Volume 4, Issue 9 S A M B A T A L K S - PAGE 3 February, 2005

FROM THE LITERATURE: - TOP


ANESTHESIA AND ANALGESIA - TOP

A Comparison of Patients’ and Health Care Professionals’ Preferences for Symptoms During Immediate Postoperative Recovery and the Management of Postoperative Nausea and Vomiting
Anna Lee, MPH, PhD, Tony Gin, MBChB, MD, FANZCA, FRCA, Angel S. C. Lau, BSN(Hons), Dip Epid Biostat, RN, and Floria F. Ng, BASc, RN
Anesth Analg 2005;100:87-93

In this study we sought to examine the differences in patients’ and health care professionals’ preferences for symptoms during immediate postoperative recovery and the management of postoperative nausea and vomiting (PONV). The key differences between symptoms during immediate postoperative recovery (PONV, sedation, and pain) and management of PONV (prophylaxis, efficacy of antiemetic, and extra cost) were used to develop 14 scenarios in a questionnaire. Fifty-two health care professionals (anesthesiologists and recovery room nurses) and 200 women undergoing elective gynecological surgery were recruited (overall response rate, 97%). From patients’ and health care professionals’ perspectives, conjoint analysis showed that the most important attribute for immediate postoperative recovery was a reduction in the risk of PONV. Health care professionals placed more importance on postoperative sedation than patients did. They were more concerned about the cost of the antiemetic to the patient than the patients were themselves. There was no preference for a policy of effective treatment versus routine prophylaxis. This study shows that there were small differences in the importance of pain, sedation, efficacy of the antiemetic, and extra cost of treatment between patients and health care professionals.
IMPLICATIONS: Patients’ and health care professionals’ preferences for recovery and antiemetic treatment were compared. There were small differences between groups in the importance of pain, sedation, efficacy of the antiemetic, and extra cost. There was no preference in either group for a policy of effective treatment versus routine prophylaxis.

Peribulbar Anesthesia: A Percutaneous Single Injection Technique with a Small Volume of Anesthetic
Leonardo Rizzo, MD, Maurizio Marini, MD, Chiara Rosati, MD, Italo Calamai, MD, Michela Nesi, MD, Roberto Salvini, MPH, Cinzia Mazzini, MD, Fiamma Campana, MD, and Enzo Brizzi, MD
Anesth Analg 2005;100:94-96

We evaluated the efficacy and safety of a single injection technique with a small volume of anesthetic for ocular peribulbar anesthesia. We included 857 patients undergoing various ophthalmic procedures. Anesthesia consisted of a medial percutaneous injection of 5–6.5 mL of 2% lidocaine. At 2 min 85.6% of the patients had a motor block of at least 50% and at 5 min 78.6% had a motor block >80%. After 5 min 100% of the patients had adequate surgical anesthesia. There were no serious block-related complications. The described technique is a simple and satisfactory alternative to the classical techniques
IMPLICATIONS: Potential complications associated with regional anesthesia in ophthalmic surgery led to the proposal of a single, rather than multiple, injection technique of regional anesthesia. The described percutaneous peribulbar medial single injection technique with very small volume of anesthetic is a simple and satisfactory alternative to the classical techniques.

Anesthesia for the Child with an Upper Respiratory Tract Infection: Still a Dilemma? (REVIEW)
Alan R. Tait, PhD, and Shobha Malviya, MD
Anesth Analg 2005;100:59-65

One of the most controversial issues in pediatric anesthesia has revolved around the decision to proceed with anesthesia and surgery for the child who presents with an upper respiratory tract infection (URI). In the past, doctrine dictated that children with URIs have their surgery postponed until the child was symptom free. This practice was based on the empirically supported premise that anesthesia increased the risk of serious complications and complicated the child’s postoperative course. Although recent clinical data confirm that some children with URIs are at increased risk of perioperative complications, these complications can, for the most part, be anticipated, recognized, and treated. Although the child with a URI still presents a challenge, anesthesiologists are now in a better position to make informed decisions regarding the assessment and management of these children, such that blanket cancellation has now become a thing of the past.

Train-of-four stimulation for adductor pollicis neuromuscular monitoring can be applied at the wrist or over the hand.
Nepveu ME, Donati F, Fortier LP.
Anesth Analg. 2005;100:149-54.

Adductor pollicis stimulation over the ulnar nerve at the wrist is the standard method of monitoring neuromuscular function. Stimulation over a muscle is believed to cause direct muscle contraction, but evidence for this is lacking. In this study we sought to determine whether direct muscle stimulation occurred during stimulation of the adductor pollicis in the hand and whether the responses were comparable to those observed with stimulation at the wrist. In 20 patients anesthetized with sevoflurane, 1 pair of stimulating electrodes was positioned over the ulnar nerve at the wrist. A second pair was placed between the first and second metacarpals on the palmar and dorsal aspects of the hand. The acceleromyographic response was monitored. Rocuronium 0.6 mg/kg was administered. Train-of-four (TOF) stimulations were applied at the wrist site until maximal blockade. Then, stimulation was applied to the hand site. During recovery, both sites were monitored alternately. After injection of rocuronium, 17 of 20 patients showed no twitch response at either site. One patient had a response at both stimulation sites, and two patients had responses only at the wrist site. With a Bland and Altman analysis, TOF ratios during recovery at the hand showed a bias of 0.5% and limits of agreement of ±11.8% as compared with the wrist. Stimulation in the hand causes no direct muscle stimulation because the response is no more than that produced by stimulation at the wrist. Both sites yield comparable TOF ratios.
IMPLICATIONS: Adductor pollicis monitoring is usually performed by applying electrodes over the ulnar nerve at the wrist. An alternative is to stimulate over the muscle itself in the hand. Train-of-four ratios at the hand and the wrist are comparable, and direct muscle stimulation does not occur.

