Volume 4, Issue 8 S A M B A T A L K S - PAGE 3 January, 2005

FROM THE LITERATURE: - TOP


ANESTHESIA AND ANALGESIA - TOP

A Comparison of Selective Spinal Anesthesia with Hyperbaric Bupivacaine and General Anesthesia with Desflurane for Outpatient Knee Arthroscopy
Anna-Maija Korhonen, MD, Jukka V. Valanne, MD, PhD, Ritva M. Jokela, MD, PhD, Pirjo Ravaska, MD, and Kari T. Korttila, MD, PhD, FRCA
Anesth Analg 2004;99:1668-1673

In this randomized and controlled trial, 64 adult ambulatory knee arthroscopy patients received either selective spinal anesthesia (SSA) with 4 mg of hyperbaric bupivacaine or general anesthesia (GA) with desflurane. We conducted the study to determine whether SSA with small-dose bupivacaine provides equal fast-tracking possibilities, a shorter stay in the postanesthesia care unit, and earlier discharge home compared with GA with desflurane. Patients with a high risk for postoperative nausea and vomiting received prophylaxis in the GA group. No difference was seen in the fast-tracking possibilities or time in the postanesthesia care unit between the groups. Home readiness was achieved after 114 (31–174) and 129 (28–245) min (NS) in the SSA and GA groups, respectively. In the hospital, the pain scores were significantly (P < 0.001) lower in the SSA group compared with the GA group and the need for postoperative opioids was significantly (P = 0.008) larger after GA. The incidence of postoperative nausea and vomiting was 0% versus 19% in the SSA and GA groups (P = 0.024), respectively. We conclude that for outpatients undergoing knee arthroscopy, SSA with hyperbaric bupivacaine provides equal recovery times with less frequent side effects compared with GA with desflurane.
IMPLICATIONS: Patients undergoing ambulatory knee arthroscopy recover equally fast when using either selective spinal anesthesia with hyperbaric bupivacaine or general anesthesia with desflurane. Spinal anesthesia is associated with decreased pain scores and less postoperative nausea and vomiting in the hospital.

The Development and Validation of a Risk Score to Predict the Probability of Postoperative Vomiting in Pediatric Patients
L. H. J. Eberhart, MD, G. Geldner, MD, P. Kranke, MD, A. M. Morin, MD,
A. Schäuffelen, MD, H. Treiber, MD, and H. Wulf, MD
Anesth Analg 2004;99:1630-1637

Risk scores to predict the occurrence of postoperative vomiting (PV) or nausea and vomiting that were developed for adult patients do not fit for children, because several risk factors are difficult to assess or are usually not applicable in pediatric patients (e.g., smoking status). Thus, in the present study, we sought to develop and to validate a simple score to predict PV in children (POVOC-score). Development and validation of the new score was based on data from 4 independent institutions of 1257 children (aged 0–14 yr) undergoing various types of surgery under general anesthesia without antiemetic prophylaxis. Preoperatively, several potential risk factors were recorded. Postoperatively, the occurrence of PV was observed for up to 24 h. The dataset was randomly split into an evaluation set (n = 657) that was analyzed using a forward logistic regression technique and a validation set (n = 600) that was used to confirm the accuracy of prediction by means of the area under a receiver operating characteristic curve. Four independent risk factors for PV were identified in the final analysis: duration of surgery >30 min, age >3 yr, strabismus surgery, and a positive history of PV in the children or PV/postoperative nausea and vomiting in relatives (mother, father, or siblings). The incidence of PV was 9%, 10%, 30%, 55%, and 70% for 0, 1, 2, 3, and 4 risk factors observed. Using these incidences as cut-off values in the validation dataset, the area under the receiver operating characteristic curve was 0.72 (95% confidence interval: 0.68–0.77). Our data suggest that PV can be predicted with an acceptable accuracy using a four-item simplified risk score.
IMPLICATIONS: The incidence of postoperative vomiting might be predicted using duration of surgery >30 min, age >3 yr, strabismus surgery, and a positive history of postoperative vomiting/postoperative nausea and vomiting in the children or in their relatives. The predicted incidence of postoperative vomiting is 9%, 10%, 30%, 55%, and 70% for 0–4 of these risk factors present.

Emergence and Recovery Characteristics of Desflurane Versus Sevoflurane in Morbidly Obese Adult Surgical Patients: A Prospective, Randomized Study
Earl M. Strum, MD, Janos Szenohradszki, MD, PhD, Wayne A. Kaufman, MD, Gary J. Anthone, MD, MS, BA, Ingrid L. Manz, CRNA, MSN, and Philip D. Lumb, MB, BS, FCCM
Anesth Analg 2004;99:1848-1853

We compared postoperative recovery after desflurane (n = 25) versus sevoflurane (n = 25) anesthesia in morbidly obese adults (body mass index ≥ 35) who underwent gastrointestinal bypass surgery via an open laparotomy. After premedication with midazolam and metoclopramide 1 h before surgery, epidural catheter placement, induction of anesthesia with fentanyl and propofol, and tracheal intubation facilitated with succinylcholine, anesthesia was maintained with age-adjusted 1 minimum alveolar concentration (MAC) desflurane or sevoflurane. Fentanyl IV, morphine or local anesthetics epidurally, and vasoactive drugs as needed were used to maintain arterial blood pressure at ±20% of baseline value and to keep bispectral index of the electroencephalogram values between 40 to 60 U. Although patients were anesthetized with desflurane for a longer time (261 ± 50 min versus 234 ± 37 min, mean ± SD; P < 0.05, desflurane versus sevoflurane, respectively) and for more MAC-hours (4.2 ± 0.9 h versus 3.7 ± 0.8 h; P < 0.05), significantly earlier recovery of response to command and tracheal extubation occurred in patients given desflurane than in patients given sevoflurane. The modified Aldrete score was greater in desflurane-anesthetized patients on admission to the postanesthesia care unit (PACU) (P = 0.01) but not at discharge (P = 0.47). On admission to PACU, patients given desflurane had higher oxygen saturations (97.0% ± 2.4%) than patients given sevoflurane (94.8% ± 4.4%, P = 0.035). Overall, the incidence of postoperative nausea and vomiting and the use of antiemetics did not differ between the two anesthetic groups. We conclude that morbidly obese adult patients who underwent major abdominal surgery in a prospective, randomized study awoke significantly faster after desflurane than after sevoflurane anesthesia and the patients anesthetized with desflurane had higher oxygen saturation on entry to the PACU.
IMPLICATIONS: Morbidly obese adult patients who underwent major abdominal surgery in a prospective, randomized study awoke significantly faster after desflurane than after sevoflurane anesthesia, and the patients anesthetized with desflurane had higher oxygen saturations on entry to the postanesthesia care unit.

