Nitrous Oxide Revisited: Evidence for Potent Antihyperalgesic Properties.
Richebe, Philippe M.D., Ph.D. ; Rivat, Cyril Ph.D. ; Creton, Cyril M.Sc. ; Laulin, Jean-Paul Ph.D. ; Maurette, Pierre M.D., Ph.D. ; Lemaire, Marc M.D. ; Simonnet, Guy Ph.D. 
Anesthesiology. 103(4):845-854, October 2005

Background: Although opioids are unsurpassed analgesics for surgery, they also induce an N-methyl-d-aspartate-dependent enhancement of postoperative hyperalgesia. Because nitrous oxide (N₂O) has anti-N-methyl-d-aspartate properties, the purpose of this study was to evaluate nitrous oxide ability to prevent such an opioid-induced hyperalgesia in rats.
Methods: First, preventive effects of 50/50% N₂O-O₂ on the development of delayed hyperalgesia observed after inflammatory pain (hind paw carrageenan injection on D0) were examined for several days. Second, the ability of nitrous oxide (10-40%) to limit opioid-induced hyperalgesia induced by fentanyl was evaluated in nonsuffering rats. Third, antihyperalgesic effects of various nitrous oxide concentrations (20-50%) were assessed in both inflammatory and incisional pain models in fentanyl-treated rats (4 x 100 [mu]g/kg subcutaneously). Finally, the analgesic effect of a single dose of morphine was evaluated 24 h after fentanyl administration and nitrous oxide (D0) to assess its preventive effect on acute morphine tolerance in both nonsuffering and hind paw-incised rats.
Results: When applied on D0, nitrous oxide reduced delayed hyperalgesia induced by inflammation. Exposure to nitrous oxide on D0 also reduced opioid-induced hyperalgesia in nonsuffering rats in a dose-dependent manner. In fentanyl-treated rats with inflammatory or incisional pain, nitrous oxide strongly limited both magnitude and duration of hyperalgesia. Moreover, nitrous oxide exposure on D0 opposed development of acute tolerance to analgesic effects of morphine administered on D1 in both nonsuffering and incised fentanyl-treated rats.
Conclusions: Nitrous oxide, an N-methyl-d-aspartate receptor antagonist, prevented the enhancement of pain sensitivity induced by both nociceptive inputs and fentanyl and opposed acute morphine tolerance. Results suggest that perioperative nitrous oxide use reduces exaggerated postoperative pain and morphine consumption.

Preoperative Clinic Visits Reduce Operating Room Cancellations and Delays.
Ferschl, Marla B. M.D. ; Tung, Avery M.D. ; Sweitzer, BobbieJean M.D. ; Huo, Dezheng M.D., Ph.D. ; Glick, David B. M.D., M.B.A.
Anesthesiology. 103(4):855-859, October 2005

Background: Anesthesiologist-directed preoperative medicine clinics are used to prepare patients for the administration of anesthesia and surgery. Studies have shown that such a clinic reduces preoperative testing and consults, but few studies have examined the impact of the clinic on the day of surgery. The authors tested whether a visit to an anesthesia preoperative medicine clinic (APMC) would reduce day-of-surgery case cancellations and/or case delays.
Methods: The authors conducted a retrospective chart review of all surgical cases during a 6-month period at the University of Chicago Hospitals. Case cancellations and rates of first-start case delay over the 6-month period were cross-referenced with a database of APMC attendees in both the general operating rooms and the same-day surgery suite. The impact of a clinic visit on case cancellation and delay in both sites were analyzed separately.
Results: A total of 6,524 eligible cases were included. In the same-day surgery suite, 98 of 1,164 (8.4%) APMC-evaluated patients were cancelled, as compared with 366 of 2,252 (16.2%) in the non-APMC group (P < 0.001). In the general operating rooms, 87 of 1,631 (5.3%) APMC-evaluated patients were cancelled, as compared with 192 of 1,477 (13.0%) patients without a clinic visit (P < 0.001). For both operating areas, APMC patients had a significantly earlier room entry time than patients not evaluated in the APMC.
Conclusions: An evaluation in the APMC can significantly impact case cancellations and delays on the day of surgery.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Peri-operative ketamine for acute post-operative pain: a quantitative and qualitative systematic review (Cochrane review)
R. F. Bell, J. B. Dahl, R. A. Moore and E. Kalso
Volume 49, Issue 10, Page 1405  - November 2005

