Volume 4, Issue 5 S A M B A T A L K S - PAGE 3 October, 2004

FROM THE LITERATURE: - TOP


ANESTHESIA AND ANALGESIA - TOP

Reliability and Validity of the Perioperative Opioid-Related Symptom Distress Scale
Jeffrey L. Apfelbaum, MD, Tong J. Gan, MD, Sean Zhao, MD PhD, David B. Hanna, MS, and Connie Chen, PharmD
Anesth Analg 2004;99:699-709

A reduction in opioid use may reduce the incidence and severity of opioid-related side effects. However, no published studies have demonstrated this relationship. In a prospective, placebo-controlled, randomized trial of analgesia for laparoscopic cholecystectomy, we validated an opioid-related symptom distress scale (SDS) questionnaire and clinically meaningful events (CMEs). A total of 193 patients completed the SDS questionnaire every 24 h after discharge for 7 days. This analysis was based on data from Day 1 only. The SDS assessed 12 common opioid-related symptoms, including nausea, vomiting, and difficulty passing urine, by 3 ordinal measures: frequency, severity, and bothersomeness. Patients with responses of "frequently" to "almost constantly," "moderate" to "very severe," or "quite a bit" to "very much bothered" were considered to have a CME. A detailed postoperative recovery survey of patient functional status and experience of adverse effects was used to validate the SDS. Validation measures in the recovery survey were categorized as nonspecific (e.g., level of normal activities) and specific (e.g., number of times vomited in 24 h, minutes of nausea in 24 h, and ability to void normally). SDS scores and CMEs for nausea, vomiting, and difficulty passing urine were strongly associated with three related validation measures from the recovery survey: minutes of nausea within 24 h, number of times vomited within 24 h, and ability to void normally, respectively (P < 0.0001). There was also a strong association between SDS scores and CMEs for nausea, vomiting, and voiding and general recovery validation measures, although the association was significantly weaker than that for symptom-specific validation measures. CMEs for nausea, vomiting, and voiding showed a high specificity and lower sensitivity with directly assessed responses. The SDS questionnaire and CMEs are valid tools for assessing postoperative opioid-related symptoms after laparoscopic cholecystectomy. Symptoms defined as CMEs through the SDS may be more sensitive than those identified by direct assessment.
IMPLICATIONS: The symptom distress scale (SDS) was designed to evaluate the level of distress associated with the adverse effects of commonly used opiates. This study reports on the reliability and validity of the SDS in a group of patients undergoing laparoscopic cholecystectomy. The validity of the SDS was demonstrated by using specific symptoms directly assessed in the clinical trial and patient responses to questions regarding general satisfaction and daily activities.

Does Benzydamine Hydrochloride Applied Preemptively Reduce Sore Throat Due to Laryngeal Mask Airway?
Ismail Kati, MD, Murat Tekin, MD, Emin Silay, MD, Urfettin A. Huseyinoglu, MD, and Huseyin Yildiz, MD
Anesth Analg 2004;99:710-712

Sore throat is a common postoperative complaint. We investigated whether preemptive benzydamine hydrochloride (BH) treatment could prevent sore throat due to a laryngeal mask airway (LMA) cuff inflated with air. One-hundred ASA status I–II patients who underwent general anesthesia were randomly divided into two groups. In the first group, four puffs of BH were applied to the pharynx 30 min before the operation and 5 min before the induction of anesthesia. Distilled water with a similar bottle was applied with the same protocol in the second group. Anesthetic induction was provided with propofol and fentanyl. The pressure of the LMA cuff inflated with room air was measured after the first adjustment and after 30, 60, and 90 min of inflation in both groups. At the end of operation, the LMA was removed after the recovery of spontaneous breathing. After the operation, patients were asked about sore throat symptoms at the first, second, and fourth hours. There were no significant differences between groups for cuff pressures, cuff volumes, analgesic doses, or operation times. However, sore throat symptoms were significantly less severe for the BH group during both resting and swallowing. In conclusion, preemptive topical BH may decrease the incidence of sore throat due to LMA use.
IMPLICATIONS: We investigated whether preemptive benzydamine hydrochloride (BH) treatment could prevent sore throat due to a laryngeal mask airway (LMA) cuff inflated with air. We conclude that preemptive topical BH treatment may prevent sore throat due to LMA use.

A Comparison of Intrathecal Plain Solutions Containing Ropivacaine 20 or 15 mg Versus Bupivacaine 10 mg
Helena Kallio, MD PhD, Eljas-Veli T. Snäll, MD, Markku P. Kero, MD, and Per H. Rosenberg, MD PhD
Anesth Analg 2004;99:713-717

Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropivacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. Motor block was tested with the Bromage scale, and sensory block was tested with pinprick. Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P = 0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.
IMPLICATIONS: In spinal anesthesia, ropivacaine provided two thirds of the duration in sensory block and half of the duration in motor block compared with bupivacaine. Both 20 and 15 mg of ropivacaine are suitable for lower-extremity surgery of 1 h in duration. The latter dose is preferable in day-case surgery because of rapid motor recovery.

