Amir Abrishami

Predictors of postoperative pain and analgesic consumption: a qualitative systematic review.

Pain is a subjective and multidimensional experience that is often inadequately managed in clinical practice. Effective control of postoperative pain is important after anesthesia and surgery. A systematic review was conducted to identify the independent predictive factors for postoperative pain and analgesic consumption. The authors identified 48 eligible studies with 23,037 patients included in the final analysis. Preoperative pain, anxiety, age, and type of surgery were four significant predictors for postoperative pain. Type of surgery, age, and psychological distress were the significant predictors for analgesic consumption. Gender was not found to be a consistent predictor as traditionally believed. Early identification of the predictors in patients at risk of postoperative pain will allow more effective intervention and better management. The coefficient of determination of the predictive models was less than 54%. More vigorous studies with robust statistics and validated designs are needed to investigate this field of interest.

Tranexamic Acid Reduces Perioperative Blood Loss in Adult Patients Having Spinal Fusion Surgery

BACKGROUND: Spinal reconstructive surgery in adults can be associated with significant blood loss, often requiring allogeneic blood transfusion. The objective of this randomized, prospective, double-blind, multicenter study was to evaluate the efficacy of tranexamic acid (TXA) in reducing perioperative blood loss and transfusion in adult patients having elective posterior thoracic/lumbar instrumented spinal fusion surgery. METHODS: One hundred fifty-one adult patients were randomized to receive either a bolus of 10 mg/kg IV of TXA after induction followed by a maintenance infusion of 1 mg/kg/hr of TXA, or an equivalent volume of placebo (normal saline). The primary outcome was the total perioperative estimated and calculated blood loss intraoperatively and 24 h postoperatively. Secondary outcomes were incidence of allogeneic blood exposure, and duration of hospital stay. RESULTS: Four patients were withdrawn for identifiable surgical bleeding, therefore 147 patients were included in the analysis. The total estimated and calculated perioperative blood loss was approximately 25% and 30% lower in patients given TXA versus placebo (1592 ± 1315 mL vs 2138 ± 1607 mL, P = 0.026; 3079 ± 2558 vs 4363 ± 3030, P = 0.017), respectively. There was no difference in the amounts of blood products transfused, and length of stay between the two groups. TXA, surgical duration, and number of vertebrae fused were independent factors related to perioperative blood loss. Predictors for the need for allogeneic red blood cell transfusion were ASA classification, surgical duration and number of levels fused. CONCLUSIONS: TXA significantly reduced the estimated and calculated total amount of perioperative blood loss in adult patients having elective posterior thoracic/lumbar instrumented spinal fusion surgery.

Preoperative pain sensitivity and its correlation with postoperative pain and analgesic consumption: a qualitative systematic review.

Pain perception to minor physical stimuli has been hypothesized to be related to subsequent pain ratings after surgery. The objective of this systematic review was to evaluate the correlation between preoperative pain sensitivity and postoperative pain intensity. After a literature search of MEDLINE, EMBASE, and meeting abstracts, we identified 15 studies (n = 948 patients) with univariate and/or multivariate analysis on the topic. In these studies, three types of pain stimuli were applied: thermal, pressure, and electrical pain. The intensity of suprathreshold heat pain (i.e., pain beyond patient threshold) was most consistently shown to correlate with postoperative pain. The most common limitation of the included studies was the method of statistical analysis and lack of multivariate analysis. More research is required to establish the correlation of other pain sensitivity variables with postoperative pain outcomes.

Efficacy and Safety of Melatonin as an Anxiolytic and Analgesic in the Perioperative Period A Qualitative Systematic Review of Randomized Trials

Melatonin possesses sedative, hypnotic, analgesic, antiinflammatory, antioxidative, and chronobiotic properties that distinguish it as an attractive alternative premedicant. A qualitative systematic review of the literature concerning the perioperative use of melatonin as an anxiolytic or analgesic in adult patients was carried out using the recommended guidelines provided by the Cochrane Handbook for Systematic Reviews of Interventions. Nine of the 10 studies showed statistically significant reduction of preoperative anxiety with melatonin premedication compared with placebo. An opioid-sparing effect or reduced pain scores were evident in five studies whereas three studies were contradictory. Thus, melatonin premedication is effective in ameliorating preoperative anxiety in adults, but its analgesic effects remain controversial in the perioperative period. Additional well designed randomized controlled trials are necessary to compare melatonin premedication with other pharmacological interventions, investigate its effect on more varied surgical populations, and to delineate its optimal dosing regimen.

