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

FROM THE LITERATURE: - TOP


ANESTHESIA AND ANALGESIA - TOP

The Development and Application of an Instrument for Assessing Resident Competence During Preanesthesia Consultation
Getúlio Rodrigues de Oliveira Filho, MD, and Leonardo Schonhorst, MD
Anesth Analg 2004;99:62-69

In this study, we aimed to construct, validate, and apply an instrument for assessing resident performance at outpatient preanesthesia consultation (PAC). A focus group and a Delphi panel of experts defined component items of a typical outpatient PAC, which could be used as indicators of competence. Items were incorporated in a checklist, which was further validated in a sample of consultations performed by board-certified anesthesiologists. The resulting instrument contained 37 items, grouped into five domains (physician-patient relationship, medical history, physical examination, patient education, and preanesthesia records), with high construct validity, high discriminant validity, moderate internal consistency, and high probability of inter-raters agreement. The instrument was applied to evaluate the performance of seven first-year residents at 317 consecutive PAC. Data were analyzed by constructing exponentially weighted moving average charts for domain and total scores. Statistically significant differing levels of performance could be consistently detected. Applying exponentially weighted moving average charts to the sequential analysis of the developed checklist scores can reliably assess resident performance at the devised criteria. The Preanesthesia Consultation Scoring Checklist is a potentially useful instrument for both formative and summative assessment of residents during their training in processes involved in outpatient preanesthesia evaluation.
IMPLICATIONS: A resident assessment score at outpatient preanesthesia consultation was constructed, validated, and applied. Quality assurance statistics were used for its interpretation. The instrument proved useful in scoring resident performance and in identifying different patterns of performance.

Nocturnal Arterial Oxygen Desaturation and Episodic Airway Obstruction After Ambulatory Surgery
T. Andrew Bowdle, MD PhD
Anesth Analg 2004;99:70-76

Some patients experience disordered breathing during sleep and arterial oxygen desaturation after major inpatient surgery. We performed this study to determine whether similar events occur after ambulatory surgery. Forty-five ambulatory surgery patients received an unrestricted anesthetic. Continuous unattended nocturnal recordings of breathing pattern and oxygen saturation were made in the patients’ homes before surgery and during the first and second postoperative nights. Nine patients had a respiratory disturbance index >10 and/or >1% of recording time with oxygen saturation <90% on at least one study night. These nine patients had a significantly older median age and a significantly larger median body mass index. Their median respiratory disturbance index and median percentage of time with oxygen saturation <90% were significantly higher on the first postoperative night than on the preoperative night.
IMPLICATIONS: We studied nocturnal breathing before and after ambulatory surgery in 45 patients without a history of the sleep apnea syndrome. Nine patients had abnormal breathing that frequently resulted in hypoxemia. Oxygen desaturation occurred in the presence and absence of obvious upper airway obstruction. Five of the nine abnormally breathing patients had abnormal breathing before and after surgery.

A Randomized Comparison of a Multimodal Management Strategy Versus Combination Antiemetics for the Prevention of Postoperative Nausea and Vomiting
Ashraf S. Habib, MBBCh MSc, FRCA, William D. White, MPH, Steve Eubanks, MD, Theodore N. Pappas, MD, and Tong J. Gan, MB FRCA, FFARCS(I)
Anesth Analg 2004;99:77-81

A multimodal management strategy for the prevention of postoperative nausea and vomiting (PONV) appears to be superior to single-drug prophylaxis. We tested the hypothesis that a multimodal PONV prophylaxis regimen incorporating total IV anesthesia (TIVA) with propofol and a combination of ondansetron and droperidol is more effective than a combination of these antiemetics in the presence of an inhaled anesthetic. Ninety patients undergoing laparoscopic cholecystectomy were randomized to one of three groups. Group 1 (multimodal group) received TIVA with propofol, droperidol, and ondansetron. Group 2 (combination group) received droperidol and ondansetron with isoflurane and nitrous oxide for the maintenance of anesthesia. Group 3 (TIVA group) received propofol for the induction and maintenance of anesthesia. The complete response rate (no PONV and no rescue antiemetic) at 2 h after surgery was 90%, 63%, and 66% in Groups 1, 2, and 3, respectively (P < 0.05, Group 1 versus Group 2). At 24 h, the complete response rate was 80%, 63%, and 43% in Groups 1, 2, and 3, respectively (P < 0.05, Group 1 versus Group 3). Patient satisfaction was also greater in the multimodal group than in the other two groups in the postanesthesia care unit (P < 0.05). In conclusion, the multimodal management strategy for PONV was associated with a higher complete response rate and greater patient satisfaction when compared with similar antiemetic prophylaxis with inhaled anesthesia or TIVA with propofol.
IMPLICATIONS: A multimodal management strategy for postoperative nausea and vomiting was superior to combination antiemetic prophylaxis with inhaled anesthetic or total IV anesthesia with propofol.

