Resúmenes De La Lietratura Agosto 2-8,2002

Resúmenes de la Lietratura Agosto 2-8,2002

Paediatric Anaesthesia
Volume 12 Issue 6 Page 519 - July 2002The correlation of bispectral index with endtidal sevoflurane concentration and haemodynamic parameters in preschoolersMary Ellen MCCANN MD, Julianne Bacsik MD, Andrew Davidson MBBS, Susan Auble RN, JD, Lorna Sullivan RN & Peter Laussen MBBS

Summary

Background : Bispectral index (BIS) is a signal processing device that potentially is a pharmacodynamic measure of the effects of anaesthesia on the central nervous system.

Methods: In this prospective blinded study, we investigated the pharmacodynamic relationship between BIS, haemodynamic changes during anaesthesia and endtidal nonsteady state concentrations of sevoflurane in 30 children, mean age 3.3±1.1 years, who were undergoing tonsillectomy and adenoidectomy. A standardized anaesthetic technique was used and included induction and maintenance with sevoflurane, nitrous oxide and oxygen. BIS, heart rate, mean arterial pressure (MAP) and endtidal sevoflurane (ETsevo) concentrations were continuously recorded and specifically noted at the time of intubation, placement of Dingman gag, incision of adenoid, adenoid out, incision of tonsil, tonsil one out, tonsil two out, last agent off, first spontaneous movement, first eye opening and extubation. The anaesthetist was blinded to BIS throughout the procedure.

Results: Using a Spearman correlation analysis, there was significant negative correlation between BIS and ETsevo concentrations (r=0.888, P0.01) and a pharmacodynamic relationship with EC50 (ETsevo at which BIS=50) of 1.48% (95% confidence interval 0.84-2.11). There was a weak negative correlation between sevoflurane and MAP (r=0.391, P0.01) but no significant correlation between sevoflurane and heart rate.

Conclusions : In preschool children undergoing sevoflurane anaesthesia for tonsillectomy and adenoidectomy, endtidal sevoflurane concentrations are more closely correlated with BIS than with MAP or heart rate.

Anesth Analg 2002;95:319-321
© 2002 International Anesthesia Research Society

CARDIOVASCULAR ANESTHESIA

Accelerated Idioventricular Rhythm Associated with Desflurane Administration

Emmanuel Marret, MD, Olivier Pruszkowski, MD, Arnaud Deleuze, MD, and Francis Bonnet, MD

Département d’Anesthésie Réanimation, Hôpital Tenon, Assistance Publique-Hopitaux de Paris, Paris, France

Address correspondence and reprint requests to Dr. Emmanuel Marret, Département d’Anesthésie Réanimation, Hôpital Tenon-4, rue de la Chine, 75970 Paris Cedex 20, France. Address e-mail to .

IMPLICATIONS: The rapid administration of desflurane results in transient hypertension and tachycardia, especially in the presence of sympathetic imbalance. We report a case in which rapid administration of desflurane precipitated an accelerated idioventricular rhythm in a patient. This may have been related to a period of inadequate anesthesia.

Anesth Analg 2002;95:294-298
© 2002 International Anesthesia Research Society

CARDIOVASCULAR ANESTHESIA

Early Postoperative Respiratory Acidosis After Large Intravascular Volume Infusion of Lactated Ringer’s Solution During Major Spine Surgery

Arzu Takil, MD, Zeynep Eti, MD, Pinar Irmak, MD, and F. Yilmaz Göü, MD

Department of Anesthesiology, Medical Faculty of Marmara University, Istanbul, Turkey

Address correspondence and reprint requests to Dr. Arzu Takil, Atakent Burç cad. Burç apt. N0: 1B/45 81240 Ümraniye, stanbul, Türkiye. Address e-mail to .

In this study, we compared the effects of large intravascular volume infusion of 0.9% saline (NS) or lactated Ringer’s (LR) solution on electrolytes and acid base balance during major spine surgery and evaluated the postoperative effects. Thirty patients aged 18–70 yr were included in the study. General anesthesia was induced with 5 mg/kg thiopental and 0.1 mg/kg vecuronium IV. Anesthesia was maintained with oxygen in 70% nitrous oxide and 1.5%–2% sevoflurane. In Group I, the NS solution, and in Group II, the LR solution were infused 20 mL · kg-1 · h-1 during the operation and 2.5 mL · kg-1 · h-1, postoperatively. Electrolytes (Na+, K+, Cl-) and arterial blood gases were measured preoperatively, every hour intraoperatively and at the 1st, 2nd, 4th, 6th, and 12th hours postoperatively. In the NS group, pHa, HCO3 and base excess decreased, and Cl- values increased significantly at the 2nd hour and Na+ values increased at the 4th hour intraoperatively (P < 0.001). The values returned to normal ranges at the 12th hour postoperatively. In the LR group, blood gas analysis and electrolyte values did not show any significant difference intraoperatively, but the increase in PaCO2 and the decrease in pHa and serum Na+ was significant at the 1st hour postoperatively. Although intraoperative 20 mL · kg-1 · h-1 LR infusion does not cause hyperchloremic metabolic acidosis as does NS infusion, it leads to postoperative respiratory acidosis and mild hyponatremia.

