Volume 4, Issue 1 S A M B A T A L K S - PAGE 3 June, 2004

FROM THE LITERATURE: - TOP


ANESTHESIA AND ANALGESIA - TOP

Sedation with Midazolam Leads to Reduced Pain After Dental Surgery
Cliff K. S. Ong, DDS MS, Robin A. Seymour, DDS PhD, and Juliana M.-H. Tan, MD MS
Anesth Analg 2004;98:1289-1293.

Our principal objective in this study was to evaluate the potential pain reducing effect of IV midazolam in patients undergoing oral surgery. One-hundred-twenty-five patients with impacted mandibular third molars requiring removal under local anesthetic were randomized into 2 groups. The first group (n = 64) was administered IV midazolam by titration until a clinical end-point of conscious sedation followed by local anesthetic before surgery; the second group (n = 61) was the control and was administered only local anesthetic before surgery. The surgery was performed in a standardized manner in both groups by the same surgeon. Outcome measures were four primary end-points: pain intensity as assessed by a 100-mm visual analogue scale and a 4-point categorized scale hourly for 8 h, time to first analgesic, total analgesic (ibuprofen) consumption over the first 48 h, and a 5-point categorical patient global assessment scale (0 = poor, 1 = fair, 2 = good, 3 = very good, and 4 = excellent). Throughout the 8-h investigation period, patients in the midazolam group reported significantly lower pain intensity scores than those in the control group (19.0 ± 13.2 mm versus 28.1 ± 12.8 mm, P < 0.05). The patients in the midazolam group also reported significantly longer time to first analgesic (165.5 ± 56.5 min versus 202.2 ± 79.0 min, P < 0.05), less analgesic consumption (1275 ± 364 mg versus 1688 ± 407 mg, P < 0.001) and better patient global assessment (3.34 ± 0.8 versus 2.4 ± 0.9, P < 0.001). We conclude that systemically administered midazolam is effective in reducing postoperative pain after third molar surgery.
IMPLICATIONS: In this observer blinded study, we found that IV midazolam treatment (0.09 mg/kg) has a pain-reducing effect after third molar surgery, thus improving postoperative pain management.

Water Intoxication and Symptomatic Hyponatremia After Outpatient Surgery
Sanjay M. Bhananker, MD FRCA, Robert Paek, MD, and Monica S. Vavilala, MD
Anesth Analg 2004;98:1294-1296.

Severe hyponatremia is associated with a mortality rate of more than 50%, primarily from cerebral edema and central nervous system dysfunction. Water intoxication is an unusual but potentially lethal cause of perioperative hyponatremia. We report a patient with severe postoperative hyponatremia resulting from excessive perioperative water consumption. Anesthesiologists should maintain an index of suspicion for hyponatremia from water intoxication in patients with neurologic symptoms during the perioperative period. Routine preoperative instructions regarding maximum perioperative water intake and inquiry into any concurrent alternative medical therapies may help to avoid this preventable complication.
IMPLICATIONS: Water intoxication is an unusual but potentially lethal cause of perioperative hyponatremia. We report a patient with severe postoperative hyponatremia resulting from excess perioperative water consumption.  

Interactive music therapy as a treatment for preoperative anxiety in children: a randomized controlled trial.
Kain ZN, Caldwell-Andrews AA, Krivutza DM, Weinberg ME, Gaal D, Wang SM, Mayes LC.
Anesth Analg. 2004 May;98(5):1260-6

In this study, we examined whether interactive music therapy is an effective treatment for preinduction anxiety. Children undergoing outpatient surgery were randomized to 3 groups: interactive music therapy (n = 51), oral midazolam (n = 34), or control (n = 38). The primary outcome of the study was children's perioperative anxiety. We found that children who received midazolam were significantly less anxious during the induction of anesthesia than children in the music therapy and control groups (P = 0.015 and P = 0.005, respectively). We found no difference in anxiety during the induction of anesthesia between children in the music therapy group and children in the control group. An analysis controlling for therapist revealed a significant therapist effect; i.e., children treated by one of the therapists were significantly less anxious than children in the other therapist group and the control group on separation to the operating room (OR) (P < 0.05) and on entrance to the OR (P < 0.05), but not on the introduction of the anesthesia mask (P = not significant). Children in the midazolam group were the least anxious even after controlling for therapist effect (P < 0.05). We conclude that music therapy may be helpful on separation and entrance to the OR, depending on the therapist. However, music therapy does not appear to relieve anxiety during the induction of anesthesia.
IMPLICATIONS: Depending on the music therapist, interactive music therapy may relieve anxiety on separation and entrance to the operating room but appears less effective during the induction of anesthesia.