Background:  Post-operative pain management is usually limited by adverse effects such as nausea and vomiting. Adjuvant treatment with an inexpensive opioid-sparing drug such as ketamine may be of value in giving better analgesia with fewer adverse effects. The objective of this systematic review was to evaluate the effectiveness and tolerability of ketamine administered peri-operatively in the treatment of acute post-operative pain in adults.
Methods:  Studies were identified from MEDLINE (1966 2004), EMBASE (19802004), the Cochrane Library (2004) and by hand searching reference lists from review articles and trials. The manufacturer of ketamine (Pfizer AS, Lysaker, Norway) provided search results from their in-house database, PARDLARS. Randomized and controlled trials (RCTs) of adult patients undergoing surgery, being treated with peri-operative ketamine, placebo or an active control were considered for inclusion.
Results:  Eighteen trials were excluded. Thirty-seven trials were included. Twenty-seven out of 37 trials found that peri-operative ketamine reduced rescue analgesic requirements or pain intensity, or both. Quantitative analysis showed that treatment with ketamine reduced 24-h patient-controlled analgesia (PCA) morphine consumption and post-operative nausea and vomiting (PONV). Adverse effects were mild or absent.
Conclusion: In the first 24 h after surgery, ketamine reduces morphine requirements. Ketamine also reduces PONV. Adverse effects are mild or absent. These data should be interpreted with caution as the retrieved studies were heterogenous and the result of the meta-analysis can not be translated into any specific administration regimen with ketamine.

Local anesthesia for functional endoscopic sinus surgery employing small volumes of epinephrine-containing solutions of lidocaine produces profound hypotension
J. J. Yang, W. Y. Li, Q. Jil, Z. Y. Wang, J. Sun, Q. P. Wang, Z. Q. Li and J. G. Xu
Volume 49, Issue 10, Page 1471 - November 2005

Background: Local anesthetic containing epinephrine is commonly used in many operations for the main purpose of hemostasis. A randomized, controlled, prospective clinical trial was designed to find out hemodynamic changes after local infiltration of different concentrations and/or different dosages of epinephrine during functional endoscopic sinus surgery (FESS) under general anesthesia.
Methods: One hundred and eight adult patients undergoing elective FESS under general anesthesia were randomly allocated into four groups. Group I received 2% lidocaine 2 ml with epinephrine (5 µg/ml); group II received 1% lidocaine 4 ml with epinephrine (2.5 µg/ml); group III received 1% lidocaine 4 ml with epinephrine (5 µg/ml); and group IV received 1% lidocaine 4 ml for local infiltration. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were monitored continuously in the radial artery and recorded in 6 min: before infiltration (baseline), 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, and 6 min after local infiltration. The lowest blood pressure (BP) in this period was also recorded.
Results: Significant hemodynamic changes, particularly a decrease in BP (P < 0.001) with a slight increase in HR (P < 0.001) at approximately 1.5 min and an increase in SBP at approximately 3 min (P < 0.01) after local infiltration, were observed in group I, group II and group III compared with the baseline, but not in group IV. No significant hemodynamic differences were observed between group I, group II and group III at the same time points (P > 0.05).
Conclusion: Local infiltration of low-dose epinephrine causes temporary significant hemodynamic changes particularly a marked decrease in BP during FESS under general anesthesia.