ANESTHESIOLOGY - TOP

Succinylcholine Dosage and Apnea-induced Hemoglobin Desaturation in Patients.
Naguib, Mohamed M.B., B.Ch., M.Sc., F.F.A.R.C.S.I., M.D. ; Samarkandi, Abdulhamid H. M.B., B.S., F.F.A.R.C.S.I. ; Abdullah, Khaled M.B., B.Ch., M.Sc., A.B., M.D. ; Riad, Waleed M.B., B.Ch., M.Sc., A.B., M.D. ; Alharby, Saleh W. M.B., B.S., F.R.C.S. (Glas.)
Anesthesiology 2005;102(1):35-40

Background: The authors examined the notion that a reduction in succinylcholine dose from 1 mg/kg to ~ 0.6 mg/kg would allow a faster recovery of spontaneous ventilation and reduction in the incidence of hemoglobin desaturation during the period of apnea in simulated complete upper airway obstruction situations.
Methods: This prospective, randomized, double-blind study involved 60 patients. After preoxygenation to an end-tidal oxygen concentration >90%, patients were anesthetized with 2 [mc]g/kg fentanyl and 2 mg/kg propofol. After loss of consciousness, patients were randomly allocated to receive 0.56 or 1.0 mg/kg succinylcholine or saline (control group). Oxygen saturation was monitored continuously at the index finger. When the patient became apneic, the face mask was removed and the patient's airway was left unsupported. If the oxygen saturation decreased to 90%, the face mask was reapplied, and ventilation was assisted until the patient was awake. Time from injection of the study drug to the first visible spontaneous diaphragmatic movements was noted.
Results: Oxygen saturation decreased <90% in 45%, 65%, and 85% of patients in the control, 0.56 mg/kg, and 1.0 mg/kg succinylcholine groups, respectively (P = 0.03). Corresponding times (mean +/- SD) to spontaneous of diaphragmatic movements were 2.7 +/- 1.2, 4.8 +/- 2.5, and 4.7 +/- 1.3 min, respectively. These times were longer (P < 0.001) after either dose of succinylcholine compared with controls.
Conclusions: Reduction in succinylcholine dose from 1.0 mg/kg to 0.56 mg/kg decreased the incidence of hemoglobin saturation <90% from 85% to 65% but did not shorten the time to spontaneous diaphragmatic movements. A significant fraction of patients would be at risk if there were failure to intubate and ventilate whether succinylcholine is administered or not and regardless of the dose of succinylcholine administered.

Influence of Obesity on Surgical Regional Anesthesia in the Ambulatory Setting: An Analysis of 9,038 Blocks.
Nielsen, Karen C. M.D. ; Guller, Ulrich M.D., M.H.S. ; Steele, Susan M. M.D. ; Klein, Stephen M. M.D. ; Greengrass, Roy A. M.D., F.R.C.P. ; Pietrobon, Ricardo M.D., Ph.D.
Anesthesiology 2005;102(1):181-187

Background: Regional anesthesia is increasing in popularity for ambulatory surgical procedures. Concomitantly, the prevalence of obesity in the United States population is increasing. The objective of the present investigation was to assess the impact of body mass index (BMI) on patient outcomes after ambulatory regional anesthesia.
Methods: This study was based on prospectively collected data including 9,038 blocks performed on 6,920 patients in a single ambulatory surgery center. Patients were categorized into three groups according to their BMI (<25 kg/m², 25-29 kg/m², >=30 kg/m²). Block efficacy, rate of acute complications, postoperative pain (at rest and with movement), postoperative nausea and vomiting, rate of unscheduled hospital admissions, and overall patient satisfaction were assessed. Linear and logistic multivariable analyses were used to obtain the risk-adjusted effect of BMI on these outcomes.
Results: Of all patients 34.8% had a BMI <25 kg/m², 34.0% were overweight (BMI 25-29 kg/m²), and 31.3% were obese (BMI >= 30 kg/m²). Patients with BMI >=30 kg/m² were 1.62 times more likely to have a failed block (P = 0.04). The unadjusted rate of acute complications was higher in obese patients (P = 0.001). However, when compared with patients with a normal BMI, postoperative pain at rest, unanticipated admissions, and overall satisfaction were similar in overweight and obese patients.
Conclusions: The present investigation shows that obesity is associated with higher block failure and complication rates in surgical regional anesthesia in the ambulatory setting. Nonetheless, the rate of successful blocks and overall satisfaction remained high in patients with increased BMI. Therefore, overweight and obese patients should not be excluded from regional anesthesia procedures in the ambulatory setting.

Anesthesia for Patients with Congenital Long QT Syndrome.
Kies, Susan J. M.D. ; Pabelick, Christina M. M.D. ; Hurley, Heather A. Pharm.D. ; White, Roger D. M.D. ; Ackerman, Michael J. M.D., Ph.D.
Anesthesiology 2005; 102(1):204-210.