IMPLICATIONS: The infusion of large-volume lactated Ringer’s solution does not cause hyperchloremic metabolic acidosis as does 0.9% saline during major surgery, but leads to postoperative mild hyponatremia and respiratory acidosis.

Anesth Analg 2002;95:273-277
© 2002 International Anesthesia Research Society

CARDIOVASCULAR ANESTHESIA

Intraoperative Tachycardia and Hypertension Are Independently Associated with Adverse Outcome in Noncardiac Surgery of Long Duration

David L. Reich, MD, Elliott Bennett-Guerrero, MD, Carol A. Bodian, DrPH, Sabera Hossain, MSc, Wanda Winfree, RN, and Marina Krol, PhD

Department of Anesthesiology, Mount Sinai School of Medicine, New York, New York

Address correspondence and reprint requests to David L. Reich, MD, Professor of Anesthesiology, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1010, New York, NY 10029-6574. Address e-mail to .

Relatively little is known about the influence of intraoperative hemodynamic variables on surgical outcomes. We drew subjects (n = 797) from a study of patients undergoing major noncardiac surgery. The physiological component of the POSSUM (Physiological and Operative Se- verity Score for the enUmeration of Mortality) operative risk stratification index was determined, and intraoperative measurements of heart rate (HR), mean arterial blood pressure, and systolic arterial blood pressure (SAP) were retrieved from computerized anesthesia records. For every 5-min epoch during the surgery, HR, mean arterial blood pressure, and SAP were each classified as low, normal, or high. Negative surgical outcome (NSO) was defined as a hospital stay of >10 days with a morbid condition or death during the hospital stay. Statistical analyses included Mantel-Haenszel tests and multiple logistic regression. There was no significant association between hemodynamic variables and NSO with short operations. In 388 patients with operations longer than the median time of 220 min, NSO occurred in 15.6%. Controlling for POSSUM score and operation time beyond 220 min, both high HR (odds ratio, 2.704; P = 0.01) and high SAP (odds ratio, 2.095; P = 0.009) were associated with NSO in longer operations. Thus, intraoperative tachycardia and hypertension were associated independently with adverse outcomes after major noncardiac surgery of long duration, over and above the risk imparted by underlying medical conditions.

IMPLICATIONS: Intraoperative tachycardia and hypertension were associated with negative postoperative outcomes after major noncardiac surgery of long duration. These results imply that intraoperative tachycardia and hypertension may have independent effects on outcome over and above the risk imparted by underlying medical conditions.

Anesth Analg 2002;95:316-318
© 2002 International Anesthesia Research Society

CARDIOVASCULAR ANESTHESIA

Treatment of Persistent Tachycardia with Dexmedetomidine During Off-Pump Cardiac Surgery

Sibylle Ruesch, MD, and Jerrold H. Levy, MD

Department of Anesthesiology, Emory University School of Medicine; and Division of Cardiothoracic Anesthesiology and Critical Care, Emory Healthcare, Atlanta, Georgia

Address correspondence and reprint requests to Jerrold H. Levy, MD, Department of Anesthesiology, Emory University Hospital, 1364 Clifton Rd., N.E., Atlanta, GA 30322. Address e-mail to .

IMPLICATIONS: After unsuccessful treatment of intraoperative tachycardia with esmolol during off-pump revascularization, heart rate was successfully reduced with a bolus and infusion of dexmedetomidine.

Anesth Analg 2002;95:308-309
© 2002 International Anesthesia Research Society

CARDIOVASCULAR ANESTHESIA

An In Situ Technique to Retrieve an Entrapped J-Tip Guidewire from an Inferior Vena Cava Filter

Muhammad A. Munir, MD, and Shelby Q. Chien, MD PhD

Department of Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas

Address correspondence and reprint requests to Shelby Q. Chien, MD, Department of Anesthesiology, Slot 515, University of Arkansas for Medical Sciences, 4301 W. Markham St., Slot 515, Little Rock, AR 72205-7199. Address e-mail to .

IMPLICATIONS: Entrapment of a guidewire in the vena cava filter during central venous catheter placement is a newly recognized complication. Complex techniques have been described to free the guidewire. We describe a simple in situ technique that may free the guidewire without the application of complex techniques.

British Journal of Anaesthesia, 2002, Vol. 89, No. 2 328-330
© 2002 The Board of Management and Trustees of the British Journal of Anaesthesia

Case Reports

Management of failed intubation in a septic parturient

D. Hinchliffe and A. Norris

Department of Anaesthesia, University Hospital, Nottingham NG7 2UH, UK*Corresponding author

We describe a case in which regional anaesthesia for Caesarean section was initially avoided because of the presence of systemic infection. However, attempted induction of general anaesthesia resulted in failed tracheal intubation and so an epidural catheter was sited and used for the operation. Awake fibreoptic tracheal intubation was performed after surgery, when it was clear that ventilatory support on the intensive care unit would be needed. The relative risks of regional versus general anaesthesia when infection and difficult laryngoscopy coincide are discussed.