Development of the Functional Recovery Index for Ambulatory Surgery and Anesthesia

Background:It is increasingly important to evaluate patients’ recovery after ambulatory surgery. The authors developed the Functional Recovery Index (FRI) to assess postdischarge functional recovery for ambulatory surgical patients. Methods:The scale development involved four phases: item generation, item selection, reliability, and validity testing. A draft questionnaire was tested and revised. Items were selected through testing endorsement frequency, factor analysis, and testing internal consistency. The interrater reliability was calculated. Construct validity was tested by multiple hypotheses on convergent validity, extreme groups, and discriminant validity. Responsiveness was assessed by measuring the FRI postoperatively and comparing minor versus more extensive surgery. The rate of response and the time for completion of the questionnaire were recorded. Results:The final questionnaire had 14 items grouped under 3 factors. Each item was scored from 0 to 10, with 0 = no difficulty and 10 = extreme difficulty with the activity. The 3 factors were summated for a total score. Internal consistency for the 3 factors (pain and social activity, lower limb activity, and general physical activity) was as follows: Cronbach &agr; = 0.90, 0.89, and 0.86, respectively. Interrater reliability was 0.99. Convergent validity for FRI versus verbal rating scale pain score was 0.76. Discriminant validity testing showed that the type of surgery was significant and that intermediate (&bgr; = 0.138) and major surgery (&bgr; = 0.337) were associated with higher FRI scores than minor surgery. The time to complete the questionnaires ranged between 4 min 10 s and 4 min 35 s. Conclusions:The FRI had excellent reliability, good validity, responsiveness, and acceptability, indicating that this questionnaire will be a good instrument for assessing functional recovery of ambulatory surgical patients.

A Perioperative Smoking Cessation Intervention with Varenicline A Double-blind, Randomized, Placebo-controlled Trial

Background:The efficacy of perioperative tobacco interventions on long-term abstinence and the safety of smoking cessation less than 4 weeks before surgery is unclear. Our objective was to determine the efficacy and safety of a perioperative smoking cessation intervention with varenicline to reduce smoking in elective surgical patients. Methods:In a prospective, multicenter, double-blind, placebo-controlled trial, 286 patients were randomized to receive varenicline or placebo. Both groups received in-hospital and telephone counseling during 12 months. The primary outcome was the 7-day point prevalence abstinence rate 12 months after surgery. Secondary outcomes included abstinence at 3 and 6 months after surgery. Multivariable logistic regression was used to identify independent variables related to abstinence. Results:The 7-day point prevalence abstinence at 12 months for varenicline versus placebo was 36.4% versus 25.2% (relative risk: 1.45; 95%: CI: 1.01–2.07; P = 0.04). At 3 and 6 months, the 7-day point prevalence abstinence was 43.7% versus 31.9% (relative risk: 1.37; 95% CI: 1.01 to 1.86; P = 0.04), and 35.8% versus 25.9% (relative risk: 1.43; 95%: CI 1.01–2.04; P = 0.04) for varenicline versus placebo, respectively. Treatment with varenicline (odds ratio: 1.76; 95% CI: 1.03–3.01; P = 0.04), and preoperative nicotine dependence (odds ratio: 0.82, 95% CI: 0.68 to 0.98; P = 0.03) predicted abstinence at 12 months. The adverse events profile in both groups was similar except for nausea, which occurred more frequently for varenicline versus placebo (13.3% vs. 3.7%, P = 0.004). Conclusions:A perioperative smoking cessation intervention with varenicline increased abstinence from smoking 3, 6, and 12 months after elective noncardiac surgery with no increase in serious adverse events.

The Facilitatory Effects of Intravenous Dexmedetomidine on the Duration of Spinal Anesthesia: A Systematic Review and Meta-Analysis

BACKGROUND:Central mechanisms have been proposed to explain the prolongation of effect reported with the off-label use of dexmedetomidine as an adjuvant in local anesthetic admixtures. We evaluated whether IV dexmedetomidine can prolong the duration of sensory block associated with spinal anesthesia. METHODS:The authors searched MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases for randomized controlled trials investigating the facilitatory effects of IV administration of dexmedetomidine (dexmedetomidine group) compared with placebo (control group) on single-injection local anesthetic-based spinal anesthesia. Durations of sensory and motor block, sensory and motor block onset times, postoperative pain scores, time to first analgesic request, analgesic consumption, and dexmedetomidine-related side effects were evaluated. Results were combined using random effects modeling when appropriate. RESULTS:A total of 364 patients were analyzed from 7 intermediate to high-quality randomized controlled trials. When IV dexmedetomidine accompanied spinal anesthesia, sensory block duration was prolonged by at least 34% (point estimate: 38%), P < 0.00001, motor block duration was prolonged by at least 17% (point estimate: 21%), P < 0.00001, and time to first analgesic request was increased by at least 53% (point estimate: 60%), P < 0.00001. The use of dexmedetomidine was associated with a 3.7-fold increase (95% confidence interval, 1.53–8.82, P = 0.004) in transient reversible bradycardia. There was no difference in the incidence of hypotension or postoperative sedation, and none of the patients experienced respiratory depression. CONCLUSION:IV dexmedetomidine can prolong the duration of sensory block, motor block, and time to first analgesic request associated with spinal anesthesia.