Single-Dose Parenteral Pharmacological Interventions for the Prevention of Postoperative Shivering: A Quantitative Systematic Review of Randomized Controlled Trials
Peter Kranke, MD, Leopold H. Eberhart, MD, Norbert Roewer, MD, and Martin R. Tramèr, MD DPhil
Anesth Analg 2004;99:718-727

Shivering is a frequent complication in the postoperative period. The relative efficacy of pharmacological interventions to prevent this phenomenon is not well understood. We performed a systematic search for full reports of randomized comparisons of prophylactic, parenteral, single-dose antishivering interventions with inactive control (placebo or no treatment). Variable doses were converted to fixed doses. Dichotomous data on the absence of shivering were analyzed by using relative benefit (RB) and number needed to treat (NNT) with 95% confidence intervals (CI). Data from 27 trials (1348 adults received an antishivering intervention; 931 were controls) were analyzed. The average incidence of shivering in controls was extremely frequent (52%). Clonidine 65–300 µg (1078 patients), meperidine 12.5–35 mg (250 patients), tramadol 35–220 mg (250 patients), and nefopam 6.5–11 mg (204 patients) were tested in at least 3 trials each. All were more effective than control. For clonidine, meperidine, and nefopam, there was some weak evidence of dose responsiveness. For small-dose clonidine (65–110 µg), the RB compared with control was 1.32 (95% CI, 1.16–1.51); for medium-dose clonidine (140–150 µg), the RB was 1.83 (95% CI, 1.47–2.27); and for large-dose clonidine (220–300 µg), the RB was 1.52 (95% CI, 1.30–1.78). For all clonidine regimens combined, the RB was 1.58 (95% CI, 1.43–1.74), with an NNT of 3.7. For all meperidine regimens combined, the RB was 1.67 (95% CI, 1.37–2.03), with an NNT of 3. For all tramadol regimens combined, the RB was 1.93 (95% CI, 1.56–2.39), with an NNT of 2.2. For all nefopam regimens combined, the RB was 2.62 (95% CI, 2.02–3.40), with an NNT of 1.7. Methylphenidate, midazolam, dolasetron, ondansetron, physostigmine, urapidil, and flumazenil were tested in no more than 3 trials each, with a limited number of patients.
IMPLICATIONS: With prophylactic clonidine or meperidine, the incidence of postoperative shivering may be reduced by a factor of approximately 1.6. When the baseline risk is extremely high, one in three to four patients may profit. Other interventions—for instance, nefopam—may be even more effective but have been less well studied.

Fires from the Interaction of Anesthetics with Desiccated Absorbent
Michael Laster, DVM, Patricia Roth, MD, and Edmond I Eger, II, MD
Anesth Analg 2004;99:769-774

Rarely, fire and patient injury have resulted from the degradation of sevoflurane by desiccated carbon dioxide absorbent. Desiccated absorbent also can degrade desflurane and isoflurane, and in the present investigation we sought to determine whether a danger of fire also arose with their use in the presence of desiccated absorbent. Baralyme^® was desiccated by heating and directing a 10 L/min flow of oxygen through the absorbent. Approximately 1200 g of this desiccated absorbent was used to fill a standard absorber placed in a standard anesthetic circuit to which we directed a 6 L/min flow of oxygen containing 1.5 or 3.0 MAC desflurane, isoflurane, or sevoflurane. A 3-L reservoir bag served as a surrogate lung, and we ventilated this lung with a minute ventilation of 10 L/min. With desflurane or isoflurane, at both 1.5 MAC and 3.0 MAC, temperatures increased in 30 to 70 min to a peak of approximately 100°C and then decreased. With 1.5 MAC sevoflurane (3.0 MAC was not studied), temperatures increased to over 200°C, and in 2 of 5 studies, flames appeared in the anesthetic circuit. In a separate study, we found that concurrent delivery of carbon dioxide and desflurane did not increase peak temperatures. We conclude that the interaction of desflurane or isoflurane with desiccated absorbent is not likely to produce the conflagrations possible with sevoflurane.
IMPLICATIONS: Fire may result from the interaction of sevoflurane, but not desflurane or isoflurane, with desiccated carbon dioxide absorbent, particularly Baralyme^®.

The Incidence of Awareness During Anesthesia: A Multicenter United States Study
Peter S. Sebel, MB BS, PhD, MBA, T. Andrew Bowdle, MD PhD, Mohamed M. Ghoneim, MD, Ira J. Rampil, MD, Roger E. Padilla, MD, Tong Joo Gan, MB BS, FRCA, FFARCS, and Karen B. Domino, MD MPH
Anesth Analg 2004;99:833-839