Anesthesiologists, General Surgeons, and Tobacco Interventions in the Perioperative Period
David O. Warner, MD, Michael G. Sarr, MD, Kenneth P. Offord, MS, and Lowell C. Dale, MD
Anesth Analg 2004;99:1766-1773

Surgery presents an opportunity for interventions in cigarette smokers that will facilitate abstinence from tobacco. However, little attention has been paid to the role of anesthesiologists and surgeons in addressing tobacco use. To determine the practices and attitudes of these physicians regarding this issue, we sent a postal mail survey to a national random sampling of anesthesiologists and general surgeons engaged in active practice within the United States (1000 in each group). Response rates were 33% and 31% for anesthesiologists and surgeons, respectively. More than 90% of both groups almost always ask their patients about tobacco use, and almost all respondents believed that surgical patients should maintain abstinence after surgery. Most believed that it was their responsibility to advise their patients to quit smoking, but only 30% of anesthesiologists and 58% of surgeons routinely do so. Nonetheless, approximately 70% of both groups would be willing to spend an extra 5 min before surgery to help their patients quit. Barriers to intervention included a lack of training regarding intervention techniques, a perceived lack of effective interventions, and insufficient time to intervene. Intervention opportunities are not exploited consistently in the surgical population; educational efforts directed at physicians in surgical specialties are indicated.
IMPLICATIONS: Although most surgeons and anesthesiologists believe that it is important for their patients to stop smoking at the time of surgery, most do not have the knowledge or experience to help them achieve this goal.

Risk Factors Assessment of the Difficult Airway: An Italian Survey of 1956 Patients
D. Cattano, MD, E. Panicucci, StD, A. Paolicchi, MD, F. Forfori, MD, F. Giunta, MD, and C. Hagberg, MD
Anesth Analg 2004;99:1774-1779

Over the last decade, there has been a heightened awareness and an increase in the amount of literature being published on recognition and prediction of the difficult airway. During the preoperative evaluation of the airway, a thorough history and physical specifically related to the airway should be performed. Various measurements of anatomic features and noninvasive clinical tests can be performed to enhance this assessment. In this study we correlated the Mallampati modified score and several other indexes with the laryngoscopic view to identify anatomical and clinical risk factors related to the difficult airway. We prospectively collected data on 1956 consecutive patients scheduled to receive general anesthesia requiring endotracheal intubation for elective surgery. The Mallampati classification versus the Cormack-Lehane (C-L) linear correlation index was 0.904. A Mallampati Class 3 correlated with a C-L Grade 2 (0.94), whereas a Mallampati Class 4 correlated with a C-L Grade 3 (0.85) and a C-L Grade 4 (0.80). Operator evaluation, performed by a simplified tracheal intubation difficulty scale, showed a linear correlation of 0.96 compared with the C-L groups. Although there is a correlation between oropharyngeal volume and difficult intubation, the Mallampati score by itself is insufficient for predicting difficult endotracheal intubation.
IMPLICATIONS: We collected data to correlate anatomical indexes and the difficult airway. The Mallampati score correlates with the laryngoscopic view (Cormack-Lehane score), but it is not useful in the prediction of difficult intubation as a single risk factor.

Pain on Injection: A Double-Blind Comparison of Propofol with Lidocaine Pretreatment Versus Propofol Formulated with Long- and Medium-Chain Triglycerides
E. Schaub, C. Kern, and R. Landau
Anesth Analg 2004;99:1699-1702

The incidence of pain on injection of propofol has been reported to be 70%. A new propofol formulation with a 10% emulsion of long- and medium-chain triglycerides (LCT/MCT) is associated with less pain on injection. Our goal was to compare the effect of propofol-LCT/MCT on the incidence of pain versus propofol with lidocaine 40 mg IV pretreatment injected as a Bier’s block. Two hundred healthy women scheduled for ambulatory gynecological procedures were allocated to 1 of 2 groups in a randomized double-blind fashion. Group LIDO received lidocaine 2% 2 mL injected with a tourniquet 1 min before propofol 1% 2 mg/kg IV; group LCT/MCT received NaCl 0.9% 2 mL with tourniquet 1 min before propofol-LCT/MCT 1% 2 mg/kg IV. Spontaneous verbal expressions of pain, movement of hand, frowning, and moaning during the injection were recorded. The incidence and severity of pain were assessed 30 min and 6 h after surgery. Recall of pain was considered with a visual analog scale (VAS) score >1, and pain was graded as VAS 0–10. More women reported spontaneous verbal expression of pain with propofol-LCT/MCT (47% versus 24%; P = 0.0014; relative risk 1.61 [95% confidence interval, 1.22–2.13]). Among women with a painful injection, there was no difference after surgery regarding the intensity of pain or recall of pain. In contrast to previous reports, we found that propofol-LCT/MCT resulted in a more frequent incidence of pain than propofol 1% with IV lidocaine pretreatment. This may be due to the diversity of pain definitions used in studies or to the lack of premedication in our study.
IMPLICATIONS: Propofol–long- and medium-chain triglycerides resulted in a more frequent incidence of pain upon injection than propofol with 40 mg IV of lidocaine pretreatment as a Bier’s block (47% versus 24%, respectively).

