Catecholamine crisis during induction of general anesthesia : A case report.

Catecholamine crises associated with pheochromocytoma may cause life-threatening cardiovascular conditions. We report the case of a 75-year-old male who developed a hypertensive crisis during induction of general anesthesia for elective resection of a cervical neuroma due to an undiagnosed pheochromocytoma. Hemodynamic instability occurred immediately after the injection of fentanyl, propofol and rocuronium, prior to laryngoscopy and in the absence of any manipulation of the abdomen. In this case report, we present the management of this incident and discuss the underlying pathophysiology triggering a catecholamine crisis.

[Gone with the wind or... Fate of scientific articles presented at large anesthesia congresses--an update]. / Vom Winde verweht oder... "Schicksal" wissenschaftlicher Beiträge auf großen Anästhesiekongressen--ein Update.

BACKGROUND: The goal of the present study was to evaluate the publication rate of abstracts presented during the German Anesthesia Congress (Deutscher Anästhesiecongress, DAC) and the meeting of the European Society of Anesthesiologists (ESA) in the years 2000 and 2005 in Medline listed journals (http://www.ncbi.nlm.nih.gov/pubmed). In addition, the respective impact factors of the journals in which the articles were published were evaluated (http://www.isiknowledge.com). METHODS: All abstracts of free papers and posters presented at the DAC and ESA from the years 2000 and 2005 were included into the study. The presence of authors and the topics of abstracts in the literature were analyzed by a Medline based inquiry over a time period of 5 years. The search was based on the last name and initials of authors and when these could not be identified in Medline the search was extended by keywords of relevant topics of the abstract. Umlauts "ä/ö/ü" were replaced by "ae/oe/ue" and "ß" was replaced by "ss". Only original papers were included in this analysis. Once an original paper was found the impact factor of the journal in that year was identified. RESULTS: A total of 465 abstracts from the DAC 2000, 378 abstracts from the DAC 2005, 644 abstracts from the ESA 2000 and 720 abstracts from the ESA 2005 were included. Of the abstracts from the DAC 2000, 183 (39%) were published in Medline listed journals, 179 (47%) from DAC 2005, 218 (34%) from ESA 2000 and 233 (32%) from ESA 2005. The ESA abstracts were published in English more often than the DAC abstracts (ESA 2000: 95%; ESA 2005: 95%; DAC 2000: 78%; DAC 2005: 86%). While the publication rate after the ESA remained nearly unchanged between 2000 and 2005, the publication rate after the DAC increased by about 7%. The average impact factors of the publications were 1.777 (DAC 2000), 2.836 (DAC 2005), 1.825 (ESA 2000) and 2.36 (ESA 2005). Independent of the congress (DAC or ESA) where the abstract was presented, most articles were published in the journal Anesthesia & Analgesia. CONCLUSION: In the year 2005 more abstracts of the DAC were published in Medline listed papers than in 2000. When comparing the number of abstracts published in Medline listed journals, more abstracts of the DAC were published compared to abstracts of the ESA. The increase in papers written in English after abstract presentation on the DAC is mostly due to the wider readership which can be reached with manuscripts in the English language. Besides a larger readership, English journals often also have a higher ranked impact factor. This analysis does not claim to be a complete registration of all published abstracts due to the limitation on Medline listed journals and publications in other journals were not rated. Medline was selected because of the widespread and international use of this database.

[Direct laryngoscopy or C-MAC video laryngoscopy? Routine tracheal intubation in patients undergoing ENT surgery]. / Direkte Laryngoskopie oder C-MAC-Videolaryngoskopie? Routineintubation von Patienten in der HNO-Heilkunde.