Awareness with recall after general anesthesia is an infrequent, but well described, phenomenon that may result in posttraumatic stress disorder. There are no recent data on the incidence of this complication in the United States. We, therefore, undertook a prospective study to determine the incidence of awareness with recall during general anesthesia in the United States. This is a prospective, nonrandomized descriptive cohort study that was conducted at seven academic medical centers in the United States. Patients scheduled for surgery under general anesthesia were interviewed in the postoperative recovery room and at least a week after anesthesia and surgery by using a structured interview. Data from 19,575 patients are presented. A total of 25 awareness cases were identified (0.13% incidence). These occurred at a rate of 1–2 cases per 1000 patients at each site. Awareness was associated with increased ASA physical status (odds ratio, 2.41; 95% confidence interval, 1.04–5.60 for ASA status III–V compared with ASA status I–II). Age and sex did not influence the incidence of awareness. There were 46 additional cases (0.24%) of possible awareness and 1183 cases (6.04%) of possible intraoperative dreaming. The incidence of awareness during general anesthesia with recall in the United States is comparable to that described in other countries. Assuming that approximately 20 million anesthetics are administered in the United States annually, we can expect approximately 26,000 cases to occur each year.
IMPLICATIONS: Data from 19,575 patients indicate that the incidence of awareness with recall after surgery under general anesthesia is 0.13%. This means that the minimum incidence of awareness is 1.3 patients per 1000.

Do Anesthesia Information Systems Increase Malpractice Exposure? Results of a Survey
Jeffrey M. Feldman, MD MSE
Anesth Analg 2004;99:840-843

Anesthesia information systems (AIS) record data from patient monitors and create a detailed electronic anesthesia record. Because the anesthesia record is a primary piece of evidence used in court during a malpractice proceeding, the ability to create an anesthesia record has fostered considerable debate concerning the impact of this method of record keeping on malpractice exposure. Fifty-five departments using AIS were surveyed to document their medicolegal experience with electronic anesthesia records. Twenty-four departments responded to the survey, 18 of which had more than 5 yr experience with the technology. Respondents reported 41 malpractice cases filed since adopting AIS technology. Of the cases filed, 30 were dropped, and 11 went on to settlement or litigation. There were no reported cases in which the automated record hindered the defense process. Eighteen respondents viewed this technology as valuable for risk management, and three more viewed it as essential. The experience reported by these departments indicates that AIS are useful for managing malpractice risk.
IMPLICATIONS: A survey of departments using an anesthesia information system for anesthesia record keeping suggests that these systems are useful for managing malpractice risk and do not increase malpractice exposure.

ANESTHESIOLOGY - TOP

Sickle Cell Disease and Anesthesia. (REVIEW)
Firth, Paul G. M.B., Ch.B.; Head, C Alvin M.D.
Anesthesiology 2004; 101(3): 766-786

The pathophysiology and anesthetic management of sickle cell disease is reviewed, approaching the disease as a problem of chronic vascular damage rather than one of acute sickling.

Comparative Analgesic and Mental Effects of Increasing Plasma Concentrations of Dexmedetomidine and Alfentanil in Humans. (ACCOMPANIED BY EDITORIAL SHOWN BELOW)
Angst, Martin S. M.D.; Ramaswamy, Bhamini M.D.; Davies, M Frances Ph.D.; Maze, Mervyn M.D.
Anesthesiology 2004; 101(3): 744-752

Background: In animals, systemic and intrathecal administration of the [alpha]2 -adrenergic receptor agonist dexmedetomidine results in robust antinociceptive effects in models of heat pain. In humans, systemically administered dexmedetomidine is approved for sedating patients in the intensive care unit. However, whether systemic administration of dexmedetomidine in humans produces significant analgesia at doses causing sedation but not unconsciousness remains controversial.
Methods: This study in human volunteers used a placebo-controlled, double-blind, and randomized design to examine whether dexmedetomidine at doses causing mild to severe sedation produces analgesia in experimental models of heat and electrical pain. Results were compared to the effects of the mu-opioid receptor agonist alfentanil. A computer-controlled infusion provided four median step-up plasma concentrations of dexmedetomidine (0.09, 0.24, 0.54, and 1.23 ng/ml) and alfentanil (13.4, 33.8, 67.8, and 126.1 ng/ml).
Results: Sedative and cognitive effects of dexmedetomidine were dose-dependent, resulting in a median sedation score of 95 of 100 and slowing of cognitive speed (reaction time, trail-making test) by a factor of about two at the highest plasma concentration. Dexmedetomidine did not attenuate heat or electrical pain. Alfentanil caused severe sedation (median sedation score 88 of 100) and slowed cognitive speed by a factor of approximately 1.4 at the highest plasma concentration. Alfentanil attenuated heat and electrical pain dose dependently.
Conclusion: This study documents that systemic dexmedetomidine lacks analgesic efficacy for heat and electrical pain at doses causing mild to severe sedation. These results provide further evidence suggesting that systemic administration of dexmedetomidine lacks broad analgesic activity in models of acute pain at doses not rendering humans unconscious.