Randomized double-blind comparison of ropivacaine fentanyl and bupivacaine fentanyl for spinal anaesthesia for urological surgery
Y. Y. Lee, W. D. Ngan Kee, K. Muchhal and C. K. Chan
Volume 49, Issue 10, Page 1477  - November 2005

Background: Early studies have suggested that ropivacaine causes less motor block than bupivacaine, which might be advantageous in spinal anaesthesia for short procedures. The aim of this study was to compare plain ropivacaine 10 mg and plain bupivacaine 10 mg, both with fentanyl 15 µg, for spinal anaesthesia in urological surgery.
Methods: This was a prospective randomized double-blind study. After written informed consent had been obtained, 34 ASA IIII patients scheduled for urological surgery were randomly assigned to receive intrathecal injection of either plain ropivacaine 10 mg with fentanyl 15 µg (ropivacaine group) or plain bupivacaine 10 mg with fentanyl 15 µg (bupivacaine group) using a combined spinalepidural technique.
Results: All patients achieved sensory block to the T10 dermatome or higher at 15 min after intrathecal injection. One patient in the ropivacaine group was excluded because of unexpectedly prolonged surgery. The primary outcome, the duration of motor block, was shorter in the ropivacaine group (median, 126 min; interquartile range, 93-162 min) compared with the bupivacaine group (median, 189 min; interquartile range, 157-234 min; difference between medians, 71 min; 95% confidence interval, 28109 min; P = 0.003). The duration of complete motor block was also shorter in the ropivacaine group compared with the bupivacaine group. There was no difference in the onset time of motor block. The characteristics of sensory block and the haemodynamic changes were similar between the groups.
Conclusion: Plain ropivacaine 10 mg plus fentanyl 15 µg provided similar sensory anaesthesia, but with a shorter duration of motor block, compared with plain bupivacaine 10 mg plus fentanyl 15 µg when used for spinal anaesthesia in urological surgery.

Plasma lidocaine levels and risks after liposuction with tumescent anaesthesia
H. Nordström and K. Stånge
Volume 49, Issue 10, Page 1487  - November 2005

Background: It is common today to use tumescent anaesthesia with large doses of lidocaine for liposuction. The purpose of the present study was to evaluate lidocaine plasma levels and objective and subjective symptoms during 20h after tumescent anaesthesia with approximately 35mg per kg bodyweight of lidocaine for abdominal liposuction.
Methods: Three litres of buffered solution of 0.08% lidocaine with epinephrine was infiltrated subcutaneously over the abdomen in eight female patients during monitored intravenous (i.v.) light sedation. Plasma levels of lidocaine and signs of subjective and objective symptoms were recorded every 3h for 20h after liposuction.
Results: Lidocaine 33.2±1.8mg/kg was given at a rate of 116 ± 11 ml/min. Peak plasma levels (2.3 ± 0.63 µg/ml) of lidocaine occurred after 5 17 h. No correlation was found between peak levels and dose per kg bodyweight or total amount of lidocaine infiltrated. One patient experienced tinnitus after 14h when a plasma level of 3.3 µg/ml was recorded.
Conclusion: Doses of lidocaine up to 35 mg/kg were sufficient for abdominal liposuction using the tumescent technique and gave no fluid overload or toxic symptoms in eight patients, but with this dose there is still a risk of subjective symptoms in association with the peak level of lidocaine that may appear after discharge.