Intravenous Lidocaine Suppresses Fentanyl-Induced Coughing: A Double-Blind, Prospective, Randomized Placebo-Controlled Study
Chandra K. Pandey, MD, Mehdi Raza, MD, Rajeev Ranjan, MD, Archana Lakra, MD, Anil Agarwal, MD, Uttam Singh, PhD, R. B. Singh, MD, PDCC, and Prabhat K. Singh, MD
Anesth Analg 2004;99:1696-1698

IV lidocaine is effective in suppressing the cough reflex of tracheal intubation, extubation, bronchography, bronchoscopy, and laryngoscopy. We investigated this effect of lidocaine on fentanyl-induced cough in 502 patients of ASA physical status I and II scheduled for elective surgery. The patients were assigned to 2 equal groups to receive either lidocaine 1.5 mg/kg or placebo (0.9% saline) over 5 s 1 min before the administration of fentanyl 3 µg/kg in a randomized and double-blind fashion. Coughs were classified as coughing and graded as mild (1–2), moderate (3–4), or severe (5 or more). The results of the study suggest that IV lidocaine 1.5 mg/kg, when administered 1 min before fentanyl, is significantly effective in suppressing fentanyl-induced cough compared to placebo (0.9% saline) (218 versus 165 patients) (P < 0.002) but without affecting the severity of cough (P > 0.05).
IMPLICATIONS: Fentanyl administration elicits cough. IV lidocaine 1.5 mg/kg suppresses fentanyl-induced coughing.

The Effects of Chin Lift and Jaw Thrust While in the Lateral Position on Stridor Score in Anesthetized Children with Adenotonsillar Hypertrophy
Young-Chang P. Arai, MD, Kayo Fukunaga, MD, Seiji Hirota, MD, and Shoji Fujimoto, MD
Anesth Analg 2004;99:1638-1641

Obstruction of the upper airway is a major challenge for anesthesiologists administering general anesthesia in spontaneously breathing patients, especially in pediatric anesthesia with adenotonsillar hypertrophy. Lateral positioning is a simple treatment for obstructive sleep apnea and also decreases collapsibility of the pharynx in anesthetized adults with obstructive sleep apnea. In this study, we examined the effects of body position shifting and common airway maneuvers, such as chin lift and jaw thrust, on airway patency (stridor score) in anesthetized children scheduled for adenotonsillectomy. Thirty children aged 1–10 yr were anesthetized with sevoflurane. During spontaneous breathing of 5% sevoflurane, stridor score was recorded. After baseline recording, chin lift and jaw thrust were performed on patients in both the supine and the lateral decubitus positions. Chin lift and jaw thrust improved the stridor score. Furthermore, lateral positioning dramatically enhanced the effects of these airway maneuvers on airway patency. Jaw thrust combined with lateral positioning provided easy airway management for the anesthesiologists. We conclude that lateral positioning combined with airway maneuvers significantly improved airway patency compared with the airway maneuvers alone for patients in the supine position.
IMPLICATIONS: We investigated the effects of body position shifting and airway maneuvers on airway patency in anesthetized children scheduled for adenotonsillectomy. Lateral positioning not only improved airway patency but also enhanced the potential of airway maneuvers.

ANESTHESIOLOGY - TOP

Intranasal Nicotine for Postoperative Pain Treatment.
Flood, Pamela M.D. ; Daniel, Danette M.D.
Anesthesiology 2004;101(6):1417-1421

Background: Despite pharmacological treatment, 70-80% of patients report moderate to severe pain after surgery. Because nicotine has been reported to have analgesic properties in animal and human volunteer studies, the authors assessed the analgesic efficacy of a single 3 mg dose of nicotine nasal spray administered before emergence from general anesthesia.
Methods: The authors conducted a randomized, double blind, placebo controlled trial of 20 healthy women (mean age 45 (SD 8) yr) who were to undergo uterine surgery through a low transverse incision. After the conclusion of surgery but before emergence from general anesthesia, the anesthesiologist administered either nicotine nasal spray or a placebo. Numerical analog pain score and morphine utilization and hemodynamic values were measured for 24 h.
Results: The patients treated with nicotine reported lower pain scores during the first hour after surgery (peak numerical analog score, 7.6 (SD 1.4) versus 5.3 (SD 1.6); P < 0.001) and used half the amount of morphine as the control group (12 (SD 6) versus 6 (SD 5) mg; P < 0.05). Patients who received nicotine still reported less pain than those in the control group 24 h after surgery (1.5 (SD 0.5) versus 4.9 (SD 1.4); P < 0.01). Systolic blood pressure was lower in the group that received nicotine (105 (SD 3) versus 122 (SD 3); P < 0.001), but there was no difference in diastolic blood pressure or heart rate.
Conclusions : Treatment with a single dose of nicotine immediately before emergence from anesthesia was associated with significantly lower reported pain scores during the first day after surgery. The decreased pain was associated with a reduction in morphine utilization and the analgesic effect of nicotine was not associated with hypertension or tachycardia.

Effect of Different Cost Drivers on Cost per Anesthesia Minute in Different Anesthesia Subspecialties.
Schuster, Martin M.D., M.A. ; Standl, Thomas M.D.; Wagner, Joachim A. Dpl. Ing. ; Berger, Jurgen Ph.D. ; Reimann, Hajo M.D.; am Esch, Jochen Schulte M.D.
Anesthesiology 2004;101(6):1435-1443

Background: Little is known about differences in costs to provide anesthesia care for different surgical subspecialties and which factors influence the subspecialty-specific costs.
Methods: In this retrospective study, the authors determined main cost components (preoperative visit, intraoperative personnel costs, material and pharmaceutical costs, and others) for 10,843 consecutive anesthesia cases from a 6-month period in the 10 largest anesthesia subspecialties in their university hospital: ophthalmology; general surgery; obstetrics and gynecology; ear, nose, and throat surgery; oral and facial surgery; neurosurgery; orthopedics; cardiovascular surgery; traumatology; and urology. Using regression analysis, the effect of five presumed cost drivers (anesthesia duration, emergency status, American Society of Anesthesiologists physical status of III or higher, patient age younger 6 yr, and placement of invasive monitoring) on subspecialty-specific costs per anesthesia minute were analyzed.
Results: Both personnel costs for anesthesiologists and total costs calculated per anesthesia minute were inversely correlated with the duration of anesthesia (adjusted R2 = 0.75 and 0.69, respectively), i.e., they were higher for subspecialties with short cases and lower for subspecialties with longer cases. The multiple regression model showed that differences in anesthesia duration alone accounted for the majority of the cost differences, whereas the other presumed cost drivers added only little to explain subspecialty-specific cost differences.
Conclusions: Different anesthesia subspecialties show significant and financially important differences regarding their specific costs. Personnel costs and total costs are highest for subspecialties with the shortest cases. Other analyzed cost drivers had little effect on subspecialty-specific costs. In the light of these cost differences, a detailed cost analysis seems necessary before the profitability of an anesthesia subspecialty can be assessed.