Pain During Injection of Propofol: The Effect of Prior Administration of Butorphanol
Anil Agarwal, MD, Mehdi Raza, MD, Sanjay Dhiraaj, MD, Ravinder Pandey, MD, Devendra Gupta, MD, Chandra Kant Pandey, MD, Prabhat K Singh, MD, and Uttam Singh, PhD
Anesth Analg 2004;99:117-119

Propofol causes pain or discomfort on injection in 28%–90% of patients. A number of techniques have been tried for minimizing propofol-induced pain with variable results. We compared the efficacy of butorphanol and lidocaine for prevention of propofol-induced pain. One-hundred-fifty ASA I–II adults, undergoing elective surgery were randomly assigned into 3 groups of 50 each. Group I (NS) received normal saline, Group II (L) received lidocaine 2% (40 mg), and Group III (B) received butorphanol 2 mg. All patients received pretreatment solutions made in 2 mL with normal saline administered over 5 s. One min after pretreatment patients received one-fourth of the total calculated dose of propofol (2.5 mg/kg) over 5 s. Assessment of pain with IV propofol was done by using a four-point scale: 0 = no pain, 1 = mild pain, 2 = moderate pain and 3 = severe pain at the time of propofol injection. In the control Group 39 (78%) patients had pain during propofol injection as compared to 21 (42%) and 10 (20%) in the lidocaine and butorphanol groups, respectively (P < 0.05). Butorphanol was the most effective. We therefore suggest the IV pretreatment with butorphanol 2 mg for attenuation of pain associated with propofol injection.
IMPLICATIONS: Pain associated with IV injection of propofol is seen in 28%–90% patients. Pretreatment with butorphanol 2 mg and lidocaine 40 mg attenuated the incidence and severity of pain associated with propofol injection. Butorphanol was the most effective and can be used routinely to prevent propofol pain.

ANESTHESIOLOGY - TOP

A Comparison of Infraclavicular Nerve Block versus General Anesthesia for Hand and Wrist Day-case Surgeries . (ACCOMPANIED BY EDITORIAL SHOWN BELOW)
Hadzic, Admir M.D., Ph.D.; Arliss, Jeffrey M.D.; Kerimoglu, Beklen M.D.; Karaca, Pelin Emine M.D.; Yufa, Marina M.D.; Claudio, Richard E. B.S.; Vloka, Jerry D. M.D., Ph.D.; Rosenquist, Richard M.D.; Santos, Alan C. M.D., M.P.H.; Thys, Daniel M. M.D.
Anesthesiology 2004;101(1):127-132

Background: General anesthesia (GA) and brachial plexus block have been used successfully for surgery on the upper extremities. Controversy exists as to which method is more suitable in outpatients undergoing hand and wrist surgery. The authors hypothesized that infraclavicular brachial plexus block (INB) performed with a short-acting local anesthetic would result in shorter time to discharge home as compared with "fast-track" GA.
Methods: After obtaining written informed consent, 52 patients (aged 18-65 yr, American Society of Anesthesiologists physical status I-III) were randomly assigned to receive either an INB or GA under standardized protocols (INB = 3% 2-chloroprocaine + HCO₃ + epinephrine 1:300,000, followed by propofol sedation; GA = 12.5 mg dolasetron, propofol induction, followed by laryngeal mask airway insertion and desflurane for maintenance; 0.25% bupivacaine for wound infiltration). At the conclusion of the procedure, nurses blinded to the study goals and the anesthetic technique used a modified Aldrete score to decide whether patients could bypass the postanesthesia care unit. Additional data were collected regarding time to postoperative pain, ambulation, home readiness, and incidence of adverse events.
Results: More patients in the INB group (79%) met the criteria to bypass the postanesthesia care unit compared with patients in the GA group (25%; P < 0.001). Compared with patients in the GA group, fewer patients in the INB group had pain (visual analog scale score > 3) on arrival to the postanesthesia care unit (3% vs. 43%; P < 0.001). None of the patients in the INB group requested treatment for pain while in the hospital, compared with 48% of patients in the GA group (P < 0.001). Patients in the INB group were able to ambulate earlier (82 +/- 41 min) compared with those in the GA group (145 +/- 70 min; P < 0.001). Time to home readiness and discharge times were shorter for patients in the INB group (100 +/- 44 and 121 +/- 37 min) compared with those in the GA group (203 +/- 91 and 218 +/- 93 min; P < 0.001). Adverse events (e.g., nausea, vomiting, sore throat) occurred less frequently in patients undergoing INB as compared with those undergoing GA.
Conclusion: Infraclavicular brachial plexus block with a short-acting local anesthetic was associated with time-efficient anesthesia, faster recovery, fewer adverse events, better analgesia, and greater patient acceptance than GA followed by wound infiltration with a local anesthetic in outpatients undergoing hand and wrist surgery.

For Outpatients, Does Regional Anesthesia Truly Shorten the Hospital Stay and How Should We Define Postanesthesia Care Unit Bypass Eligibility? (EDITORIAL)
Williams, Brian A. M.D., M.B.A.
Anesthesiology 2004;101(1):3-6

No abstract available.

Sciatic Nerve Block via Posterior Labat Approach Is More Efficient Than Lateral Popliteal Approach Using a Double-injection Technique: A Prospective, Randomized Comparison.
Taboada, Manuel M.D.; Rodriguez, Jaime M.D., Ph.D.; Alvarez, Julian M.D., Ph.D.; Cortes, Joaquin M.D., Ph.D.; Gude, Francisco M.D.; Atanassoff, Peter G. M.D.
Anesthesiology 101(1):138-142

Background: For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine.
Methods: A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery.
Results: A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05).
Conclusion: A double injection with a relatively low volume of 0.75% ropivacaine generated a higher success rate and a shorter onset time of sensory and motor blockade after the classic Labat approach than after a lateral popliteal approach.