Dexmedetomidine: Another Arrow for the Clinician's Quiver (EDITORIAL)
Ebert, Thomas M.D., Ph.D.; Maze, Mervyn M.B., Ch.B., F.R.C.P., F.R.C.A., F.Med.Sci Anesthesiology 2004; 101(3) : 568-570

No abstract available.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Presurgical intravenous parecoxib sodium and follow-up oral valdecoxib for pain management after laparoscopic cholecystectomy surgery reduces opioid requirements and opioid-related adverse effects
T. J. Gan, G. P. Joshi, S. Z. Zhao, D. B. Hanna, R. Y. Cheung and C. Chen
Acta Anaesthesiologica Scandinavica 2004 ; 48(9):1194-1207

Background:  Opioids are associated with numerous adverse effects. It is unclear if reduced postoperative opioid consumption lowers the incidence and severity of opioid-related adverse effects. This analysis - from a multicenter, randomized, double-blind trial - tested if the reduction of opioid consumption among patients who received intravenous preoperative parecoxib 40 mg, followed by oral valdecoxib 40 mg qd postoperatively, in Days 1-4 after outpatient laparoscopic cholecystectomy surgery, reduced opioid-related symptoms.
Methods:  Patients received intravenous fentanyl for pain before discharge, and oral acetaminophen 500 mg hydrocodone 5 mg q 4-6 h prn postdischarge for up to 7 days postsurgery. Patients also received intravenous parecoxib 40 mg administered 30-45 min preoperatively, and valdecoxib 40 mg qd up to Day 4 and prn Days 5-7 postsurgery, or placebo. Patients completed an opioid-related Symptoms Distress Scale (SDS) questionnaire every 24 h for 7 days. Opioid use was converted to morphine-equivalent doses (MEDs). Clinically meaningful events (CMEs) for 12 opioid-related symptoms were assessed by three ordinal measures: frequency, severity, and bothersomeness. Reduction of CMEs on Day 1 and number of patient-days with CMEs on Days 1-4 were examined.
Results:  Cumulative MEDs on Day 0, Day 1, and Days 1-4 were significantly lower in the parecoxib/valdecoxib group compared with the placebo group (P < 0.001). At the end of Day 1, parecoxib/valdecoxib-treated patients had significantly lower SDS scores (P < 0.02), a significantly reduced incidence of CMEs (P < 0.05), and significantly fewer patient-days with CMEs in Days 1-4 than placebo patients (P < 0.05). Patients in the parecoxib/valdecoxib group were less likely to have CMEs for multiple symptoms than those in the placebo group (P < 0.001).
Conclusions:  Treatment with parecoxib and valdecoxib significantly reduced the cumulative MED requirements, the incidence of opioid-related adverse effects, and patient-days with CMEs.

Propacetamol and diclofenac alone and in combination for analgesia after elective tonsillectomy
A. Hiller, M. Silvanto, S. Savolainen and P. Tarkkila
Acta Anaesthesiologica Scandinavica 2004; 48(9):1185-9 

Background:  Diclofenac and paracetamol have different mechanisms and sites of action. Therefore, we tested if their combination is more effective for analgesia after tonsillectomy than either drug alone with respect to rescue analgesic consumption and visual analog scale values.
Methods:  The analgesic effects of intravenously administered propacetamol (injectable pro-drug of paracetamol) and diclofenac or a combination on postoperative pain were compared in 71 adult elective tonsillectomy patients in a randomized, double-blind study. After induction of anesthesia the patients received monotherapy with 2 g propacetamol (n = 25) or 75 mg diclofenac (n = 25), or a combined treatment with 2 g propacetamol and 75 mg diclofenac (n = 21) in physiologic saline as an infusion. Postoperatively the propacetamol dosage was repeated twice and diclofenac once on the ward. Oxycodone (0.03 mg kg^-1) was used as a rescue analgesic by patient-controlled analgesia.
Results:  On average the patients needed oxycodone 15.3, 13.2 and 10.6 times in the propacetamol, diclofenac and combination groups, respectively (NS). A verbal rating scale and a visual analog scale were employed for assessing post-tonsillectomy pain, nausea and patient satisfaction in all groups. No statistically significant differences were found between the groups. Twelve of the 25 (48%) patients having received propacetamol complained of pain at the cannulation site.
Conclusion:  Combined treatment with propacetamol and diclofenac with the dosages used provided clinically only a minor advantage over monotherapy with propacetamol or diclofenac with respect to postoperative analgesia or the incidence of side-effects in adult tonsillectomy patients.

BRITISH JOURNAL OF ANAESTHESIA - TOP

A new and feasible model for predicting operative risk
A. Donati, M. Ruzzi, E. Adrario, P. Pelaia, F. Coluzzi, V. Gabbanelli and P. Pietropaoli
British Journal of Anaesthesia 2004 93(3):393-399 

