Safety and Efficacy of the Cyclooxygenase-2 Inhibitors Parecoxib and Valdecoxib after Noncardiac Surgery
Anesthesiology. 104(3):518-526, March 2006.
Nussmeier, Nancy A. M.D. ; Whelton, Andrew A. M.D., F.A.C.P. ; Brown, Mark T. M.D. ; Joshi, Girish P. M.D. ; Langford, Richard M. F.R.C.A. ; Singla, Neil K. M.D.; Boye, Mark E. M.P.H., Ph.D. ; Verburg, Kenneth M. Ph.D. 
Anesthesiology. 104(3):518-526, March 2006

Background: Valdecoxib and its intravenous prodrug parecoxib are reported to increase thromboembolic risk after coronary artery bypass grafting. The authors conducted a randomized trial to examine their safety and analgesic efficacy in patients recovering from major noncardiac surgical procedures.
Methods: The trial was randomized and double-blind, with 10 days of treatment and 30 days of follow-up. Patients (n = 1,062) received either parenteral parecoxib for 3 days and oral valdecoxib for the rest of the treatment period or placebo medications throughout. The frequency of predefined adjudicated postrandomization adverse events, including cardiovascular thromboembolism, renal dysfunction, gastroduodenal ulceration, and wound-healing complications, was assessed in each group. Secondary efficacy endpoints included patients' pain ratings, opioid analgesic consumption (recorded as morphine equivalents), and reports of opioid-related adverse effects.
Results: Predefined adjudicated adverse events had similar frequencies among patients who received parecoxib and valdecoxib (2.7%) and placebo patients (3.2%) (P = 0.58), including cardiovascular thromboembolic events (1.0% in each group; P = 1.0). Placebo patients consumed more morphine equivalents (66.2 +/- 92.4 mg) than did patients receiving parecoxib and valdecoxib (43.2 +/- 65.7 mg) (P < 0.001). Placebo patients had higher mean pain ratings on each of study days 2-10 (P < 0.01) and reported more opioid-related symptom distress on days 2-6 (P < 0.01).
Conclusions: Parecoxib and valdecoxib are useful adjuncts to opioids for the treatment of postoperative pain in noncardiac surgical patients. Further study will be required to determine the safety profile of parecoxib and valdecoxib administered to patients with known atherosclerotic disease after noncardiac surgery.

Heart Rate Variability Predicts Severe Hypotension after Spinal Anesthesia
Hanss, Robert M.D.; Bein, Berthold M.D.; Weseloh, Hendrik M.S.; Bauer, Martin M.D.; Cavus, Erol M.D.; Steinfath, Markus M.D.; Scholz, Jens M.D.; Tonner, Peter H. M.D. 
Anesthesiology. 104(3):537-545, March 2006

Background: Hypotension due to vasodilatation after spinal anesthesia (SA) may be harmful. Heart rate variability, an indirect measure of autonomic control, may predict hypotension.
Methods: One hundred patients were studied. Retrospectively, heart rate variability was analyzed in 30 patients, classified depending on the lowest systolic blood pressure (SBP) after SA. Seventy patients were studied prospectively, assigned to one of two groups by their low to high frequency ratio (LF/HF) before SA. Sensitivity and specificity of LF/HF for prediction of decrease of SBP greater 20% of baseline were tested.
Results: Retrospective analysis showed differences of LF/HF depending on the degree of hypotension after SA. Prospective analysis demonstrated significant differences of SBP after SA depending on baseline LF/HF (mean +/- SD): low LF/HF (1.3 +/- 0.7) = > SBP: 91 +/- 8% of baseline versus high LF/HF (5.5 +/- 2.4) = > SBP: 66 +/- 10% of baseline (P < 0.05). Baseline LF/HF as well as high frequency and proportional decrease of SBP after SA correlated significantly, in contrast to baseline hemodynamic parameters heart rate and SBP. A receiver operator curve characteristic analysis showed a sensitivity and specificity of LF/HF > 2.5 of 85% to predict SBP decrease of greater than 20% of baseline after SA.
Conclusions: Heart rate variability analysis before SA may predict hypotension after SA with high sensitivity and specificity. LF/HF may be a tool to detect patients at high risk of hypotension due to SA. This indicates that the predictive value of LF/HF is superior to established predictors.