Time Sequence of Sensory Changes after Upper Extremity Block: Swelling Sensation Is an Early and Accurate Predictor of Success
Paqueron, Xavier M.D.; Gentili, Marc E. M.D.; Willer, Jean Claude M.D., Ph.D.; Coriat, Pierre M.D.; Riou, Bruno M.D., Ph.D.
Anesthesiology 2004;101(1): 162-168

Background: Sensory assessment to estimate spread and effectiveness of a peripheral nerve block is difficult because no clinical test is specific for small sensory fibers. Occurrence of a swelling illusion (SI) during a peripheral nerve block corresponds to the impairment of small sensory fibers. The authors investigated the usefulness of SI in predicting successful peripheral nerve block by assessing the temporospatial correlation between progression of sensory impairment in cutaneous distributions anesthetized and localization of SI during peripheral nerve block installation.
Methods : Interscalene, infracoracoid, or sciatic nerve blocks were performed using a nerve stimulator and 1.5% mepivacaine in 53 patients, with a total of 201 nerves to be anesthetized. Pinprick, cold, warm, touch, and proprioception were assessed every 3 min, while patients were asked to describe their perception of size and shape of their anesthetized limb and localization of these illusions. Data are presented as mean +/- SD and percentage (95% confidence interval).
Results: Failure occurred in 12 cutaneous distributions out of a total of 201 theoretically blocked nerves. SI appeared earlier than warmth impairment (4.3 +/- 2.7 vs. 6.2 +/- 2.0 min; P < 0.05), always corresponding to successfully anesthetized cutaneous distributions, with the exception of 1 patient, who developed SI in 2 cutaneous distributions while sensory testing indicated failure in 1 distribution. SI successfully predicted the blockade of a cutaneous distribution with a sensitivity of 1.00 (0.98-1.00), a specificity of 0.92 (0.65-0.99), and an accuracy of 0.99 (0.97-1.00).
Conclusions: Swelling illusion may provide an early assessment of the success of a peripheral nerve block in unsedated patients.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Anaesthesia in day case laparoscopic female sterilization: a comparison of two anaesthetic methods
L. K. Rognås and P. ElkjÆr
Acta Anaesthesiologica Scandinavica 2004 ; 48:899-902 

Background: Laparoscopic sterilization (LS) in women is a procedure frequently carried out in a day case setting. The purpose of the study was to measure postoperative pain, nausea and vomiting (PONV), the incidence of unplanned overnight admissions and patient satisfaction with two different anaesthetic methods.
Methods: From August 1997 to January 1999 the LS patients were anaesthetized with propofol + fentanyl/alfentanil, N₂O and atracurium, and from January 1999 to end of 2001 they were given TIVA with propofol + remifentanil. Postoperative pain was managed with standardized high doses of paracetamol and NSAID in both groups. Data were collected from hospital records and from questionnaires given to all the patients.
Results: Six hundred and eighty-one women were sterilized. There were no significant differences in postoperative pain between the two groups, with 8.2 and 12.1 per cent, respectively, experiencing severe pain. Significantly fewer patients experienced moderate or severe postoperative nausea after the introduction of remifentanil anaesthesia (3.3 vs. 11.7%, P = 0.001). Eleven patients (1.8%) were admitted overnight, with no difference between the two groups. 94.5% and 96.3% of the patients were either satisfied or very satisfied with their treatment (P = 0.50).
Conclusion: Both anaesthetic methods provide equally good postoperative pain relief, few unplanned admissions and a high degree of patient satisfaction when combined with postoperative paracetamol and NSAID. Patients anaesthetized with remifentanil and propofol have less postoperative nausea.

Is a double-injection technique superior to a single injection in posterior subgluteal sciatic nerve block?
M. Taboada, J. Álvarez, J. Cortés, J. Rodríguez and P. G. Atanassoff
Acta Anaesthesiologica Scandinavica 2004; 48:883-887

Background and objectives:  Currently, no information is available on the effects of a double-injection technique on onset time and efficacy following subgluteal sciatic nerve blockade. We hypothesized that the success rate and time to onset of subgluteal nerve block following a double-injection technique would be superior to that after a single injection.
Methods:  Fifty ASA I or II patients undergoing foot or ankle surgery randomly received a single or double injection subgluteal sciatic nerve block. Group S (n=25) received a single injection of 30 ml of 0.75% ropivacaine to the sciatic nerve. In Group D (n = 25), 15 ml of the same solution was injected to each sciatic nerve component. Completion of sensory and motor blockade, and patient acceptance, was evaluated by a blinded anesthesiologist.
Results:  Complete sensory and motor blockade of the foot was achieved faster with the double injection (7.4 [5.9-8.8] min and 12.3 [10.4-14.2] min, respectively) than with the single-injection technique (12.5 [10.7-14.3] min and 18.8 [16.7-21.0] min, respectively) (P<0.001 and P<0.001, respectively). Success rate and acceptance were similar in both groups. Severe or moderate discomfort during the procedure was less frequent after a single injection (P = 0.013).
Conclusions : Both the single- and double-injection technique for subgluteal sciatic nerve blockade resulted in acceptable anesthesia in most patients. The double injection generated a faster onset of anesthesia than the single injection. However, the double-injection technique caused more patient discomfort during establishment of the nerve block.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Comparability of Narcotrend ^TM index and bispectral index during propofol anaesthesia
S. Kreuer, J. Bruhn, R. Larsen, P. Bialas and W. Wilhelm
British Journal of Anaesthesia 2004 93(2):235-240