Long QT syndrome is a malfunction of cardiac ion channels resulting in impaired ventricular repolarization that can lead to a characteristic polymorphic ventricular tachycardia known as torsades de pointes. Stressors, by increasing sympathetic tone, and drugs can provoke torsade de pointes, leading to syncope, seizures, or sudden cardiac death in these patients. Beta blockade, implantation of cardioverter defibrillators, and left cardiac sympathetic denervation are used in the treatment of these patients. However, these treatment modalities do not guarantee the prevention of sudden cardiac death. Certain drugs, including anesthetic agents, are known to contribute to QT prolongation. After reviewing the literature the authors give recommendations for the anesthetic management of these patients in the perioperative period.

No Evidence of Memory Function during Anesthesia with Propofol or Isoflurane with Close Control of Hypnotic State.
Kerssens, Chantal Ph.D. ; Ouchi, Takashi M.D. ; Sebel, Peter S. M.B. B.S., Ph.D., M.B.A.
Anesthesiology 2005;102(1):57-62

Background: The authors previously demonstrated memory function during apparently adequate general anesthesia in trauma patients. Hypnotic state fluctuations, stress, and variable amnesic qualities of commonly used anesthetics could account for this effect.
Methods: The authors replicated the trauma investigation in 90 elective surgical patients to enable anesthetic titration to a bispectral index value of 50-55 during auditory presentation of word stimuli. Patients were randomly assigned to maintenance with propofol (n = 48) or isoflurane (n = 42). Before surgery, state anxiety and trait anxiety were assessed using self-report measures. Postoperative memory assessment relied on the process dissociation procedure using a word stem completion task.
Results: There were no differences between groups for relevant demographic, preoperative, or supplemental drug variables. Ninety-eight percent of words were presented within a bispectral index range of 40-60, with values averaging 48.8 (SD = 5.7) during word presentation. Neither the process dissociation procedure nor standard measures of conscious recall and recognition memory showed evidence of explicit or implicit memory. Preoperative stress levels did not correlate with postoperative memory test scores in either study group.
Conclusions: In contrast to the results of their previous study, the authors found no evidence of memory function with close control of hypnotic state. This suggests that hypnotic state fluctuations are important to memory activation under anesthesia. Other variables may contribute to preserved memory function as well. Propofol and isoflurane block memory equally well during adequate anesthesia.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Influence of the injection site (L2/3 or L3/4) and the posture of the vertebral column on selective spinal anesthesia for ambulatory knee arthroscopy
A-M. Korhonen, J. V. Valanne, R. M. Jokela, P. Ravaska, P. Volmanen and K. Korttila
Acta Anaesthesiologica Scandinavica 2005; 49; 72-7

Background: We tested the hypothesis that selective spinal anesthesia for ambulatory knee arthroscopy can be accomplished with a small dose of bupivacaine at the L3/4 interspace with or without a head-down tilt of 5° when the patients were in the lateral decubitus position.
Methods: In this double-blind study, 123 patients were randomly allocated to receive spinal anesthesia with 4 mg of hyperbaric bupivacaine inserted at either the L2/3 interspace, while the vertebral column was kept horizontal (L2/3 group), or the L3/4 level, with the vertebral column horizontal (L3/4H) or tilted 5° head-down (L3/4T). At 7 min, an additional head down tilt was used in all groups if the sensory block was inadequate.
Results: In the L3/4T group the sensory block (Th8) reached a significantly higher level 30 min after spinal injection, compared with both the L2/3 (Th10) and L3/4H (Th11) groups. In the L3/4H group, 39% of the patients needed an additional tilt for 3 min at 7 min, compared with 10% (P=0.004) in the L3/4T group. Sacral block developed later and recovered faster (P<0.05) in the L3/4T group compared to the L3/4H group. Home-readiness was achieved equally fast in all groups.
Conclusion: When producing selective spinal anesthesia, the posture of the vertebral column is a major determinant of both sensory and motor segments to be blocked. A 4-mg dose of hyperbaric bupivacaine at the L3/4 interspace with a 5° head-down tilt of the vertebral column for 6 min is recommended for knee arthroscopy.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Comparison of plain and hyperbaric solutions of ropivacaine for spinal anaesthesia
P. D. W. Fettes, G. Hocking, M. K. Peterson, J. F. Luck and J. A. W. Wildsmith
British Journal of Anaesthesia 2005 94(1):107-111  

Background. Preliminary work has shown that ropivacaine provides spinal anaesthesia of shorter duration than bupivacaine, and may be of particular use in the day-case setting. However, there are few data comparing the actions of plain and hyperbaric solutions of this drug.
Methods. Forty ASA grade I–II patients undergoing elective perineal surgery under spinal anaesthesia were randomized to receive 3 ml ropivacaine 5 mg ml^-1, either in plain solution or with glucose 50 mg ml^-1. The extent and duration of sensory and motor block, pulse rate, blood pressure, and time to mobilization were recorded.
Results. Two patients (one per group) were withdrawn because of total block failure. There were significant differences in median time to onset of sensory block at T10 (plain 10 min; hyperbaric 5 min; P<0.01), median maximum extent (plain T8; hyperbaric T4; P<0.05), and median duration of sensory block at T10 (plain 25 min; hyperbaric 115 min; P<0.001). However, median times to complete regression of both sensory (270 vs 240 min; P<0.05) and motor (180 vs 120 min; P<0.001) block were longer in the plain group. Patients therefore mobilized sooner in the hyperbaric group (218 [n=16] vs 286 min [n=17]; P<0.01). All the hyperbaric blocks were adequate for surgery, but three patients receiving plain ropivacaine required general anaesthesia.
Conclusion. Addition of glucose 50 mg ml^-1 to ropivacaine 5 mg ml^-1 increases the speed of onset, block reliability, duration of useful block for perineal surgery, and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of L1.

