Oral clonidine premedication preserves heart rate variability for patients undergoing larparoscopic cholecystectomy

Intraoperative clonidine in endometriosis and spine surgery: A protocol for two randomised, blinded, placebo-controlled trials

BACKGROUND

A high proportion of patients who undergo surgery continue to suffer from moderate to severe pain in the early postoperative period despite advances in pain management strategies. Previous studies suggest that clonidine, an alpha2 adrenergic agonist, administered during the perioperative period could reduce acute postoperative pain intensity and opioid consumption. However, these studies have several limitations related to study design and sample size and hence, further studies are needed.

AIM

To investigate the effect of a single intravenous (IV) dose of intraoperative clonidine on postoperative opioid consumption, pain intensity, nausea, vomiting and sedation after endometriosis and spine surgery.

METHODS

Two separate randomised, blinded, placebo-controlled trials are planned. Patients scheduled for endometriosis (CLONIPAIN) will be randomised to receive either 150 μg intraoperative IV clonidine or placebo (isotonic saline). Patients undergoing spine surgery (CLONISPINE) will receive 3 μg/kg intraoperative IV clonidine or placebo. We aim to include 120 patients in each trial to achieve power of 90% at an alpha level of 0.05.

OUTCOMES

The primary outcome is opioid consumption within the first three postoperative hours. Secondary outcomes include pain intensity at rest and during coughing, nausea, vomiting and sedation within the first two postoperative hours and opioid consumption within the first six postoperative hours. Time to discharge from the PACU will be registered.

CONCLUSION

This study is expected to provide valuable information on the efficacy of intraoperative clonidine in acute postoperative pain management in patients undergoing endometriosis and spine surgery.

A Randomized Controlled Study to Compare Hemodynamic Effects between Clonidine and Pregabalin in Laparoscopic Cholecystectomy

Background:

Laparoscopic cholecystectomy (LC) is associated with pneumoperitoneum and hemodynamic disturbances. Pregabalin and Clonidine have been used for anesthetic effects, but a better drug for controlling hemodynamic parameters is being investigated.

Aims:

The study was done to assess and compare the efficacy of preoperative single oral dose of pregabalin and clonidine in maintaining the hemodynamic parameters in the LC.

Settings and Design:

The prospective, interventional, randomized, comparative, single-blinded study was conducted in the department of anesthesia and surgery from January 2015 to September 2016 after taking approval from the institutional ethical committee.

Materials and Methods:

The study included a total of 90 patients, aged between 18 and 56 years of both sexes scheduled for elective LC. Patients were randomized into three groups of 30 each who received oral pregabalin 150 mg, clonidine 200 ug, and placebo. The hemodynamic parameters were recorded at various time intervals along with any adverse events.

Statistical Analysis:

Quantitative variables were compared using unpaired t-test (when the data sets were not normally distributed) between the two groups. Qualitative variables were compared using Chi-square test/Fisher's exact test. P < 0.05 was considered statistically significant.

Results:

There was a significant increase in the heart rate (HR) and systolic, diastolic, and mean blood pressure during laryngoscopy and pneumoperitoneum in the control group as compared to both pregabalin and clonidine. HR was significantly lower in clonidine group after extubation and in postoperative period than both control group and pregabalin group. There was no major difference in the incidence of side effects.

Conclusion:

Both pregabalin (150 mg) and clonidine (200 ug) were effective in controlling the hemodynamic parameters during LC, with clonidine providing better hemodynamic stability than Pregabalin.

Effect of Clonidine on Hemodynamic Responses During Laparoscopic Cholecystectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Clonidine might be beneficial to the patients undergoing laparoscopic cholecystectomy. This meta-analysis focused on the influence of clonidine on hemodynamic responses in patients undergoing laparoscopic cholecystectomy.

METHODS

We searched several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. This meta-analysis included randomized controlled trials regarding the influence of clonidine versus placebo on laparoscopic cholecystectomy. The primary outcomes were mean arterial pressure (MAP) and heart rate (HR) at pneumoperitoneum. The random-effect model was applied for this study.

RESULTS

Compared with control intervention, clonidine intervention was found to significantly reduce the MAP at pneumoperitoneum [standard mean difference=-2.58; 95% confidence interval (CI),-4.63 to -0.53; P=0.01), HR at pneumoperitoneum (standard mean difference=-3.67; 95% CI, -6.57 to -0.76; P=0.01), MAP at intubation (standard mean difference=-2.40; 95% CI, -4.75 to -0.06; P=0.04), HR at intubation (standard mean difference=-3.39; 95% CI, -5.75 to -1.02; P=0.005), propofol requirement (standard mean difference=-2.25; 95% CI, -4.01 to -0.48; P=0.01), as well as postoperative nausea and vomiting (risk ratio, 0.35; 95% CI, 0.19-0.63; P=0.0005).

