replacement surgeries. A total of 40 patients in each Group A and Group B received 0.5% bupivacaine 3 ml with 25 mcg fentanyl and 25 mcg butorphanol respectively, in a total volume of 3.5 ml made with saline. Duration of analgesia, number of rescue analgesia, sensory, and motor block characteristics were compared between the two groups. Statistical analysis was done using t test and Chi-square test with SPSS 19.0 software.

Results:

Mean duration of analgesia was found more in Group B in comparison to Group A (P < 0.05). A number of doses of analgesic required postoperatively were more in Group A compared to Group B (P < 0.001). Time required for onset of sensory and motor block was comparable in both the groups. However, two segment regression of sensory block was slower in Group B compared to Group A (P < 0.05).

Conclusion:

We conclude that addition of butorphanol 25 μg as an adjuvant to 0.5% hyperbaric bupivacaine provided prolonged duration of analgesia compared to 25 mg fentanyl.

Comparative study of hemodynamic effects of intrathecal bupivacaine with butorphanol in cardiac and non-cardiac patients

Background and Aims:

The synergism between intrathecal opioids and low dose local anesthetics makes it possible to achieve reliable spinal anesthesia (SA) with minimal hypotension. The study objective was to compare the hemodynamic effects of reduced dose of 0.5% intrathecal bupivacaine (2mL) with 25 μg butorphanol in cardiac vs non-cardiac patients.

Material and Methods:

We included sixty patients aged 30-80 years, undergoing infraumbilical surgeries in the study and compared thirty cardiac patients with mild to moderate reduction in left ventricular ejection fraction (LVEF) on 2D echocardiography (Group C) with 30 non-cardiac patients (Group NC) for similar types of surgery. Both the groups received 0.5% bupivacaine 2.0 ml with 25 μg butorphanol.

Results:

The spinal block characteristics were similar in both groups (P > 0.05). The blood pressure of the patients in the two groups was comparable till 80 min P > 0.05 after which Group NC had significant increase in blood pressure compared to Group C upto 95 min (P < 0.05). Similarly, heart rate was comparable until 90 min (P > 0.05) after which Group NC had significant increase in heart rate versus Group C upto 100 min (P < 0.05). Eight patients in group C and five patients in group NC showed hypotension. Bradycardia was seen in 4 patients in group C in comparison to only one patient in group NC.

Conclusion:

We can safely consider spinal anesthesia with 10 mg bupivacaine and 25μg butorphanol in cardiac patients with mild to moderately reduced ejection fraction presenting for infraumbilical non-cardiac surgeries with the advantage of intraoperative hemodynamic stability and adequate postoperative analgesia.

Comparison of pre-emptive butorphanol or metamizole with ketamine +medetomidine and s-ketamine + medetomidine anaesthesia in improving intraoperative analgesia in mice

In accordance with the 'refinement' component of the 3Rs, the primary aim of this study was to investigate and compare ketamine + medetomidine (KM) and s-ketamine + medetomidine (SKM) anaesthetic protocols in C57BL/6J mice (both sexes). We sought to determine whether s-ketamine could provide adequate surgical tolerance at a 50% dose relative to that of ketamine racemate and whether antagonism of medetomidine could be initiated 15 min earlier. The second aim was to investigate the potential improvement in analgesia for both anaesthetic protocols by adding butorphanol or metamizole. Analgesia was tested via the pedal withdrawal reaction (PWR) to a painful stimulus. During anaesthesia, respiratory frequency, pulse oximetry, body temperature and PWR were monitored. Among the 16 mice in each group, the PWR was lost in all the KM + metamizole (35:56 ± 6:07 min), KM + butorphanol (43:45 ± 2:14 min) and SKM + butorphanol (24:03 ± 5:50 min) mice, 15 of the non-premedicated KM (37:00 ± 8:11 min) mice, and 9 of the pure SKM (20:00 ± 4:19 min) mice; the latter group increased to 11 mice (17:16 ± 5:10 min) with premedication of metamizole. In contrast to the racemic combination, s-ketamine at the dose used here did not lead to sufficient loss of the PWR. However, earlier partial antagonism of SKM resulted in a slightly shorter and qualitatively better recovery than later partial antagonism of SKM. The addition of metamizole or butorphanol to KM or SKM anaesthesia positively influences the analgesic quality. However, when butorphanol is added, controlled ventilation may be necessary, especially for male mice.

Pharmacological advances in the multimodal management of perioperative analgesia

The concept of multimodal analgesia is currently widespread in our clinical practice. The aim of multimodal analgesia is to reduce the side effects derived from the drugs or techniques used for the control of pain together with greater effectiveness (combination of multiple mechanisms of action) with the maximum efficiency, that is, to combine different pharmacodynamics (synergistic or additive effects) and pharmacokinetics, in the context of a predictable acute pain model, thus allowing a prior strategy such as the model of acute postoperative pain. Pain is a complex physiological phenomenon. Postoperative pain involves multiple pathways including nociceptive, inflammatory, and neuropathic sources. In the transmission of pain therefore, different molecules participate, which means that there are multiple pharmacological targets on which to act, and therefore a wide range of drugs to be used following the physiology of pain.