A comparison of the vertical infraclavicular and axillary approaches for brachial plexus anaesthesia
H. C. Rettig, M. J. M. Gielen, E. Boersma and J. Klein
Volume 49, Issue 10, Page 1501  - November 2005

Background: This prospective, randomized study compared the efficacy of the vertical infraclavicular and axillary approaches using a single injection blockade of the brachial plexus. The primary endpoint was complete blockade in dermatomes C5-Th1, while secondary endpoints included onset time, motor block, block performance time, surgical success rate, patient satisfaction, and side-effects/complications.
Methods: Sixty patients, American Society of Anesthesiologists physical status I or II, scheduled for surgery of the forearm or hand received either a vertical infraclavicular (n = 30) or an axillary block (n = 30). A single injection of 0.5 ml/kg ropivacaine 7.5 mg/ml was made after electrolocalization of nerve fibres corresponding to the median nerve at maximum 0.5 mA (2 Hz, 0.1 ms). Onset and distribution of analgesia and motor block were assessed at 5, 10, 15, 20, 30 and 60 min after the local anaesthetic injection. A complete block was defined as analgesia in all dermatomes (C5-Th1) at 60 min post-injection.
Results: The vertical infraclavicular approach provided complete blockade in 29 patients (97%) and the axillary approach in 23 patients (77%). Analgesia in C5-C6 dermatomes and corresponding motor block occurred significantly more frequently in the vertical infraclavicular approach, which also had the shortest onset time. Block procedure was quicker in the axillary approach. Side-effects were similar in both groups, and there were no permanent sequelae. Patient satisfaction was equally high in both groups.
Conclusion: The vertical infraclavicular approach provides a more complete block than the axillary approach when using a single injection technique and equal volumes/doses of local anaesthetic.

Intrathecal clonidine does not reduce post-spinal shivering
Y. T. Jeon, Y. S. Jeon, Y. C. Kim, J. H. Bahk, S. H. Do and Y. J. Lim
Volume 49, Issue 10, Page 1509 - November 2005

Background: After general or epidural anesthesia, clonidine is known to be effective in suppressing established shivering. The aim of this study was to assess the preventive effect of intrathecal clonidine on post-spinal shivering compared with intravenous (i.v.) clonidine.
Methods: One hundred and fifty patients scheduled for orthopedic surgery were randomly allocated into three groups to receive either 1 µg/kg clonidine i.v. (IV group) or the same volume of isotonic saline (control and IT groups) at 5 min before spinal anesthesia. Spinal anesthesia was performed with 12 15 mg hyperbaric bupivacaine 0.5% plus either 1 ml of saline (control and IV groups) or 150 µg clonidine (IT group). Shivering was evaluated for a period of 90 min and graded as none, mild, moderate, and severe.
Results: Twenty patients (40%) in the control group and 17 patients (34%) in the IT group showed shivering compared with four (8%) in the IV group. Patients with moderate-to-severe shivering were only seen in the control and IT group, and the maximal intensity of shivering was not different between the two groups. Patients in the IV group were significantly more sedated than the other groups.
Conclusions: The intrathecal administration of clonidine 150 µg fails to prevent post-spinal shivering; by contrast, we have confirmed that i.v. clonidine 1 µg/kg is an effective method to prevent shivering in patients undergoing spinal anesthesia for orthopedic surgery.

The effect of adding intrathecal magnesium sulphate to bupivacaine-fentanyl spinal anaesthesia.
Volume 49, Issue 10, Page 1514 - November 2005

Methods: One hundred and two ASA I or II adult patients undergoing lower extremity surgery were recruited. They were randomly allocated to receive 1.0 ml of preservative-free 0.9% sodium chloride (group S) or 50 mg of magnesium sulphate 5% (1.0 ml) (group M) following 10 mg of bupivacaine 0.5% plus 25 µg of fentanyl intrathecally. We recorded the following: onset and duration of sensory block, the highest level of sensory block, the time to reach the highest dermatomal level of sensory block and to complete motor block recovery and the duration of spinal anaesthesia.
Results: Magnesium caused a delay in the onset of both sensory and motor blockade. The highest level of sensory block was significantly lower in group M than in group S at 5, 10 and 15 min (P < 0.001). The median time to reach the highest dermatomal level of sensory block was 17 min in group M and 13 min in group S (P < 0.05). The mean degree of motor block was also lower in group M at 5, 10 and 15 min (P < 0.001). The median duration of spinal anaesthesia was longer in group M (P < 0.001)
Conclusion: In patients undergoing lower extremity surgery, the addition of IT magnesium sulphate (50 mg) to spinal anaesthesia induced by bupivacaine and fentanyl significantly delayed the onset of both sensory and motor blockade, but also prolonged the period of anaesthesia without additional side-effects.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Tolerability of acute postoperative pain management: nausea, vomiting, sedation, pruritus, and urinary retention. Evidence from published data (REVIEW ARTICLE)
S. J. Dolin and J. N. Cashman
British Journal of Anaesthesia 2005 95(5):584-591