Clonidine as an adjuvant to local anaesthetic axillary brachial plexus block: a randomized, controlled study
A. Duma, B. Urbanek, C. Sitzwohl, A. Kreiger, M. Zimpfer and S. Kapral
British Journal of Anaesthesia 2005 94(1):112-116

Background. We compared the effects of clonidine added to levobupivacaine and bupivacaine on axillary brachial plexus block as well as the effectiveness of levobupivacaine alone compared with bupivacaine alone.
Methods. In this prospective, randomized, controlled, double-blind trial, four groups of 20 patients each were investigated, using (i) 40 ml of levobupivacaine 0.5% plus 0.150 mg of clonidine, (ii) 40 ml of levobupivacaine 0.5% plus 1 ml of NaCl 0.9%, (iii) 40 ml of bupivacaine 0.5% plus 0.150 mg of clonidine, and (iv) 40 ml of bupivacaine 0.5% plus 1 ml of NaCl 0.9%, respectively. The onset of motor and sensory block and duration of sensory block were recorded.
Results. There was no significant difference in duration between groups, but a significantly higher variance (P<0.001) was found in the two groups with clonidine than in the two groups without.
Conclusions. These findings suggest responder and non-responder behaviour is a result of the addition of clonidine.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Prophylactic Diclectin^® reduces the incidence of postoperative vomiting
Brenda K. Reeve, MD, Deborah J. Cook, MD, Denise Babineau, MSc, L. Cory Scholes, MD and D. Norman Buckley, MD
Canadian Journal of Anesthesia 52:55-61 (2005)

Background: Diclectin^® (DCL) is an effective antiemetic used for relief of nausea and vomiting in pregnancy. It is unknown whether DCL is effective in the prevention of postoperative nausea and vomiting (PONV).
Methods: We conducted a randomized, stratified, double-blind placebo-controlled trial to examine the incidence of PONV in women undergoing elective laparoscopic tubal ligation in the day surgery setting. DCL (doxylamine succinate 10 mg and pyridoxine hydrochloride 10 mg) was administered orally the night before surgery, the morning of surgery, and upon hospital discharge.
Results: We enrolled 146 women in the trial, 127 of whom were included in the effectiveness analysis and 102 of whom were included in the efficacy analysis. We did not detect a difference in the incidence of nausea and vomiting in the first six hours postoperatively after adjusting for additional antiemetics administered. Patients receiving DCL as compared with placebo were significantly less likely to experience vomiting six to 24 hr postoperatively [5/59 (8.5%) vs 14/55 (25.4%), P < 0.017]. Treated patients tended to return to work earlier than those who received placebo (1.74 vs 3.7 days P = NS).
Conclusion: Perioperative oral DCL reduces the incidence of postoperative vomiting in women undergoing elective laparoscopic tubal ligation, and may accelerate return to work.

Needle placement and injection posterior to the axillary artery may predict successful infraclavicular brachial plexus block: a report of three cases
Jennifer M. Porter, MD, Colin J. L. McCartney, FRCA and Vincent W. S. Chan, FRCPC
Canadian Journal of Anesthesia 52:69-73 (2005)

Purpose: The combined use of ultrasound and nerve stimulation for localization of the brachial plexus during infraclavicular block has not been evaluated. We describe three cases of infraclavicular block where we used ultrasound to place the needle and catheter, observe type of muscle twitch obtained and local anesthetic spread after injection.
Clinical features: Injection of local anesthetic after obtaining proximal muscle stimulation was associated with local anesthetic spread between the axillary artery and pectoral muscle. This resulted in block failure (case 1).
In case 2, proximal stimulation was associated with anterior spread after a test injection. The needle and subsequently the catheter were repositioned posterior to the axillary artery and distal muscle stimulation obtained. Injection through the catheter resulted in local anesthetic spread posterior to the artery and successful block.
In case 3, no distal twitch could be obtained but in light of previous experience the needle and then the catheter were placed posterior to the axillary artery. Posterior local anesthetic spread was observed and successful block ensued despite absence of any muscle stimulation.
Conclusion: Ultrasound guidance during infraclavicular brachial plexus block enables direct visualization of needle/catheter tip location and confirmation of appropriate local anesthetic spread. Our early experience suggests that spread of injectate posterior to the second part of the axillary artery is associated with successful block.