Prevention of Atelectasis Formation During the Induction of General Anesthesia in Morbidly Obese Patients
Marta Coussa, MD, Stefania Proietti, MD, Pierre Schnyder, MD, Philippe Frascarolo, PhD, Michel Suter, MD PhD, Donat R. Spahn, MD, and Lennart Magnusson, MD PhD
Anesth Analg 2004;98:1491-1495

Atelectasis caused by general anesthesia is increased in morbidly obese patients. We have shown that application of positive end-expiratory pressure (PEEP) during the induction of anesthesia prevents atelectasis formation in nonobese patients. We therefore studied the efficacy of PEEP in morbidly obese patients to prevent atelectasis. Twenty-three adult morbidly obese patients (body mass index >35 kg/m²) were randomly assigned to one of two groups. In the PEEP group, patients breathed 100% oxygen (5 min) with a continuous positive airway pressure of 10 cm H₂O and, after the induction, mechanical ventilation via a face mask with a PEEP of 10 cm H₂O. In the control group, the same induction was applied but without continuous positive airway pressure or PEEP. Atelectasis, determined by computed tomography, and blood gas analysis were measured twice: before the induction and directly after intubation. After endotracheal intubation, patients of the control group showed an increase in the amount of atelectasis, which was much larger than in the PEEP group (10.4% ± 4.8% in control group versus 1.7% ± 1.3% in PEEP group; P < 0.001). After intubation with a fraction of inspired oxygen of 1.0, PaO₂ was significantly higher in the PEEP group compared with the control group (457 ± 130 mm Hg versus 315 ± 100 mm Hg, respectively; P = 0.035) We conclude that in morbidly obese patients, atelectasis formation is largely prevented by PEEP applied during the anesthetic induction and is associated with a better oxygenation.
IMPLICATIONS: Application of positive end-expiratory pressure during induction of general anesthesia in morbidly obese patients prevents atelectasis formation and improves oxygenation. Therefore, this technique should be considered for anesthesia induction in morbidly obese patients.

ANESTHESIOLOGY - TOP

Corticosteroids and Inhaled Salbutamol in Patients with Reversible Airway Obstruction Markedly Decrease the Incidence of Bronchospasm after Tracheal Intubation
Silvanus, Marie-Therese M.D.; Groeben, Harald M.D.; Peters, Jürgen M.D.
Anesthesiology : Volume 100(5) May 2004 pp 1052-7

Background: In patients with bronchial hyperreactivity, airway instrumentation can evoke life-threatening bronchospasm. However, the best strategy for the prevention of bronchospasm has not been defined. Therefore, in a randomized, prospective, placebo-controlled study, the authors tested whether prophylaxis with either combined salbutamol-methylprednisolone or salbutamol alone (1) improves lung function and (2) prevents wheezing after intubation.
Methods: Thirty-one patients with partially reversible airway obstruction (airway resistance > 180%, forced expiratory volume in 1 s [FEV₁] < 70% of predicted value, and FEV₁ increase > 10% after two puffs of salbutamol), who were naive to anti-obstructive treatment, were randomized to receive daily for 5 days either 3 × 2 puffs (0.2 mg) of salbutamol alone (n = 16) or salbutamol combined with methylprednisolone (40 mg/day orally) (n = 15). Lung function was evaluated daily. Another 10 patients received two puffs of salbutamol 10 min before anesthesia. In all patients, wheezing was assessed before and 5 min after tracheal intubation.
Results : Within 1 day, both salbutamol and salbutamol-methylprednisolone treatment significantly improved airway resistance (salbutamol, 4.3 ± 2.0 [SD] to 2.9 ± 1.3 mmHg · s · l^-1; salbutamol-methylprednisolone, 5.5 ± 2.9 to 3.4 ± 1.7 mmHg · s · l^-1) and FEV₁ (salbutamol, 1.79 ± 0.49 to 2.12 ± 0.61 l; salbutamol-methylprednisolone, 1.58 ± 0.66 to 2.04 ± 1.05 l) to a steady state, with no difference between groups. However, regardless of whether single-dose salbutamol preinduction or prolonged salbutamol treatment was used, most patients (8 of 10 and 7 of 9) experienced wheezing after intubation. In contrast, only one patient receiving additional methylprednisolone experienced wheezing ( P = 0.0058).
Conclusions: Pretreatment with either salbutamol alone or salbutamol combined with methylprednisolone significantly and similarly improves lung function within 1 day. However, only combined salbutamol-methylprednisolone pretreatment decreases the incidence of wheezing after tracheal intubation. Therefore, in patients with bronchial hyperreactivity, preoperative treatment with combined corticosteroids and salbutamol minimizes intubation-evoked bronchoconstriction much more effectively than the inhaled β 2-sympathomimetic salbutamol alone.

Comparison of a Lower-lipid Propofol Emulsion with the Standard Emulsion for Sedation during Monitored Anesthesia Care
Song, Dajun M.D., Ph.D.; Hamza, Mohamed A. M.D.; White, Paul F. Ph.D., M.D.; Byerly, Stephanie I. M.D.; Jones, Stephanie B. M.D.; Macaluso, Amy D. M.D.
Anesthesiology : Volume 100(5) May 2004 pp 1072-5

Background: The currently used emulsion formulations of 1% propofol contain 10% soybean oil. However, a new emulsion of 1% propofol (Ampofol) containing 50% less lipid has recently become available for clinical investigation. This study was designed to compare the pharmacodynamic properties of Ampofol with those of a standard formulation (Diprivan) when administered for intraoperative sedation.
Methods: Sixty healthy outpatients undergoing minor operations with local anesthesia were randomly assigned to receive either Ampofol (n = 31) or Diprivan (n = 29) for intravenous sedation. The sedation was initiated with an intravenous loading dose of propofol, 0.75 mg/kg, followed by an initial infusion rate of 50 μg · kg^-1 ·min^-1 to achieve an Observer's Assessment of Alertness/Sedation score of 3. The targeted level of sedation was maintained with a variable-rate propofol infusion during the operation. The onset times to achieving a sedation score of 3, the severity of pain on injection of the loading dose, intraoperative hemodynamic variables, and electroencephalographic Bispectral Index values were recorded. In addition, recovery times, postoperative pain and nausea, and patient satisfaction with the sedative medication were assessed.
Results: There were no significant differences between Ampofol and Diprivan with respect to onset times, dosage requirements, Bispectral Index values, hemodynamic variables, recovery times, or patient satisfaction scores. The incidence of moderate pain on injection was higher in the Ampofol group (26% vs. 7% with Diprivan; P < 0.05).
Conclusions: Ampofol was equipotent to Diprivan with respect to its sedative properties during monitored anesthesia care. Although both groups received pretreatment with intravenous lidocaine, Ampofol was associated with more pain on injection.