BACKGROUND: Previous studies have shown that video laryngoscopy enhances laryngeal view in patients with apparently normal and difficult airways. The utility of the novel, portable, battery-powered C-MAC video laryngoscope is as yet unproven. It was hypothesized that in routine patients undergoing ENT surgery, the rate of glottic views considered unsatisfactory, i.e. Cormack and Lehane grades IIb, III, and IV, could be significantly reduced with the C-MAC video laryngoscope compared to direct laryngoscopy. METHODS: Following ethical approval and sample size estimates 108 consecutive patients undergoing ENT surgery under general anesthesia were studied. First, direct laryngoscopy was performed with the naked eye. The best view obtained was graded by the first anesthesiologist without looking at the video monitor. A second anesthesiologist blinded to the laryngeal view obtained under direct laryngoscopy graded the laryngeal view on the video monitor. Endotracheal intubation using Ring-Adair-Elwyn (RAE) tracheal tubes was then attempted under video-aided visualization. The tubes were not reinforced with a stylet. The C-MAC video laryngoscopy system (Karl Storz, Tuttlingen, Germany) is a novel device that can be used with Macintosh laryngoscope blades in different sizes. A camera and light source are located recessed from the tip of the blade. The camera unit sits in a handle attached to the laryngoscope blade and is connected by a wire to a TFT video monitor. It allows for both direct and indirect laryngoscopy and the low profile of the original British Macintosh blades may prove advantageous in patients with limited mouth opening. RESULTS: A total of 108 patients were enrolled in the study but for various reasons only 94 completed the study (post hoc power 97%). In 89 patients a size 3 Macintosh laryngoscope was used while a size 4 blade was used in the remaining 5 patients. With direct laryngoscopy the glottic view was considered unsatisfactory in 40 patients (42%), but this was the case in only 15 patients (16%) when video laryngoscopy was used (p<0.0001). Endotracheal tube placement was successful in all but one patient where the Bonfils intubation fiberscope needed to be employed. No complications related to the C-MAC system were observed. CONCLUSIONS: Compared to direct laryngoscopy with a Macintosh laryngoscope blade in unselected patients undergoing ENT surgery and thus patients more susceptible to an unexpected difficult airway than a general patient population, the mobile C-MAC video laryngoscope significantly enhanced laryngeal view. Using RAE tracheal tubes seems to compensate the unfavorable deviation of optical and anatomical axes when indirect laryngoscopy is performed with the C-MAC system.

Incidence of gastrointestinal complications in cardiopulmonary bypass patients.

Gastrointestinal complications after cardiac surgery are associated with a high mortality rate. Because of the absence of early specific clinical signs, diagnosis is often delayed. The present study seeks to determine predictive risk factors for subsequent gastrointestinal complications after cardiosurgical procedures. Within a 1-year period, a total of 1116 patients who had undergone open heart surgery with cardiopulmonary bypass were prospectively studied for gastrointestinal complications. To determine predictive factors, all case histories of the patients were analyzed. Of the 1116 patients, 23 (2.1%) had gastrointestinal complications during the postoperative period, 10 of whom had to undergo subsequent abdominal surgery. Of these 23 patients, 20 died. Early gastrointestinal complications, which occurred mostly on postoperative days 6 or 7, consisted of bowel ischemia or hepatic failure. Late complications were gastrointestinal bleeding, pseudomembranous colitis, cholecystitis, and septic rupture of a spleen. The relative risk for abdominal complications after cardiopulmonary bypass was highly increased in association with (1) a cardiac index less than 2.0 l/min-1/(m2)-1, (2) postoperative onset of atrial fibrillation, (3) emergency surgery, (4) need for vasopressors, (5) need for intraaortic balloon counterpulsation, and (6) need for early redo thoracotomy due to surgical complications. All patients with necrotic bowel disease had elevated serum lactate levels. Furthermore, cardiopulmonary bypass and aortic clamping times were significantly prolonged in patients who developed gastrointestinal complications. A number of predictive factors contribute to the development of gastrointestinal complications after cardiopulmonary bypass surgery. Knowledge of these factors may lead to earlier identification of patients at increased risk and may allow more efficient and earlier interventions to reduce mortality.

Occupational exposure to nitrous oxide and desflurane during ear-nose-throat-surgery.

