Severe perioperative anaphylaxis: Incidence in a tertiary hospital in Spain over a 20-year period. A historical cohort study.

OBJECTIVE: To assess the incidence of severe perioperative anaphylaxis, the mechanisms involved, the value of laboratory/skin tests, and the most effective treatments. METHODS: A historical cohort study conducted in a tertiary public hospital in Spain. Patients that had undergone anaesthesia during the 20-year period were included. In these patients, 66 cases of severe anaphylaxis were found. In patients with suspicion of severe anaphylaxis, levels of blood histamine at less than 15min and serum tryptase at 2, 6, and 24h following the reaction were determined. Skin and specific IgE tests were performed between 4 and 8 weeks later. RESULTS: Over the 20-year period, 288 594 anaesthetic procedures were performed. We observed cases of 66 severe anaphylaxis reaction (59% men; age, 60.8±17.3 years. Symptoms observed were cardiovascular (86%), respiratory (73%), and mucocutaneous (56%). Elevated serum tryptase levels were associated with degree of severity at 2 (P<.0001) and 6h (P=.026) and were highest in IgE-mediated reactions (P=.020). All patients required treatment, and 3 events were fatal. In 84.8% of patients, skin and/or specific IgE tests were positive for antibiotics (35.8%), non-steroidal anti-inflammatory drugs (23.1%), neuromuscular blocking agents (15.4%) and latex (15.4%). CONCLUSIONS: The incidence of severe anaphylaxis in our hospital was 1 in 4.373 anaesthetic procedures, with a death rate of 4.5%. All cases required treatment. Serum tryptase was a good predictor of reaction severity. The most frequent causative agents were antibiotics, non-steroidal anti-inflammatory drugs, neuromuscular blocking agents and latex.

Epidural vs. intravenous fentanyl during colorectal surgery using a double-blind, double-dummy design.

BACKGROUND: The overall therapeutic effectiveness of epidural fentanyl vs. the intravenous route is controversial. The present work describes a randomized, controlled, double-blind, double-dummy study of the intraoperative requirements of fentanyl administered by the intravenous or epidural routes during open colon surgery. METHODS: Thirty patients were randomized to receive intraoperative analgesia with boluses of fentanyl administered by either the epidural or intravenous route (2 µg/kg). The first fentanyl bolus was administered 10 min before incision, and repeated boluses were given when mean arterial pressure or heart rate increased more than 20% over basal values. General anaesthesia was maintained with a propofol infusion. Intraoperative fentanyl and propofol requirements, time to awakening, time to analgesia request, and incidence of adverse effects were recorded. RESULTS: Median [interquartile range (range)] fentanyl requirements in the epidural and intravenous groups were 0.81 [0.65 (0.47-2.61)] and 2.5 [1.08 (1.07-4.85)] µg/kg/h, respectively (P < 0.001). The epidural group had a shorter time to awakening, with a median of 8 min [4.5 (3-18)] compared with 20 min [12.5 (7-34)] for the intravenous group (P < 0.001). There were no significant differences in propofol requirements. The time to analgesia request was also delayed in the epidural group, with a median of 5 h [5.5 (1-16)] vs. 2 h [1 (1-5)] when fentanyl was administered intravenously (P < 0.001). The incidence of adverse effects was similar in both groups. CONCLUSION: During major abdominal surgery, epidural administration requires lower doses of intraoperative fentanyl when compared with the intravenous route. Epidural fentanyl also facilitates early awakening and residual analgesia without increasing adverse events.

[Utility of bispectral vs auditory evoked potential monitoring during anesthetic maintenance in combined sevoflurane-regional anesthesia in pediatric patients: comparison with standard practice]. / Utilidad del BIS y AEP monitor/2 para el mantenimiento de la anestesia combinada sevoflurano-regional, comparada con la práctica estándar en población pediátrica.

OBJECTIVES: To compare the indices computed by a bispectral (BIS) monitor and an auditory evoked potential (AEP) monitor during maintenance of anesthesia in pediatric patients. A secondary objective was to compare anesthetic consumption and recovery times. MATERIAL AND METHODS: Patients aged 6 months to 12 years under inhaled anesthesia with sevoflurane were administered a penile or caudal nerve block. BIS and AEP monitoring was then started. The patients were randomized to 3 groups in which the sevoflurane dosage was guided by the BIS index, the A-line ARX index (AAI), or standard procedures (control group). The BIS index, the AAI, the fraction of expired sevoflurane, hemodynamic parameters, and recovery time were the variables recorded for all patients. RESULTS: Thirty-five patients were enrolled. Significant differences between the 2 monitor groups were observed. The mean (SD) AAI was lower in patients whose dosage was controlled by the BIS index (19 [2]) than in those whose dosage was based on the AEP monitor's reading (22 [4]) (P=.04). According to a Bland and Altman plot, there was good agreement between the BIS index and the AAI except for the highest and, in particular, the lowest values. The volumes of sevoflurane used and the recovery times were similar between groups. There was a positive correlation between the 2 indices (Pearson correlation coefficient, 0.207; P<.001). CONCLUSIONS: BIS monitoring provided a more stable index than did AEP monitoring and BIS-index guidance achieved a deeper level of hypnosis. There was good correlation between the 2 indices during maintenance of anesthesia. Neither monitor offered advantages over standard procedures with regard to movement, volume of anesthetic consumed, or recovery time.