Opioid-induced Hyperalgesia: A Qualitative Systematic Review
Angst, Martin S. M.D. ; Clark, J David M.D., Ph.D. 
Anesthesiology. 104(3):570-587, March 2006

Opioids are the cornerstone therapy for the treatment of moderate to severe pain. Although common concerns regarding the use of opioids include the potential for detrimental side effects, physical dependence, and addiction, accumulating evidence suggests that opioids may yet cause another problem, often referred to as opioid-induced hyperalgesia. Somewhat paradoxically, opioid therapy aiming at alleviating pain may render patients more sensitive to pain and potentially may aggravate their preexisting pain. This review provides a comprehensive summary of basic and clinical research concerning opioid-induced hyperalgesia, suggests a framework for organizing pertinent information, delineates the status quo of our knowledge, identifies potential clinical implications, and discusses future research directions.

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The influence of the weather and the phase of the moon on post-operative nausea and vomiting
M. Kredel, C. Goepfert, D. Bassi, N. Roewer and C. C. Apfel
Volume 50 Page 488  - April 2006

Background: Post-operative nausea and vomiting (PONV) is believed and previously reported to be influenced by the weather and the phase of the moon. We therefore determined the effects of specific and general weather patterns as well as the lunar phase on PONV in adults undergoing balanced inhalation anaesthesia.
Methods: The incidence of PONV was prospectively evaluated in 1801 patients undergoing elective surgical, urologic and head and neck procedures. Air temperature, barometric pressure, air water vapour pressure and the general weather situation were obtained from the National Weather Institute in Germany on the days of surgery. Corresponding categories of temperature, pressure, vapour pressure and their day-to-day changes, the general weather situation and the phase of the moon were used to group the patient data. The differences between the proportion of patients having PONV and the proportion predicted to have PONV according to their calculated risk were determined for each category. Further, bivariate and multivariate testing was applied.
Results: Within 24 h after anaesthesia, PONV occurred in 555 of the patients (31%). There was no correlation between weather conditions and PONV occurrence or between the phase of the moon and PONV occurrence. Even when corrected for the patients' risk and other potentially confounding factors in multivariate logistic regression analysis, no statistically significant impact of the hypothesized factors could be detected.
Conclusion: These data suggest that neither the weather nor the phases of the moon have any clinically relevant effect on the incidence of PONV after general anaesthesia.

 
Clonidine addition prolongs the duration of caudal analgesia
T. S. Yildiz, F. Korkmaz, M. Solak and K. Toker
Volume 50 Page 501  - April 2006

Background: In this study, using a dose-ranging design, we examined the effects of clonidine with 0.125% bupivacaine on the duration of post-operative analgesia in caudal anaesthesia in children.
Methods: We conducted a controlled, prospective study of clonidine in caudal anaesthesia in 60 children, aged 1–10 years, undergoing elective inguinal hernia repair. Induction and maintenance of anaesthesia were performed by inhalation of sevoflurane and nitrous oxide. The children were randomized in a double-blind fashion to four groups, and were given a caudal anaesthetic with either 0.125% plain isobaric bupivacaine (1 ml/kg) or bupivacaine plus 1, 1.5 or 2 µg/kg of clonidine. The blood pressure and heart rate were recorded peri-operatively. Analgesia was evaluated by the modified Children's Hospital of Eastern Ontario Pain Scale (mCHEOPS) or a visual analogue scale (VAS). Paracetamol was given when the mCHEOPS score was greater than five or when the VAS score was greater than 30 mm. The monitoring of scores for pain, haemodynamic changes and post-operative nausea and vomiting was performed by nurses blind to the study allocation.
Results: The duration of analgesia was found to be significantly longer in the group given bupivacaine plus 2 µg/kg of clonidine (median, 650 min; range, 300–900 min). Peri-operative hypotension and bradycardia, post-operative respiratory depression and motor block were not recorded in any patient.
Conclusions: The addition of clonidine to 0.125% bupivacaine prolongs the duration of post-operative analgesia without any respiratory or haemodynamic side-effects.