Background. The dimensionless Narcotrend^TM (NCT) index (MonitorTechnik, Germany, version 4.0), from 100 (awake) to 0, is a new index based on electroencephalogram pattern recognition. Transferring guidelines for titrating the Bispectral Index^TM (BIS, Aspect Medical Systems, USA, version XP) to the NCT index depends on their comparability. We compared the relationship between BIS and NCT values during propofol anaesthesia.
Methods. Eighteen adult patients about to have radical prostatectomy were investigated. An epidural catheter was placed in the lumbar space and electrodes for BIS and NCT were applied as recommended by the manufacturers. After i.v. fentanyl 0.1 mg, anaesthesia was induced with a propofol infusion. After intubation, patients received bupivacaine 0.5% 15 ml via the epidural catheter. Forty-five minutes after induction, the propofol concentration was increased to substantial burst suppression pattern and then decreased. This was done twice in each patient, and BIS and Narcotrend values were recorded at intervals of 5 s. The efficacy of NCT and BIS in predicting consciousness vs unconsciousness was evaluated using the prediction probability (P K).
Results. We collected 38 629 artefact-free data pairs of BIS and NCT values from the respective 5-s epochs. Because of artefacts, another 5008 epochs had been excluded from data analysis (3855 epochs for the NCT index alone, 245 epochs for the BIS alone and 908 epochs for both indices). Mean (SD) values in awake patients were 94 (6) for Narcotrend and 91 (8) for BIS. With loss of the eyelash reflex, both values were significantly reduced, to 72 (9) for NCT (P<0.001) and to 77 (11) for the BIS index (P<0.001). The P K value for loss of eyelash reflex was similar for BIS (0.95) and NCT (0.93). Decreasing BIS values coincided with decreasing NCT values. A sigmoid model [NCT index=52.8+26.8/(1+exp(–(BIS–78.3)/4.8)) ^0.4; r=0.52] described the correlation between BIS and NCT index in a BIS range between 100 and 50. For BIS values lower than 50, a second sigmoid model with a correlation of r=0.83 was applied [NCT index=6.6+45.3/(1+exp(–(BIS–29.8)/2.4)) ^0.6r=0.83]. The relationship between burst suppression ratio (BSR) and NCT index was best described by the following sigmoid model: NCT index=265/(1+exp((–BSR+108)/–49); r=0.73.
Conclusions. We found a sufficient correlation between BIS and NCT index, but deviations from the line of identity in some ranges require attention. Therefore, a simple 1:1 transfer from BIS to NCT values is not adequate. Our results might serve as a blueprint for the rational translation of BIS into NCT values.

Updates in perioperative coagulation: physiology and management of thromboembolism and haemorrhage
T. Bombeli and D. R. Spahn
British Journal of Anaesthesia 2004 93(2):275-287

Understanding of blood coagulation has evolved significantly in recent years. Both new coagulation proteins and inhibitors have been found and new interactions among previously known components of the coagulation system have been discovered. This increased knowledge has led to the development of various new diagnostic coagulation tests and promising antithrombotic and haemostatic drugs. Several such agents are currently being introduced into clinical medicine for both the treatment or prophylaxis of thromboembolic disease and for the treatment of bleeding. This review aims to elucidate these new concepts and to outline some consequences for clinical anaesthesia and perioperative medicine.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Contemporary anesthesia ventilators incur a significant "oxygen cost"
Gudmundur K. Klemenzson, MD and Misha Perouansky, MD
Canadian Journal of Anesthesia 51:616-620 (2004)

Purpose: Anesthesia ventilators use oxygen or oxygen/air mixtures to drive the bellows during controlled ventilation. As a practitioner may find himself in a situation that the only available oxygen source is a compressed oxygen cylinder, it is important to know the oxygen consumption of anesthesia ventilators during controlled ventilation.
Methods: We tested the Datex-Ohmeda 7900 ventilator mounted on an Excel 210 anesthesia machine under a variety of conditions. For comparison, we also tested the Ohmeda 7800 and the Dräger AV-2 ventilator under control conditions. All experiments were performed using a test lung.
Results: The oxygen consumption of the AV-2 and the Datex-Ohmeda ventilators averaged 302 ± 17 L·hr^-1 and 564 ± 68 to 599 ± 56 L·hr^-1, respectively (P < 0.01 AV-2 vs 7800 and 7900). When using an E-type cylinder, this would result in a mean time to alarm of 93 min and 54 to 57 min, respectively. Decreased lung compliance increased the oxygen consumption to 848 ± 16 L·hr^-1.
Conclusions: Machine-driven mechanical ventilation incurs a significant "oxygen cost." We show that the amount of oxygen consumed by mechanical ventilation with contemporary anesthesia ventilators is influenced by patient-dependent factors and may greatly exceed the amount of oxygen delivered to the patient.