[Usefulness of activated recombinant factor VII for controlling massive bleeding: 4 years' experience in a university hospital]. / Utilidad del factor VII recombinante para el control de la hemorragia masiva. Experiencia de cuatro años en un centro hospitalario universitario.

OBJECTIVE: Massive bleeding that cannot be controlled by the usual means, such as transfusion, is a serious medical problem with high associated mortality. Our aim was to assess the efficacy and safety of treatment with activated recombinant factor VII (rFVIIa) to control massive bleeding after the failure of other methods. PATIENTS AND METHODS: This was a retrospective study of all cases of rFVIIa-treated massive bleeding in patients without a history of coagulation disorder from January 2003 through June 2007. RESULTS: The prevalence of rFVIIa treatment for this indication was 1 in 5200 hospitalized patients. Thirty patients were treated. Bleeding was reduced or stopped in 80% and consumption of blood products was reduced after administration of rFVIIa. Mortality was 43% and death was due to continued bleeding in 5 cases. No deaths were due to thromboembolism. CONCLUSIONS: rFVIIa is efficacious for controlling bleeding and reducing transfusion requirements in cases of massive hemorrhage, but mortality unrelated to bleeding is high in patients experiencing this complication. Further study is needed to better assess the utility, dosing, and ideal timing in the use of this drug.

[Incidence in Catalonia of spinal cord compression due to spinal hematoma secondary to neuraxial anesthesia]. / Incidencia de hematomas espinales con compresión medular relacionados con anestesias neuroaxiales en Cataluña.

OBJECTIVE: To study the incidence in Catalonia of spinal cord compression due to spinal hematoma secondary to neuraxial anesthesia. METHODS: The incidence of hematoma was based on published cases (MEDLINE, the Spanish Medical Index [Indice Medico Español], and Google) or cases reported at medical meetings or conferences by anesthesiologists from Catalan hospitals from 1996 to 2005, inclusive. The annual number of neuraxial anesthesias (spinal, epidural, and combined) was estimated based on the ANESCAT 2003 survey and the total number of anesthesias was calculated using the ANESCAT 2003 survey in conjunction with the surgical reports of Catalan hospitals. RESULTS: A total of 11 cases of spinal hematoma after neuraxial anesthesia (7 after spinal anesthesia and 4 after epidural anesthesia) were reported or published from 1996 to 2005, inclusive. A total of 194 154 neuraxial anesthesias were performed in 2003 (126 560 spinal anesthesias and 5926 combined spinal-epidural anesthesias) and it was estimated that somewhat over 1 700 000 neuraxial anesthesias were performed over the 10 years reviewed. The incidence (95% confidence interval [CI]) of hematoma was 0.6 (95% CI, 0.3-1.2) per 100 000 neuraxial anesthesias, 0.6 (95% CI, 0.3-1.3) per 100 000 spinal anesthesias, and 0.7 (95% CI, 0.2-1.9) per 100 000 epidural anesthesias. CONCLUSIONS: The incidence of spinal hematoma after neuraxial anesthesia is slightly more than 1 per 150 000 anesthesias-a similar finding to that of other epidemiological studies. The incidence is slightly higher in epidural anesthesia. These data imply a risk of approximately 1 spinal hematoma per year in Catalonia.

[Severe anaphylactic reaction to metamizol during subarachnoid anesthesia]. / Reacción anafiláctica grave al metamizol durante una anestesia subaracnoidea.

A 59-year-old man with no relevant medical history underwent a right saphenectomy under subarachnoid anesthesia with mepivacaine. Administration of intravenous metamizol for postoperative analgesia was followed by severe anaphylactic reaction with respiratory failure and ventricular fibrillation. The patient recovered after orotracheal intubation and defibrillation. High serum tryptase levels 2 and 6 hours after the episode and positive skin prick tests confirmed the diagnosis of anaphylactic reaction mediated by immunoglobulin-E antibodies. Anaphylactic reactions to metamizol may be more common than would appear based on reports in the literature. When signs present suddenly with cardiovascular or respiratory involvement, symptomatic treatment should be started even in the absence of cutaneous or mucosal signs and allergy tests should be carried out immediately.

[Spinal cord compression caused by hematoma related to neuroaxial anesthesia in Spain]. / Hematomas raquídeos con compresión medular relacionados con las anestesias neuroaxiales en España.