Laser Ignition of Surgical Drape Materials in Air, 50% Oxygen, and 95% Oxygen
Wolf, Gerald L. M.D.; Sidebotham, George W. Ph.D.; Lazard, Jackson L. P. M.D.; Charchaflieh, Jean G. M.D.
Anesthesiology : Volume 100(5) May 2004 pp 1167-71.

Background: Operating room fires fueled by surgical drapes and ignited by high-energy surgical tools in air and oxygen-enriched atmospheres continue to occur.
Methods: The authors examined the time to ignition of huck towels and three commonly used surgical drape materials ignited in air with decreasing times to ignition. All tested materials ignited in 50% and 95% oxygen in air, 50% oxygen, and 95% oxygen using a carbon dioxide surgical laser as an ignition source. In addition, a phenol-polymer fabric was tested.
Results: In air, polypropylene and phenol polymer do not ignite. For polypropylene, the laser instantly vaporized a hole, and therefore, interaction between the laser and material ceased. When tested in combination with another material, the polypropylene time to ignition assumed the behavior of the material with which it was combined. For phenol polymer, the laser did not penetrate the material. Huck towels, cotton-polyester, and non-woven cellulose-polyester ignited in air with decreasing times to ignition. All tested materials ignited in 50% and 95% oxygen.
Conclusion: The results of this study reveal that with increasing oxygen concentration, the time to ignition becomes shorter, and the consequences become more severe. The possibility exists for manufacturers to develop drape materials that are safer than existing materials.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

A systematic review of COX-2 inhibitors compared with traditional NSAIDs, or different COX-2 inhibitors for post-operative pain.
Romsing J, Moiniche S.
Acta Anaesthesiol Scand. 2004 May;48(5):525-46.

BACKGROUND: We have reviewed the analgesic efficacy of cyclooxygenase-2 (COX-2) inhibitors compared with traditional non-steroidal anti-inflammatory drugs (NSAIDs), different COX-2 inhibitors, and placebo in post-operative pain.
METHODS: Randomized controlled trials were evaluated. Outcome measures were pain scores and demand for supplementary analgesia 0-24 h after surgery.
RESULTS: Thirty-three studies were included in which four COX-2 inhibitors, rofecoxib 50 mg, celecoxib 200 and 400 mg, parecoxib 20, 40 and 80 mg, and valdecoxib 10, 20, 40, 80 mg were evaluated. Ten of these studies included 18 comparisons of rofecoxib, celecoxib, or parecoxib with NSAIDs. Rofecoxib 50 mg and parecoxib 40 mg provided analgesic efficacy comparable to that of the NSAIDs in the comparisons, and with a longer duration of action after dental surgery but possibly not after major procedures. Celecoxib 200 mg and parecoxib 20 mg provided less effective pain relief. Four studies included five comparisons of rofecoxib 50 mg with celecoxib 200 and 400 mg. Rofecoxib 50 mg provided superior analgesic effect compared with celecoxib 200 mg. Data on celecoxib 400 mg were too sparse for firm conclusions. Thirty-three studies included 62 comparisons of the four COX-2 inhibitors with placebo and the COX-2 inhibitors significantly decreased post-operative pain.
CONCLUSION: Rofecoxib 50 mg and parecoxib 40 mg have an equipotent analgesic efficacy relative to traditional NSAIDs in post-operative pain after minor and major surgical procedures, and after dental surgery these COX-2 inhibitors have a longer duration of action. Besides, rofecoxib 50 mg provides superior analgesic effect compared with celecoxib 200 mg.  

Preoperative stellate ganglion blockade prevents tourniquet-induced hypertension during general anesthesia.
Arai YC, Ogata J, Matsumoto Y, Yonemura H, Kido K, Uchida T, Ueda W.
Acta Anaesthesiol Scand. 2004 May;48(5):613-8.

BACKGROUND: Prolonged and excessive inflation of pneumatic tourniquets leads to a hyperdynamic circulatory response. Sympathomimetic activity is an important factor in tourniquet-induced hypertension. Stellate ganglion block specifically blunts sympathetic efferent nerves and prevents hypertension induced by sympathomimetic stimulation. The present study was performed to investigate the effects of stellate ganglion block (SGB) on arterial pressure and heart rate during prolonged tourniquet use under general anesthesia.
METHODS: Twenty patients scheduled for knee arthroscopy were either treated with 10 ml of 1% lidocaine for SGB (SGB group; n = 10), or intramuscular injection (IM group; n = 10) before tourniquet inflation. Comparisons of systolic and diastolic arterial pressure and heart rate were made before and after the induction of anesthesia, 10 min after the lidocaine treatment, every 5 min during the first 60 min after tourniquet inflation, and immediately before and 5 min following deflation. The maximum values of the circulatory variables were compared.
RESULTS: Tourniquet inflation caused increases in the circulatory variables in both groups. Systolic arterial pressure in the SGB group was significantly lower than that in the IM group after 55 min of tourniquet inflation. Diastolic arterial pressure also was significantly lower in the SGB group immediately before the deflation. The maximum values of the three hemodynamic variables were significantly lower in the SGB group. Arterial pressure significantly decreased after tourniquet deflation in the IM group.
CONCLUSION : Ipsilateral SGB attenuated the hyperdynamic response mediated by prolonged tourniquet inflation during knee arthroscopy.