Interventions in the preoperative clinic for long term smoking cessation: a quantitative systematic review

Purpose: To assess the efficacy of interventions offered to patients in the preoperative clinic to promote long-term (≥ three months) smoking cessation following surgery.Methods: We searched The Cochrane Library, MEDLINE, EMBASE and CINAHL for all randomized controlled trials (RCTs) on smoking-cessation interventions initiated in the preoperative clinic. Trial inclusion, quality assessment, and data extraction were performed independently by two authors. Standard meta-analytic techniques were applied.Results: Four RCTs (n=610 patients) were included in the review. Interventions included pharmacotherapy, counseling, educational literature and postoperative telephone follow-up. The follow-up period ranged between three to 12 months with only one RCT following up patients for τ one year. Two studies used biochemical methods to validate subjects’ self-reporting of smoking cessation at the follow-up assessment. Overall, the interventions were associated with a significantly higher cessation rate vs control at the three to six month follow-up period (pooled odds ratio: 1.58, 95% confidence interval (CI) 1.02–2.45,P value=0.01, 12=0%). The only trial with longer follow-up period (12 months), however, failed to show any significant difference between the intervention and control groups (odds ratio: 1.05, 95% CI 0.53–2.09,P value=0.88).Conclusion: This systematic review suggests that smoking-cessation interventions initiated at the preoperative clinic can increase the odds of abstinence by up to 60% within a three- to six-month follow-up period. To evaluate the possibility of longer abstinence, future trials with at least one-year follow-up are recommended.RésuméObjectif: Évaluer l’efficacité des interventions destinées à promouvoir la cessation du tabagisme à long terme (≥ trois mois) après une chirurgie mises à la disposition des patients en clinique préopératoire.Méthode: Nous avons effectué des recherches dans la Bibliothèque Cochrane et les bases de données MEDLINE, EMBASE et CINAHL pour identifier toutes les études randomisées contrôlées (ERC) traitant des interventions de cessation du tabagisme mises en oeuvre en clinique préopératoire. Les critères d’inclusion de l’étude, l’évaluation de la qualité et l’extraction des données ont été menés de façon indépendante par deux auteurs. Les techniques standard de méta-analyse ont été utilisées.Résultats: Notre compte-rendu a inclus quatre ERC (n=610 patients). La pharmacothérapie, la consultation, la littérature de formation et le suivi postopératoire par téléphone constituaient les interventions analysées. La période de suivi allait de trois à douze mois, une seule étude randomisée contrôlée effectuant un suivi de plus d’un an. Deux études ont eu recours à des méthodes biochimiques pour valider les déclarations volontaires des patients concernant la cessation du tabagisme lors de l’évaluation de suivi. D’une manière générale, les interventions ont été associées à un taux significativement plus élevé de cessation que le groupe témoin à trois et six mois de suivi (rapport de cotes pondéré : 1,58, intervalle de confiance à 95 % (IC) 1,02–2,45, valeur P=0,01, 12=0 %). Cependant, la seule étude comportant une période de suivi plus longue (12 mois), n’a pas montré de différence significative entre les groupes intervention et témoin (rapport de cotes : 1,05, 95 % IC 0,53–2,09, valeur P=0,88).Conclusion: Ce compte-rendu systématique suggère que les interventions pour la cessation du tabagisme mises en oeuvre en clinique préopératoire peuvent augmenter de 60 % au maximum les chances d’abstinence dans une période de suivi de trois à six mois. Toutefois, nous recommandons des études supplémentaires avec un suivi d’au moins un an pour évaluer la possibilité d’une période d’abstinence plus longue.

A Perioperative Smoking Cessation Intervention With Varenicline, Counseling, and Fax Referral to a Telephone Quitline Versus a Brief Intervention: A Randomized Controlled Trial

BACKGROUND: The effectiveness of perioperative interventions to quit smoking with varenicline has not been compared with brief interventions. Our objective was to determine the efficacy of a comprehensive smoking cessation program versus a brief intervention for smoking cessation. METHODS: In this prospective, multicenter study, 296 patients were randomized to participate in a smoking cessation program (one 10- to 15-minute counseling session, pharmacotherapy with varenicline, an educational pamphlet, and a fax referral to a telephone quitline); or brief advice and self-referral to a telephone quitline. The primary outcome was the 7-day point prevalence (PP) abstinence at 12 months after surgery. Secondary outcomes included abstinence at 1, 3, and 6 months. Multivariable generalized linear regression was used to identify independent variables related to abstinence. RESULTS: The 7-day PP abstinence for the smoking cessation program versus brief advice group was 42.4% vs 26.2% (relative risk [RR], 1.62; 95% confidence interval [CI], 1.16–2.25; P = .003) at 12 months. The 7-day PP abstinence at 1, 3, and 6 months was higher in the smoking cessation group versus the brief advice group: 45.7% vs 25.5% (RR, 1.79; 95% CI, 1.29–2.49; P < .001), 46.4% vs 26.9% (RR, 1.72; 95% CI, 1.25–2.37; P< .001), and 45.0% vs 26.2% (RR, 1.72; 95% CI, 1.24–2.38; P < .001), respectively. Participating in the smoking cessation group predicted abstinence at 12 months (RR, 1.58; 95% CI, 1.12–2.21; P = .0087). CONCLUSIONS: A perioperative smoking cessation program with counseling, pharmacotherapy with varenicline, an educational pamphlet, and a fax referral to a quitline increased abstinence from smoking 1, 3, 6, and 12 months after surgery versus a brief intervention.