Nerve stimulator guided pudendal nerve block decreases posthemorrhoidectomy pain
Zouheir Naja , MD , Mohammad Fouad Ziade, PhD and Per-Arne Lönnqvist, MD PhD
Canadian Journal of Anesthesia 52:62-68 (2005)

Purpose: Based on our institution’s initial results that reflected reduced postoperative pain using a modified pudendal nerve block technique, we conducted a prospective, randomized, double-blind study to investigate whether a combination of general anesthesia and bilateral nerve stimulator guided pudendal nerve blocks could provide better postoperative pain relief compared to general anesthesia alone or in combination with placebo nerve blocks.
Methods: Following Ethical Committee approval and informed consent 90 patients scheduled for hemorrhoidectomy were randomized to three different groups of 30 patients each: general anesthesia alone, general anesthesia plus nerve stimulator guided pudendal nerve block or general anesthesia plus placebo nerve blocks. Postoperative pain, the primary outcome variable of the study, was assessed by visual analogue scale scores at predetermined time intervals during the postoperative period. Total amount of analgesics, time to return to normal activities and patient satisfaction were also recorded.
Results: The pudendal nerve block group was found to have better postoperative pain-relief (P < 0.005), reduced need for analgesics (P < 0.05), and also a more rapid return to normal activities (P < 0.001) compared to general anesthesia alone or in combination with placebo blocks. The pudendal nerve block group was also associated with significantly higher patient satisfaction (P < 0.001) compared to the other two groups.
Conclusion: A combination of general anesthesia and nerve stimulator guided pudendal nerve block showed significantly reduced postoperative pain, shortened hospital stay, and earlier return to normal activity. Thus, this technique deserves more widespread use in patients undergoing hemorrhoidectomy.

The "BURP" maneuver worsens the glottic view when applied in combination with cricoid pressure
Douglas D. Snider, FRCPC, Donna Clarke, RT and Brendan T. Finucane, MBBCH FRCPC
Canadian Journal of Anesthesia 52:100-104 (2005)

Purpose: The purpose of this study was to determine if the application of a BURP maneuver to the cricoid cartilage would combine the benefits of both the BURP and the Sellick maneuvers, resulting in an improved glottic view and offer the potential of protection against passive gastric regurgitation.
Methods: This was a double-blind, prospective, randomized, crossover trial. Forty-three patients scheduled for elective surgery participated in this study. General anesthesia was induced using fentanyl, propofol and rocuronium. In a random sequence for each case and blinded to the laryngoscopist, one of three maneuvers was carried out. Direct vertical pressure, using 30 newtons, a BURP maneuver with cricoid pressure, or no pressure was applied to the cricoid and the laryngoscopic view was ascertained. A separate laryngoscopy was conducted for each maneuver and the views were graded as good (part of the glottis seen), poor (only the arytenoids were seen) or no view (only the epiglottis was seen). Endotracheal intubation was then performed in each case.
Results: The results showed that the combination of the BURP maneuver and cricoid pressure worsened the view obtained at laryngoscopy in 30% of cases (P = 0.007). Cricoid pressure alone worsened the view in 12.5% of cases (P = 0.279). No difference was seen in 65% of cases. All patients but one were intubated easily.
Conclusion: There is no benefit to routinely applying a modified "BURP" maneuver to the cricoid cartilage during rapid sequence induction of anesthesia.

A priming technique accelerates onset of neuromuscular blockade at the laryngeal adductor muscles
Joachim Schmidt, MD, Andrea Irouschek, Tino Muenster, MD, Thomas M. Hemmerling, MD DEAA and Sven Albrecht, MD
Canadian Journal of Anesthesia 52:50-54 (2005)

Purpose: Priming is a known technique to accelerate onset of neuromuscular blockade (NMB). Its effect on NMB of the larynx has not been studied yet.
Methods: We compared a priming technique with a bolus application of rocuronium on the onset of NMB at the laryngeal adductor and the adductor pollicis muscles (AP). In 30 female patients, after induction of anesthesia a tube with a surface electrode was placed into the trachea prior to the administration of any neuromuscular blocking agent to monitor electromyography (EMG) of the laryngeal adductor muscles. Neuromuscular monitoring consisted of EMG of the laryngeal adductor muscles and the left AP. Patients were randomized into two groups. After transcutaneous stimulation of the recurrent laryngeal nerve and ulnar nerve, a bolus of rocuronium 0.6 mg·kg^-1 (Bolus group) or a priming dose of rocuronium 0.06 mg·kg^-1 followed by rocuronium 0.54 mg·kg^-1 three minutes later (Priming group) were injected. Lag time, onset 90%, onset time and peak effect of NMB were recorded and compared; a P < 0.05 was considered significant.
Results: The onset 90% and onset time measured at the laryngeal adductor muscles (onset: 44.7 ± 7.4 vs 74.0 ± 23.8 sec) and at the AP (onset: 105.4 ± 29.9 vs 139.2 ± 51.5 sec) were significantly shorter in the Priming group than in the Bolus group. Within groups, the onset times were significantly shorter at the laryngeal muscles in comparison to AP.
Conclusion: Our results indicate that a priming technique with rocuronium significantly accelerates the onset of NMB at the laryngeal adductor muscles. Our results further support the use of rocuronium as an alternative to succinylcholine for rapid sequence induction.