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Tracheal tube-tip displacement in children during head-neck movement—a radiological assessment
M. Weiss, W. Knirsch, O. Kretschmar, A. Dullenkopf, M. Tomaske, C. Balmer, K. Stutz, A. C. Gerber and F. Berger
British Journal of Anaesthesia 2006 96(4):486-491

Background. Aims of this study were to assess the maximum displacement of tracheal tube tip during head-neck movement in children, and to evaluate the appropriateness of the intubation depth marks on the Microcuff Paediatric Endotracheal Tube regarding the risk of inadvertent extubation and endobronchial intubation.
Methods. We studied children, aged from birth to adolescence, undergoing cardiac catheterization. The patients' tracheas were orally intubated and the tracheal tubes positioned with the intubation depth mark at the level of the vocal cords. The tracheal tube tip-to-carina distances were fluoroscopically assessed with the patient supine and the head-neck in 30° flexion, 0° neutral position and 30° extension.
Results. One hundred children aged between 0.02 and 16.4 yr (median 5.1 yr) were studied. Maximum tracheal tube-tip displacement after head-neck 30 degrees extension and 30degrees flexion demonstrated a linear relationship to age [maximal upward tube movement (mm)=0 0.71xage (yr)+9.9 (R2=0.893); maximal downward tube movement (mm)=0.83xage (yr)+9.3 (R2=0.949)]. Maximal tracheal tube-tip downward displacement because of head-neck flexion was more pronounced than upward displacement because of head-neck extension.
Conclusions. The intubation depth marks were appropriate to avoid inadvertent tracheal extubation and endobronchial intubation during head-neck movement in all patients. However, during head-neck extension the tracheal tube cuff may become positioned in the subglottic region and should be re-adjusted when the patient remains in this position for a longer time.

Evaluation of the CTrach^TM—an intubating LMA with integrated fibreoptic system
A. Timmermann, S. Russo and B. M. Graf
British Journal of Anaesthesia 2006 96(4):516-521

Background. The laryngeal mask airway CTrach^TM (CTrach) is a variant of the intubating laryngeal mask airway. It provides visualization of the larynx during intubation and is designed to increase the success rates of ventilation and tracheal intubation.
Methods. Sixty healthy anaesthetized and paralysed patients with normal airways were studied. The success rates of ventilation and intubation using CTrach^TM were determined. Laryngeal view scoring ranged from grade I (full view of arytenoids and glottis), II (arytenoids and glottis partly visible), III (view of arytenoids, glottis or epiglottis blurred, or view clear with only epiglottis visible) to IV (no part of larynx identifiable). Adjusting manoeuvres were undertaken to improve the laryngeal view in grades II or worse.
Results. CTrach insertion and ventilation was possible in all patients. Initial views were scored as grade I in 22 (36.7%), grade II in 14 (23.3%), grade III in 7 (11.7%) and grade IV in 17 (28.3%) patients. Adjusting manoeuvres were undertaken in 38 patients with grade II and worse (63.3%), resulting in improved views of grade I in 33 (55.0%), grade II in 18 (30.0%), grade III in 4 (6.7%) and grade IV in 5 (8.3%) patients. Tracheal intubation was successful in 58 (96.6%) patients at first attempt and in one at second. Tracheal intubation failed once.
Conclusions. In 60 patients with normal airways, the CTrach was used successfully for ventilation, with successful tracheal intubation in 59 patients. Tracheal intubation can be successful despite grade III or IV views.

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Preemptive gabapentin reduces postoperative pain and opioid demand following thyroid surgery
Hussain Al-Mujadi, FRCA, Abdul Rahman A-Refai, FRCPC, Mario Gueorguiev Katzarov, MD, Najat Abbas Dehrab, MD, Yatindra Kumar Batra, MD MNAMS and Abdul Rahim Al-Qattan, MD PhD
Canadian Journal of Anesthesia 53:268-273 (2006)

Purpose: Gabapentin is reported to possess antihyperalgesic and antiallodynia properties. Recently, reports have indicated that gabapentin may have a place in the treatment of postoperative pain. In this study, we sought to determine whether preemptive use of gabapentin reduced postoperative pain and morphine demand following thyroidectomy.
Methods: In this prospective, randomized, double-blind clinical trial, we gave gabapentin 1200 mg or placebo two hours prior to induction of anesthesia to patients undergoing elective thyroidectomy. Post-thyroidectomy pain was assessed on a visual analogue scale at rest and during swallowing in the first 24 hr postoperatively. All patients received morphine 3 mg iv every five minutes until visual analogue scale scores were 4 or less at rest, and 6 or less with swallowing. Total morphine consumption for each patient was recorded from zero to 24 hr postoperatively.
Results: Thirty-seven patients in the gabapentin group and 35 patients in the placebo group completed the study. Overall, pain scores at rest and during swallowing in the gabapentin group were significantly lower when compared with the placebo group. Total postoperative morphine consumption in the gabapentin group was 15.2 ± 7.6 mg (mean ± SD) vs 29.5 ± 9.9 mg in the placebo group (P < 0.001). No significant differences in side effects were observed between groups.
Conclusions: Preoperative gabapentin decreased pain scores and postoperative morphine consumption in patients following thyroid surgery.