This review examines the evidence from published data concerning the tolerability (indicated by the incidence of nausea, vomiting, sedation, pruritis, and urinary retention), of three analgesic techniques after major surgery; intramuscular analgesia (i.m.), patient-controlled analgesia (PCA), and epidural analgesia. A MEDLINE search of publications concerned with the management of postoperative pain and these indicators identified over 800 original papers and reviews. Of these, data were extracted from 183 studies relating to postoperative nausea and vomiting, 89 relating to sedation, 166 relating to pruritis, and 94 relating to urinary retention, giving pooled data which represent a total of more than 100 000 patients. The overall mean (95% CI) incidence of nausea was 25.2 (19.3–32.1)% and of emesis was 20.2 (17.5–23.2)% for all three analgesic techniques. PCA was associated with the highest incidence of nausea but the emesis was unaffected by analgesic technique. There was considerable variability in the criteria used for defining sedation. The overall mean for mild sedation was 23.9 (23–24.8)% and for excessive sedation was 2.6 (2.3–2.8)% for all three analgesic techniques (significantly lower with epidural analgesia). The overall mean incidence of pruritus was 14.7 (11.9–18.1)% for all three analgesic techniques (lowest with i.m. analgesia). Urinary retention occurred in 23.0 (17.3–29.9)% of patients (highest with epidural analgesia). The incidence of nausea and excessive sedation decreased over the period 1980–99, but the incidence of vomiting, pruritus, and urinary retention did not. From these published data it is possible to set standards of care after major surgery for nausea 25%, vomiting 20%, minor sedation 24%, excessive sedation 2.6%, pruritus 14.7%, and urinary retention requiring catheterization 23%. Acute Pain Services should aim for incidences less than this standard of care.

Why do women wake up faster than men from propofol anaesthesia?
S. C. Hoymork and J. Raeder
British Journal of Anaesthesia 2005 95(5):627-633

Background. It has repeatedly been shown that female patients wake up faster from propofol anaesthesia than male patients. The reason for this is not clear. It is possible that female patients have a more rapid decline in plasma propofol concentration after termination of an infusion, or there could be gender differences in the sensitivity to propofol, making women wake up at higher concentrations. We tested the hypothesis that women wake up faster because of a more rapid decline in plasma propofol.
Methods. Sixty adult patients (30 female and 30 male; ASA I or II) undergoing lower limb surgery under regional anaesthesia, were enrolled in an open study. Propofol was given as the only hypnotic drug, administered by the plasma target control system (TCI) Diprifusor®, titrated to bispectral index (BIS) values of 40–60. Blood samples for propofol measurements were taken just before the propofol infusion was stopped and when the patients woke up.
Results. The female patients woke up faster than the male patients (5.6 vs 8.2 min, P=0.003). The plasma propofol concentration declined more rapidly in the women (P=0.02). An additional significant finding was that the TCI algorithm had a better fit for the women than for the men, with a median prediction error (MDPE) of 2% in the female patients compared with 40% in the male patients (P<0.001). At emergence the men had a significantly higher measured propofol concentration than the women (P=0.05).
Conclusion. The female patients had a more rapid decline in plasma propofol at the end of infusion. Gender differences in pharmacokinetics could explain the faster emergence for female patients after propofol anaesthesia, and gender differences in propofol sensitivity may also be present.