Background. Although the POSSUM (Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity) score can be used to calculate operative risk, its complexity makes its use unfeasible in the immediate clinical setting. The aim of this study was to create a new model, based on ASA status, to predict mortality.
Methods. Data were collected in two hospitals. All types of surgery were included except for cardiac surgery and Caesarean delivery. Age, sex and preoperative information, including the presence of cardiocirculatory and/or lung disease, renal failure, diabetes mellitus, hepatic disease, cancer, Glasgow Coma Score, ASA grade, surgical diagnosis, severity of the procedure and type of surgery (elective, urgent or emergency), were recorded for each patient. The model was developed using a data set incorporating data from 1936 surgical patients, and validated using data from a further 1849 patients. Forward stepwise logistic regression was used to build the model. Goodness of fit was examined using the Hosmer–Lemeshow test and receiver operating characteristic (ROC) curve analyses were performed on both data sets to test calibration and discrimination. In the validation data set, the new model was compared with POSSUM and P-POSSUM for both calibration and discrimination, and with ASA alone to compare discrimination.
Results. The following variables were included in the new model: ASA status, age, type of surgery (elective, urgent, emergency) and degree of surgery (minor, moderate or major). Calibration and discrimination of the new model were good in both development and validation data sets. This new model was better calibrated in the validation data set (Hosmer–Lemeshow goodness-of-fit test: x²=6.8017, P=0.7440) than either P-POSSUM (x²=14.4643, P=0.1528) or POSSUM, which was not calibrated (x²=31.8147, P=0.0004). POSSUM and P-POSSUM had better discrimination than the new model, although this was not statistically significant. Comparing the two ROC curves, the new model had better discrimination than ASA alone (difference between areas, 0.077, SE 0.034, 95% confidence interval 0.012–0.143, P=0.021).
Conclusions. This new, ASA status-based model is simple to use and can be performed routinely in the operating room to predict operative risk for both elective and emergency surgery.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Intravenous lidocaine and ephedrine, but not propofol, suppress fentanyl-induced cough
Chin-Shuang Lin, MD, Wei-Zen Sun, MD, Wei-Hung Chan, MD, Chen-Jung Lin, MD, Huei-Ming Yeh, MD and Martin S. Mok, MD
Canadian Journal of Anesthesia 51:654-659 (2004)

Purpose: The aim of this study was to evaluate the effectiveness of lidocaine, propofol and ephedrine in suppressing fentanyl-induced cough.
Methods: One hundred and eighteen patients were randomly assigned into four groups and the following medications were given intravenously: patients in Group I (n = 31) received normal saline 2 mL, Group II (n = 29) received lidocaine 2 mg·kg^–1, Group III (n = 30) received propofol 0.6 mg·kg^–1 and Group IV (n = 28) received ephedrine 5 mg. At one minute after the study medication, fentanyl 2.5 µg·kg^–1 was given intravenously within two seconds. The occurrence of cough and vital sign profiles were recorded within two minutes after fentanyl bolus by an anesthesiologist blinded to study design.
Results: Sixty-five percent of patients in the placebo group had cough, whereas the frequency was significantly decreased in Groups II (14%) and IV (21%). Although a numerically lower frequency of cough was noted in Group III (37%), it was not statistically different from that of the placebo group. SpO₂ decreased significantly in patients of Group III compared to placebo; one patient experienced hypoxemia necessitating mask ventilation. Patients in Group III showed a decrease in heart rate and systolic blood pressure (2 beats·min^–1 and 8 mmHg vs baseline). Patients in Group IV showed an increase in both measurements (5 beats·min^–1 and 8 mmHg vs baseline). No truncal rigidity was observed throughout the study.
Conclusions: Intravenous lidocaine 2 mg·kg^–1 or ephedrine 5 mg, but not propofol 0.6 mg·kg^–1, was effective in preventing fentanyl-induced cough. The results provide a convenient method to decrease fentanyl-induced cough.

PUB MED - TOP

Nine episodes of anaphylaxis following cystoscopy caused by Cidex OPA (ortho-phthalaldehyde) high-level disinfectant in 4 patients after cytoscopy.
Sokol WN.
J Allergy Clin Immunol. 2004 Aug;114(2):392-7

BACKGROUND: Ortho-phthalaldehyde (OPA) is a high-level disinfectant commonly used for processing heat-sensitive medical devices.
OBJECTIVE: We report 4 patients who experienced 9 episodes of anaphylaxis following cystoscopy after a urology practice switched from using Cidex (glutaraldehyde [GTA]) to OPA for disinfecting their cystoscopes.
METHODS: Allergic evaluations consisted of: skin testing to saline, histamine, glycerin, lidocaine, latex, GTA, and OPA and blood tests for total immunoglobulin E (IgE) and latex specific IgE.
FINDINGS: The 4 patients were evaluated after 3 of them had experienced 2 episodes of anaphylaxis and one of them 3 episodes following outpatient cystoscopy for ongoing evaluation of bladder cancer. Skin testing of subjects and controls to lidocaine, latex, latex specific IgE, and GTA was negative. Skin testing to OPA resulted in immediate wheal and flare reactions in all 4 patients within 20 minutes and late reactions at 24 hours but negative reactions in controls. Subsequent to the testing, 3 of the patients returned for repeat cystoscopy in which GTA but not OPA was used to disinfect the cystoscopes and tolerated the procedure.
CONCLUSIONS: OPA solution should be considered a cause of anaphylactic/allergic reactions following cystoscopy and possibly following instrumentation with other medical devices disinfected by this material.