CONCLUSIONS

Compared with control intervention, clonidine intervention was found to significantly reduce MAP and HR at pneumoperitoneum and intubation, propofol requirement, as well as postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy.

Alpha-2 adrenergic agonists for the prevention of cardiac complications among adults undergoing surgery

BACKGROUND

The surgical stress response plays an important role on the pathogenesis of perioperative cardiac complications. Alpha-2 adrenergic agonists attenuate this response and may help prevent postoperative cardiac complications.

OBJECTIVES

To determine the efficacy and safety of α-2 adrenergic agonists for reducing mortality and cardiac complications in adults undergoing cardiac surgery and non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL (2017, Issue 4), MEDLINE (1950 to April Week 4, 2017), Embase (1980 to May 2017), the Science Citation Index, clinical trial registries, and reference lists of included articles.

SELECTION CRITERIA

We included randomized controlled trials that compared α-2 adrenergic agonists (i.e. clonidine, dexmedetomidine or mivazerol) against placebo or non-α-2 adrenergic agonists. Included trials had to evaluate the efficacy and safety of α-2 adrenergic agonists for preventing perioperative mortality or cardiac complications (or both), or measure one or more relevant outcomes (i.e. death, myocardial infarction, heart failure, acute stroke, supraventricular tachyarrhythmia and myocardial ischaemia).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, extracted data and independently performed computer entry of abstracted data. We contacted study authors for additional information. Adverse event data were gathered from the trials. We evaluated included studies using the Cochrane 'Risk of bias' tool, and the quality of the evidence underlying pooled treatment effects using GRADE methodology. Given the clinical heterogeneity between cardiac and non-cardiac surgery, we analysed these subgroups separately. We expressed treatment effects as pooled risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included 47 trials with 17,039 participants. Of these studies, 24 trials only included participants undergoing cardiac surgery, 23 only included participants undergoing non-cardiac surgery and eight only included participants undergoing vascular surgery. The α-2 adrenergic agonist studied was clonidine in 21 trials, dexmedetomidine in 24 trials and mivazerol in two trials.In non-cardiac surgery, there was high quality evidence that α-2 adrenergic agonists led to a similar risk of all-cause mortality compared with control groups (1.3% with α-2 adrenergic agonists versus 1.7% with control; RR 0.80, 95% CI 0.61 to 1.04; participants = 14,081; studies = 16). Additionally, the risk of cardiac mortality was similar between treatment groups (0.8% with α-2 adrenergic agonists versus 1.0% with control; RR 0.86, 95% CI 0.60 to 1.23; participants = 12,525; studies = 5, high quality evidence). The risk of myocardial infarction was probably similar between treatment groups (RR 0.94, 95% CI 0.69 to 1.27; participants = 13,907; studies = 12, moderate quality evidence). There was no associated effect on the risk of stroke (RR 0.93, 95% CI 0.55 to 1.56; participants = 11,542; studies = 7; high quality evidence). Conversely, α-2 adrenergic agonists probably increase the risks of clinically significant bradycardia (RR 1.59, 95% CI 1.18 to 2.13; participants = 14,035; studies = 16) and hypotension (RR 1.24, 95% CI 1.03 to 1.48; participants = 13,738; studies = 15), based on moderate quality evidence.There was insufficient evidence to determine the effect of α-2 adrenergic agonists on all-cause mortality in cardiac surgery (RR 0.52, 95% CI 0.26 to 1.04; participants = 1947; studies = 16) and myocardial infarction (RR 1.01, 95% CI 0.43 to 2.40; participants = 782; studies = 8), based on moderate quality evidence. There was one cardiac death in the clonidine arm of a study of 22 participants. Based on very limited data, α-2 adrenergic agonists may have reduced the risk of stroke (RR 0.37, 95% CI 0.15 to 0.93; participants = 1175; studies = 7; outcome events = 18; low quality evidence). Conversely, α-2 adrenergic agonists increased the risk of bradycardia from 6.4% to 12.0% (RR 1.88, 95% CI 1.35 to 2.62; participants = 1477; studies = 10; moderate quality evidence), but their effect on hypotension was uncertain (RR 1.19, 95% CI 0.87 to 1.64; participants = 1413; studies = 9; low quality evidence).These results were qualitatively unchanged in subgroup analyses and sensitivity analyses.