PUB MED - TOP

Patient injuries from surgical procedures performed in medical offices: three years of Florida data
Coldiron B, Shreve E, Balkrishnan R.
Dermatol Surg 30:1435-43, 2004

BACKGROUND : Many state medical boards and legislatures are in the process of developing regulations that restrict procedures in the office setting with the intention of enhancing patient safety. The highest quality data in existence on office procedure adverse incidents have been collected by the state of Florida.
OBJECTIVE: The objective was to determine and analyze the nature of surgical incidents in office-based settings using 3 years of Florida data from March 2000 to March 2003.
METHODS: An incidence study with prospective data collection was performed. Individual reports that resulted in death or a hospital transfer were further investigated by determining the reporting physician's board certification status, hospital privilege status (excluding procedure specific operating room privileges), and office accreditation status.
RESULTS: In 3 years there were 13 procedure-related deaths and 43 procedure-related complications that resulted in a hospital transfer. Seven of the 13 deaths involved elective cosmetic procedures, 5 of which were performed under general anesthesia and 2 of which were performed with intravenous sedation anesthesia. Forty-two percent of the offices reporting deaths and 50% of the offices reporting procedural incidents that resulted in a hospital transfer were accredited by an independent accreditation agency. Ninety-six percent of physicians reporting surgical incidents were board-certified, and all had hospital privileges.
CONCLUSIONS: Restrictions on office procedures for medically necessary procedures, such as requiring office accreditation, board certification, and hospital privileges, would have little effect on overall safety of surgical procedures. These data also show that the greatest danger to patients lies not with surgical procedures in office-based settings per se, but with cosmetic procedures that are performed in office-based settings, particularly when under general anesthesia. Our conclusions are dramatically different from those of a recent study, which claimed a 12-fold increased risk of death for procedures in the office setting.

Incisional local anaesthesia versus placebo for pain relief after appendectomy in children - a double-blinded controlled randomised trial.
Jensen SI, Andersen M, Nielsen J, Qvist N.
Eur J Pediatr Surg. 2004 Dec;14(6):410-3

Incisional local anaesthesia is widely used for postoperative pain relief after surgery. We present the results of a double-blinded and randomised controlled study of incisional bupivacaine versus placebo in 68 children undergoing open appendectomy. The trial medicine (0.5 ml/kg) was infiltrated into the subcutis after wound closure. Patients with a weight below 40 kg received a bupivacaine concentration of 0.25 % and the patients above 40 kg a concentration of 0.5 %. During the first 24 hours after surgery the patients in the bupivacaine group received on average 0.065 mg morphine/kg and in the placebo group 0.073 mg/kg. This difference was not statistically significant. The patients in the bupivacaine group tended to experience pain relief for a longer period of time compared to the patients in the placebo group. However, the difference was not significant. In conclusion, the use of subcutaneous infiltration with bupivacaine in the wound after open appendectomy had no significant effect on the use of morphine during the first postoperative day in children.

Maximum recommended doses of local anesthetics: A multifactorial concept.
Rosenberg PH, Veering BT, Urmey WF.
Reg Anesth Pain Med. 2004 Nov-Dec;29(6):564-75

The current recommendations regarding maximum doses of local anesthetics presented in textbooks, or by the responsible pharmaceutical companies, are not evidence based (ie, determined by randomized and controlled studies). Rather, decisions on recommending certain maximum local anesthetic doses have been made in part by extrapolations from animal experiments, clinical experiences from the use of various doses and measurement of blood concentrations, case reports of local anesthetic toxicity, and pharmacokinetic results. The common occurrence of central nervous system toxicity symptoms when large lidocaine doses were used in infiltration anesthesia led to the recommendation of just 200 mg as the maximum dose, which has remained unchanged for more than 50 years. In most cases, there is no scientific justification for presenting exact milligram doses or mg/kg doses as maximum dose recommendations. Instead, only clinically adequate and safe doses (ranges) that are block specific are justified, taking into consideration the site of local anesthetic injection and patient-related factors such as age, organ dysfunctions, and pregnancy, which may influence the effect and the pharmacokinetics of the local anesthetic. Epinephrine in concentrations of 2.5 to 5 mug/mL should be added to the local anesthetic solution when large doses are administered, providing there are no contraindications for the use of epinephrine. As a rule, conditions (eg, end-stage pregnancy, high age in epidural, or spinal block) or diseases (uremia) that may increase the rate of the initial uptake of the local anesthetic are indications to reduce the dose in comparison to one normally used for young, healthy, and nonpregnant adults. On the other hand, the reduced clearance of local anesthetics associated with renal, hepatic, and cardiac diseases is the most important reason to reduce the dose for repeated or continuous administration. The magnitude of the reduction should be related to the expected influence of the pharmacodynamic or pharmacokinetic change.

Propofol versus Midazolam/Fentanyl for Reduction of Anterior Shoulder Dislocation.
Taylor DM, O'brien D, Ritchie P, Pasco J, Cameron PA.
Acad Emerg Med. 2005 Jan;12(1):13-9.

OBJECTIVE: The authors aimed to compare propofol and midazolam/fentanyl for reduction of anterior shoulder dislocations using the modified Kocher's maneuver.
METHODS: This was a multicenter, randomized, clinical trial of patients with anterior shoulder dislocation. Patients were randomized to either propofol or midazolam/fentanyl. The randomized drug was titrated to a clinical sedation end point (spontaneous eye closure). One physician sedated the patient. Another, blinded to the drug administered, reduced the shoulder and recorded details of muscle tone and ease of reduction.
RESULTS: Eighty-six patients were randomized to treatment with propofol (n = 48) or midazolam/fentanyl (n = 38). Patients in the propofol group had shorter mean times to first wakening (difference in means, 4.6 minutes; 95% confidence interval [CI] = 0.7 to 8.6; p = 0.097) and full consciousness (difference in means, 21.7 minutes; 95% CI = 14.7 to 28.7; p <0.001), had easier shoulder reduction (difference in mean rating, 0.5; 95% CI = 0.0 to 0.9; p = 0.047), and needed fewer reduction attempts (difference in means, 0.5; 95% CI = 0.1 to 1.0; p = 0.02). Patients in the propofol group also had less mean muscle tone at the first reduction attempt (p = 0.08) and needed fewer reduction maneuvers (p = 0.40) but had more respiratory depression (11 vs. six patients; difference in proportions, 7.1%; 95% CI = -11.8 to 26.1; p = 0.58) and had one patient who vomited.
CONCLUSIONS : Propofol appears to be as effective as midazolam/fentanyl for reduction of anterior shoulder dislocation using the modified Kocher's maneuver. However, the advantage of shorter wakening times associated with propofol should be weighed against the possibility of adverse events, particularly respiratory depression and vomiting.

