Atlantoaxial Subluxation in Different Intraoperative Head Positions in Patients with Rheumatoid Arthritis.
Tokunaga, Daisaku M.D., Ph.D. ; Hase, Hitoshi M.D., Ph.D. ; Mikami, Yasuo M.D., Ph.D. ; Hojo, Tatsuya M.D., Ph.D. ; Ikoma, Kazuya M.D., Ph.D. ; Hatta, Yoichiro M.D. ; Ishida, Masashi M.D. ; Sessler, Daniel I. M.D. ; Mizobe, Toshiki M.D., Ph.D. ; Kubo, Toshikazu M.D., Ph.D.
Anesthesiology. 104(4):675-679, April 2006.

Background: Disorders of the cervical spine are often observed in patients with rheumatoid arthritis (RA). However, the best head position for RA patients with atlantoaxial subluxation in the perioperative period is unknown. This study investigated head position during general anesthesia for the patients with RA and proven atlantoaxial subluxation.
Methods: During anesthesia of patients with RA and proven atlantoaxial subluxation, the authors used fluoroscopy to obtain a lateral view of the upper cervical spine in four different positions: the mask position, the intubation position, the flat pillow position, and the protrusion position. Copies of the still fluoroscopic images were used to determine the anterior atlantodental interval, the posterior atlantodental interval, and the angle of atlas and axis (C1-C2 angle).
Results: The anterior atlantodental interval was significantly smaller in the protrusion position (2.3 mm) than in the flat pillow position (5.1 mm) (P < 0.05). The posterior atlantodental interval was significantly greater in the protrusion position (18.9 mm) than in the flat pillow position (16.2 mm) (P < 0.05). The C1-C2 angle was, on average, 9.3[degrees] greater in the protrusion position than in the flat pillow position (P < 0.05).
Conclusion: This study showed that the protrusion position using a flat pillow and a donut-shaped pillow during general anesthesia reduced the anterior atlantodental interval and increased the posterior atlantodental interval in RA patients with atlantoaxial subluxation. This suggests that the protrusion position, which involves support of the upper cervical spine and extension at the craniocervical junction, might be advantageous for these patients.

Titration of Propofol for Anesthetic Induction and Maintenance Guided by the
Bispectral Index: Closed-loop versus Manual Control: A Prospective, Randomized,
Multicenter Study.
Liu, Ngai M.D. ; Chazot, Thierry M.D. ; Genty, Antoine M.D. ; Landais, Alain M.D. ;
Restoux, Aymeric ; McGee, KathleenM.D. ; Laloe, Pierre-Antoine ; Trillat, Bernard
M.Sc. ; Barvais, Luc M.D. ; Fischler, Marc M.D.
Anesthesiology. 104(4):686-695, April 2006.

Background: This report describes a closed-loop titration of propofol target control infusion based on a proportional-differential algorithm guided by the Bispectral Index (BIS) allowing induction and maintenance of general anesthesia and compares this to manual propofol target control infusion.
Methods: One hundred sixty-four patients scheduled to undergo elective minor or major surgery were prospectively randomized in a multicenter study into the closed-loop (n = 83) or manual target control infusion group (n = 81). The goal was to reach a BIS target of 50 during induction and to maintain it between 40 and 60 during maintenance. For both groups, remifentanil target control infusion was adjusted manually, and ventilation was without nitrous oxide.
Results: Closed-loop control was able to provide anesthesia induction and maintenance for all patients. During induction, propofol consumption was lower in the closed-loop group (1.4 +/- 0.5 vs. 1.8 +/- 0.6 mg/kg; P < 0.0001), but the duration was longer (320 +/- 125 vs. 271 +/- 120 s; P < 0.0002). Adequate anesthesia maintenance, defined as the BIS in the range of 40-60, was significantly higher in the closed-loop group (89 +/- 9 vs. 70 +/- 21%; P < 0.0001), with a decrease of the occurrence of BIS less than 40 (8 +/- 8 vs. 26 +/- 22%; P < 0.0001). Time from discontinuation of propofol infusion to tracheal extubation was shorter in the closed-loop group (7 +/- 4 vs. 10 +/- 7 min; P < 0.017). Unwanted somatic events and hemodynamic instability were similar.
Conclusion: Automatic control of consciousness using the BIS is clinically feasible and
outperforms manual control.