High-dose bupivacaine, levobupivacaine and ropivacaine in axillary brachial plexus block.
Liisanantti O, Luukkonen J, Rosenberg PH.
Acta Anaesthesiol Scand. 2004 May;48(5):601-6.

BACKGROUND: Racemic bupivacaine is clinically similar to levobupivacaine, or ropivacaine. The drugs were compared in brachial plexus block for the first time in the same randomized and double-blind study.
METHODS: In 90 patients scheduled for hand and forearm surgery, a perivascular axillary brachial plexus block was performed with 45 ml of 5 mg ml^-1 of either racemic bupivacaine-HCl, levobupivacaine-HCl, or ropivacaine-HCl. Sensory (cold) and motor (hand clasp, and movement of elbow) block were scored, and the patient was interviewed in the postoperative evening and the following morning. Time to normal function of the arm was registered.
RESULTS: After similar onsets of sensory block, the sum of completely anaesthetized innervation areas of the four main nerves at 45 min was greater in the ropivacaine group than in the levobupivacaine group (P < 0.01). Simultaneously, complete motor block at the elbow was more frequent in the ropivacaine group (67%) than in the bupivacaine (47%) and levobupivacaine groups (30%) (P < 0.01). In the hand, the corresponding results were 83%, 77%, and 57%, respectively (NS). Two patients in the levobupivacaine and one in the ropivacaine group needed general anaesthesia. Mean duration of the blocks was similar in the bupivacaine, levobupivacaine and ropivacaine groups at 19.3 h, 19.5 h, and 17.3 h, respectively (NS). Two patients were dissatisfied with the long block duration.
CONCLUSION: Ropivacaine-HCl 5 mg ml^-1 produced slightly better sensory and motor block intensity than the same dose of levobupivacaine-HCl. General success in relation to surgery and in the duration of the blocks was similar in the three groups.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Is prolongation of the QTc interval during isoflurane anaesthesia more prominent in women pretreated with anthracyclines for breast cancer?
R. Owczuk, M. A. Wujtewicz, W. Sawicka, M. Wujtewicz and M. Swierblewski
British Journal of Anaesthesia 2004; 92(5): 658-661

Background. Inhalation anaesthetics and anthracycline chemotherapeutic drugs may both prolong the QT interval of the electrocardiogram. We investigated whether isoflurane may induce or augment QTc prolongation in patients who had previously received cancer chemotherapy including anthracycline drugs.
Methods. Forty women undergoing surgery for breast cancer were included in the study. They were divided into two groups: (A) women previously treated with anthracyclines (n=20); and (B) women not treated with antineoplastic drugs (n=20). All patients received a standardized balanced anaesthetic in which isoflurane 0.5 vol% was used. The QT and corrected QT intervals were measured before anaesthesia, after induction and tracheal intubation, after 1, 5, 15, 30, 60 and 90 min of anaesthesia, and during recovery.
Results. In both groups we observed a tendency to QTc prolongation, but statistically significant differences among baseline values and values observed during isoflurane-containing anaesthesia were seen only in group A. During anaesthesia, significant differences in QTc values between the two groups were observed.
Conclusion. In female patients pretreated with anthracyclines for breast cancer, the tendency to QTc prolongation during isoflurane-containing general anaesthesia was more strongly expressed than in patients without previous chemotherapy.

Perioperative use of the modified nasal trumpet in 346 patients
S. Metz
British Journal of Anaesthesia 2004; 92(5): 694-696

Background . The modified nasal trumpet (MNT) is a prepackaged nasopharyngeal airway modified with distal holes and fitted with a 15 mm adaptor allowing connection to an anaesthesia circuit. It may be useful for airway management during anaesthesia.
Methods . After applying a spray to constrict the nasal mucosa, we used the MNT in 346 spontaneously breathing patients for three indications: alone as an airway device during general anaesthesia, to provide supplemental oxygen immediately after extubation instead of by facemask, and to facilitate fibreoptic intubation during general anaesthesia.
Results. The device was successful for giving supplemental oxygen after extubation (n=244) and facilitating fibreoptic intubation (n=28). When used as an airway for general anaesthesia, it was only successful without manipulation in 33 of 74 patients (45%). The MNT was easy to insert in awake patients. We encountered six complications: one MNT folded in the pharynx, and five patients (1.4%) experienced nosebleeds.
Conclusions. The MNT was disappointing as a primary airway device under general anaesthesia but was useful for giving oxygen after extubation and for facilitation of fibreoptic intubation. It can cause nosebleeds.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Ambulatory surgery adult patient selection criteria – a survey of Canadian anesthesiologists
Zeev Friedman , MD, Frances Chung, FRCPC and David T. Wong, MD
Canadian Journal of Anesthesia 51:437-443 (2004)