Making Management Decisions on the Day of Surgery Based on Operating Room Efficiency and Patient Waiting Times.
Dexter, Franklin M.D., Ph.D. ; Epstein, Richard H. M.D. ; Traub, Rodney D. Ph.D. ; Xiao, Yan Ph.D.
Anesthesiology 2004;101(6):1444-1453

The authors review the scientific literature on operating room management operational decision making on the day of surgery. (1) Some decisions should rely on the expected (mean) duration of the scheduled case. Other decisions should use upper prediction bounds, lower prediction bounds, and other measures reflecting the uncertainty of case duration estimates. One single number cannot be used for good decision making, because durations are uncertain. (2) Operational decisions can be made on the day of surgery based on four ordered priorities. (3) Decisions to reduce overutilized operating room time rely on mean durations. Limited additional data are needed to make these decisions well, specifically, whether a patient is in each operating room and which cases are about to finish. (4) Decisions involving reducing patient (and surgeon) waiting times rely on quantifying uncertainties in case durations, which are affected highly by small sample sizes. Future studies should focus on using real-time display of data to reduce patient waiting.

Is Low-dose Haloperidol a Useful Antiemetic?: A Meta-analysis of Published and Unpublished Randomized Trials.
Buttner, Michael D.M.D. ; Walder, Bernhard M.D. ; von Elm, Erik M.D., M.Sc. ; Tramer, Martin R. M.D., D.Phil.
Anesthesiology 2004;101(6):1454-1463

The antiemetic efficacy of haloperidol was studied using data from 15 published (1962-1988) and 8 unpublished randomized trials; 1,397 adults received haloperidol, and 1,071 were controls. Settings were postoperative nausea or vomiting (1,994 patients), gastroenterology (261), chemotherapy (189), and radiation therapy (24). The relative benefit to prevent postoperative nausea or vomiting during 24 h with 0.5-4 mg haloperidol compared with placebo was 1.26-1.51 (number needed to treat, 3.2-5.1), without evidence of dose responsiveness; 0.25 mg was not antiemetic. With 1 mg haloperidol, the relative benefit to stop postoperative nausea or vomiting during 2-4 h compared with placebo was 1.53 (95% confidence interval, 1.17-2.00; number needed to treat, 6); with 2 mg, the relative benefit was 1.73 (1.11-2.68; number needed to treat, 4). In gastroenterology, 2 mg haloperidol was more effective than 1 mg. For chemotherapy and radiation therapy, no conclusions could be drawn. With 4 mg, one patient had extrapyramidal symptoms. With 5 mg, sedation was increased, with a relative risk of 2.09 (95% confidence interval, 1.73-2.52; number needed to treat, 4.4). There were no reports on cardiac toxicity. Postoperatively and in gastroenterology, haloperidol is antiemetic, with minimal toxicity. For other clinical settings and for children, valid data are unavailable.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Comparison of the analgesic efficacy of ketobemidone and morphine for management of postoperative pain in children: a randomized, controlled study
L. Jylli, S. Lundeberg, A. Langius-Eklöf and G. L. Olsson
Acta Anaesthesiologica Scandinavica 2004; 48; 1256-9

Background:  Ketobemidone has been used as an analgesic for postoperative pain in children, but to our knowledge the effect and occurrence of adverse effects of ketobemidone compared to morphine is not known. The aim was to determine if the analgesic potency and the occurrence of adverse effects of ketobemidone differ from morphine when administered to children, as measured by patient-controlled analgesia consumption (PCA) for postoperative pain.
Methods: Sixty healthy children, aged 6 to 16 years, scheduled for elective surgery were randomized to receive either ketobemidone (Ke) 1 mg ml^-1 or morphine (Mo) 1 mg ml^-1 for postoperative pain through PCA. Drug consumption (µg kg^-1 h^-1), the number of PCA doses, pain intensity, and adverse effects were recorded at regular intervals.
Results: Data on total drug consumption were based on 26 children in the Ke group and 28 in the Mo group. A non-statistically significant difference for total mean consumption of ketobemidone (18.6 µg kg^-1h^-1) and morphine (23.2 µg kg^-1h^-1) was obtained. The mean dose ratio (Mo/Ke) was 0.80 and the median was 0.94. Children's characteristics, loading dose, PCA doses, VAS scores, and adverse effects showed no significant differences between the groups.
Conclusion: The analgesic potency and adverse effects of ketobemidone are similar to morphine when used for postoperative pain management in children.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Fast-tracking (bypassing the PACU) does not reduce nursing workload after ambulatory surgery (ACCOMPANIED BY EDITORIAL SHOWN BELOW)
D. Song, F. Chung, M. Ronayne, B. Ward, S. Yogendran and C. Sibbick
British Journal of Anaesthesia 2004 93(6):768-774

Background. Postoperative day-case patients are usually allowed to recover from anaesthesia in a postanaesthesia care unit (PACU) before transfer back to the day surgical unit (DSU). Bypassing the PACU can decrease recovery time after day surgery. Cost savings may result from a reduced nursing workload associated with the decreased recovery time. This study was designed to evaluate the effects of bypassing the PACU on patient recovery time and nursing workload and costs.
Methods. Two hundred and seven consenting outpatients undergoing day surgery procedures were enrolled. Anaesthesia was induced and maintained with a standardized technique and the electroencephalographic bispectral index was monitored and maintained at 40–60 during anaesthetic maintenance. At the end of surgery, patients were randomly assigned to either a routine or fast-tracking (FT) group. Patients in the FT group were transferred from the operating room to the DSU (i.e. bypassing the PACU) if they achieved the FT criteria. All other patients were transferred to the PACU and then to the DSU. Nursing workload was evaluated using a patient care hour chart based on the type and frequency of nursing interventions in the PACU and DSU. A cost associated with the nursing workload was calculated.
Results. The overall time from end of anaesthesia to discharge home was significantly decreased in the fast-tracking group. However, overall patient care hours and costs were similar in the two recovery groups.
Conclusion. Bypassing the PACU after these short outpatient procedures significantly decreases recovery time without compromising patient satisfaction. However, the overall nursing workload and the associated cost were not significantly affected.