Effects of fentanyl on the incidence of emergence agitation in children receiving desflurane or sevoflurane anaesthesia.
Demirbilek S, Togal T, Cicek M, Aslan U, Sizanli E, Ersoy MO.
Eur J Anaesthesiol. 2004 Jul;21(7):538-42

BACKGROUND AND OBJECTIVE: In children, emergence agitation frequently complicates sevoflurane and desflurane anaesthesia. The effect of intravenous fentanyl 2.5 microg kg^-1 was examined on the incidence of emergence agitation in children who received desflurane or sevoflurane after midazolam premedication and intravenous thiopental induction.
METHODS: One hundred and twenty children (2-7 yr) undergoing adenoidectomy or tonsillectomy, or both, were studied. All children were premedicated orally with midazolam 0.5 mg kg^-1. After intravenous induction with thiopental and atracurium to facilitate endotracheal intubation, patients were randomly assigned to one of four groups: Patients in Groups 1 and 3 received physiological saline solution, whereas patients in Groups 2 and 4 received intravenous fentanyl 2.5 microg kg^-1 during induction. Anaesthesia was maintained with sevoflurane in Groups 1 and 2 and with desflurane in Groups 3 and 4. After discontinuation of the volatile anaesthetic, the times to tracheal extubation and response to verbal stimuli (emergence time), and emergence behaviours were recorded.
RESULTS: The time to tracheal extubation was significantly shorter in Groups 3 (5.2+/-1.7 min) and (6.4+/-2.1 min) than in Groups 1 (8.1+/-2.1 min) (P = 0.0001 and 0.006, respectively) and 2 (8.8+/-1.9 min) (P = 0.0001). The emergence time was significantly shorter in Group 3 (10.0+/-3.9 min) than in Groups 1 (13.8+/-4.9 min) (P = 0.017) and 2 (14.9+/-4.1 min) (P = 0.003). The incidence rate of severe agitation was 13% in Groups 1 and 3, and 7 and 10% in Groups 2 and 4, respectively (P > 0.05).
CONCLUSIONS: After midazolam premedication and intravenous induction of anaesthesia with thiopental administration of intravenous fentanyl 2.5 microg kg^-1 did not provide any clinically significant benefit on emer gence agitation in children who receive sevoflurane or desflurane anaesthesia.

Comparison of cuff-pressure changes in LMA-Classic and the new Soft Seal laryngeal masks during nitrous oxide anaesthesia in spontaneous breathing patients.
van Zundert AA, Fonck K, Al-Shaikh B, Mortier EP.
Eur J Anaesthesiol. 2004 Jul;21(7):547-52

BACKGROUND AND OBJECTIVE: There are concerns over the intra-cuff pressure of the laryngeal mask and laryngopharyngeal morbidity. In a randomized study, the authors compared cuff-pressure changes in the LMA-Classic and the new disposable Soft Seal laryngeal mask during nitrous oxide anaesthesia.
METHODS: Two-hundred adult patients were randomly assigned to a size 4 laryngeal mask in two equal-sized groups for airway management: (a) the re-usable LMA-Classic, or (b) the new disposable Soft Seal laryngeal mask. Anaesthesia was administered with fentanyl, propofol, nitrous oxide, O2 and sevoflurane. The cuff pressures, adjusted to 45 mmHg at insertion, were monitored continuously until the end of the operation without any further attempt to reduce cuff pressure. On removal of the laryngeal mask, any blood at all was considered positive. Patients were requested to report any sore throat at 2 and 24 h postoperatively.
RESULTS: During nitrous oxide anaesthesia, cuff pressures increased in the LMA-Classic group from 45 to 100.3 mmHg and from 45 to 46.8 mmHg in the Soft Seal laryngeal mask group (P < 0.001). The incidence of sore throat was significantly higher at 2 h postoperatively when using the LMA-Classic, although there was no difference at 24 h following the operation. Macroscopic blood was only seen on four occasions in the LMA-Classic group (not significant).
CONCLUSIONS: During nitrous oxide anaesthesia, cuff pressure increases in the LMA-Classic mask were significantly higher than those of the Soft Seal laryngeal mask. Trauma to patients, as assessed by the incidence of sore throat in the early postoperative period was significantly higher in the LMA-Classic group. Cuff pressures should be monitored during nitrous oxide anaesthesia when LMA-Classic is used but to do so is of less importance when using the disposable Soft Seal laryngeal mask.
 

Comparison of single-breath vital capacity rapid inhalation with sevoflurane 5% and propofol induction on QT interval and haemodynamics for laparoscopic surgery.
Sen S, Ozmert G, Boran N, Turan H, Caliskan E.
Eur J Anaesthesiol. 2004 Jul;21(7):543-6