Purpose: An increasing number of patients with complex medical problems are now considered suitable for ambulatory surgery. The purpose of this study was to identify the current clinical practice of ambulatory surgical patient selection.
Methods: A standardized questionnaire specifying 30 clinical conditions was sent to all practicing anesthesiologists who are members of the Canadian Anesthesiologists’ Society. Recipients were asked to indicate if they would provide ambulatory anesthesia (yes/no answers) for an adult patient with each of those isolated conditions. A 75% agreement was considered a majority opinion.
Results: One thousand three hundred thirty-seven questionnaires were sent and 774 replies were received (57.8%). Over 75% of anesthesiologists were willing to include in their selection criteria American Society of Anesthesiologists’ (ASA) physical status III, patients with low-grade angina pectoris (AP) and congestive heart failure (CHF), prior myocardial infarction, asymptomatic valvular disease, sleep apnea without use of narcotics, morbid obesity (MO) without co-morbidities, insulin dependent diabetes mellitus and malignant hyperthermia (MH) susceptible patients. Over 75% of responders found ASA IV patients, high grade AP and CHF, sleep apnea with postoperative narcotics, MO with co-morbidities and no patient escort to be unsuitable for ambulatory anesthesia.
Conclusion: Our survey demonstrated that medical conditions with extreme grades of severity (mild or severe) are associated with majority opinion to proceed or not to proceed with ambulatory surgery. Issues with over 75% agreement reflect the common practice.
Similar surveys may form a part of patient selection guidelines development in the future.

Forehead is as sensitive as finger pulse oximetry during general anesthesia
Shigekazu Sugino, MD, Noriaki Kanaya, MD PhD, Masahito Mizuuchi, MD, Masayasu Nakayama, MD PhD and Akiyoshi Namiki, MD PhD
Canadian Journal of Anesthesia 51:432-436 (2004)

Purpose: To compare the performance of a forehead probe to a conventional finger pulse oximetry probe in anesthetized patients.
Methods: Eighteen patients participated in the study. Each probe was connected to a Nellcor N-550 pulse oximeter. Anesthesia was induced and maintained with propofol. After intubation, the patients received air to achieve a steady-state of peripheral arterial oxygen saturation (SpO₂). Ventilation was interrupted to induce a hypoxic state. As soon as one of the two SpO₂’s decreased to 90%, the patients’ lungs were ventilated with 100% oxygen. To evaluate the performance of the two pulse oximeters, time to the lowest (TL), time of recovery (TR) and lag times to beginning of SpO₂ decrease (Lag) were measured.
Results: There were no significant differences in TL and TR between forehead and finger pulse oximetry under normal perfusion conditions during general anesthesia. When the axillary artery was compressed to mimic reduced peripheral perfusion, SpO₂ in the forehead decreased sooner than in the finger during hypoxia. The forehead and finger TLs were similar, however, TR was significantly longer in the finger.
Conclusion: The forehead SpO₂ sensor can be used as an alternative to the conventional finger sensor during general anesthesia.

The bispectral index does not correlate with clinical signs of inhalational anesthesia during sevoflurane induction and arousal in children
Rosendo A. Rodriguez, MD PhD, Leslie E. Hall, MD, Scott Duggan, MD and William M. Splinter, MD
Canadian Journal of Anesthesia 51:472-480 (2004)

Purpose: Validation of the bispectral index (BIS) in children requires correlating BIS with several levels of sedation, hypnosis and anesthesia. Our purpose was to compare BIS values with objective assessments of the level of hypnosis in children. We postulated that BIS predicted the level of anesthesia during induction and emergence in children.
Methods: In a prospective observational study, we evaluated the BIS monitor in 87 children (ages: 0.3 to 14 yr) ASA physical status I–II undergoing general surgery under sevoflurane and nitrous oxide. Clinical signs of inhalational anesthesia (CSA), the motor response to surgical incision and signs of arousal were used as indicators of the depth of anesthesia. CSA and BIS measurements were paired every minute during induction and emergence until arousal.
Results: CSA scores decreased during induction and increased during emergence (P < 0.001) and correlated with changes in sevoflurane concentrations (r = –0.46; P < 0.001). BIS was associated with changes in CSA scores during induction (r = 0.49; P < 0.01) and emergence (r = 0.62; P < 0.01), but the ranges of individual BIS values overlapped several levels of hypnosis. A BIS value greater than 50 had a positive predictive value of 25% for distinguishing between responders and non-responders to surgical incision. A BIS score equal or greater than 72 had a predictive value of 63% for discriminating between pre-arousal and arousal.
Conclusions: BIS correlates with several levels of hypnosis during inhalational induction and emergence in children, but individual BIS values show large inter-individual variability. The BIS monitor identified the physiological changes associated with arousal and distinguished the effects of preoperative sedation during emergence. The use of movement as an endpoint of hypnosis during surgical stimulation does not correlate with BIS values in children. The large inter-individual variability of BIS at different levels of anesthetic depth may limit the applicability of BIS to pediatric anesthesia.

PUB MED - TOP

Effect of perioperative administration of ropivacaine with epinephrine on postoperative pediatric adenotonsillectomy recovery.
Park AH, Pappas AL, Fluder E, Creech S, Lugo RA, Hotaling A.
Arch Otolaryngol Head Neck Surg. 2004 Apr;130(4):459-64.