OBJECTIVES: Spinal cord compression from a hematoma is a rare serious complication of neuroaxial anesthesia. Our objective was to investigate cases reported and published by Spanish authors. MATERIAL AND METHODS: Cases of spinal cord compression related to neuroaxial hematomas (epidural, subarachnoid, or both) reported at congreses and meetings in Spain or published in Medline-indexed journals from 1989 through December 2002 were reviewed. The clinical characteristics, risk factors, treatments, and outcomes were described for each case. RESULTS: Since 1996, when the first cases were reported, 20 cases in all have appeared: 8 related to sub-arachnoid anesthesia, 8 to epidural anesthesia, 1 to a combination, and 1 to diagnostic lumbar puncture. In 2 cases, the neuroaxial technique used was poorly defined. Factors that might have caused the complication could be identified in 11 cases, among which there were 7 cases of anesthetic puncture or manipulation of an epidural catheter during a period of hemorrhagic risk because of antithrombotic therapy. The hematoma was evacuated surgically in 11 cases, and medical treatment was provided in 9 cases. The neurologic outcome was satisfactory in 14 cases. CONCLUSIONS: The number of compressive spinal hematomas reported or published by Spanish authors is fairly high, and there are cases related to both sub-arachnoid and epidural anesthesia. Nonsurgical treatment was provided in 45% of the cases and the outcome was satisfactory in 70%. Risk factors were identified in over half of the reported cases.

[Prospective epidemiologic study of perioperative anaphylactoid reactions occurring in Catalonia (1996-7)]. / Estudio epidemiológico prospectivo de las reacciones anafilactoides perioperatorias ocurridas en Cataluña (1996-97).

OBJECTIVES: To determine the incidence, immunological mechanisms, severity and clinical course of perioperative allergic reactions. PATIENTS AND METHODS: Prospective epidemiological study lasting 2 years (1996-97). In 20 hospitals in Catalonia (Spain), we studied patients who suffered allergic reactions equal to or greater than grade Ib according to the classification of Laxenaire. Serum and urine samples were collected during the first and sixth hours after the onset of a reaction. Complement factors, total serum and latex-specific serum IgE antibodies, hemostatic markers, serum tryptase and urinary methylhistamine were assayed. Tests for allergy to the drugs used during the perioperative period were performed on all patients who consented. RESULTS: Anesthetic procedures were performed 328,430 times in the 20 hospitals. Thirty-two allergic reactions were reported (1 case/10,263 anesthesias); the frequency was greater during general anesthesia (1 case/6,978 anesthesias). Women suffered 58.3% of the reactions, and the mean patient age was 47.8 +/- 16.5 years. Fifty-six percent of the reactions were severe (grades III-IV), and 68.7% occurred upon immediate exposure. Induction was the moment of greatest risk (50%). Treatment was required by 90.6% of the patients, but no deaths or serious sequelae occurred. Complete analyses could be carried out immediately for 25 patients. High urinary methylhistamine and/or serum tryptase levels were found for 57% of the patients with grade Ib reactions, for 80% of those with grade II reactions, and for 91.7% of those with grade III reactions (p = 0.05). High serum tryptase levels were the only findings for 53.8% of the grade III reactions (p = 0.007). Skin tests were positive for 62.5% of the patients. CONCLUSIONS: The frequency of allergic reactions in Catalonia is 1 case per 10,263 anesthesias performed, but the rate is higher in general anesthesia. Fifty-six percent of the reactions were severe. Most developed immediately and the moment of induction involved the greatest risk. Early assessment of methylhistamine and tryptase levels has been shown to be useful and positivity is linearly associated with severity of reaction. In 62.5% of the patients, positive results were seen in skin tests performed later.

[Failure in the functioning of an implanted automatic defibrillator due to pneumothorax occurring during its implantation ]. / Fallo en el funcionamiento de un desfibrilador automático implantable durante su colocación ocasionado por un neumotórax.

A 67-year-old man with chronic bronchitis and coronary artery disease was scheduled to receive an implantable cardioverter defibrillator (ICD) after an episode of sustained monomorphic ventricular tachycardia. During implantation through the left subclavian vein, oxygen saturation decreased to slightly below baseline. Nevertheless, the procedure continued, given that the patient experienced neither breathing difficulties nor pain. When the ICD failed to reverse ventricular fibrillation induced to test the device, an external defibrillator was used. At that point, left-sided pneumothorax was observed by x-ray. Air in the pleural cavity caused an increase in the defibrillation threshold. After insertion of a thoracic drain, the ICD implantation procedure was completed successfully.

[Cardiorespiratory arrest: a rare complication of subdural block]. / Parada cardiorrespiratoria: una complicación infrecuente del bloqueo subdural.

We report a case of accidental subdural block after epidural anesthesia that manifested as cardiac arrest due to extensive spinal blockade 20 minutes after administration of 50 mg of 0.5% bupivacaine. The event resolved without sequelae. Subdural placement of the catheter was verified by computed axial tomography contrast medium. Clinical signs of subdural block are highly variable, extensive neural block being among the possible rare presentations, with latency ranging from a few minutes to as long as 30. Recent electron microscope observations with new methods for fixing and preparing tissues suggest that the dubdural space does not exist naturally, but rather forms artificially within a low-resistance cell plane composed of neurothelial cells, as a result of trauma or the injection of a local anesthetic. The characteristics of the space depend, therefore, on factors that come together at the site. These data explain the great variability in the clinical manifestations of a subdural block. The case of cardiopulmonary arrest we report is rare in the literature.