BACKGROUND AND OBJECTIVE: To compare two techniques to achieve induction of anaesthesia for laparoscopic surgery. A single-breath vital capacity rapid inhalation induction with sevoflurane was compared to intravenous propofol. Their effects on haemodynamics and the QT interval of the electrocardiogram were assessed.
METHODS: Forty-four ASA I-II patients scheduled to undergo elective laparoscopic gynaecological surgery were divided into two groups. In the sevoflurane group (Group S, n = 22), general anaesthesia was induced with a single-breath vital capacity rapid inhalation of sevoflurane 5% with nitrous oxide (N₂O) 65% in O₂and then anaesthesia was maintained with sevoflurane 1-1.5% with N₂O 65% in O₂. In the propofol group (Group P, n = 22), general anaesthesia was induced with propofol 2 mg kg^-1 intravenously and maintained with propofol 6 mg kg^-1 h^-1. Systolic, diastolic and mean arterial pressures, heart rate and end-tidal CO₂values were recorded before anaesthesia (basic value), during the induction period (time X), at 10 min (time Y) and at 30 min (time Z) of CO₂ insufflation in all patients. QT intervals were calculated using Bazett's equation.
RESULTS: Systolic, diastolic and mean arterial pressure values during the induction period (time X) were lower than the basic value in both groups (P < 0.05). In Group S, QTc intervals were significantly longer during the induction period (time X) and at the tenth min of CO₂insufflation (time Y) than Group P (P < 0.05). Five patients at time X and two patients at time Y developed ventricular dysrhythmias, which improved spontaneously in Group S. In Group P, there was no significant difference in QTc intervals and only one patient developed a ventricular dysrhythmia at time Y.
CONCLUSIONS: Single-breath vital capacity rapid inhalation induction technique with sevoflurane can cause prolongation of the QT interval and dysrhythmias, compared with induction and maintenance of anaesthesia with propofol in laparoscopic surgery.
 

Perioperative effects of melatonin and midazolam premedication on sedation, orientation, anxiety scores and psychomotor performance.
Acil M, Basgul E, Celiker V, Karagoz AH, Demir B, Aypar U.
Eur J Anaesthesiol. 2004 Jul;21(7):553-7

BACKGROUND AND OBJECTIVE: To compare the perioperative effects of melatonin and midazolam given in premedication, on sedation, orientation, anxiety scores and psychomotor performance.
METHODS: Exogenous administration of melatonin not only facilitates the onset of sleep but also improves its quality. A prospective, randomized, double-blind, placebo-controlled study was performed in 66 patients undergoing laparoscopic cholecystectomy. Patients were given melatonin 5 mg, midazolam 15 mg or placebo, 90 min before anaesthesia, sublingually. Sedation, orientation and anxiety were quantified before; 10, 30, 60 and 90 min after premedication; and 15, 30, 60 and 90 min after admission to the recovery room. Neurocognitive performance was evaluated at these times, using the Trail Making A and B and Word Fluency tests. The differences between the groups were analysed by ANOVA. Two-way comparisons were performed by Scheffe analysis. Sedation and amnesia were analysed by the chi 2 test.
RESULTS: Patients who received premedication with either melatonin or midazolam had a significant increase in sedation and decrease in anxiety before operation compared with controls. After operation, there was no difference in sedation scores of all groups. Whereas, 30, 60 and 90 min after premedication the melatonin and midazolam groups exhibited a significantly poorer performance in Trail Making A and B tests compared with placebo, there were no significant differences among the groups in terms of neuropsychological performance after the operation. Amnesia was notable only in the midazolam group for one preoperative event.
CONCLUSION: Melatonin premedication was associated with preoperative anxiolysis and sedation without postoperative impairment of psychomotor performance.  

The effect of premedication with OTFC, with or without ondansetron, on postoperative agitation, and nausea and vomiting in pediatric ambulatory patients. Binstock W, Rubin R, Bachman C, Kahana M, McDade W, Lynch JP.
Paediatr Anaesth. 2004 Sep;14(9):759-67

Summary Background: The purpose of this study was to evaluate, in the pediatric ambulatory surgical population, the efficacy of: (i) oral transmucosal fentanyl citrate (OTFC), when given preoperatively, to reduce postoperative excitement associated with sevoflurane, and (ii) intravenous ondansetron to reduce postoperative nausea and vomiting (PONV) associated with OTFC.
Methods: This randomized, double-blinded, placebo controlled study evaluated the efficacy of OTFC [normal dose (ND) = 10-15 microg.kg^-1 or low dose = 100 microg] compared with placebo in the prevention of postoperative agitation; and the efficacy of ondansetron (0.1 mg.kg^-1 to 4 mg) compared with placebo to reduce PONV associated with OTFC.
Results: There were 125 patients evaluated (2-10 years old, ASA class I or II and weight 10-40 kg). Preoperatively OTFC was associated with an increased likelihood of cooperation at baseline (P = 0.018). Postoperatively there was a higher incidence of vomiting in children that received OTFC. The anxiety/agitation of patients entering the PACU was significantly less in children who received OTFC ND (P < 0.001). This effect decreased over time. Patients with respiratory adverse events related to the study drug were significantly higher in groups who received OTFC, however, they were not of clinical significance. OTFC was associated with delays in time for eligibility to PACU discharge (P = 0.003).
Conclusions: Even though OTFC reduced early postoperative agitation the increase in side effects, namely PONV and prolonged recovery times, limits its clinical usefulness. The study demonstrates the tradeoffs between anxiety and agitation vs vomiting, respiratory events and prolonged recovery times. Ambulatory pediatric patients undergoing procedures in which opioids would be routinely used might benefit the most from OTFC combined with ondansetron as part of the anesthetic technique.