Interscalene brachial plexus anesthesia with ropivacaine 5 mg/mL and bupivacaine 5 mg/mL: Effects on electrocardiogram.
Borgeat A, Ekatodramis G, Blumenthal S.
Reg Anesth Pain Med. 2004 Nov-Dec;29(6):557-63.

Background: Cardiotoxicity is the most severe complication of long-acting local anesthetics. The aim of this trial is to compare early signs of depression of cardiac conduction linked with the administration of either ropivacaine or bupivacaine for interscalene block.
Methods: Thirty-two patients (American Society of Anesthesiologists I/II) scheduled for elective shoulder arthroscopy were prospectively enrolled to receive, in a randomized and double-blind fashion, either 40 mL of ropivacaine 5 mg/mL or 40 mL of bupivacaine 5 mg/mL for interscalene block. Holter monitoring was started the night before surgery and continued until the end of the study. Peripheral blood sampling was performed before administration of local anesthetics (= baseline) and 15, 20, 25, 30, 35, 40, 45, 60, and 360 minutes after completion of the interscalene block for measurement of total and unbound concentration of the 2 local anesthetics. Alpha-1-acid-glycoprotein was measured at baseline, t 30 , and t 360.
Results: All anesthetic blocks in both groups were successful and comparable. Electrocardiographic recordings for QRS, QT, and QTC intervals did not change and were similar in both groups. In the bupivacaine group, significant prolongation of the PQ interval was noted 15 minutes after drug application and remained significantly prolonged until t 60 . Total and unbound plasma local-anesthetic concentrations were comparable between both groups at all times. In both groups, local-anesthetic plasma mean levels reached a peak between 30 and 45 minutes after the bolus application. The highest mean plasma levels were 0.103 (+/-0.05) mg/L for unbound ropivacaine and 0.084 (+/-0.03) mg/L for unbound bupivacaine, which occurred in both groups at t 30.
Conclusions: Electrocardiographic recordings were similar in both groups, except for a significant prolongation of the PQ interval in the bupivacaine group at plasma levels below threshold for cardiotoxicity.

A clinical comparison of equal concentration and volume of ropivacaine and bupivacaine for interscalene brachial plexus anesthesia and analgesia in shoulder surgery.
Eroglu A, Uzunlar H, Sener M, Akinturk Y, Erciyes N.
Reg Anesth Pain Med. 2004 Nov-Dec;29(6):539-43.

Background and objectives The aim of this study was to compare the same volume and concentration of bupivacaine and ropivacaine for interscalene brachial plexus block anesthesia and postoperative analgesia in shoulder surgery.
Methods: Forty-four patients scheduled for elective shoulder surgery were prospectively randomized to receive in a double-blind fashion 30 mL of either 0.5% bupivacaine or ropivacaine for interscalene block. The block was prolonged after surgery by using a patient-controlled interscalene analgesia with 0.15% of either bupivacaine or ropivacaine. The mean onset times of surgical blocks were determined after interscalene block. Pain relief was regularly assessed by using a visual analog scale, side effects were noted, and the patients were asked to rate their satisfaction at the end of the study.
Results: Two patients with bupivacaine and 1 with ropivacaine failed to achieve surgical block and were excluded. The mean onset times of surgical blocks were 18 +/- 12 minutes with ropivacaine and 21 +/- 13 minutes with bupivacaine. The pain scores, total volume infused of local anesthetics, incremental dose requested and received, total rescue analgesic, and side effects were similar between the groups. Postoperative pain control was similarly effective and patient satisfaction was high in both groups.
Conclusions: This study shows that the same volume and concentration of bupivacaine and ropivacaine (30 mL of 0.5%) for interscalene brachial plexus block anesthesia produce similar surgical block. When prolonging the block with a patient-controlled interscalene analgesia infusion, 0.15% bupivacaine or ropivacaine provide adequate pain relief, similar side effects, and high patient satisfaction after shoulder surgery.

Comparison of sedation requirements for cataract surgery under topical anesthesia or retrobulbar block.
Balkan BK, Iyilikci L, Gunenc F, Uzumlu H, Kara HC, Celik L, Durak I, Gokel E.
Eur J Ophthalmol. 2004 Nov-Dec;14(6):473-7.