PUB MED - TOP

Residual sleepiness after N₂O sedation: a randomized control trial.
Lichtor JL, Lane BS, Zimmerman MB 
BMC Anesthesiol. 2004 May 12;4(1):5

BACKGROUND: Nitrous oxide (N₂O) provides sedation for procedures that result in constant low-intensity pain. How long do individuals remain sleepy after receiving N₂O? We hypothesized that drug effects would be apparent for an hour or more.
METHODS : This was a randomized, double blind controlled study. On three separate occasions, volunteers (N = 12) received 100% oxygen or 20% or 40% N₂O for 30 min. Dependent measures included the multiple sleep latency test (MSLT), a Drug Effects/Liking questionnaire, visual analogue scales, and five psychomotor tests. Repeated measures analysis of variance was performed with drug and time as factors.
RESULTS : During inhalation, drug effects were apparent based on the questionnaire, visual analogue scales, and psychomotor tests. Three hours after inhaling 100% oxygen or 20% N₂O, subjects were sleepier than if they breathed 40% N₂O. No other drug effects were apparent 1 hour after inhalation ceased. Patients did not demonstrate increased sleepiness after N₂O inhalation.
CONCLUSION: We found no evidence for increased sleepiness greater than 1 hour after N₂O inhalation. Our study suggests that long-term effects of N₂O are not significant.

Knee arthroscopy with different anesthesia methods: a comparison of efficacy and cost.
Forssblad M, Jacobson E, Weidenhielm L.
Knee Surg Sports Traumatol Arthrosc. 2004 May 28 [Epub ahead of print]

To evaluate the cost and time effectiveness for different anesthesia methods when performing knee arthroscopy, this study compared three different anesthesia methods. Four hundred healthy patients scheduled for knee arthroscopy were randomized to either local anesthesia (LA) ( n=200), spinal anesthesia (SA) ( n=100) or general anesthesia (GA) ( n=100). The LA arthroscopies were performed in a facility set up in our outpatient department without anesthesia service. The SA and GA arthroscopies were performed in our central operating department with full anesthesia service. Comparisons were made between total hospital stay, anesthesia time, surgery time, recovery time, pharmaceutical and total cost. The total hospital time was 130.4 min (SD 35.14, range 63-383) in the LA group compared to 280.4 min (SD 79.29, range 155-589) in the GA group (p<0.001). The total hospital time in the GA group was also shorter than that of 350.3 min (SD 65.37, range 198-502) in the SA group (p<0.001). The time from start of anesthesia to start of surgery was significantly longer in the LA group, 39.2 min (SD 13.13, range 17-87), compared to 20.1 min (SD 4.93, range 11-35) in the SA group and to 17.6 min (SD 4.64, range 9-44) in the GA group. There were no differences in the surgery time for the three groups. The use of LA was shown to save SEK 1011 (Swedish Crowns) per patient compared to SA and GA.

Successful Treatment of Severe Anaphylactic Shock with Vasopressin. Two Case Reports.
Kill C, Wranze E, Wulf H.
Int Arch Allergy Immunol. 2004 Jun 1;134(3):260-261. Epub 2004 Jun 01.

Severe anaphylactic shock is a life-threatening situation that needs immediate treatment of progressive hemodynamic failure. We report two cases of severe anaphylactic shock treated with arginine-vasopressin (AVP): In a 42-year-old male patient anaphylactic shock was caused by the sting of a hornet. At the scene, he was found unconscious, cyanotic, with a heart rate of 130/min without measurable blood pressure. The patient was intubated and ventilated with 100% oxygen, intravenous epinephrine (1 mg over 2 min) had no effect on blood pressure. After injection of 10 IU vasopressin, followed by infusion of 40 IU vasopressin, hemodynamics could be stabilized at once. In the second case, a 47-year-old male patient was stung by a wasp. At the scene he was unconscious, blood pressure was not measurable, heart rate was 140/min. The patient was treated with 40 IU vasopressin followed by rapid infusion of 500 ml NaCl 0.9%. After injection of vasopressin, blood pressure raised to 80/50 mm Hg and heart rate decreased to 90/min. Both patients needed ventilator therapy for several days and recovered fully.

Intraoperative and postoperative analgesia with subcutaneous ring block of the penis with levobupivacaine for circumcision in children.
Matsota P, Papageorgiou-Brousta M.
Eur J Pediatr Surg. 2004 Jun;14(3):198-202

The purpose of the study is to evaluate both the efficacy of ring block of the penis with levobupivacaine in preventing intraoperative and postoperative pain associated with circumcision in children and the quality of the recovery. Thirty boys aged 3 - 12 years who underwent circumcision under general anaesthesia as day case patients were allocated randomly to receive either a subcutaneous ring block with levobupivacaine or intravenous fentanyl (2 micro g/kg) and paracetamol (30 mg/kg) rectally, after induction of anesthesia but before surgery. The efficacy of intraoperative analgesia was estimated using the heart rate and alterations in blood pressure. The quality of the recovery was assessed based on the Aldrete Scoring System (First Value and Time of Maximum Value were recorded). Postoperative pain was estimated using a four degree scale by nurses in the Postanaesthesia Care Unit and over the next 24 hours by the parents. Paracetamol was given depending on the pain score and the time of first dose given was recorded. The quality of postoperative analgesia was based on the children's activity and mobilisation. The ring block group showed intraoperative cardiovascular stability and a faster and better recovery (p < 0.0005) while the postoperative analgesia tended to be longer and more adequate, although that no statistically significant difference was noted (p < 0.1).
 