Jet injector compared with oral midazolam for preoperative sedation in children.
Fine B, Castillo R, McDonald T, Paisansathan C, Zsigmond E, Hoffman WE.
Paediatr Anaesth. 2004 Sep;14(9):739-43

Summary Background: This study compared onset of sedation and satisfaction with two needleless jet injectors with the oral route for the administration of midazolam.
Methods: Forty-five children ages 1-6 years were randomly assigned to receive either 0.5 mg kg^-1 oral midazolam, 0.2 mg kg^-1 subcutaneous midazolam by J-Tip injector or 0.2 mg kg^-1 intramuscular midazolam by Bioject injector. After midazolam administration the children were monitored for oxygen saturation, heart rate and level of sedation (0, alert; 1, calm; 2, drowsy; 3, dozing; 4, asleep) every 2 min for 20 min by a physician blinded to the route of administration. Patient satisfaction, resistance to treatment, success of delivery, problems with separation, and acceptance of mask at the time of induction were evaluated after midazolam treatment.
Results: The Bioject showed a faster onset of sedation than either the J-Tip injector or the oral midazolam (P < 0.05). The children were significantly less satisfied with the Bioject and J-Tip administration vs oral midazolam (P < 0.05). There were no differences in resistance, success of delivery, problems with separation, mask acceptance, arterial oxygen saturation or heart rate.
Conclusion: Despite children being less satisfied with Bioject injection of midazolam, the procedure is safe, effective and provides a more rapid onset of preoperative sedation in children than either the J-Tip injection or oral route.
 

Perianal blockage with 0.5% bupivacaine for postoperative pain relief in hemorrhoidectomy.
Jirasiritham S, Tantivitayatan K, Jirasiritham S.
J Med Assoc Thai. 2004 Jun;87(6):660-4

Hemorrhoidectomy can be done in many positions under many anesthetic techniques as an ambulatory surgery. Post-procedural pain is frequently severe enough to delay home discharge. A combination between preincisional local anesthetics and general anesthesia looks attractive in terms of preemptive analgesia and starting time of surgery. The study aimed to compare anesthetic time, pain-free period and pain relief in patients with and without 0.5% plain bupivacaine infiltration after mask inhalation, total intravenous anesthesia or endotracheal tube general anesthesia.
MATERIAL AND METHOD: 142 patients were randomized into control (C) and study (S) groups with n = 70 and 72 respectively. Patient characteristics in both groups were: age 40.45 +/- 13.03 VS 37.48 +/- 13.63 years old, BW 59.77 +/- 11.19 VS 58.80 +/- 9.76 kg, male:female 31/39 VS 43/29, PS 1/2/3/E = 48/19/1/2 VS 53/15/3/1 for C and S respectively. All underwent surgery in lithotomy under ET/TIVA/mask: 53/13/4 VS 22/27/23 and anesthetic time was 49.02 +/- 18.04 VS 33.33 +/- 10.31 min (p < 0.05).
RESULTS: Pain-free periods in C and S were 204.44 +/- 878.07 and 540 +/- 298.03 min with median times of 57.5 (n = 67) VS 560 (n = 58) min. Pain severity in S was mainly none or mild degree while in C it was moderate or severe, apparently when analysed in subgroups of ET and TIVA. Analgesic requirements were statistically more in group C.
CONCLUSION: Better postoperative pain relief could be accomplished by preincisional 0.5% plain bupivacaine infiltration after general anesthesia. The technique helped relax anal muscles for surgical ease and avoided patient discomfort in case of a prolonged procedure. Preemptive analgesia and key pain management were discussed.
 

Propofol-based fast-track for ambulatory surgery.
Jirasiritham S, Tantivitayatan K, Jirasiritham S.
J Med Assoc Thai. 2004 Jun;87(6):656-9

The purpose of this study was to provide data of propofol-based total intravenous anesthesia (TIVA) for ambulatory surgery in developing a fast-track technique. One hundred and forty-two patients scheduled for elective surgery were studied: mean (SD) age 42.21 (16.23) years, male to female 72:70, mean (SD) body weight 60.75 (11.67) kg and American Society of Anesthesiologists (ASA) physical status I/II/III 66/38/38. Mean (SD) thiopental induction 225 (55.69) mg was maintained with mean (SD) propofol 199.64 (86.26) mg for mean (SD) anesthetic time 29.02 (11.21) minutes. Various narcotics were used: fentanyl 73.48 +/- 24.38 microg for 123 cases, morphine 3.27 +/- 1.10 mg for 10 cases, remifentanil 492 +/- 105.26 microg for 7 cases and pethidine 23.33 +/- 2.88 mg for 2 cases. Midazolam was given 2.70 +/- 1.05 mg. Patients were positioned in supine, lithotomy or lateral decubitus. One-fourth were PS III with a diagnosis of chronic renal failure and renal transplants coming for incision and drainage of perianal abscess. The mean (SD) wake-up time was 36.02 (17.69) seconds. Only one case (chronic renal failure) had severe hypotension after induction. Anesthetic agents and ideas of fast-track anesthesia were discussed.

TOP