Perioperative care of patients with obstructive sleep apnea – a survey of Canadian anesthesiologists
Kim Turner, MD MSc, Elizabeth VanDenKerkhof, DRPH, Miu Lam, PhD and William Mackillop, MB CHB
Canadian Journal of Anesthesia 53:299-304 (2006)

Purpose: At present, there are no guidelines and insufficient evidence to guide the decision-making of anesthesiologists in the perioperative care of patients with obstructive sleep apnea (OSA). The purpose of this study was to examine the current perioperative care provided, and to obtain opinions from anesthesiologists regarding evidence/consensus based guidelines to assist them in providing care to patients with OSA.
Methods: Canadian anesthesiologists were sent a postal questionnaire examining their opinions and perioperative care of patients with OSA. Respondents were asked to indicate the postoperative monitoring they would most likely select for two clinical scenarios, representing administration of a general and regional anesthetic, which was altered to reflect: treatment of OSA; use of postoperative opioids; presence of morbid obesity; and increased severity of OSA.
Results: The survey had a response rate of 70% (746/1,063). Sixty-seven percent of respondents provided perioperative care to one to five patients with OSA per month, and 72% reported not having departmental policies for care of OSA patients. Ninety-two percent reported asking patients about OSA preoperatively. There was 75% respondent agreement in two of the five alterations of the general anesthesia case scenario and in none of the alterations of the regional anesthesia case scenario. Eighty-two percent reported that guidelines would assist them in caring for patients with OSA.
Conclusion: This study demonstrates a variation amongst anesthesiologists in their postoperative monitoring of patients with OSA. The majority surveyed do not have departmental policies, and believed that guidelines would assist them in providing care to patients with OSA.

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Thyroidectomy Using Monitored Local or Conventional General Anesthesia: An Analysis of Outpatient Surgery, Outcome and Cost in 1,194 Consecutive Cases.
Spanknebel K, Chabot JA, Digiorgi M, Cheung K, Curty J, Allendorf J, Logerfo P.
World J Surg. 2006 Mar 13;

BACKGROUND: Critical appraisal of safety, feasibility, and economic impact of thyroidectomy procedures using local (LA) or general anesthesia (GA) is performed.
METHODS: Consecutive patients undergoing thyroidectomy procedures were selected from a prospective database from January 1996 to June 2003 of a single-surgeon practice at a tertiary center. Statistical analyses determined differences in patient characteristics, outcomes, operative data, and length of stay (LOS) between groups. A cohort of consecutive patients treated in 2002-2003 by all endocrine surgeons at the institution was selected for cost analysis.
RESULTS: A total of 1,194 patients underwent thyroidectomy, the majority using LA (n = 939) and outpatient surgery (65%). Female gender (76%), body mass index >/=30 kg/m(2) (29%), median age (49 years), and cancer diagnosis (45%) were similar between groups. Extent of thyroidectomy (59% total) and concomitant parathyroidectomy (13%) were similarly performed. GA was more commonly utilized for patients with comorbidity [15% vs. 10%, Anesthesia Society of America (ASA) >/=3; P < 0.001], symptomatic goiter (13% vs. 7%; P = 0.004), reoperative cases (10% vs. 6%; P = 0.01), and concomitant lymphadenectomy procedures (15% vs. 3%; P < 0.001). GA was associated with significant increase in LOS >/=24 hours (17 % vs. 4%) or overnight observation (49 % vs. 14%), P < 0.001. Operative room utilization was significantly associated with type of anesthesia (180 min vs. 120 min, GA vs. LA, P < .001) and impacted to a lesser degree by surgeon operative time (89 minutes vs. 76 minutes, GA vs. LA; P = .089). Overall morbidity rates were similar between groups (GA 5.8 % vs. LA 3.2%). The actual total cost (ATC) per case for GA was 48% higher than for LA and 30% higher than the ATC for all procedures (P = 0.006), with the combined weighted average impacted by more LA cases (n = 217 vs. 85).
CONCLUSION: These data from a large, unselected group of thyroidectomy patients suggest LA results in similar outcomes and morbidity rates to GA. It is likely that associated LA costs are lower.

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