Parascalene block for shoulder arthroscopic surgery [Article in Spanish]
Call Reig L, de Vicente Sole J, Estany Raluy E.
Rev Esp Anestesiol Reanim. 2004 May;51(5):247-52

OBJECTIVE: To evaluate the effectiveness of a parascalene block of the brachial plexus as the single form of anesthesia for arthroscopic surgery on the shoulder and for postoperative analgesia.
MATERIAL AND METHODS : A parascalene block was performed in 151 ASA I-III patients using a plumb-bob technique with the aid of nerve stimulation and with the needle entering at a point 3 cm cephalad to the clavicle and 0.5-1 cm lateral to (and outside) the sternocleidomastoid muscle. We recorded the success or not of blockade, the incidence of side effects, clinical course during and after surgery, and patient and surgeon satisfaction with the technique.
RESULTS: A full block was achieved in all patients, although 19 (13%) required a second puncture. Midazolam was administered to 34 patients for anxiety and 48 required urapidil to normalize blood pressure. Complications (incidental blocks) were rare, transitory, and mild: 6 patients with Claude Bernard-Horner syndrome, 13 with dysphonia due to recurrent nerve blockade, and 1 with diaphragmatic paresis. Postoperative pain was practically nonexistent. Administration of diclofenac as indicated was sufficient for 91.2% of the patients. The remaining 8.8% needed top-up doses. Patients and surgeons assessed the block as excellent.
CONCLUSION : The parascalene technique to provide a brachial plexus block is effective for arthroscopic shoulder surgery.

Propofol reduces cognitive impairment after electroconvulsive therapy.
Butterfield NN, Graf P, Macleod BA, Ries CR, Zis AP.
J ECT. 2004 Mar;20(1):3-9

BACKGROUND: Cognitive impairments are the main complication after electroconvulsive therapy (ECT). Modification of treatment parameters has been shown to affect the magnitude of these impairments, but the role of anesthetic type remains unclear. This study tested whether there is a difference in cognitive impairments immediately after ECT with propofol compared to thiopental anesthesia.
METHODS: This randomized, double-blind, crossover study included 15 patients receiving right unilateral ECT for depression. Patients received propofol or thiopental on alternating ECTs up to 6 treatments. Immediate and delayed verbal memory, motor speed, reaction speed, visuospatial, and executive functions were assessed 45 minutes after each ECT. Differences were assessed with repeated measures analysis of variance.
RESULTS : Cognitive impairments were reduced after ECT with propofol compared to thiopental. Time to emergence was quicker and EEG seizure duration was shorter after propofol treatments. There was no significant correlation between seizure duration and neuropsychological test performance.
CONCLUSIONS: Our results indicate that cognitive impairments in the early recovery period after ECT are reduced with propofol compared to thiopental anesthesia. We suggest that, in addition to ECT parameters, the type of anesthetic agent should be considered to reduce cognitive impairments after ECT.

Preoperative intravenous midazolam: benefits beyond anxiolysis.
Bauer KP, Dom PM, Ramirez AM, O'Flaherty JE.
J Clin Anesth. 2004 May;16(3):177-83

STUDY OBJECTIVE: To evaluate the effect of midazolam on the global perioperative experience, including patient satisfaction, postoperative nausea and vomiting, postoperative pain, and perioperative anxiety and amnesia.
DESIGN : Prospective, randomized, placebo-controlled study.
SETTING: Ambulatory surgical center affiliated with a tertiary-care hospital.
PATIENTS : 88 ASA physical status I, II, and III patients scheduled for outpatient surgery.
INTERVENTIONS: Patients were randomized into two groups to receive either 0.04 mg/kg of midazolam or placebo intravenously (IV) 20 minutes preoperatively.
MEASUREMENTS : Perioperative measurements included blood pressure, heart rate, and oxygen saturation and the patient's level of anxiety; type of anesthetic administered; the anesthesiologist's guess at the treatment arm; perioperative dosages of fentanyl, morphine, and ondansetron; recovery room length of stay; frequency of nausea and vomiting, and level of postoperative pain in the 24 hours after surgery; the patient's overall satisfaction with the anesthetic, and whether the patient would recommend the premedication to a friend.
MAIN RESULTS : Patient demographics, type of surgery/anesthesia, vital signs, case duration, recovery duration, and postoperative pain were all similar between the midazolam and placebo groups. As expected, IV midazolam was an effective anxiolytic. There was no evidence of retrograde amnesia. Fewer patients in the midazolam group suffered from postoperative nausea than did those in the placebo group (25% vs. 50%;p = 0.03), despite receiving similar perioperative antiemetic and opioid administration. Similarly, fewer patients in the midazolam group experienced postoperative vomiting than placebo group patients (8% vs. 21%), although this difference did not reach statistical significance. Only 42% of patients in the placebo group would recommend their premedication to a friend, compared with 85% of patients in the midazolam group (p < 0.001).
CONCLUSIONS : In addition to the known anxiolytic effects of midazolam, midazolam premedication is an effective way to reduce the frequency of postoperative nausea, and perhaps vomiting, and increase patient satisfaction.