AUTHORS' CONCLUSIONS

Our review concludes that prophylactic α-2 adrenergic agonists generally do not prevent perioperative death or major cardiac complications. For non-cardiac surgery, there is moderate-to-high quality evidence that these agents do not prevent death, myocardial infarction or stroke. Conversely, there is moderate quality evidence that these agents have important adverse effects, namely increased risks of hypotension and bradycardia. For cardiac surgery, there is moderate quality evidence that α-2 adrenergic agonists have no effect on the risk of mortality or myocardial infarction, and that they increase the risk of bradycardia. The quality of evidence was inadequate to draw conclusions regarding the effects of alpha-2 agonists on stroke or hypotension during cardiac surgery.

Effect of Magnesium Sulfate and Clonidine in Attenuating Hemodynamic Response to Pneumoperitoneum in Laparoscopic Cholecystectomy

BACKGROUND

Pneumoperitoneum in laparoscopic procedures is associated with hemodynamic response, due to the release of catecholamines and vasopressin. Magnesium and clonidine have been used to attenuate such hemodynamic responses by inhibiting release of these mediators. We conducted this randomized, double-blinded study to assess which of the two attenuates hemodynamic response better.

MATERIALS AND METHODS

Ninety American Society of Anesthesiologists health status Classes I and II patients posted for elective laparoscopic cholecystectomy were randomized into three groups of thirty patients each. Group C received injection clonidine 1 μg/kg diluted in 10 mL normal saline over 10 min, prior to pneumoperitoneum. Group M received injection magnesium sulfate 50 mg/kg diluted in 10 mL normal saline over 10 min, prior to pneumoperitoneum. Group NS received 10 mL normal saline intravenously over 10 min, prior to pneumoperitoneum. Hemodynamic parameters were recorded before induction (baseline values), at the end of magnesium sulfate/clonidine/saline administration and before pneumoperitoneum (P0), 5 min (P5), 10 min (P10), 20 min (P20), 30 min (P30), and 40 min (P40) after pneumoperitoneum.

RESULTS

Systolic blood pressure, diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were all significantly higher in the normal saline group compared to magnesium and clonidine. On comparing patients in Group M and Group C, DBP, MAP, and HR were significantly lower in the magnesium group. Mean extubation time and time to response to verbal commands were significantly longer in the magnesium group.

CONCLUSIONS

Both magnesium and clonidine attenuated the hemodynamic response to pneumoperitoneum. However, magnesium 50 mg/kg, attenuated hemodynamic response better than clonidine 1 μg/kg.

Laparoscopic surgery: a narrative review of pharmacotherapy in pain management

Laparoscopic surgery is widespread, and an increasing number of surgeries are performed laparoscopically. Early pain after laparoscopy can be similar or even more severe than that after open surgery. Thus, proactive pain management should be provided. Pain after laparoscopic surgery is derived from multiple origins; therefore, a single agent is seldom sufficient. Pain is most effectively controlled by a multimodal, preventive analgesia approach, such as combining opioids with non-opioid analgesics and local anaesthetics. Wound and port site local anaesthetic injections decrease abdominal wall pain by 1-1.5 units on a 0-10 pain scale. Inflammatory pain and shoulder pain can be controlled by NSAIDs or corticosteroids. In some patient groups, adjuvant drugs, ketamine and α2-adrenergic agonists can be helpful, but evidence on gabapentinoids is conflicting. In the present review, the types of pain that need to be taken into account while planning pain management protocols and the wide range of analgesic options that have been assessed in laparoscopic surgery are critically assessed. Recommendations to the clinician will be made regarding how to manage acute pain and how to prevent persistent postoperative pain. It is important to identify patients at the highest risk for severe and prolonged post-operative pain, and to have a proactive strategy in place for these individuals.

Preemptive Oral Clonidine Provides Better Sedation Than Intravenous Midazolam in Brachial Plexus Nerve Blocks

Background

Preemptive analgesia is the blocking of pain perception afferent pathways before noxious painful stimuli. Clonidine is an alpha agonist drug that is partially selective for α-2 adrenoreceptors. Clonidine is used as anti-anxiety medication and an, analgesic, and it prolongs the duration of the block in the brachial plexus block.

Objectives

To compare the effect of preemptive clonidine with midazolam on intraoperative sedation, duration of block, and postoperative pain scores.

Patients and Methods

In a randomized clinical trial, 80 patients with orthopedic fractures of an upper extremity who underwent supraclavicular nerve block were randomly assigned to receive 0.2 mg oral clonidine or 2 mg oral midazolam. Intraoperative sedation was measured at one hour after the start of urgery and again in the PACU (Post-Anesthesia Care Unit) using the Ramsay scale. The duration of sensory blockade was measured. Postoperative pain scores were measured using the VAS (Visual Analogue Scale) after entrance to recovery up to 2 hours.