Fast-tracking in day surgery. Is your journey to the recovery room really necessary? (EDITORIAL)
J. Millar
Br. J. Anaesth. 2004 93: 756-758

No abstract available

CANADIAN JOURNAL OF ANESTHESIA - TOP

Non-narcotic adjuvants may improve the duration and quality of analgesia after knee arthroscopy: a brief review
Silviu Brill , MD and Miguel Plaza, MD
Canadian Journal of Anesthesia 51:975-978 (2004)

Purpose: We have evaluated randomized controlled trials of the administration of clonidine, neostigmine, steroids and non-steroidal anti-inflammatory agents intra-articularly as adjuvants to local anesthetic drugs after arthroscopic knee surgery.
Methods: Twenty-five studies were reviewed using specific inclusion criteria and, accordingly, included in the final assessment. These studies were assessed for pain scores, total analgesic consumption and time to first analgesic request to determine a possible peripheral effect, as opposed to possible systemic effects of an adjuvant administered intra-articularly.
Results: A total of 16 studies, met the inclusion criteria. These studies considered the use of non-steroidal anti-inflammatory drugs, steroids, neostigmine and clonidine. Ketorolac was used in four studies (for a total of 230 patients) and showed a significant improvement in analgesia. Clonidine has shown considerable analgesic effect, with minimal adverse effects. All seven studies assessed in this review were supportive (a total of 424 patients). Furthermore the addition of clonidine to bupivacaine or morphine was found to increase duration and quality of postoperative analgesia.
Conclusions: Current evidence indicates that a variety of agents have synergistic effects when added to local anesthetics and there is evidence that the improvement in analgesia is, at least partially, through a local rather than a central mechanism. The results of this review suggest that clonidine and ketorolac, when administered intra-articulary after arthroscopic knee surgery, may reduce postoperative pain.

The Microcuff^TM tube allows a longer time interval until unsafe cuff pressures are reached in children
Alexander Dullenkopf, MD, Andreas Gerber, MD and Markus Weiss, MD
Canadian Journal of Anesthesia 51:997-1001 (2004)

Purpose: To compare cuff pressures during nitrous oxide exposure in the new Microcuff pediatric tracheal tube (MPT) with ultrathin high volume - low pressure polyurethane cuff to a tube with a standard polyvinyl chloride (PVC) cuff.
Methods: With approval of the local Ethics Committee, 30 pediatric patients requiring tracheal intubation [tube size internal diameter (ID) 4.0 mm, or ID 7.0 mm) were included. Patients were randomly divided in three groups: A) MPT, baseline cuff pressure 20 cm H₂O; B) PVC, baseline cuff pressure 20 cm H₂O; and C) MPT, baseline cuff pressure set to sealing pressure. Anesthesia technique and ventilator settings were standardized. The time required for cuff pressure to increase to 25 cm H₂O was recorded and pressure reduced to baseline. The number of gas removals required during the first hour was noted. Data are median (range). Groups were compared by the Kruskal-Wallis test (P < 0.05).
Results: There were no differences between groups in patient characteristics. PVC and MPT cuffs inflated to a baseline pressure of 20 cm H₂O were similar regarding the time to first removal of gas [A: nine minutes (4–24), B: eight minutes (4–46)], and number of removals required [A: four (2–6), B: three (1–5)]. In MPT with baseline pressure set to sealing pressure [10 cm H₂O (8–14)] time to first gas removal and number of removals were significantly less (P < 0.05).
Conclusion: When baseline inflation pressure was set at 20 cm H₂O, cuff pressure increased similarly in MPT and PVC tubes. When inflated just to sealing pressure, the MPT allowed a longer time interval until the upper limit of 25 cm H₂O was reached.

Use of the Laryngeal Tube^TM in two unexpected difficult airway situations: lingual tonsillar hyperplasia and morbid obesity
Adrian A. Matioc, MD and John Olson, MD
Canadian Journal of Anesthesia 51:1018-1021 (2004)

Purpose: The 2003 ASA Practice Guidelines for Management of the Difficult Airway suggest the early use of the Laryngeal Mask Airway and Combitube as rescue airway devices in the cannot ventilate–cannot intubate situation, switching the focus from laryngoscopy and intubation to ventilation and oxygenation. The Practice Guidelines are not intended as standards but as recommendations. Multiple new alternative airway devices were described in the last ten years. The Laryngeal Tube^TM (LT) is a new Food and Drug Administration approved supraglottic airway device. The device is in use in Europe since 1999 and in the United States since 2002.
Clinical features: We report two cases in which the LT was used to solve two unexpected difficult airway situations. The first case ("cannot intubate-inadequate mask ventilation") involved an undiagnosed lingual tonsillar hyperplasia and the LT provided the means to ventilate and administer the anesthetic. In the second case ("cannot ventilate-cannot intubate") we report the successful use of the LT to rescue the airway in a morbidly obese patient. In both cases an endotracheal tube was ultimately inserted using an awake fibreoptic technique with the patient in the sitting position.
Conclusions: In these clinical situations of unexpected difficult airway with significant periglottic obstruction the LT provided adequate ventilation after the first insertion. The LT may complement the laryngeal mask airway in difficult airway management. Further research is needed to define the role of the LT in the management of difficult airways.

Emergency gum elastic bougie-assisted tracheal intubation in four patients with upper airway distortion
Xavier Combes, MD, Marc Dumerat, MD and Gilles Dhonneur, MD
Canadian Journal of Anesthesia 51:1022-1024 (2004)

Purpose: The gum elastic bougie (GEB) has been in use for a long time and allows tracheal intubation in most cases of difficult direct laryngoscopy. Use of the GEB when anatomical landmarks of the upper airway are not recognizable has not been reported. We describe our experience of airway management with the GEB in cases of severe upper airway distortion.
Clinical features: Four patients with severe respiratory distress caused by upper airway distortion secondary to various non-malignant causes were managed with the GEB. For these four patients, a rapid sequence induction of anesthesia was performed with a surgeon present during the procedure. The GEB was used as the initial intubating technique in all cases and allowed a rapid and successful tracheal intubation in spite of non-recognizable anatomical structures. The distal hold-up feeling after GEB insertion confirmed, in all cases, the correct intratracheal position of the GEB.
Conclusion: The GEB can be a valuable tool in cases of difficult airway management caused by upper airway distortion. The lack of visualization of normal pharyngeal structures did not prevent the successful insertion of the GEB in the trachea in the four patients reported.