PURPOSE: Topical anesthesia is increasingly being used for cataract surgery. However, it is believed that topical anesthesia causes an increased risk of intraoperative complications from unrestricted eye movement and insufficient pain control and more need for sedation. It is difficult to compare pain and anxiety experienced by individual patients; therefore, the authors used the method of patient-controlled sedation to determine whether there is a difference in sedation requirements under topical or retrobulbar anesthesia.
METHODS: In this prospective study, patients received either topical anesthesia (n=87) or retrobulbar block (n=104) and self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 microg) in increments using a patient controlled analgesia infuser to achieve sedation. At the end of surgery, patients rated their pain on a 10-point numerical rating scale and their comfort on a 5-point scale. The number of demands and deliveries were noted from the patient controlled analgesia infuser display.
RESULTS: Pain scores were between 0 and 2 in 95.4% in the topical and in 94.2% in the retrobulbar group (p>0.05). Patient comfort was equal in both groups with 2.94+/-0.92 in the topical group and 2.92+/-0.99 in the retrobulbar group (p>0.05). Mean sedation requirements were similar in both groups: 26.4% of patients in the topical group and 19.2% in the retrobulbar group did not request any sedation (not significant, p>0.05).
CONCLUSIONS: Sedation requirements were similar for cataract surgery under topical and retrobulbar anesthesia.

Granisetron and ondansetron for prevention of nausea and vomiting in patients undergoing modified radical mastectomy.
Dua N, Bhatnagar S, Mishra S, Singhal AK.
Anaesth Intensive Care. 2004 Dec;32(6):761-4.

Modified radical mastectomy is associated with a relatively high incidence of postoperative nausea and vomiting (PONV). This study was undertaken to evaluate the comparative profile and efficacy of ondansetron and granisetron to prevent PONV after modified radical mastectomy. In a randomized, double-blind, placebo-controlled trial, sixty female patients received ondansetron 4 mg, granisetron 1 mg or saline intravenously just before induction of anaesthesia (n = 20 for each group). A standardized general anaesthetic technique was employed. The incidence of PONV and adverse events were recorded for the first 24h postoperatively. The incidence of PONV was 25% with ondansetron, 20% with granisetron and 70% with saline (P < 0.05, Chi-square test with Yates' correction factor). The incidence of adverse events was comparable among the groups. Ondansetron and granisetron are both effective for reducing the incidence of PONV in female patients undergoing modified radical mastectomy.

Effect of diclofenac pretreatment on pain during propofol injection.
Mohta M, Agarwal D, Sethi AK, Sandhu K.
Anaesth Intensive Care. 2004 Dec;32(6):765-9.

In a randomized, double-blind, controlled trial, 120 ASA 1 or 2 patients were allocated to receive diclofenac or normal saline as pretreatment to assess their effect on incidence and severity of pain during propofol injection. Diclofenac in two different doses, i.e. 25 mg and 15 mg, was tried for this purpose. The overall incidence of pain did not significantly differ among the groups, but the incidence of moderate to severe pain following propofol injection was significantly less in patients who received diclofenac 25 mg (P = 0.0017) or 15 mg (P = 0.0363) than in those who received saline. However, the diclofenac itself was associated with mild pain in some patients.

Comparison of laser acupuncture and metoclopramide in PONV prevention in children.
Butkovic D, Toljan S, Matolic M, Kralik S, Radesic L.
Paediatr Anaesth. 2005 Jan;15(1):37-40.

Background: Postoperative nausea and vomiting (PONV) are frequent side effects of general anesthesia in children. The aim of this study was to compare the effectiveness of laser acupuncture with metoclopramide in prevention of PONV in children after sevoflurane anesthesia.
Methods: A total of 120 children ASA I and II, scheduled for hernia repair, circumcision or orchidopexy were randomly assigned into three groups: group I, received laser acupuncture on P6 point and saline infusion; group II, metoclopramide 0.1 mg.kg^-1 i.v. and sham laser; group III had sham laser and saline infusion. Anesthesia was maintained with sevoflurane and N₂O/O₂. Patients were monitored for any symptoms of retching and vomiting at 2, 6 and 24 h postoperatively.
Results: The incidence of vomiting was higher in the control group in the first 2 h postoperatively (P < 0.001), compared with the other groups. There was no statistically significant difference between acupuncture and metoclopramide groups in occurrence and timing of vomiting (P < 0.001).
Conclusion: Laser acupuncture is equally effective as metoclopramide in preventing PONV in children.

Costing day case anesthesia: obtaining accurate patient-based costs for adults and children.
Elliott RA, Davies LM, Payne K, Moore JK, Harper NJ.
Int J Technol Assess Health Care. 2004 Fall;20(4):552-61.

OBJECTIVES: This study proposes the method requirements for a valid costing study in anesthesia to allow differences to be identified between treatments and uses these method requirements to design and conduct a robust costing study.
METHODS: A prospective, patient-based costing study was carried out in adult and pediatric day surgery in the United Kingdom. The perspective was that of the National Health Service and the patient. Data were collected for each patient until 7 days after hospital discharge.
RESULTS: Data were collected for 1063 adults and 322 children undergoing day surgery between October 1999 and January 2001. Statistically significant differences were found only between variable costs, which accounted for 11.4 percent and 9.0 percent of adult and pediatric costs, respectively. There were no differences in length of stay, fixed costs, or semi-fixed costs. Differences were not found in total costs in adults but were found in children. By day 7, postdischarge primary and secondary care costs were not different between groups in either study. No differences were found in costs to patients or parents.
CONCLUSIONS: The use of prospective, patient-based cost data enabled the detection of differences in variable costs between difference anesthetic regimens in day surgery. The stochastic nature of the data provided a measure of variability around mean cost estimates. Practice patterns in the study reflected normal practice in the United Kingdom so the costing data have direct clinical relevance. The use of different anesthetic agents only affected variable costs and had no effect on larger cost drivers such as length of stay or staff input.

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