Results

The percentages of patients in the calm and sedated scale were significantly higher in clonidine group (35 and 42.5%, respectively), compared to the midazolam group (17.5 and 17.5%, respectively) (P = 0.042, 0.029; respectively). Those administered fentanyl in the clonidine group 105 ± 30.8 was significantly lower than that for the midazolam group 165 ± 34.5 (P = 0.0018). The percentages of patients in the calm scale were significantly higher in the clonidine group (52.5), compared to the midazolam group (17.5) (P = 0.001) in the post-operative period. VAS scores were significantly lower at one (P = 0.01) and two hours (P = 0.001) after operation in the clonidine group, compared to the midazolam group.

Conclusions

Preemptive clonidine has many marvelous advantages over midazolam, including better sedation inside the operating room and then in the post-operative care unit, lower fentanyl doses are required during surgery, more stable heart rate and blood pressure are observed during the procedure, and patients report lower post-operative pain scores.

Clonidine versus nitroglycerin infusion in laparoscopic cholecystectomy

Background and Objectives:

Laparoscopic surgery offers the advantages of minimally invasive surgery; however, pneumoperitoneum and the patient's position induce pathophysiological changes that may complicate anesthetic management. We studied the effect of clonidine and nitroglycerin on heart rate and blood pressure, if any, in association with these drugs or the procedure, as well as the effect of these drugs, if any, on end-tidal carbon dioxide pressure and intraocular pressure.

Methods:

Sixty patients (minimum age of 20 years and maximum age of 65 years, American Society of Anesthesiologists class I or II) undergoing laparoscopic cholecystectomy were randomized into 3 groups and given an infusion of clonidine (group I), nitroglycerin (group II), or normal saline solution (group III) after induction and before creation of pneumoperitoneum. We observed and recorded the following parameters: heart rate, mean arterial blood pressure, end-tidal carbon dioxide pressure, and intraocular pressure. The mean and standard deviation of the parameters studied during the observation period were calculated for the 3 treatment groups and compared by use of analysis of variance tests. Intragroup comparison was performed with the paired t test. The critical value of P, indicating the probability of a significant difference, was taken as < .05 for comparisons.

Results:

Statistically significant differences in heart rate were observed among the various groups, whereas comparisons of mean arterial pressure, intraocular pressure, and end-tidal carbon dioxide pressure showed statistically significant differences only between groups I and III and between groups II and III.

Conclusion:

We found clonidine to be more effective than nitroglycerin at preventing changes in hemodynamic parameters and intraocular pressure induced by carbon dioxide insufflation during laparoscopic cholecystectomy. It was also found not to cause hypotension severe enough to stop the infusion and warrant treatment.

Pharmacological interventions for prevention or treatment of postoperative pain in people undergoing laparoscopic cholecystectomy

BACKGROUND

While laparoscopic cholecystectomy is generally considered less painful than open surgery, pain is one of the important reasons for delayed discharge after day-surgery and overnight stay following laparoscopic cholecystectomy. The safety and effectiveness of different pharmacological interventions such as non-steroidal anti-inflammatory drugs, opioids, and anticonvulsant analgesics in people undergoing laparoscopic cholecystectomy is unknown.

OBJECTIVES

To assess the benefits and harms of different analgesics in people undergoing laparoscopic cholecystectomy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, and the World Health Organization International Clinical Trials Registry Platform portal (WHO ICTRP) to March 2013 to identify randomised clinical trials of relevance to this review.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing different pharmacological interventions with no intervention or inactive controls for outcomes related to benefit in this review. We considered comparative non-randomised studies with regards to treatment-related harms. We also considered trials that compared one class of drug with another class of drug for this review.

DATA COLLECTION AND ANALYSIS

Two review authors collected the data independently. We analysed the data with both fixed-effect and random-effects models using Review Manager 5 analysis. For each outcome, we calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 25 trials with 2505 participants randomised to the different pharmacological agents and inactive controls. All the trials were at unclear risk of bias. Most trials included only low anaesthetic risk people undergoing elective laparoscopic cholecystectomy. Participants were allowed to take additional analgesics as required in 24 of the trials. The pharmacological interventions in all the included trials were aimed at preventing pain after laparoscopic cholecystectomy. There were considerable differences in the pharmacological agents used and the methods of administration. The estimated effects of the intervention on the proportion of participants who were discharged as day-surgery, the length of hospital stay, or the time taken to return to work were imprecise in all the comparisons in which these outcomes were reported (very low quality evidence). There was no mortality in any of the groups in the two trials that reported mortality (183 participants, very low quality evidence). Differences in serious morbidity outcomes between the groups were imprecise across all the comparisons (very low quality evidence). None of the trials reported patient quality of life or time taken to return to normal activity. The pain at 4 to 8 hours was generally reduced by about 1 to 2 cm on the visual analogue scale of 1 to 10 cm in the comparisons involving the different pharmacological agents and inactive controls (low or very low quality evidence). The pain at 9 to 24 hours was generally reduced by about 0.5 cm (a modest reduction) on the visual analogue scale of 1 to 10 cm in the comparisons involving the different pharmacological agents and inactive controls (low or very low quality evidence).