Predicting Patient Nonappearance for Surgery as a Scheduling Strategy to Optimize Operating Room Utilization in a Veterans' Administration Hospital.
Basson, Marc D. M.D., Ph.D. ; Butler, Timothy W. Ph.D. ; Verma, Harish Ph.D.
Anesthesiology. 104(4):826-834, April 2006.

Background: Previous attempts at improving operating room utilization have generally emphasized more accurate scheduling, starting the first case on time, and reducing turnover time. Surgical case cancellations have largely been ignored except for recommendations for preoperative screening and good physician-patient communication to improve patient compliance.
Methods: A retrospective review of operating room records was initially used to identify reasons for surgical cancellations. This was followed by a retrospective stratified casecontrol study of patient records to identify preexisting factors that predict the failure of patients to appear for surgical procedures as scheduled. Factors assessed included demographics, type of surgical procedure, compliance with previous healthcare visits, substance abuse, mental illness, travel distance, and neurologic problems.
Results: The authors reviewed their operating room utilization and found patient nonappearance rates to be a substantial source of surgical cancellations. Furthermore, multivariate analysis demonstrated that patient nonappearance could be strongly predicted from patient noncompliance with clinic visits and other clinical procedures without reference to the other variables assessed. Further analysis of data from an independent sample of patients confirmed this observation.
Conclusions: Noncompliance with hospital visits for surgical procedures can be predicted from noncompliance with other healthcare encounters. Surgical procedures for previously noncompliant patients should be booked at the end of the operating room day, when the cancellation is least likely to interfere with operating room flow.

Analgesic Treatment after Laparoscopic Cholecystectomy: A Critical Assessment of the Evidence.
Bisgaard, Thue M.D., D.Sc.
Anesthesiology. 104(4):835-846, April 2006.

Acute pain after laparoscopic cholecystectomy is complex in nature. The pain pattern does not resemble pain after other laparoscopic procedures, suggesting that analgesic treatment might be procedure specific and multimodal. Randomized trials of analgesia after laparoscopic cholecystectomy were identified by systematic electronic literature searches (1985 to June 2005) supplemented with manual searching. The trials were categorized by well-defined criteria into high, moderate, or poor methodologic quality. Conclusions were based on trials of high and moderate methodologic quality. In total, 64 randomized analgesic trials were identified, comprising a total of 5,018 evaluated patients. The literature suggests a multimodal analgesic regimen consisting of a preoperative single dose of dexamethasone, incisional local anesthetics (at the beginning or at the end of surgery, depending on preference), and continuous treatment with nonsteroidal antiinflammatory drugs (or cyclooxygenase-2 inhibitors) during the first 3-4 days. Opioids should be used only when other analgesic techniques fail.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Desflurane vs. sevoflurane as the main inhaled anaesthetic for spontaneous breathing via a laryngeal mask for varicose vein day surgery: a prospective randomized study
G. B. Saros, A. Doolke, R. E. Anderson and J. G. Jakobsson
Volume 50 Page 549  - May 2006

Background: Sevoflurane has become widely used in day surgery; however, desflurane may be a valuable alternative even in this setting. This study compares emergence from anaesthesia for day surgery with spontaneous breathing using either desflurane or sevoflurane.
Methods: This prospective, randomized, single-blinded study examined 70 ASA III patients undergoing elective ambulatory varicose vein surgery. Primary endpoint was emergence time (cessation of anaesthetic gas to communicating). Secondary endpoints included post-operative pain, nausea, time to discharge, and patient satisfaction. Patients were anaesthetized according to a standardized protocol including multimodal analgesia and antiemetic therapy and were randomized to receive sevoflurane or desflurane as the main anaesthetic while breathing spontaneously through a laryngeal mask airway. Fresh gas flow was oxygen in air 1 : 2 l/min.
Results: Intra-operative anaesthesia was uneventful apart from airway irritation observed in 5/35 desflurane and 1/35 sevoflurane patients. Emergence was 25–40% faster in patients anaesthetized with desflurane. Pain and post-operative nausea and vomiting (PONV) were equally infrequent in both groups. Overall, patient satisfaction was high with no difference between the groups.
Conclusion: Desflurane is associated with a faster emergence with no differences during the post-operative course except a somewhat higher incidence of airway irritation.