Br J Anaesth 2002; 89: 328–30

PEDIATRIC ANESTHESIA

Thoracic Epidural Catheter Placement Via the Caudal Approach in Infants by Using Electrocardiographic Guidance

Ban C. H. Tsui, MSC MD, FRCP(C), R. Seal, MD FRCP(C), and J. Koller, MD FRCP(C)

Department of Anesthesiology and Pain Medicine, University of Alberta Hospitals, Walter Mackenzie Health Sciences Centre, Edmonton, Alberta, Canada

Address correspondence and reprint requests to Ban C. H. Tsui, Department of Anesthesiology and Pain Medicine, University of Alberta Hospitals, 3B2.32 Walter Mackenzie Health Sciences Centre, 8440-112 Street, Edmonton, Alberta, Canada T6G 2B7. Address e-mail to .

We examined the success of inserting epidural catheters via the caudal route in infants by using electrocardiographic guidance. A case series of 20 patients with thoracic epidural analgesia was studied. After the induction of general anesthesia, an 18-gauge IV catheter was inserted into the caudal space to allow threading of a 20-gauge epidural catheter. The electrocardiogram (ECG) tracings via the epidural catheter, as well as the surface ECG at the target spine level, were recorded simultaneously with a modified two-channel five-lead ECG system. The epidural catheter was advanced from the caudal space until the tip reached the target level as demonstrated by a match in the configuration of the epidural ECG tracing to that of the surface ECG tracing at the target level. The catheter tip location was verified by postoperative radiographs. All catheter tips were located within two vertebrae of the target level, and satisfactory intraoperative epidural anesthesia was achieved in all subjects.

IMPLICATIONS: Epidural electrocardiography may be used to guide the positioning of the thoracic epidural catheter tip via the caudal approach to the appropriate dermatome for optimum analgesia.

AMBULATORY ANESTHESIA

Distal Nerve Blocks at the Wrist for Outpatient Carpal Tunnel Surgery Offer Intraoperative Cardiovascular Stability and Reduce Discharge Time

Ralf E. Gebhard, MD, Tameem Al-Samsam, MD, Jennifer Greger, MD, Ahmad Khan, MD, and Jacques E. Chelly, MD PhD, MBA

Department of Anesthesiology and International Regional Research Center, The University of Texas Medical School at Houston, Houston, Texas

Address correspondence and reprint requests to Jacques E. Chelly, MD, PhD, MBA, Department of Anesthesiology, University of Texas-Houston Medical School, 6431 Fannin MSB 5.020, Houston, TX 77030-1503. Address e-mail to .

Carpal tunnel release is often performed as an outpatient procedure. We designed this retrospective study to assess the effect of different anesthesia techniques on intraoperative cardiovascular stability and discharge time. According to the anesthesia technique received, 62 consecutive patients were categorized in Group BIER (IV regional anesthesia), Group BLOCK (distal nerve blocks), and Group GENERAL (general anesthesia). Incidences of intraoperative periods of tachycardia or bradycardia and hyper- or hypotension were studied, as were tourniquet, surgical, operating room, and discharge times. Cardiovascular stability was better achieved in Group BLOCK, as indicated by a significantly smaller incidence of periods of hypertension compared with Group BIER (5% vs 25%) and a significantly less frequent incidence of periods of hypotension compared with Group GENERAL (14% vs 42%). Patients in Group BLOCK spent significantly less time in the hospital after surgery than patients in Group BIER (65 vs 88 min) or patients in Group GENERAL (65 vs 133 min). We conclude that distal nerve blocks for outpatient carpal tunnel surgery are associated with greater intraoperative cardiovascular stability than general anesthesia. After surgery, patients in Group BLOCK could be discharged earlier than patients who received IV regional anesthesia or general anesthesia; this could be related to the superior postoperative analgesia provided by this technique.

IMPLICATIONS: This retrospective analysis of three different anesthetic techniques for ambulatory carpal tunnel surgery shows that nerve blocks performed at the wrist provided excellent intraoperative cardiovascular stability and allowed for earlier discharge.

Sedation in the intensive care unit

Brian K. Gehlbach, MD; John P. Kress, MD

Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois, USA.

CURRENT OPINION IN CRITICAL CARE 2002;8:290-298

Although the administration of sedatives is a commonplace activity in the ICU, few guidelines are available to aid the clinician in this practice. The first principle of sedative administration is to define the specific problem requiring sedation and to rationally choose the drug and depth of sedation appropriate for the indication. Next, the clinician must recognize the diverse and often unpredictable effects of critical illness on drug pharmacokinetics and pharmacodynamics. Failure to recognize these effects may lead initially to inadequate sedation and subsequently to drug accumulation. Drug accumulation may result in prolonged encephalopathy and mechanical ventilation and may mask the development of neurologic or intra-abdominal complications. Daily interruption of continuous sedative infusions is a simple and effective way of addressing this problem. A glossary of sedative drugs commonly used in the ICU is included in this review.