OBJECTIVES: To determine whether perioperative administration of ropivacaine hydrochloride with epinephrine decreases postoperative pain following adenotonsillectomy and to determine the pharmacokinetics of ropivacaine following injection.
DESIGN: Prospective, randomized, double-blind clinical trial.
SETTING: University pediatric ambulatory center.
PARTICIPANTS: A total of 130 children, aged 2 to 12 years, undergoing adenotonsillectomy.
INTERVENTION: Patients received injections, in the tonsillar fossae, of isotonic sodium chloride solution or 0.5% ropivacaine hydrochloride with epinephrine immediately following tonsillectomy.
MAIN OUTCOME MEASURES: Modified objective pain score, time to 100 mL of oral intake, serial plasma ropivacaine levels, use of analgesics, incidence of retching and emesis, and other symptoms.
RESULTS: Fifty-three patients (80%) in the ropivacaine group had detectable plasma levels in at least 3 of the 4 measurement time periods. The mean +/- SD peak concentration (C(max)) was 0.71 +/- 0.33 micro g/mL and the half-life was 0.96 hours. The average modified objective pain scores over all time points favored the placebo group (P =.06 test of between-subjects effects). Similarly, the average behavior score over time favored the placebo group (P =.046 test of between-subjects effects). Neck pain was better in the placebo group when averaged over postoperative days 1, 3, 7, and 14 (P =.04). The percentage of patients who had retching in the recovery room was greater in the ropivacaine group (41% vs 19%, P =.006).
CONCLUSIONS: The injection of 0.5% ropivacaine with epinephrine immediately following adenotonsillectomy results in a measurable plasma level. Ropivacaine with epinephrine injection does not reduce pain postoperatively and adversely affects behavior scores, neck pain scores, and retching frequency compared with placebo. Ropivacaine with epinephrine injection for postoperative analgesia is not recommended for this patient population.

Caudal epidural block for minor gynecologic procedures in outpatient
surgery.
Wong SY, Li JY, Chen C, Tseng CH, Liou SC, Tsai SC, Kau YC, Wong KM.
Chang Gung Med J. 2004 Feb;27(2):116-21.

BACKGROUND: Caudal epidural block (CEB) has become increasingly important
for pediatric analgesia in recent years. However, data regarding CEB in adult ambulatory surgery are scarce. The aim of this study was to verify whether CEB could be applied as a simple, safe and economic method of anesthesia for adult patients undergoing minor gynecologic procedures (MGP).
METHODS: One hundred and seventy-two female patients were enrolled in this study. Each patient received a 20-mL bolus of 1.5% lidocaine caudal epidural injection. The efficacy of CEB was evaluated. Types and duration of surgery, success rate, sensory level of analgesia, caudal epidural depth, complications and duration in the postanesthesia care unit (PACU) were also under investigation.
RESULTS: No side effects occurred and only few hemodynamic changes were noted in the study. All patients experienced excellent surgical anesthesia except seven patients, who required rescue supplement opioids (4.1% of failure rate). The success rate of CEB was 95.9% (165/172). Duration of anesthesia and surgery were 46.66 +/- 11.76 min and 23.08 +/- 9.54 min, respectively. The highest sensory dermatome level reached below T10. The average epidural depth was 3.06 +/- 0.23 cm. No postoperative anti-emetic was given in the study. Only three patients required postoperative narcotics. Four patients had spontaneous voiding before discharge. The average PACU stay was 74.30 +/- 10.80 min.
CONCLUSION: Single-dose CEB with 1.5% lidocaine 20-mL was an easy and simple technique. It provided satisfactory anesthesia for MGP and did not prolong patients'
discharge time. CEB may be another choice of anesthetic technique in such cases of clinical practice.

Effect of Single-Dose fentanyl on the cardiorespiratory system in elderly patients undergoing cataract surgery.
Aydin ON , Ugur B, Kir E, Ozkan SB.
J Clin Anesth. 2004 Mar;16(2):98-103.

STUDY OBJECTIVES: To evaluate the effects of fentanyl on the cardiorespiratory system in elderly patients undergoing cataract surgery with phacoemulsification method.
DESIGN: Randomized, prospective, double-blind study.
SETTING: University hospital.
PATIENTS: 70 ASA physical status I, II, and III patients (>60 years) who underwent cataract surgery with topical anesthesia.
INTERVENTIONS: Patients were randomly divided into two groups. The fentanyl group (35 patients) received fentanyl in 0.7 microg/kg bolus doses in a 2-mL balanced salt solution prior to surgery. The control group (35 patients) received a 2-mL balanced salt solution without any analgesic drug.
MEASUREMENTS AND MAIN RESULTS : Systolic (SBP), diastolic (DBP), mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO₂), respiratory rate (RR), end-tidal carbon dioxide (ETCO₂), inspired CO₂ concentration, and sedation scores were measured preoperatively and at 5, 10, 15, 20, and 30 minutes intraoperatively. Postoperatively, patients were questioned about the presence of intraoperative pain. In the fentanyl group, no significant differences were observed in SPB, DBP, MAP, RR, or peripheral SpO₂. In the control group, RR was higher than baseline values at 10, 15, and 20 minutes. Diastolic blood pressure was higher than baseline values at 20 minutes. End-tidal CO₂ and inspired CO₂ levels were higher than baseline levels in both groups at all measurement times. Intraoperative ETCO₂ levels were higher in the fentanyl group than the control group (p < 0.01). Finally, no hypoxemia was observed in either group.
CONCLUSION: Fentanyl can be used safely in 0.7-microg/kg dosages in elderly patients to improve patient comfort without any cardiorespiratory side effects, when undergoing cataract surgery with topical anesthesia.

Conventional stepwise vs. vital capacity rapid inhalation induction at two concentrations of sevoflurane.
Martin-Larrauri R, Gilsanz F, Rodrigo J, Vila P, Ledesma M, Casimiro C.
Eur J Anaesthesiol. 2004 Apr;21(4):265-71.