AUTHORS' CONCLUSIONS

There is evidence of very low quality that different pharmacological agents including non-steroidal anti-inflammatory drugs, opioid analgesics, and anticonvulsant analgesics reduce pain scores in people at low anaesthetic risk undergoing elective laparoscopic cholecystectomy. However, the decision to use these drugs has to weigh the clinically small reduction in pain against uncertain evidence of serious adverse events associated with many of these agents. Further randomised clinical trials of low risk of systematic and random errors are necessary. Such trials should include important clinical outcomes such as quality of life and time to return to work in their assessment.

The comparative evaluation of intravenous with intramuscular clonidine for suppression of hemodynamic changes in laparoscopic cholecystectomy

Background:

Clonidine diminishes stress response by reducing circulating catecholamines and hence increases perioperative circulatory stability in patients undergoing laparoscopic surgeries. The aim of this study was to compare intravenous (IV) clonidine (2 μg/kg) with intramuscular (IM) clonidine (2 μg/kg) for attenuation of stress response in laproscopic surgeries.

Methods:

Eighty adult patients classified as ASA physical status I or II, aged between 20 and 60 years undergoing elective cholecystectomy under general anesthesia were enrolled for a prospective, randomized, and double-blind controlled trial. They received either IV clonidine (2 μg/kg) 15 min prior to the scheduled surgery (Group I) or IM clonidine (2 μg/kg) 60-90 min prior to the scheduled surgery (Group II). Hemodynamic variables (Heart rate, systolic (SBP), diastolic (DBP), mean arterial pressure (MAP)), SpO₂ and EtCO₂ were recorded at specific times - baseline, prior to induction, 1 min after intubation, before CO₂, insufflation, after CO₂ insufflation at 1,5,10,20,30,45,60 min, after release of CO₂, at 1 and 10 minutes after extubation. Secondary outcomes included evaluation of adverse effect profile of the two groups.

Results:

No significant difference was observed in the HR throughout the intraoperative period in between the two groups (P>0.05). There was statistically significant difference in SBP between the two groups starting from 1 minute after induction till 1 min after extubation (P<0.05) but not in DBP except at 1 minute after intubation (P=0.042). Significant difference in MAP was noted at 1 minute after intubation (P=0.004) and then from 5 minutes after CO₂ insufflation to 1 minute after extubation (P<0.05). Incidence of adverse effects were higher in group II (P=0.02) especially incidence of hypertension requiring treatment (0.006).

Conclusion:

We conclude that under the conditions of this study, hemodynamic parameters (SBP, DBP and MAP) were better maintained in the IV as compared to the IM route that had significantly higher incidence of hypertension requiring treatment.

Comparison of fentanyl and clonidine for attenuation of the haemodynamic response to laryngocopy and endotracheal intubation

INTRODUCTION

Laryngoscopy and tracheal intubation after the induction of anaesthesia, are nearly always associated with sympathetic hyperactivity. To 'blunt' this pressor response, various methods have been tried, but very few studies have been done to assess the effects of fentanyl orI.V. clonidine on the haemodynamic response during laryngoscopy and tracheal intubation. The purpose of this study was to compare these agents, to find the drug which was best suited for this purpose and the most favourable time for its administration.

METHODS

This was a prospective study which involved 3 groups of patients. The patients in group-1 (control) were given normal saline and the groups 2 and 3 were given i.v. fentanyl and clonidine respectively. Each group had 50 patients who presented for elective, non-cardiovascular surgeries. All the patients were ASA-1 or ASA-II and were operated in PESIMSR, Kuppam.

RESULTS

The heart rate rise was 48.07% in the control group, whereas it was significantly lower in the fentanyl (II) 27.75% and the clonidine groups (III) 12.57% (p<0.001). In the control group, the systolic blood pressure increased maximally after 5 minutes (42.62%) i.e., immediately after the laryngoscopy and the intubation. It decreased gradually over 10 minutes (17.39%). With the administration of fentanyl, the maximum increase as compared to the preinduction value was 9.91%, but it was only 7.38% in the clonidine group. Both, when they were compared with the control, showed a significant suppression (P<.001), with clonidine showing better results. The maximum increase in the diastolic blood pressure was 30.12% in the control group (P<.001) at 5 min and it was 18.22%, and 6.15% in the fentanyl and the clonidine groups respectively, with clonidine faring better again (P<.001).