PUB MED - TOP

Regional anaesthesia in the elderly: a clinical guide.
Tsui BC, Wagner A, Finucane B.
Drugs Aging. 2004;21(14):895-910

The number of elderly patients presenting for anaesthesia and surgery has increased exponentially in recent years. Regional anaesthesia is frequently used in elderly patients undergoing surgery. Although the type of anaesthesia (general versus regional anaesthesia) has no substantial effect on perioperative morbidity and mortality in any age group; it intuitively makes sense that elderly patients would benefit from regional anaesthesia because they remain minimally sedated throughout the procedures and awaken with excellent postoperative pain control. However, a multitude of factors influence the outcome, such as the type, duration and invasiveness of the operation, co-existing medical and mental status of the patient and the skill and expertise of the anaesthesiologist and surgeon. These factors make it difficult to decide if and when one technique is equivocally better than another. Thus, it is more important to optimise the overall management of the patient during the perioperative period and, in most cases, it is the quality of the anaesthetic administered rather than the type of anaesthetic which is most important. Sedatives used for regional anaesthesia in the elderly should be short acting, easy to administer, have a low adverse effect profile and high safety margin. Midazolam, lorazepam, ketamine, propofol and low-dose opioids have been successfully used for sedation in the elderly. Aging affects the pharmacokinetics and pharmacodynamics of local anaesthetics, composition and characteristics of tissues and organs within the body, and physiological functions of the body. Changes in the systematic absorption, distribution and clearance of local anaesthetics lead to an increased sensitivity, decreased dose requirement and a change in the onset and duration of action in the elderly. Decreases in neural population, neural conduction velocity and inter-Schwann cell distance can lead to an increased sensitivity to local anaesthetics in the elderly. The addition of an opioid and epinephrine (adrenaline) has been shown to be useful in central neuraxial blockade. Epinephrine also can prolong the duration of peripheral nerve blocks. However, caution must be exercised as epinephrine has the potential for causing ischaemic neurotoxicity in peripheral nerves. Regional anaesthesia appears to be safe and beneficial in elderly patients; however, every anaesthetic administered must be assessed on a case-by-case basis and particular consideration should be given to the health status of the patient, the operation being performed and the expertise of the anaesthesiologist.

EMLA cream is an effective topical anesthetic for bronchoscopy
B Sohmer, GL Bryson, S Bencze, MM Scharf
Canadian Respiratory Journal November/December 2004, Volume 11, Number 8 : 587-588

BACKGROUND: EMLA cream (AstraZeneca Inc, Canada) (1:1 eutectic mixture of lidocaine 2.5% and prilocaine 2.5%) has traditionally been used for topical anesthesia of the skin. Recent reports of EMLA’s use for anesthesia of the oral mucosa suggest an application in topical anesthesia for bronchoscopy.
OBJECTIVES: To evaluate the amount of local anesthetic administered during bronchoscopy; to assess the time required to obtain topical anesthesia; to assess the quality of the topical anesthesia as described by bronchoscopists; and to document any complications.
METHODS: Fifty-seven unpremedicated patients had 4 mL of EMLA cream applied to the posterior third of their tongues on arrival in the bronchoscopy suite. Liquid lidocaine was applied through the bronchoscope for laryngeal anesthesia.
RESULTS: The mean time from the application of EMLA cream to insertion of the bronchoscope was 5.10±0.48 min. Fifty-six patients (98.2%) required no supplemental anesthesia. Bronchoscopy conditions were described as ‘excellent’ in 55 cases (96.5%) and ‘good’ in the remaining two cases (3.5%).
CONCLUSIONS: EMLA is an effective alternative for oropharyngeal topical anesthesia that is well-tolerated by patients.

Use of alpha-agonists for management of anaphylaxis occurring under anaesthesia: case studies and review.
Heytman M, Rainbird A.
Anaesthesia. 2004 Dec;59(12):1210-5

Anaphylaxis is an uncommon but serious complication of anaesthesia. Most current guidelines for the management of anaphylaxis list only epinephrine as a vasopressor to use in the event of cardiovascular collapse. We present two cases of anaphylaxis under anaesthesia where return of spontaneous circulation was refractory to epinephrine, but occurred following the administration of the alpha-agonist metaraminol. Potential advantages and disadvantages of using epinephrine in this setting, the role of alpha-agonists and some potential mechanisms accounting for their role in successful management are reviewed.

Comparison of Propofol-Lipuro with propofol mixed with lidocaine 10 mg on propofol injection pain.
Kam E, Abdul-Latif MS, McCluskey A.
Anaesthesia. 2004 Dec;59(12):1167-1169

A common drawback of propofol is pain on injection and lidocaine is commonly mixed with propofol to reduce its incidence and severity. We conducted a randomised, prospective, double-blind study to compare injection pain following the administration of two different formulations of propofol in 200 unpremedicated ASA I-III adult patients scheduled for elective surgery under general anaesthesia. Patients were allocated randomly into two groups to receive either Propofol^R-Lipuro without added lidocaine or Diprivan^R mixed with lidocaine 10 mg. Five ml of the study solution was injected at a constant rate over 15 s and patients graded any associated pain or discomfort using a four-point verbal rating scale. The incidence of propofol injection pain was virtually identical in both study groups with 37/98 (38%) patients experiencing pain or discomfort following Propofol^R-Lipuro compared with 35/98 (36%) after Diprivan^R (p = 0.88). We observed no significant difference in pain scores between the groups (p = 0.67). Moderate or severe injection pain was experienced by 12/98 (12%) patients given Propofol^R-Lipuro compared with 8/98 (8%) given Diprivan^R (p = 0.48).