BACKGROUND AND OBJECTIVE: A multicentre study was conducted to compare three methods of inhalation induction with sevoflurane in adult premedicated patients.
METHODS: One-hundred-and-twenty-five adult patients of ASA I-II were scheduled for short elective surgical procedures (< 90 min) under general anaesthesia with spontaneous ventilation of the lungs via a laryngeal mask airway. Patients were randomly assigned to one of three groups: conventional stepwise inhalation induction group (Group C) or vital capacity rapid inhalation induction groups at 4.5% (Group VC4.5) or at 8% sevoflurane (Group VC8). Before anaesthetic induction, fentanyl 1 micro kg^-1 was given and the face mask applied with the anaesthetic breathing system primed with sevoflurane 4.5% or 8% in the respective vital capacity groups. Loss of eyelash reflex, time to cessation of finger tapping, laryngeal mask insertion, side-effects and adequacy of induction were recorded.
RESULTS: The time to loss of eyelash reflex was significantly shorter in both vital capacity groups vs. the control group: VC8: 68 +/- 7 s; and VC4.5: 94 +/- 6.5 s vs. C: 118 +/- 6.4s (P < 0.0001). Significant differences were found in all pairwise comparisons for time to cessation of tapping: Group VC8 (62 +/- 7 s), Group VC4.5 (85 +/- 6 s) and Group C (116 +/- 6 s; P < 0.0001). The time to laryngeal mask insertion was significantly shorter in the Group VC8 (176 +/- 13 s) compared with the other two groups, Group VC4.5 (219 +/- 13 s) and Group C (216 +/- 9 s). There were no significant differences in the incidence of side-effects between the three groups.
CONCLUSIONS: Inhalation induction of anaesthesia with sevoflurane with the three techniques tested is safe, reliable and well accepted by the patients. The vital capacity rapid inhalation group primed with sevoflurane 8% was the fastest method with no relevant side-effects.

Valdecoxib versus rofecoxib in acute postsurgical pain: results of a randomized controlled trial.
Christensen KS , Cawkwell GD.
J Pain Symptom Manage. 2004 May;27(5):460-70.

The analgesic efficacy of the cyclooxygenase-2 specific inhibitors, valdecoxib and rofecoxib, were evaluated in patients following oral surgery. In a randomized, double-blind, controlled trial, patients experiencing moderate or severe pain received single-dose valdecoxib 40 mg (n=99), rofecoxib 50 mg (n=101), or placebo (n=50) within 4 hours after multiple third molar extraction with bone removal. Onset of action was significantly faster with valdecoxib 40 mg (30 minutes) compared with rofecoxib 50 mg (45 minutes), as measured by pain intensity difference and pain relief scores (P <== 0.05). Valdecoxib and rofecoxib provided a similar magnitude of analgesic effect, as measured by time-weighted sum of total pain relief, at 6 hours post dosing. However, valdecoxib was significantly superior to rofecoxib with respect to mean time-specific pain intensity difference and pain relief scores from 30 minutes to 1.5 hours post dose (P < 0.05). All treatments were well tolerated. 

Percutaneous electrode guidance using the insulated needle for prelocation of peripheral nerves during axillary plexus blocks.
Capdevila X, Lopez S, Bernard N, Dadure C, Motais F, Biboulet P, Choquet O.
Reg Anesth Pain Med. 2004 May-Jun;29(3):206-11.

BACKGROUND AND OBJECTIVES: Short reports have noted that percutaneous prelocation is helpful in determining the anatomic course of a peripheral nerve, and, thereby, may serve as a guide for block needle insertion. We prospectively studied percutaneous electrode guidance to assist axillary brachial plexus blocks.
METHODS: In 131 consecutive patients, the tip of an insulated needle emitting 5 mA was placed on the skin above and below the axillary artery to obtain a hand motor response characteristic of the median, ulnar, and radial nerves in succession. The current was reduced until all movement had ceased. The needle was then inserted toward the nerve to be blocked, decreasing the intensity from 2 mA to 0.5 mA, so that the same selected motor response was still obtained. The length of the needle inserted was noted, and 1.5% lidocaine was injected. Pain verbal analogic score (VAS) values were noted during both procedures. Complete sensory blockade was evaluated at 30 min.
RESULTS: Rates of successful percutaneous electrode guidance were 94.6% for the median nerve, 89.4% for the radial nerve, 88.5% for the ulnar nerve, and 85.5% for all 3 nerves together. A significant correlation was found between the lowest percutaneous current applied and the depth of the nerve stimulated at 0.5 mA. Pain VAS values were significantly lower during percutaneous stimulation than during needle insertion (P <.05). Sensory block for all 3 nerves was noted in 92% of patients.
CONCLUSIONS: Percutaneous electrode guidance using the insulated needle enabled clinicians to locate the terminal branches of the plexus in the axilla and appreciate their depth. This method could, therefore, minimize patient discomfort and perhaps the risk of nerve trauma.

Bolus application of remifentanil with propofol for dilatation and curettage.
Castillo T, Avellanal M, Garcia de Lucas E.
Eur J Anaesthesiol. 2004 May;21(5):408-11.