PURPOSE: To determine occupational exposure of the anesthesiologist and surgeon to nitrous oxide and desflurane during general anesthesia for ear-nose-throat (ENT) surgery in children and adults. METHODS: An observational clinical trial was performed in ten children (C) and ten adults (A). Tracheas were intubated, in adults, with cuffed tubes and in children with uncuffed tubes. The operating room was equipped with modern air conditioning and waste anesthetic gas scavengers. Gas samples were obtained during the operative procedure every 90 sec from the breathing zone of subjects. Time-weighted averages (TWA) over the time of exposure were calculated for nitrous oxide and desflurane. RESULTS: Nitrous oxide TWAs for anesthesiologists were 0.41 +/- 0.23 ppm (A) and 1.20 +/- 0.32 ppm (C, P < 0.0001), and 2.24 +/- 1.93 ppm (A) and 5.30 +/- 0.60 ppm (C, P = 0.0001) for the surgeon who worked close to the patient's airway and thus had higher exposure (P < 0.05 [A], P < 0.0001 [C]). With regard to desflurane, the anesthesiologists' TWAs were 0.02 +/- 0.03 ppm for both adults and children. The surgeon was exposed to 0.21 +/- 0.24 ppm desflurane (A) and 0.30 +/- 0.14 ppm (C, P: n.s.). Although the surgeon's exposure was greater (P < 0.05 [A], P < 0.0001 [C]), the threshold limits of 25 ppm for nitrous oxide and 2 ppm for desflurane recommended by the National Institute of Occupational Safety and Health were not exceeded. CONCLUSIONS: Under modern air conditioning, occupational exposure to inhalational anesthetics is low, and inhalational anesthesia is safe from the standpoint of modern workplace laws and health-care regulations.

[Exposure of anesthetists to sevoflurane and nitrous oxide during inhalation anesthesia induction in pediatric anesthesia]. / Exposition des Anästhesisten gegenüber Sevofluran und Lachgas während inhalativ eingeleiteter Narkosen in der Kinderanästhesie.

Inhalational mask induction with nitrous oxide and sevoflurane in young children is an appropriate alternative to intravenous induction and is considered safe and of rapid onset. Disadvantages of this technique are environmental pollution and occupational exposure to the inhalation agents used. Moreover, the potential health hazards are not yet completely clear. The purpose of the present study was to examine the anaesthesiologist's occupational exposure to nitrous oxide and sevoflurane in paediatric anaesthesia and mask induction. Twenty children underwent inhalational induction with nitrous oxide and sevoflurane in the operating theatre (air exchange rate 20.2/h, anaesthetic waste gas scavenger 40 l/min). Anaesthesia was maintained with the same agents. Air samples were taken from the edge of the anaesthesiologist's mouth continuously every 90 seconds, and trace concentrations of nitrous oxide and sevoflurane were analyzed with a direct reading infrared spectrometer (Brüel & Kjaer 1302, Denmark). Measurements taken during anaesthesia showed an increase in the concentrations of the anaesthetics used, but these were low. The highest mean concentrations occurred during induction (3.35 +/- 4.23 ppm for sevoflurane and 37.09 +/- 11.65 ppm for nitrous oxide). The overall peak levels measured were 6.31 +/- 4.23 ppm for sevoflurane and 68.78 +/- 40.79 ppm for nitrous oxide. Though the induction period was short compared to the whole length of anaesthesia, its impact on the overall waste gas exposure was 46.3% for sevoflurane (nitrous oxide 40.6%). Nonetheless, applicable German health law regulations were never infringed. The trace concentrations measured during inhalational mask induction and maintenance of anaesthesia were very low. With regard to modern workplace laws and health care regulations, gaseous induction in paediatric anaesthesia does not threaten the personnel's health.

[No contamination of medical personnel by desflurane and nitrous oxide inhalation anesthetics during surgical interventions in ophthalmology]. / Keine Kontamination des ärztlichen Personals mit den Inhalationsanästhetika Desfluran und Lachgas während operativer Eingriffe in der Augenheilkunde.

BACKGROUND: Possible health hazards from chronical exposure to inhalational anesthetics cannot definitively be excluded. PATIENTS AND METHODS: Trace concentrations of nitrous oxide and desflurane were continuously every 90 seconds determined in the breathing zone of both ophthalmologist and anesthesiologist during strabism surgery in 20 children by a infrared spectrometer. RESULTS: During anesthesia, the surgeon was exposed to the inhalational agents used, but concentrations were well within the legal limits. CONCLUSIONS: Despite minor occupational exposure of the operating room staff during the operative procedures, inhalational anesthesia in ophthalmologic operative procedures can be considered safe from the standpoint of modern work place laws and health care regulations.