Landmarks of the sacral hiatus for caudal epidural block: an anatomical study
N. Senoglu, M. Senoglu, H. Oksuz, Y. Gumusalan, K. Z. Yuksel, B. Zencirci, M. Ezberci and E. K z lkanat
British Journal of Anaesthesia 2005 95(5):692-695 

Background. This study determined the landmarks for caudal epidural block (CEB) after morphometric measurements of the sacral hiatus on dry sacral bones. Anatomical features of the sacral hiatus of clinical importance during CEB, along with distances and angles of use in detecting the apex, were measured. This provides detailed knowledge of the anatomy of the sacral hiatus and practical landmarks.
Methods. Ninety-six dry sacral bones were used. Anatomical measurements were made with a Vernier caliper accurate to 0.1 mm.
Results. Two sacral bones were excluded since they had total posterior closure defect. Agenesis of the sacral hiatus was detected in six sacral bones. As the posterior superior iliac spines impose on the superolateral sacral crests of the sacrum, the latter were accepted as forming the base of a triangle. The distance between the two superolateral sacral crests and the distances between the sacral apex and the right and left superolateral sacral crest were 66.5 (SD 53.5), 67.1 (10.0) and 67.5 (9.5) mm respectively, on average.
Conclusion. The triangle formed between the apex of the sacral hiatus and the superolateral sacral crests was found to have the features of an equilateral triangle. The sacrum and sacral hiatus are variable anatomical structures. However, the equilateral triangle located between the apex of the sacral hiatus and superolateral sacral crests will certainly be of use in determining the location of the sacral hiatus during CEB.

Pre-oxygenation in the obese patient: effects of position on tolerance to apnoea
F. R. Altermatt, H. R. Muñoz, A. E. Delfino and L. I. Cortínez
British Journal of Anaesthesia 2005 95(5):706-709

Background. In obese patients, reduced functional residual capacity exacerbated by supine position might decrease the effectiveness of pre-oxygenation and the tolerance to apnoea. The aim of this study was to compare the effect of body posture during pre-oxygenation, sitting or supine, on its effectiveness in obese patients.
Methods. Forty obese patients (BMI 35 kg m^-2) undergoing surgery with general anaesthesia were randomly assigned to one of two groups: Group 1 (sitting, em>n=20) or Group 2 (supine, n=20). In the predetermined body position, pre-oxygenation was achieved with eight deep breaths within 60 s and an oxygen flow of 10 litre min^-1. After rapid sequence induction of anaesthesia in decubitus position, the trachea was intubated and the patient was left apneic and disconnected from the anaesthesia circuit until SpO² decreased to 90%. The time taken for desaturation to 90% from the end of induction of anaesthesia was recorded. Arterial blood oxygen tension was measured before (baseline) and after pre-oxygenation. Values were compared with two-way ANOVA and unpaired Student's t-test.
Results. Oxygen and carbon dioxide tensions were similar between groups, both at baseline and after pre-oxygenation. However, the mean time to desaturation to 90% was significantly longer in the sitting group compared with the supine group [mean (SD): 214 (28) vs 162 (38) s, P<0.05].
Conclusions. Pre-oxygenation in sitting position significantly extends the tolerance to apnoea in obese patients when compared with the supine position.

Tracheal intubating conditions and apnoea time after small-dose succinylcholine are not modified by the choice of induction agent
M. I. El-Orbany, N. J. Joseph and M. R. Salem
British Journal of Anaesthesia 2005 95(5):710-714