Paradoxical vocal cord motion: an often misdiagnosed cause of postoperative stridor.
Larsen B, Caruso LJ, Villariet DB.
J Clin Anesth. 2004 May;16(3):230-4

This conference reports a case of acute functional airway obstruction occurring in the postoperative anesthesia care unit, which was diagnosed by fiberoptic laryngoscopy and successfully treated with intravenous midazolam after other more common causes of stridor were ruled out. The presentation, etiology, diagnosis, and treatment of paradoxical vocal cord motion as it relates to the care of the postoperative patient are discussed.

Use of spinal anaesthesia in paediatric patients: a single centre experience with 1132 cases.
Puncuh F, Lampugnani E, Kokki H.
Paediatr Anaesth. 2004 Jul;14(7):564-7

Summary Background : Spinal anaesthesia has been used in children for over 100 years and in the last two decades its popularity for newborns and infants has increased, but there are still unanswered questions with the technique.
Methods : We evaluated the characteristics of spinal block including ease of performance, efficacy, adverse effects and complications in 1132 children, aged 6 months to 14 years, undergoing surgery in the lower part of the body. Local ethical committee approved the protocol of this prospective study, and parents gave written informed consent and older children their assent. All patients were sedated with midazolam, thiopental or propofol intravenously during spontaneous ventilation. No inhalation anaesthetics were used. Spinal block was performed with 0.5% hyperbaric bupivacaine at a dose of 0.2 mg.kg^-1.
Results : Efficacy, safety and ease of performance of the spinal block were shown to be satisfactory in most children. Only 27 of the 1132 children needed any supplementation. The incidence and severity of complications was low. Only nine of 942 children, <10 years of age and eight of 190 children, 10 years or older, developed hypotension. The incidences of postdural puncture headache, in five of the 1132 children, and backache, in nine of the 1132, were low. No other neurological complications were reported.
Conclusions : Spinal anaesthesia with hyperbaric bupivacaine is a feasible anaesthetic method in children for surgery in the lower part of the body.

General anaesthesia combined with bilateral paravertebral blockade (T5-6) vs. general anaesthesia for laparoscopic cholecystectomy: a prospective, randomized clinical trial.
Naja MZ, Ziade MF, Lonnqvist PA.
Eur J Anaesthesiol. 2004 Jun;21(6):489-95

BACKGROUND AND OBJECTIVE: The efficiency of bilateral paravertebral blockade combined with general anaesthesia (active) vs. general anaesthesia alone (control) in reducing postoperative pain following laparoscopic cholecystectomy was evaluated using a prospective randomized study design.
METHODS: Patients were randomly assigned to either group. Nerve-stimulator guided paravertebral blockade at the T5-6 level was performed with a local anaesthetic mixture (0.30 mL kg^-1). Twenty millilitres of the mixture contained lidocaine 2% 6 mL; lidocaine 2% 6 mL with epinephrine 1/200 000; bupivacaine 0.5% 5 mL; fentanyl 1 mL (50 microg mL^-1) and clonidine 2 mL (150 microg mL^-1). Postoperative pain and consumption of opioids were assessed during the first 72 h.
RESULTS: Two-times 30 patients were analysed. Patient characteristics data, and pre- and peroperative variables were similar in both groups. Mean pain scores visual analogue scale were significantly less with active compared with control (P < 0.05) at 6h (1.56 +/- 1.58 vs. 4.78 +/- 1.67), at 12 h (1.52 +/- 1.58 vs. 3.81 +/- 1.63), at 24 h (1.16 +/- 1.34 vs. 2.71 +/- 1.50), at 36h (0.68 +/- 1.02 vs. 2.29 +/- 1.41), at 48h (0.60 +/- 1.04 vs. 1.61 +/- 1.33) and at 72 h (0.40 +/- 0.86 vs. 1.19 +/- 1.16). The number of patients consuming supplemental analgesics was significantly less (P < 0.05) with active compared with control, at 6 h (6 vs. 29), at 12 h (2 vs. 26), at 24 h (1 vs. 23) and at 36 h (2 vs. 15). More patients were free from nausea (P < 0.05) with active compared with control at 6 h (23 vs. 9) and at 12 h (29 vs. 19).
CONCLUSION: When used as a complement to general anaesthesia, bilateral nerve-stimulator guided paravertebral blockade with lidocaine, bupivacaine, fentanyl and clonidine may improve postoperative pain relief.

Ibuprofen vs. acetaminophen vs. ibuprofen and acetaminophen after arthroscopically assisted anterior cruciate ligament reconstruction.
Dahl V, Dybvik T, Steen T, Aune AK, Rosenlund EK, Raeder JC.
Eur J Anaesthesiol. 2004 Jun;21(6):471-5