BACKGROUND AND OBJECTIVE: This study was designed to determine which single bolus dose of remifentanil in combination with propofol and nitrous oxide is best to control the haemodynamic, autonomous and somatic responses in patients scheduled for dilatation and curettage of the uterine cervix. We evaluated the adequacy of different bolus doses of remifentanil, associated with propofol and nitrous oxide, for dilatation and curettage in a prospective double-blind study.
METHODS: After institutional approval and informed consent, 34 healthy females undergoing curettage to remove material from the uterus after spontaneous abortion were randomized to receive remifentanil 0.5 microg kg^-1 intravenously (i.v.) (Group A; n = 4), 1 microg kg^-1 i.v. (Group B; n = 15) or 1.5 microg kg^-1 i.v. (Group C; n = 15), with propofol 2 mg kg^-1 i.v. in all groups. Anaesthesia was maintained with 60% nitrous oxide in oxygen. Haemodynamic, somatic and autonomic signs of light anaesthesia were registered to assess the response to surgical stress. Recovery times and Aldrete score were recorded at the end of the procedure.
RESULTS: The groups were similar with regard to biometric data and duration of surgery. The poor results using the lowest dose of remifentanil obliged us to abandon this dose. The total dose of remifentanil was larger in Group C (100 +/- 5.7 microg vs. 65 +/- 4.1 microg in Group B; P < 0.05), but more patients required extra bolus injections in Group B (69% vs. 38% in Group C; P < 0.01). Recovery times were significantly shorter in Group C. Aldrete scores when leaving the operation room was similar.
CONCLUSIONS: Remifentanil 1.5 microg kg^-1 i.v. with propofol 2 mg kg^-1 i.v. and 60% nitrous oxide in oxygen provided the best anaesthetic control with the fastest recovery times.

Taking the 'ouch' out - effect of buffering commercial xylocaine on infiltration and procedure pain - a prospective, randomised, double-blind, controlled trial.
Younis I, Bhutiani RP.
Ann R Coll Surg Engl. 2004 May;86(3):213-7.

AIMS: To compare the effect of buffered commercial 1% xylocaine (with 1:200,000 adrenaline) and the unbuffered commercial 1% xylocaine (with 1:200,000 adrenaline) preparation on pain during infiltration and procedure.
PATIENTS AND METHODS: A randomised, double blind controlled trial involving 85 patients who underwent bilateral vasectomy under local infiltration anaesthesia.
RESULTS: Each patient served as his own control by receiving the buffered commercial preparation on one side and unbuffered commercial preparation on the other. Linear analogue pain scores during infiltration and procedure were recorded and analysed. The study demonstrated that pain perceived by the patient both during infiltration and the procedure was significantly lower when buffered commercial xylocaine was used as compared to the pain perceived with the use of unbuffered commercial xylocaine.
CONCLUSIONS: Use of buffered xylocaine is a simple, inexpensive and significantly effective way of reducing pain during infiltration and in surgical procedures performed under local anaesthesia.  

Parents' experiences of caring for their child following day case surgery: a diary study.
Hughes JM, Callery P.
J Child Health Care. 2004 Mar;8(1):47-58.

The development of children's health care over the last 15-20 years has resulted in an increased move towards ambulatory care, including day case surgery, which has implied benefits in reduced hospitalization and cost. The wider impact on the child and family is less clear. The study aimed for greater insight into the impact of day case surgery on the child and family from the parent's perspective. Using a qualitative approach and descriptive and inductive methods, the design focused on the parent's experiences of their child's surgery. Diaries were completed by 11 families over a 7-14-day period following their child's surgery. Findings demonstrated that there were significant issues for families in managing the care of their child with regard to the social impact for the parent and child, emotional issues for parent and child, and the need for formal and informal support systems.  

Analysis of outpatient surgery center safety using an internet-based quality improvement and peer review program.
Keyes GR, Singer R, Iverson RE, McGuire M, Yates J, Gold A, Thompson D.
P last Reconstr Surg. 2004 May;113(6):1760-70

Assessing the quality of care delivered in office-based outpatient surgery centers is difficult because formerly there was no central data collection system. The American Association for Accreditation of Ambulatory Surgery Facilities (AAAASF), in its ongoing effort to assess and improve patient care, has developed an Internet-based quality improvement and peer review program to analyze outcomes for surgery centers it accredits. Reporting is mandatory for all surgeons operating in AAAASF-accredited facilities. Each surgeon must report all unanticipated sequelae and at least six random cases reviewed by an accepted peer review group biannually. A total of 411,670 procedures were analyzed during a 2-year period (from 2001 to 2002). There were 2597 sequelae reported during this period. The most common sequela was hematoma formation following breast augmentation. Infection occurred in 388 cases. Deep vein thrombosis, pulmonary embolism, and intraoperative cardiac arrhythmias were found to occur in a frequency consistent with previous reports. Significant complications (hematoma, hypertensive episode, wound infection, sepsis, and hypotension) were infrequent. A total of 1378 significant sequelae were reported for 411,670 procedures. This calculates to one unanticipated sequela in 299 procedures (an incidence of 0.33 percent). Seven deaths were reported. A death occurred in one in 58,810 procedures (0.0017 percent). The overall risk of death was comparable whether the procedure was performed in an AAAASF-accredited office surgery facility or a hospital surgery facility. This study documents an excellent safety record for surgical procedures performed in accredited office surgery facilities by board-certified surgeons.
 

Ambulatory surgery centers--current legal issues 2004 (Part 1).
Becker S, Szabad M, Foltushansky S.
Health Care Law Mon. 2004 Apr;:9-21.

No abstract available.

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