Background. In a randomized, double-blind clinical trial, we studied the effect of different i.v. induction drugs on tracheal intubation conditions and apnoea time after small-dose (0.6 mg kg^-1) succinylcholine used to facilitate orotracheal intubation at an urban, university-affiliated community medical centre.
Methods. One hundred and seventy-five ASA I and II adult patients scheduled to undergo surgical procedures requiring general anaesthesia and tracheal intubation were allocated to one of five groups according to i.v. anaesthetic induction drug used. General anaesthesia was induced by i.v. administration of lidocaine 30 mg and propofol 2.5 mg kg^-1 (Group 1), thiopental 5 mg kg^-1 (Group 2), lidocaine 30 mg and thiopental 5 mg kg^-1 (Group 3), etomidate 0.3 mg kg^-1 (Group 4), or lidocaine 30 mg and etomidate 0.3 mg kg^-1 (Group 5). After loss of consciousness, succinylcholine 0.6 mg kg^-1 was given i.v. followed by direct laryngoscopy and tracheal intubation after 60 s. Measurements included intubation conditions recorded during laryngoscopy 60 s after succinylcholine administration, and apnoea time.
Results. Overall, clinically acceptable intubation conditions were met in 168 out of the 175 patients studied (96%). They were met in 35/35 patients in Group 1, 33/35 patients in Group 2, 34/35 patients in Group 3, 33/35 patients in Group 4, and 33/35 patients in Group 5. Mean (SD) apnoea time was 4.0 (0.4), 4.2 (0.3), 4.2 (0.6), 4.1 (0.2) and 4.1 (0.2) min respectively in Groups 1–5. There were no differences in the intubation conditions or apnoea times between the groups.
Conclusions. The use of succinylcholine 0.6 mg kg^-1 produced the same favourable intubation conditions and a short apnoea time regardless of the induction drug used.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Brachial plexus block with midazolam and bupivacaine improves analgesia
Koj Jarbo, MD, Yatindra Kumar Batra, MD MNAMS and Nidhi Bidyut Panda, MD
Canadian Journal of Anesthesia 52:822-826 (2005)

Purpose: Adjuncts to local anesthetics for brachial plexus block may enhance the quality and duration of analgesia. Midazolam, a water-soluble benzodiazepine, is known to produce antinociception and enhance the effect of local anesthetics when given epidurally or intrathecally. The purpose of this study was to assess the effect of midazolam added to brachial plexus anesthesia.
Methods: A prospective, randomized, double blind study was conducted on 40 ASA I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly divided into two groups. Patients in Group B (n = 20) were administered 30 mL of 0.5% bupivacaine and Group BM (n = 20) were given 30 mL of 0.5% bupivacaine with midazolam 50 µg·kg^-1. Hemodynamic variables (i.e., heart rate, noninvasive blood pressure), pain scores and rescue analgesic requirements were recorded for 24 hr postoperatively.
Results: The onset of sensory and motor block was significantly faster in Group BM compared to Group B (P < 0.05). Pain scores were significantly higher in Group B compared to Group BM from two hours to 24 hr postoperatively (P < 0.05). Rescue analgesic requirements were significantly less in Group BM compared to Group B (P < 0.05). Hemodynamics and sedation scores did not differ between groups in the post-operative period.
Conclusion: Midazolam (50 µg·kg^-1) in combination with 30 mL of bupivacaine (0.5%) hastened onset of sensory and motor block, and improved postoperative analgesia when used in brachial plexus block, without producing any adverse events.

Bupivacaine/ketamine is superior to intra-articular ketamine analgesia following arthroscopic knee surgery
Yatindra Kumar Batra, MD MNAMS, Rajesh Mahajan, MD, Sushil Kumar Bangalia, MD, Onkar Nath Nagi, MS FAMS and Mandeep Singh Dhillon, MS
Canadian Journal of Anesthesia 52:832-836 (2005)