The effects of alfentanil or remifentanil pretreatment on propofol injection pain.
Iyilikci L, Balkan BK, Gokel E, Gunerli A, Ellidokuz H.
J Clin Anesth. 2004 Nov;16(7):499-502

STUDY OBJECTIVE: To compare the efficacy of alfentanil, remifentanil, and saline in minimizing the propofol injection pain.
DESIGN: Randomized, double-blind study.
SETTING: University hospital.
PATIENTS: 175 ASA physical status I and II, adult female patients undergoing minor gynecological procedures with general anesthesia.
INTERVENTIONS: Unpremedicated patients were randomly allocated to one of four groups. Patients received 2 mL (1 mg) of alfentanil (n = 43), 2 mL of remifentanil 0.01 mg (n = 43), 2 mL of remifentanil 0.02 mg (n = 45), or 2 mL of saline (n = 44) 30 seconds prior to administration 5 mL of propofol 1%.
MEASUREMENTS: Patients were asked whether they had pain due to propofol injection. Their pain scores were evaluated with a Visual Analogue Scale. In the Postanesthesia Care Unit, frequency of postoperative nausea, vomiting, hypotension, and flushing were all determined.
MAIN RESULT: The remifentanil and alfentanil groups showed significantly less frequency and severity of pain than the saline group (p < 0.05). When the alfentanil group was compared with the remifentanil groups, significant differences in pain relief associated with injection of propofol (p < 0.001) were noted. Remifentanil 0.02 mg relieved pain associated with injection of propofol more effectively than remifentanil 0.01 mg (p < 0.001).
CONCLUSIONS: The remifentanil and alfentanil groups showed significantly less frequency and severity of pain than did the saline group. Remifentanil was effective in preventing propofol injection pain, and should be used at a dose of at least 0.02 mg for this purpose. Remifentanil may be an alternative drug for prevention of propofol injection pain.

Suxamethonium administration prolongs the duration of action of subsequent rocuronium.
Robertson EN, Driessen JJ, Booij LH.
Eur J Anaesthesiol. 2004 Sep;21(9):734-7

BACKGROUND AND AIM: Rocuronium may be given to patients for intubation and also after they have received suxamethonium for intubation. The neuromuscular profile of rocuronium given after recovery from suxamethonium may not be identical to that when rocuronium has been given alone. The neuromuscular effects of suxamethonium and rocuronium, and their effects on intraocular pressure (IOP), heart rate (HR) and arterial pressure were also recorded.
METHODS: Thirty patients were randomly allocated to receive either 0.6mg kg^-1 rocuronium (n = 15) or 1 mg kg^-1 suxamethonium (n = 15) for intubation. Anaesthesia was first induced using propofol 2.5 mg kg^-1 and fentanyl 2 microg kg^-1 and maintained with propofol 6-12 mg kg^-1 h^-1. The response of the thumb to supramaximal train-of-four (TOF) ulnar nerve stimulation at the wrist was measured using a mechanomyograph. In the suxamethonium group, when the first twitch of the TOF had recovered to 90%, rocuronium 0.6 mg kg^-1 was administered. Before administration of relaxant, baseline readings of HR, arterial pressure and IOP were measured until stable, then the appropriate relaxant administered. Thereafter, all readings were repeated at 30, 90, 150, 210 and 270 s. Tracheal intubation was performed 300 s after the intubating dose and all recordings repeated 30 s later. Mechanomyographic monitoring was continued until 70% TOF recovery.
RESULTS: Suxamethonium had a more rapid onset than rocuronium (49s vs. 74s, P < 0.0001). The onset time of rocuronium after suxamethonium was significantly reduced (56 s) and the time to recover to a TOF of 70% following rocuronium was increased by previous suxamethonium administration (47 vs. 58 min, P < 0.05). Suxamethonium caused a marked rise in IOP (>30%) and HR (>10%) while rocuronium had little effect on either.
CONCLUSION: Previous suxamethonium administration decreases the onset time and increases the duration of action of rocuronium. Unlike suxamethonium, rocuronium has few cardiovascular effects and causes little change in IOP.

Prevention of nausea and vomiting after middle ear surgery: combination of ondansetron and dexamethasone is the right choice.
Panda NB, Bharadwaj N, Kapoor P, Chari P, Panda NK.
J Otolaryngol. 2004 Apr;33(2):88-92

OBJECTIVE: To determine the efficacy of a combination of ondansetron and dexamethasone in preventing postoperative nausea and vomiting after middle ear surgery compared with ondansetron alone.
DESIGN: A prospective, randomized, double-blind study with prestudy power analysis performed to determine the sample size.
SETTING: A tertiary teaching hospital.
METHOD: One hundred patients undergoing tympanomastoidectomy under general anesthesia were included in the study. Patients in group O (n = 50) received ondansetron 4 mg and those in group OD (n = 50) received ondansetron 4 mg with dexamethasone 8 mg 30 minutes before the end of surgery. All patients were monitored for nausea score, episodes of vomiting, and rescue antiemetic requirement in 48 hours after surgery. The total number of complete responders was calculated. Patients' satisfaction at the end of the study period was also estimated.
RESULTS: In patients receiving combination antiemetic (group OD), the nausea score was significantly less (p < .01) at 6, 12, and 24 hours after surgery. The total incidence of vomiting was reduced from 28% in group O to 6% in group OD. Rescue antiemetic requirement was significantly less (p < .01) in group OD. The number of complete responders significantly improved in the combination group (92% vs 62%). The patients were also found to be more satisfied in this group.
CONCLUSION: Prophylaxis with a combination of ondansetron and dexamethasone decreased the incidence of nausea and vomiting after middle ear surgery to a minimum and improved patients' satisfaction significantly in the postoperative period.

Perioperative Management and Monitoring of a Super-obese Patient.
Pellis T, Leykin Y, Albano G, Zannier G, Di Capua G, Marzano B, Gullo A.
Obes Surg. 2004 Oct;14(10):1423-7

Anesthetic management of super-obese patients is inferred from evidence which has been based on obese or morbidly obese patients. We present the perioperative management and monitoring of a 44-year-old 232-kg patient (BMI 70) admitted for laparoscopic gastric bypass surgery. Awake fiberoptic endotracheal intubation preceded induction with propofol and rocuronium. Anesthesia was maintained with desflurane and remifentanil. Desflurane was titrated on BIS values, whereas remifentanil was based on hemodynamic monitoring (invasive arterial pressure and HemoSonic^TM). Rocuronium was administered based on ideal body weight and recovery of twitch tension. Safe and rapid extubation in the operating theatre was made possible by the use of short-acting agents coupled with continuous intraoperative monitoring. Recovery in the post-anesthesia care unit was uneventful, pain was managed with meperidine, and after 5 hours the patient was discharged to the surgical ward. Oxygen therapy and SpO₂ monitoring were continued overnight. No desaturation episodes were recorded. Pain was managed with I.V. drip of ketorolac and tramadole.