Evaluation of a new recommendation for improved cuffed tracheal tube size selection in infants and small children
B. Salgo, A. Schmitz, G. Henze1, K. Stutz, A. Dullenkopf, S. Neff, A. C. Gerber and M. Weiss
Volume 50 Page 557  - May 2006

Background: The purpose of this study was to evaluate a new recommendation for tracheal tube size selection using second-generation Microcuff paediatric endotracheal tubes (PETs) with optimized outer diameter (OD) of the distal tube.
Methods: With Ethics Committee approval, patients aged from birth to 5 years, requiring general anaesthesia with orotracheal intubation, were included. Tracheal tube sizes were selected as follows: internal diameter (ID) 3.0 mm, birth (if ≥3 kg) to <6 months; ID 3.5 mm, 6 to <18 months; ID 4.0 mm, 18 months to <3 years; ID 4.5 mm, 3 to <5 years. Tracheal tubes with the cuff not inflated were classified as too large if no air leak was obtained at an airway pressure of ≤20 cmH2O. Post-intubation stridor requiring therapy was noted.
Results: Three hundred and fifty children were studied. Nine tracheal tubes (2.6%) were too large and had to be exchanged: in patients requiring tracheal tubes of ID 3.0 mm and 3.5 mm, three and four tracheal tubes, respectively, and, in patients requiring tracheal tubes of ID 4.0 mm and 4.5 mm, one tracheal tube in each group. In three patients (0.9%), post-intubation stridor occurred which required therapy.
Conclusion: The new recommendation presented for the use of second-generation Microcuff PETs with improved OD to ID ratio allows the selection of cuffed tracheal tubes with larger IDs than previously recommended for small children without increased need for tracheal tube exchange or increased incidence of post-intubation stridor in these age groups.

Effect of needle insertion site on ilioinguinal-iliohypogastric nerve block in children
P. Kundra1, T. Sivashanmugam and M. Ravishankar
Volume 50 Page 622  - May 2006

Background: Three different sites of needle insertion have been proposed for ilioinguinal-iliohypogastric (ILIH) nerve block. This double-blind study was designed to assess the quality of analgesia produced from these different sites.
Methods: One hundred and thirty-two children of ASA grade I and II were randomly allocated into four groups to receive no nerve block (control group, n = 30) or ILIH block at 1 cm inferio-medial to the anterior superior iliac spine (ASIS) in group IM (n = 34), 1–2 cm medial to the ASIS in group M (n = 34) and 2 cm superio-medial to the ASIS in group SM (n = 34) with 0.25 ml/kg of 0.25% bupivacaine after induction of anaesthesia. Pain was assessed using the All India Institute of Medical Sciences (AIIMS) pain discomfort scale (APDS) score. The amount and pattern of fentanyl consumed over the ensuing 24-h period was noted.
Results: APDS score and fentanyl requirement were similar in all the study groups but significantly higher until 8 h after surgery in the control group, P < 0.05. Twenty-two out of 102 children in the study groups and all patients in the control group received additional fentanyl during the post-operative period. Only 6 out of 22 children required additional fentanyl supplementation beyond the 30-min interval. Overall failure rate of ILIH nerve block was 6%.
Conclusion: ILIH block can be successfully accomplished from any point if the needle bevel lies between the two muscle planes above and below the internal oblique.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Comparison of ropivacaine 2 mg ml^-1 and prilocaine 5 mg ml^-1 for i.v. regional anaesthesia in outpatient surgery
T. T. Niemi, P. J. Neuvonen and P. H. Rosenberg
British Journal of Anaesthesia 2006 96(5):640-644