INTERPRETATION AND CONCLUSION

Clonidine showed better attenuation of the sympathetic response, which is statistically highly significant and it remained so till the end of 10 minutes. Intravenous clonidine 2;g/kg which is administered 5 minutes before the laryngoscopy can be recommended to attenuate the sympathetic response to the laryngoscopy and the intubation.

Hemodynamic stress response during laparoscopic cholecystectomy: Effect of two different doses of intravenous clonidine premedication

Background:

Clonidine has emerged as an attractive premedication desirable in laparoscopic surgery wherein significant hemodynamic stress response is seen. The minimum safe and effective dose of intravenous clonidine to attenuate the hemodynamic stress response during laparoscopic surgery has however not yet been determined.

Materials and Methods:

This prospective, randomized, double-blind controlled study was conducted on 90 adults of ASA physical status I and II, scheduled for laparoscopic cholecystectomy under general anesthesia. Patients were randomized to one of the three groups (n= 30). Group I received 100 ml of normal saline, while groups II and III received 1 μg/ kg and 2 μg/ kg of clonidine respectively, intravenous, in 100 ml of normal saline along. All patients received glycopyrrolate 0.004 mg/kg and tramadol 1.5 mg/kg intravenously, 30 min before induction. Hemodynamic variables (heart rate, systolic, diastolic, mean arterial pressure), SpO2, and sedation score were recorded at specific timings. MAP above 20% from baseline was considered significant and treated with nitroglycerine.

Results:

In group I, there was a significant increase in hemodynamic variables during intubation pneumoperitoneum and extubation (P<0.001). Clonidine given 1 μg/kg intravenous attenuated hemodynamic stress response to pneumoperitoneum (P<0.05), but not that associated with intubation and extubation. Clonidine 2 μg/kg intravenous prevented hemodynamic stress response to pneumoperitoneum and that associated with intubation and extubation (P<0.05). As against 14 and 2 patients in groups I and II respectively, no patient required nitroglycerine infusion in group III.

Conclusions:

Clonidine, 2 μg/ kg intravenously, 30 min before induction is safe and effective in preventing the hemodynamic stress response during laparoscopic cholecystectomy.

Comparative study of intravenously administered clonidine and magnesium sulfate on hemodynamic responses during laparoscopic cholecystectomy

Background:

Both magnesium and clonidine are known to inhibit catecholamine and vasopressin release and attenuate hemodynamic response to pneumoperitoneum. This randomized, double blinded, placebo controlled study has been designed to assess which agent attenuates hemodynamic stress response to pneumoperitoneum better.

Materials and Methods:

120 patients undergoing elective laparoscopic cholecystectomy were randomized into 4 groups of 30 each. Group K patients received 50 ml normal saline over a period of 15 min after induction and before pneumoperitoneum, group M patients received 50 mg/kg of magnesium sulfate in normal saline (total volume 50 ml) over same time duration. Similarly group C1 patients received 1 μg/kg clonidine and group C2 1.5 μg/kg clonidine respectively in normal saline (total volume 50 ml). Blood pressure and heart rate were recorded before induction (baseline value), at the end of infusions and every 5 min after pneumoperitoneum.

Statistical Analysis:

Paired t test was used for intra-group comparison and ANOVA for inter-group comparison.

Results:

Systolic blood pressure was significantly higher in control group as compared to all other groups during pneumoperitoneum. On comparing patients in group M and group C1, no significant difference in systolic BP was found at any time interval. Patients in group C2 showed best control of systolic BP. As compared to group M and group C1, BP was significantly lower at 10, 30 and 40 min post pneumoperitoneum. No significant episodes of hypotension were found in any of the groups. Extubation time and time to response to verbal command like eye opening was significantly longer in group M as compared to other groups.

Conclusion:

Administration of magnesium sulfate or clonidine attenuates hemodynamic response to pneumoperitoneum. Although magnesium sulfate 50 mg/kg produces hemodynamic stability comparable to clonidine 1 μg/kg, clonidine in doses of 1.5μg/kg blunts the hemodynamic response to pneumoperitoneum more effectively.

A systematic review of interventions to facilitate ambulatory laparoscopic cholecystectomy

OBJECTIVES

  We aimed to perform a systematic review of the literature to identify interventions that may facilitate ambulatory laparoscopic cholecystectomy (LC).

METHODS

The PubMed and CENTRAL databases were interrogated for key MeSH headings. To be eligible for systematic review, trials were required to include outcome measures of postoperative pain, nausea or vomiting and time to discharge following LC. Interventions were subsequently assessed for the level of evidence and grade of recommendation given.