[Maternal protection law and exposure of personnel in the recovery room and surgical intensive care unit by inhalation anesthetics]. / Mutterschutzgesetz und Kontamination des Personals im Aufwachraum und auf der chirurgischen Intensivstation durch Inhalationsanästhetika.

UNLABELLED: According to Section 4 of the German maternity law (MuSchG), pregnant and nursing women are not allowed to work in places where they may be exposed to hazardous gases. Due to MuSchG these women are often effered work in the recovery room (RR) and the surgical intensive-care unit (ICU). The present study examined the occupational exposure in the RR and the ICU to nitrous oxide, isoflurane and the new volatile agents desflurane and sevoflurane in accordance with the German work place safety and maternity laws. METHODS: Trace concentrations of inhalational agents which 10 (ICU) and 207 (RR) patients exhaled after anaesthesia were measured in the RR air and the rooms of the ICU. Measurements were effected with a real-time infrared spectrometer continuously every 90 seconds for period of 6 (ICU) and 14.5 (RR) hours. RESULTS: The mean concentrations exceeded both in RR and ICU the legal limits of workplace concentrations prescribed by the German maternity law. Concentrations for both desflurane and seroflurane were up to more than twice as high as those of isoflurane. Exposition levels at the ICU and in the RR exceeded those measured in the operating theatre. The ICU personnel had a higher exposure to anaesthetic gases than those working in the RR. CONCLUSION: To reduce the working-place concentrations below the legal threshold it is necessary to use local scavenging devices in addition to appropriate ventilation systems. According to our data, pregnant and nursing women should not be allowed to work in the RR or to nurse mechanically ventilated patients after surgery in the ICU.

Nitric oxide inhalation in acute pulmonary hypertension after cardiac surgery reduces oxygen concentration and improves mechanical ventilation but not mortality.

Impaired right-ventricular function may benefit from afterload reduction. Inhalation of nitric oxide (NO) reduces pulmonary hypertension without systemic circulatory depression. Influence of NO inhalation on oxygenation, ventilation, and hemodynamic parameters in 10 patients with acute pulmonary hypertension after cardiac surgery was examined in this study. Ten patients without NO treatment served as a control group. NO patients showed significantly improved oxygenation and recovery of right-ventricular function. Pulmonary artery pressure (12.8%), inspiratory oxygen demand (34.7%), PEEP (13.2%), and inspiration time (18.8%) decreased significantly during inhalation of nitric oxide. Mortality in both groups was identical. We therefore conclude that NO, by improving oxygenation and right-ventricular function, temporarily reduces invasiveness of mechanical ventilation. Reduction of invasiveness of ventilation did not influence mortality as compared with patients who did not receive NO. To finally estimate the benefit of NO inhalation, larger patient groups need to be examined.

[Inhalation of nitric oxide in severe lung failure]. / Inhalation von Stickoxid (NO) bei schwerem Lungenversagen.

Despite intensive therapeutic efforts, adult respiratory distress syndrome (ARDS) is still associated with a lethality ranging from 50 to 80%. Besides hypoxemia, fatal outcome is caused by myocardial insufficiency due to a progressive decrease in pulmonary vascular conductance. Inhalation of NO can selectively dilate pulmonary vessels in ventilated lung regions, thus increasing mean pulmonary artery conductance and decreasing venous admixture. This study determines the effects of NO inhalation in patients with severe ARDS on pulmonary gas exchange, haemodynamics and mortality. Twenty surgical patients (mean age 50.3 +/- 9.25 years) with severe ARDS (Murray score 3.4 +/- 0.3) were treated with variable concentrations of NO during mechanical ventilation with continuous positive pressure. Pulmonary artery catheters were used to measure pressures, flow and venous admixture. Mortality with NO inhalation was compared with that of previous ARDS patients (n = 20) who had not received NO. Mean duration of NO inhalation was 120.1 +/- 33.12 hours (n = 20) (range 40 to 254 hours). Mean NO concentration during the first hour of delivery was 18.5 +/- 3.88 ppm. Sixteen patients had FiO2 of 1.0 when NO was started. Within the first hour of NO inhalation, the PaO2/FiO2 ratio increased from 82.1 +/- 10.28 to 124.6 +/- 28.18. Eighteen patients were responders. Mean ventilatory pressure was lowered. Oxygenation improvement was most marked during the first 36 hours and then gradually declined. Despite the significant increase in NO related oxygenation, pulmonary artery pressures did not consistently decrease. Sixteen patients in the NO group died. In the group without NO 15 patients died. Compared with ARDS patients of similar severity not receiving NO, the NO-treated patients had the same lethality. In severe ARDS, oxygenation significantly improves with the initiation of NO inhalation, but this effect declines over time. With NO, FiO2 and ventilatory pressures can be lowered. Whether the theoretically reduced oxygen toxicity and the reduced invasiveness of mechanical ventilation with NO reduces patient mortality must be determined in larger patient groups.