Background. Ropivacaine 2 mg ml^-1 (0.2%) provides longer-lasting analgesia after deflation of the tourniquet cuff, with fewer side-effects, than lidocaine 5 mg ml^-1 (0.5%) after i.v. regional anaesthesia (IVRA). Whether ropivacaine 2 mg ml^-1 also exerts this advantage over prilocaine 5 mg ml^-1, the local anaesthetic of choice in IVRA in most European countries was investigated in this study.
Methods. Sixty outpatients scheduled for forearm or hand surgery received IVRA with 40 ml of ropivacaine 2 mg ml^-1 (Ropi) or prilocaine 5 mg ml^-1 (Prilo) in a randomized, double-blinded fashion. The development and recovery of pin-prick analgesia and motor power of the hand, as well as ropivacaine and prilocaine plasma concentrations (n=30), were assessed during and after operation.
Results. Anaesthesia for surgery was adequate in both groups. Pin-prick analgesia was achieved at a similar rate, except in the radial nerve distribution area where at 10 min 60% of Ropi and 90% of Prilo patients had analgesia (P=0.017). At 10 min 100 and 97% had motor block of the hand in the Ropi and Prilo groups, respectively. Recovery of the sensory block in all innervation areas was already observed 2 min after the tourniquet cuff release. At 10 min after releasing the tourniquet cuff 31% of the Ropi patients and none of the Prilo patients still had analgesia in the median nerve distribution (P=0.004). At 12 min, 42% in the Ropi group and none in the Prilo group had decreased grip strength. After the release of the tourniquet, mean plasma concentrations of ropivacaine were higher than those of prilocaine. The highest individual concentration of ropivacaine was 1.65 µg ml^-1 and that of prilocaine 0.6 µg ml^-1. None of the Ropi patients experienced any symptoms of local anaesthetic toxicity.
Conclusions. Compared with prilocaine 5 mg ml^-1, analgesia in IVRA with ropivacaine 2 mg ml^-1 developed slightly more slowly, while motor block developed at a similar rate. After the release of the tourniquet, sensation recovered quickly and at a similar rate in the two groups, except for a slightly slower recovery after ropivacaine in the innervation area of the median nerve, but no surgically useful extended analgesia after the cuff deflation was observed. Despite a 60% lower milligram-dose, ropivacaine plasma concentrations were markedly higher than those of prilocaine.

BIS guided sedation with propofol during spinal anaesthesia: influence of anaesthetic level on sedation requirement
T. Ozkan-Seyhan, M. Orhan Sungur, E. Senturk, M. Karadeniz, A. Basel, M. Senturk and K. Akpir
British Journal of Anaesthesia 2006 96(5):645-649

Background. In this prospective, clinical study we tested the hypothesis whether two different doses of spinal administered bupivacaine and accordingly, two different levels of spinal anaesthesia can affect the dose requirement of propofol during BIS guided sedation.
Methods. Fifty women undergoing vaginal hysterectomy (high spinal group, HS) or transvaginal tape (TVT) procedure for urinary incontinence (low spinal group, LS) under spinal anaesthesia were enrolled to the study. In group HS, 17.5 mg and in group LS, 7.5 mg of hyperbaric bupivacaine were given intrathecally. After 15 min to obtain the appropriate level of spinal anaesthesia, propofol infusion was started at a rate of 100 µg kg–1 min–1 to reach a BIS level of less than 75 (onset time), and titrated to maintain the BIS value between 65 and 75. Propofol infusion was stopped 45 min after placing the spinal to measure the time to reach a BIS level of 90 (recovery time).
Results. Median anaesthetic level was T3 (T1–4) in the HS group and T10 (T9-11) in the LS group. In both the HS and the LS groups, onset time was 226 (47) vs 273 (48) s (P=0.001), recovery time was 234 (47) vs 202 (56) s (P=0.03), total dose of propofol was 2.17 (0.43) vs 3.14 (0.56) mg kg–1 (P<0.001), respectively.
Conclusion. A high spinal block obtained with hyperbaric bupivacaine 17.5 mg was associated with a faster onset, delayed recovery and lower doses of propofol sedation compared with a low spinal block with 7.5 mg of the same drug.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Preoperative predictors of difficult intubation in patients with obstructive sleep apnea syndrome
Jie Ae Kim, MD and Jeong Jin Lee, MD
Canadian Journal of Anesthesia 53:393-397 (2006)