Lower adverse event and mortality rates in physician offices compared with ambulatory surgery centers: a reappraisal of Florida adverse event data.
Venkat AP, Coldiron B, Balkrishnan R, Camacho F, Hancox JG, Fleischer AB Jr, Feldman SR.
Dermatol Surg. 2004 Dec;30(12 Pt 1):1444-53

Background. A recent study using Florida adverse event data found an increased risk of mortality in offices as opposed to ambulatory surgical centers. A major limitation of Florida adverse event data is the lack of uniform collection of the number of cases performed.
Objective. The objective was to reassess the risk of mortality from physician office and ambulatory surgical center procedures using improved estimates of the numbers of cases performed in these settings. Methods. Adverse incident reports from March 2000 to March 2003 were obtained from the Florida Board of Medicine. We used data from the National Ambulatory Medical Care Survey and from the Medicare Current Beneficiary Survey to estimate the number of office procedures in Florida for both the general and the Medicare populations. The number of procedures performed and the number of deaths in ambulatory surgical centers was obtained from the Florida Agency of Healthcare Administration for the years 2000 through 2002. These data were used to calculate adverse event and mortality rates.
Results. For physician offices, the adverse event rates and mortality rates calculated per 100,000 procedures from National Ambulatory Medical Care Survey data were 2.1 and 0.41, respectively, and 0.24 and 0.10 using Medicare Current Beneficiary Survey data. For ambulatory surgical centers, the mean adverse event rate was 4.4 and the mean mortality rate was 0.90.
Discussion. Florida's adverse event data do not show higher adverse event rates in physician offices compared with ambulatory surgical centers. Incident reporting and public availability of incidents are important, as is standardization of reporting rules for both adverse events and number of procedures performed in different settings.

Outpatient laparoscopic hysterectomy in a rural ambulatory surgery center.
Morrison JE Jr, Jacobs VR.
J Am Assoc Gynecol Laparosc. 2004 Aug;11(3):359-64

STUDY OBJECTIVE: To evaluate a cost-optimized operative technique for outpatient laparoscopic hysterectomy in a rural ambulatory surgery center focusing on shortening hospital stay and substitution of expensive disposable laparoscopic instruments with standard surgical techniques.
DESIGN: Prospective feasibility and observational study (Canadian Task Force classification II-3).
SETTING: Rural ambulatory surgery center in Lamar, Alabama.
PATIENTS: Fifty-two women.
INTERVENTION: Outpatient laparoscopic hysterectomy.
MEASUREMENTS AND MAIN RESULTS: From September 2001 through September 2003, 52 consecutive procedures with a modified classical intrafascial supracervical hysterectomy (CISH) technique without disposable instruments have been performed on patients with an average age of 42.2 years (range 25-62 years) and a follow-up of 12.5 months (range 0.4-23.6 months). Mean postoperative length of stay was 6 hours, 79 minutes (range 3 hours, 10 minutes-17 hours, 30 minutes), and overall length of stay was 11 hours, 37 minutes (range 6 hours, 45 minutes-22 hours, 50 minutes). Five patients (9.6%) stayed overnight, three for medical and two for social reasons. With an average of 2 hours, 14 minutes, the operating room time was about 1 hour longer than with disposable instruments. Health insurance reimbursement for the ambulatory surgery center was on average $1814.11. No complications occurred, and no readmission to the hospital was necessary.
CONCLUSION: Outpatient laparoscopic hysterectomy is feasible and safe and can be performed cost effectively in ambulatory surgery centers, even in rural areas. Development of a protocol with patient selection, preoperative and postoperative patient teaching, caring family environment, and round-the-clock medical telephone backup is necessary.

Pain relief and outpatient hysteroscopy: a literature review.
Readman E, Maher PJ.
J Am Assoc Gynecol Laparosc. 2004 Aug;11(3):315-9

Our early experience in setting up an ambulatory hysteroscopy service provoked a review of the literature, due to an unacceptably high failure rate. A literature review has been undertaken to establish the accepted success rates and reasons for failure, and to assess evidence for various analgesic protocols through randomized controlled trials. The data suggest the procedure is acceptable to most patients, with a completion success rate over 90%, and the use of analgesia may enhance the success rate. Analgesic protocols studied were nonsteroidal anti-inflammatory drugs, intracervical block, paracervical block, transcervical block, and topical analgesia. Failures are due predominantly to pain, stenosis, and poor view.

The safety of office-based surgery: review of recent literature from several disciplines.
Hancox JG, Venkat AP, Coldiron B, Feldman SR, Williford PM.
Arch Dermatol. 2004 Nov;140(11):1379-82

OBJECTIVE: To review recent literature pertaining to adverse outcomes and mortality associated with office-based surgery.
STUDY SELECTION: Representative articles from the general and plastic surgery, medical, health regulatory, and dermatology literature.
DATA EXTRACTION: Information regarding which surgical treatments should be performed, which specialties should perform them, what level of anesthesia is appropriate, and who should administer it was assessed, with particular attention to issues of patient safety.
CONCLUSIONS: Office-based surgery is safe and cost-effective. We caution against attempts to prohibit or severely restrict this important aspect of medical care.

Why are there differences in the perceived safety of office-based surgery?
Hancox JG, Venkat AP, Hill A, Graham GF, Williford PM, Coldiron B, Feldman SR, Balkrishnan R.
Dermatol Surg. 2004 Nov;30(11):1377-9

BACKGROUND: Office-based surgery has become an important method of health-care delivery, but there is controversy about its safety and which practitioners should perform it. Several states have already or are preparing to enact legislation regulating office-based surgery.
OBJECTIVE: The objective was to discuss recent literature pertaining to the safety of office surgery and to discuss reasons why there are perceived differences in its safety.
METHODS: The pertinent literature is reviewed.
RESULTS: The majority of studies suggest that office surgery is safe. A recent study that found to the contrary may have methodologic flaws.
CONCLUSION: The medical and legislative community should seek to scientifically examine office surgery. Overregulation or loss of office surgery would have a tremendous impact on the management of skin cancers and the delivery of quality cosmetic and laser surgery.

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