RESULTS

A total of 331 trials were identified, 68 of which met the predefined study inclusion criteria. Interventions which met Level I, Grade A recommendation included the administration of 8 mg i.v. dexamethasone, preoperative administration of analgesia including the use of non-steroidal anti-inflammatory or COX II inhibitors, intraoperative use of an anti-emetic, pre-incisional use of bupivacaine, administration of intraperitoneal bupivacaine on establishment of pneumoperitoneum, and avoidance of drains.

CONCLUSIONS

  High-quality evidence describing interventions that minimize barriers to ambulatory LC exists. Further studies will be required to determine the optimal combination of these interventions.

Effect of oral clonidine premedication on perioperative haemodynamic response and postoperative analgesic requirement for patients undergoing laparoscopic cholecystectomy

Clonidine has anti-hypertensive properties and augments the effects of anaesthesia, hence we considered it to be an ideal agent to contain the stress response to pneumoperitoneum. We studied the clinical efficacy of oral clonidine premedication in patients undergoing laparoscopic cholecystectomies. Fifty patients scheduled for elective laparoscopic cholecystectomy under general anaesthesia were randomly allocated to receive premedication with either oral clonidine 150 μg (Group I, n = 25) or placebo (Group II, n = 25) 90 minutes prior to induction. The patients were managed with a standard general anaesthetic. The two groups were compared with respect to haemodynamic parameters, isoflurane concentration, pain and sedation scores, time to request of analgesic and cumulative analgesic requirements. Oral clonidine was found to be significantly better in terms of maintaining stable haemodynamics, having an isoflurane sparing effect and having a prolonged time interval to the first request of analgesia postoperatively compared to the control group. Administration of oral clonidine 150 μg as a pre-medicant in patients undergoing laparoscopic cholecystectomy results in improved perioperative haemodynamic stability and a reduction in the intra-operative anaesthetic and post-operative analgesic requirements.

Alpha-2 adrenergic agonists for the prevention of cardiac complications among patients undergoing surgery

BACKGROUND

The surgical stress response plays an important role on the pathogenesis of perioperative cardiac complications. Alpha-2 adrenergic agonists attenuate this response and may thereby prevent cardiac complications.

OBJECTIVES

This review assessed the efficacy and safety of preoperative (within 24 hours), intraoperative, and postoperative (first 48 hours) alpha-2 adrenergic agonists for preventing mortality and cardiac complications after surgery performed under either general or neuraxial anaesthesia, or both.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 3), MEDLINE (1950 to August week 4 2008), EMBASE (1980 to week 36 2008), the Science Citation Index, and reference lists of articles.

SELECTION CRITERIA

We included randomized controlled trials that compared alpha-2 adrenergic agonists (clonidine, dexmedetomidine, or mivazerol) against placebo or non-alpha-2 adrenergic agonists. Included studies had to report on mortality, myocardial infarction, myocardial ischaemia, or supraventricular tachyarrhythmia.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial quality and extracted data. Two authors independently performed computer entry of abstracted data. We contacted study authors for additional information. Adverse event data were gathered from the trials.

MAIN RESULTS

We included 31 studies (4578 participants). Study quality was generally inadequate, with only six studies clearly reporting methods for blinding and allocation concealment. Overall, alpha-2 adrenergic agonists reduced mortality (relative risk (RR) 0.66; 95% CI 0.44 to 0.98; P = 0.04) and myocardial ischaemia (RR 0.68; 95% CI 0.57 to 0.81; P < 0.0001). However, their effects appeared to vary with the surgical procedure. The most encouraging data pertained to vascular surgery, where they reduced mortality (RR 0.47; 95% CI 0.25 to 0.90; P = 0.02), cardiac mortality (RR 0.36; 95% CI 0.16 to 0.79; P = 0.01), and myocardial infarction (RR 0.66; 95% CI 0.46 to 0.94; P = 0.02). With regard to adverse effects, alpha-2 adrenergic agonists significantly increased perioperative hypotension (RR 1.32; 95% CI 1.07 to 1.62; P = 0.009) and bradycardia (RR 1.66; 95% CI 1.14 to 2.41; P = 0.008).

AUTHORS' CONCLUSIONS

Our study provides encouraging evidence that alpha-2 adrenergic agonists may reduce cardiac risk, especially during vascular surgery. Nonetheless, these data remain insufficient to make firm conclusions about their efficacy and safety. A large randomized trial of alpha-2 adrenergic agonists is therefore warranted. Additionally, future research must determine which specific alpha-2 adrenergic agonist should be used, and whether it is safe to combine them with other perioperative interventions (for example beta-adrenergic blockade).