Purpose: It has been speculated that the severity of obstructive sleep apnea syndrome (OSAS) is related to difficult intubation. However, this has not been confirmed in OSAS patients. Thus, we undertook a retrospective study to assess this relationship in patients who had undergone uvulopalatopharyngoplasty (UPPP) surgery for OSAS.
Methods: A retrospective case-control study was undertaken following approval from the Institutional Review Board on human studies. The data from 90 patients with a polysomnograph-confirmed diagnosis of OSAS, who had undergone UPPP surgery under general anesthesia, were used to evaluate the apnea-hypopnea index (AHI), the preoperative lowest arterial saturation, the occurrence of difficult intubation as assessed by the operator intubation difficulty scale score, extubation time, lowest arterial saturation in postanesthesia care unit, and length of stay in postanesthesia care unit. We compared OSAS patients with 90 age and sex-matched control patients with respect to the prevalence of difficult intubation.
Results: The prevalence of difficult intubation was higher in the OSAS group than in the control group (16.7% vs 3.3%, P = 0.003). When evaluating the OSAS group according to the occurrence of difficult intubation, AHI was significantly higher in the difficult intubation subgroup (67.4 ± 22.5 vs 49.9 ± 28.0, P = 0.026), and patients with an AHI  40 showed a significantly higher prevalence of difficult intubation.
Conclusion: This study shows that the occurrence of difficult intubation can be predicted using AHI in patients who undergo UPPP surgery for OSAS.

Suction catheter guided insertion of the ProSeal^TM laryngeal mask airway is superior to the digital technique
Roberto García-Aguado, MD PhD, Juan Viñoles, MD, Joseph Brimacombe, MB CHB FRCA MD, Miguel Vivó, MD, Rosario López-Estudillo, MD and Guillermo Ayala, PhD
Canadian Journal of Anesthesia 53:398-403 (2006)
 
Purpose: We tested the hypothesis that digital insertion of the ProSeal^TM laryngeal mask airway (ProSeal^TM LMA) is more successful when using a suction catheter (SC) as a guide.
Methods: Two hundred and forty-three patients (ASA physical status I–III; aged 18–84 yr) were randomly allocated for the digital or SC-guided technique. The digital technique was performed according to the manufacturer’s instructions. The SC technique involved priming the drain tube with the SC so that it protruded by 15 cm, blindly inserting the SC into the pharynx to a depth of 15 cm, followed by the digital technique. Failed insertion was defined by any of the following criteria: 1) failed passage into the pharynx; 2) malposition; and 3) ineffective ventilation. Any airway trauma, and visible or occult blood was noted. Sore throat, dysphonia and dysphagia were assessed 16 to 24 hr postoperatively.
Results: Fewer insertion attempts were required with the SC-guided technique (P = 0.02), but first attempt and overall success were similar. The time taken to provide an effective airway was shorter for the SC-guided technique (36 ± 24 sec vs 44 ± 28 sec, P = 0.02). A lateral approach was required less frequently with the SC-guided technique (0% vs 4%, P = 0.0004). There were no adverse events. Mouth trauma was more frequent with the digital technique (P = 0.04), but overall trauma was similar. There were no differences in the frequency of visible or occult blood. There were no differences in postoperative airway morbidity.
Conclusions: The SC-guided technique is more frequently successful than the digital technique and is associated with less mouth trauma during insertion of the ProSeal^TM LMA. We suggest that the SC technique may be a useful alternative when the digital technique fails.

PUB MED - TOP

      
Performance of a pediatric ambulatory anesthesia program - a developing country experience.
Hariharan S, Chen D, Merritt-Charles L, Rattan R, Muthiah K.
Paediatr Anaesth. 2006 Apr;16(4):388-93.

Department of Anaesthesia and Intensive Care, Eric Williams Medical Sciences Complex, Trinidad, West Indies.

Summary Background: The aim of this study was to evaluate the performance of a pediatric ambulatory anesthesia program in a tertiary care teaching hospital in a developing country.
Methods: Data on all pediatric patients (<16 years of age) scheduled to have elective day-care surgery during a 1 year period from January 1999 to December 1999 were collected retrospectively. An audit form was used to determine the specialty of the procedures, anesthesia techniques, postoperative analgesia, perioperative complications, unplanned admissions and outcomes with respect to morbidity and mortality.
Results: A total of 763 pediatric ambulatory surgical procedures were performed during the year of 1999. The procedures included general surgery, ENT, orthopedic and plastic surgery. The most common procedure was inguinal hernia repair followed by umbilical hernia repair, adenotonsillectomy and circumcision and 96% of the patients had general anesthesia. There were only three unplanned admissions (0.4%); one for a surgical reason and two for anesthetic reasons. There was no serious morbidity or mortality in any patient.
Conclusions: Performance of pediatric day-care anesthesia has been good in our day-care unit and we have a successful ambulatory surgery program, despite the limitations of a developing country.

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