BACKGROUND AND OBJECTIVE: The analgesic potency of non-steroidal anti-inflammatory drugs and acetaminophen are still being debated. We have assessed the relative analgesic effect of ibuprofen, acetaminophen or the combination of both after orthopaedic surgery.
METHODS: Sixty-one ASA I patients, scheduled for an elective anterior cruciate ligament reconstruction under general anaesthesia were randomized, in a double blind fashion, into one of three groups. The ibuprofen group (n = 17) received ibuprofen 800 mg orally 1 h before operation and again at 6 and 12 h after the initial dose. The acetaminophen group (n = 20) received of acetaminophen 1 g orally at the same time intervals. The combination group (n = 24) received both ibuprofen 800 mg and acetaminophen 1 g. Surgery was performed under general anaesthesia with propofol and fentanyl for induction and maintenance with propofol and nitrous oxide in oxygen. The patients were monitored for 24 h thereafter, and the following variables were assessed: pain by visual analogue and verbal scales, need for rescue intravenous opioid analgesia (i.e. ketobemidone) and adverse events.
RESULTS : The ibuprofen group and the combination group experienced significantly less pain during the first 6 h after surgery than the acetaminophen group using the visual analogue and the verbal scales. The acetaminophen group also had a significantly higher average consumption of opioids during the first 6 and 24 h. There were no significant differences between the ibuprofen group and the combination group in respect of experienced pain or consumption of rescue analgesia. The incidence of side-effects, postoperative haemoglobin concentration and renal function, judged by creatinine clearance, were identical between the groups.
CONCLUSION : Ibuprofen 800 mg thrice daily reduced pain to a greater degree than acetaminophen 1 g thrice daily, after anterior cruciate ligament reconstruction under general anaesthesia. The combination of acetaminophen and ibuprofen did not provide any superior analgesic effect.

Special anesthetic concerns in mentally handicapped institutionalized patients undergoing gynecological procedures in an outpatient setting.
Vadivelu N, Harkness P, Richman S, Shelley KH
Conn Med. 2004 Jun-Jul;68(6):359-62

STUDY OBJECTIVE: To evaluate the anesthesia issues involved in caring for mentally handicapped outpatients.
DESIGN: Retrospective chart review.
SETTING : University-affiliated outpatient ambulatory center.
PATIENTS : Twenty adult patients scheduled for gynecological procedures. INTERVENTIONS: None.
MEASUREMENTS: Data collection sheet was used to record patients' age, ASA status, procedure, premedication, intravenous placement, degree of agitation, airway control, induction (method and drugs), intraoperative anesthesia care, postoperative medications, total time in hospital, postanesthesia care unit time and disposition.
MAIN RESULTS: Agitation was present in 100% of the patients. A significant number of these patients were ASA III, needing oral or intramuscular sedation (35%) or mask induction prior to placement of an intravenous line. Severely agitated patients had the longest stays in the postanesthesia care unit (PACU).
CONCLUSIONS: Agitation was the main reason why 90% of the patients required intubation for relatively minor procedures. Agitation was the main factor leading to prolonged recovery room time.

Remifentanil used to supplement propofol does not improve quality of sedation during spontaneous respiration.
Moerman AT, Struys MM, Vereecke HE, Herregods LL, De Vos MM, Mortier EP
J Clin Anesth. 2004 Jun;16(4):237-43

STUDY OBJECTIVE: To evaluate whether the use of remifentanil to supplement propofol during spontaneous respiration confers any benefits in terms of quality of sedation and recovery, or in terms of reduction in propofol requirements.
DESIGN: Prospective, randomized, double-blind study.
SETTING: University hospital.
PATIENTS : 50 ambulatory adult ASA physical status I and II patients scheduled for total colonoscopy.
INTERVENTIONS: Patients were randomized to receive either propofol alone or propofol plus remifentanil 0.1 microg/kg/min, while independently maintaining spontaneous respiration.
MEASUREMENTS : Cardiovascular and respiratory variables were measured before induction and at 1-minute intervals thereafter. Recovery from anesthesia was assessed using simple verbal commands and the Steward Post Recovery Score. Patient satisfaction was measured with a visual analog scale. Computer simulation was used to calculate the effect-site concentrations of propofol and remifentanil.
MAIN RESULTS : The depressant effects on blood pressure and respiratory function were significantly higher when propofol and remifentanil were combined. Although the addition of remifentanil resulted in a decrease of propofol usage, recovery of anesthesia was faster and patient satisfaction was higher when using propofol alone.
CONCLUSIONS : The addition of remifentanil to propofol during spontaneous ventilation offered no benefits compared with the use of propofol alone.

Morbidity following dental treatment of children under intubation general anaesthesia in a day-stay unit.
Atan, S., P. Ashley, et al.
Int J Paediatr Dent 2004; 14(1): 9-16

OBJECTIVES: To determine which variables were best related to the overall morbidity of a child undergoing dental general anaesthetic (GA) and then to use these variables to determine those factors that might influence the extent and severity of morbidity experienced by healthy children following dental GA.
SAMPLE AND METHODS: Data were collected on anxiety, pain and morbidity, GA procedure and dental procedure from 121 children attending a day stay GA unit for dental treatment. Patients were interviewed preoperatively, postoperatively before discharge then four further times over the next 148 h. Data were analysed using multivariate regression.
RESULTS : Thirty-one per cent of subjects had restorative work, 60% had at least one tooth extracted, 54% had a surgical procedure. Use of local analgesia reduced postoperative pain whilst an increase in the number of surgical procedures increased it. Increase in anaesthetic time was related to increased odds of feeling sleepy and nauseous, females were more likely to complain of sleepiness or weakness. Feelings of dizziness were increased if the patient was given local analgesia during the procedure.
CONCLUSIONS: Pain following dental GA was the most prevalent and long lasting symptom of postoperative morbidity in this study. Reductions in operating time and improvement in pain control have the potential to reduce reported morbidity following dental GA.

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