Purpose: Centroneuraxial and parenteral administration of ketamine has been shown to produce analgesia. However, this analgesia is limited by adverse effects. The purpose of this study was to determine whether ketamine alone or in combination with bupivacaine provides superior pain relief after surgery in patients undergoing knee arthroscopy.
Methods: Sixty patients (classified as ASA status I or II) under-going arthroscopic meniscus repair during general anesthesia were randomized to receive 1.0 mg·kg^-1 ketamine (Group K), 0.25% bupivacaine (Group B) or a combination of 1.0 mg·kg^-1 ketamine and 0.25% bupivacaine (Group BK) to a total volume of 20 mL by intra-articular route following surgery. Visual analogue score in the postanesthesia care unit at 0.5, 1, 2, 4, 6, 8, 12 and 24 hr after surgery, duration of analgesia and subsequent 24 hr consumption of rescue analgesic (dextroproxyphene/acetaminophen) were evaluated.
Results: The results showed significantly higher pain scores in Group K as compared to Group B and Group BK. The duration of analgesia was significantly shorter in Group K as compared to the other two groups (Group B = 5.7 ± 0.8; Group BK = 5.1 ± 1.1 vs Group K = 1.7 ± 0.9 hr; P < 0.05). However, 24 hr consumption of analgesic was similar in the three groups.
Conclusion: We conclude that intra-articular bupivacaine-ketamine combination provides better pain relief than intra-articular ketamine after day care arthroscopic knee surgery.

PUB MED - TOP

Clown Doctors as a Treatment for Preoperative Anxiety in Children: A Randomized, Prospective Study
Laura Vagnoli, PhD; Simona Caprilli, PhD; Arianna Robiglio, BA; and Andrea Messeri, MD
Pediatrics 2005;116;563-567

 

Background. The induction of anesthesia is one of the most stressful moments for a child who must undergo surgery: it is estimated that 60% of children suffer anxiety in the preoperative period. Preoperative anxiety is characterized by subjective feelings of tension, apprehension, nervousness, and worry. These reactions reflect the child’s fear of separation from parents and home environment, as well as of loss of control, unfamiliar routines, surgical instruments, and hospital procedures. High levels of anxiety have been identified
as predictors of postoperative troubles that can persist for 6 months after the procedure. Both behavioral and pharmacologic interventions are available to treat preoperative anxiety in children.
Objective. The aim of this study was to investigate the effects of the presence of clowns on a child’s preoperative anxiety during the induction of anesthesia and on the parent who accompanies him/her until he/she is asleep.
Methods. The sample was composed of 40 subjects (5–12 years of age) who had to undergo minor day surgery and were assigned randomly to the clown group (N₂0), in which the children were accompanied in the preoperative room by the clowns and a parent, or the control group (N₂0), in which the children were accompanied by only 1 of his/her parents. The anxiety of the children in the preoperative period was measured through the Modified Yale Preoperative Anxiety Scale instrument (observational behavioral checklist to measure
the state anxiety of young children), and the anxiety of the parents was measured with the State-Trait Anxiety Inventory (Y-1/Y-2) instrument (self-report anxiety behavioral instrument that measures trait/baseline and state/situational anxiety in adults). In addition, a questionnaire for health professionals was developed to obtain their opinion about the presence of clowns during the induction of anesthesia, and a self-evaluation form was developed to be filled out by the clowns themselves about their interactions with the child.
Results. The clown group was significantly less anxious during the induction of anesthesia compared with the control group. In the control group there was an increased level of anxiety in the induction room in comparison to in the waiting room; in the clown group anxiety was not significantly different in the 2 locations. The questionnaire for health professionals indicated that the clowns were a benefit to the child, but the majority of the
staff was opposed to continuing the program because of perceived interference with the procedures of the operating room. The correlation between the scores of the form to self-evaluate the effectiveness of the clowns and of the Modified Yale Preoperative Anxiety Scale is significant for both the waiting room and induction room.
Conclusions. This study shows that the presence of clowns during the induction of anesthesia, together with the child’s parents, was an effective intervention for managing children’s and parents’ anxiety during the preoperative period. We would encourage the promotion of this form of distraction therapy in the treatment of children requiring surgery, but the resistance of medical personnel make it very difficult to insert this program in the activity of the operating room.

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