[Premedication with intraoperative clonidine and low-dose ketamine in outpatient laparoscopic cholecystectomy]

OBJECTIVE

To determine the efficacy of premedication with intraoperative clonidine in association with low-dose ketamine to reduce the need for postoperative opiate analgesia in outpatient laparoscopic cholecystectomy.

PATIENTS AND METHODS

We performed a prospective study of patients undergoing outpatient laparoscopic cholecystectomy between November 2005 and November 2006. The patients were distributed randomly in 2 groups: patients in the clonidine-ketamine group received clonidine (0.15 mg orally 60 minutes before surgery) and ketamine (20-mg intravenous bolus followed by intraoperative perfusion of 20 mg h(-1)); patients in the control group did not receive this medication. Pain assessed on a verbal numerical scale, number of times rescue analgesia was required to achieve a value below 3, and adverse effects of the medication were recorded in the postoperative period.

RESULTS

Thirty-one patients (16 in the clonidine-ketamine group and 15 in the control group) were enrolled. Rescue analgesia was required on 2 occasions by 25% of patients in the clonidine-ketamine group and on 2 or 3 occasions by 533% of patients in the control group. Adverse effects were reported by 87.5% of patients in the clonidine-ketamine group (mainly visual disturbances, sedation, and nausea) and by 46.7% in the control group. This difference was significant during the patients' stay in the postanesthesia recovery unit.

CONCLUSIONS

Patients receiving clonidine and ketamine required less additional opiate analgesia to achieve mild pain values (<3 on the numerical verbal scale) but suffered more adverse effects during their stay in the postanesthesia recovery unit. Discharge was not delayed, however.

A procedure-specific systematic review and consensus recommendations for postoperative analgesia following laparoscopic cholecystectomy

BACKGROUND

Laparoscopic cholecystectomy has advantages over the open procedure for postoperative pain. However, a systematic review of postoperative pain management in this procedure has not been conducted.

METHODS

A systematic review was conducted according to the guidelines of the Cochrane Collaboration. Randomized studies examining the effect of medical or surgical interventions on linear pain scores in patients undergoing laparoscopic cholecystectomy were included. Qualitative and quantitative analyses were performed. Recommendations for patient care were derived from review of these data, evidence from other relevant procedures, and clinical practice observations collated by the Delphi method among the authors.

RESULTS

Sixty-nine randomized trials were included and 77 reports were excluded. Recommendations are provided for preoperative analgesia, anesthetic and operative techniques, and intraoperative and postoperative analgesia.

CONCLUSIONS

A step-up approach to the management of postoperative pain following laparoscopic cholecystectomy is recommended. This approach has been designed to provide adequate analgesia while minimizing exposure to adverse events.

Hemodynamic Effects of Perioperative Stressor Events during Rhinoplasty

The hemodynamic effects of perioperative stressors, including preoperative patient anxiety, intraoperative local anesthetic/adrenaline infiltrations, and some painful interventions, have not been fully elucidated in plastic surgery procedures. The present study was designed to determine the hemodynamic effects of perioperative stressor events in American Society of Anesthesiologists class I patients undergoing rhinoplasty procedures under general anesthesia. The study included 50 healthy patients, 18 to 51 years of age (mean age, 27 +/- 7 years), who underwent a rhinoplasty procedure in the authors' department. All patients were connected to a digital ambulatory Holter recorder for 24 hours starting on the day before the operation and continuing throughout the procedure. All of the patients received 10 ml of 2% lidocaine with 1:80,000 adrenaline 15 minutes after intubation. Observations consisted of heart rate, noninvasive blood pressure, and power spectral heart rate variability analyses, the latter of which is indicative of the sympathovagal balance of the patients. The majority of patients developed a persistent, moderate sinus tachycardia before the induction of anesthesia. After the infiltration of lidocaine/adrenaline, a mild to moderate and short-lasting tachycardia was detected. A similar increase in pulse rate was also noticed during lateral osteotomies. No significant blood pressure changes attributable to perioperative stressors (with the exclusion of general anesthesia induction, intubation, and extubation) were observed. Sympathetic activity was found to be responsible from marked tachycardia before the induction, which was attributable to preoperative anxiety. The authors' study has demonstrated that there are three hemodynamically unstable periods causing tachycardia for rhinoplasty patients that directly concern the plastic surgeon: immediate preoperative anxiety, local anesthetic/adrenaline injection, and lateral osteotomies. The authors conclude that these patients would benefit from routine use of premedications and that a lidocaine/adrenaline combination is a safe adjunct to general anesthesia in young rhinoplasty patients. In addition, a deeper anesthesia during local infiltration and osteotomies would be appropriate.