[Exposure of recovery room personnel to inhalation anesthetics]. / Exposition des Aufwachraumpersonals mit Inhalationsanästhetika.

Both desflurane and sevoflurane have a favourable blood/gas distribution coefficient. There is concern, however, that environmental contamination is higher when these agents are employed since they must be used in relatively high concentrations. Our study seeks to determine the degree of exposure of recovery room staff to trace amounts of these two agents. Two hundred and seven surgical patients were included in the study. The recovery room studied had a volume of 243 cubic metres. The hourly fresh air supply for this room was 1,845 cubic metres, which results in 7.6 air exchanges per hour without air return. Measurements of trace concentrations of the inhalational agents were taken for 12 days. Concentrations of these anaesthetics were assessed in the recovery room with a real-time infrared spectrometer every 90 seconds. Mean exposure to nitrous oxide in the recovery room was 11.5 +/- 3.97 ppm and to isoflurane 1.4 +/- 0.31 ppm. All measured values were below the standard German threshold values. Trace concentrations of desflurane were 2.8 +/- 0.84 ppm and of sevoflurane 3.2 +/- 0.62 ppm. We conclude that the exposure to the inhalational anaesthetics in the climatised recovery room was low. The threshold values of 100 ppm for nitrous oxide and 10 ppm for isoflurane recommended by German law were not exceeded. When the new volatile anaesthetics are used, exposure of recovery room staff to trace concentrations of these agents is higher, but the concentrations do not exceed the levels allowed applicable German health regulations.

[Workplace contamination from sevoflurane. Concentration measurement during bronchosopy in children]. / Arbeitsplatzbelastung durch sevofluran. Konzentrationsmessungen während Bronchoskopien bei Kindern.

UNLABELLED: General anaesthetic agents are frequently used for paediatric bronchoscopy. A disadvantage of open-system anaesthesia is the contamination of the working environment. The aim of this study was to determine the exposure of the anaesthesiologist and endoscopist during paediatric bronchoscopy under general anaesthesia in different working environments and to compare these measurements to the currently valid international threshold limits. MATERIALS AND METHODS: Twenty-five children (ASA I-III) scheduled for diagnostic bronchoscopy were included in the study. After inhalational induction, all patients were intubated with a nonflexible bronchoscope and manually ventilated through a side-arm of the bronchoscope. Maintenance of anaesthesia was achieved with sevoflurane (2-3 vol.%) in pure oxygen. Trace concentrations were measured every 90 s in the breathing zones of the operating theatre (OT) personnel by means of a highly sensitive direct-reading instrument (Brüel & Kjaer 1302). The lower detection limit was 0.02 ppm. The investigation was done in an OT with and without air-conditioning and a scavenging system. RESULTS: The mean age of the children was 50.3 months (range: 3-109 months). Ventilation and oxygenation were stable throughout the bronchoscopic procedure. Mean exposure to sevoflurane in the OT without air-conditioning and a scavenging system was over 40 ppm for the anaesthetist and 50 ppm for the endoscopist. All international threshold limit values were exceeded. Peak concentrations higher than 100 ppm could be detected during 40% of the anaesthetics. CONCLUSION: The main finding of the present study is that under inhalation anaesthesia with sevoflurane for paediatric bronchoscopy, occupational exposure is higher than all known health regulation guidelines permit. Therefore, the use of total intravenous anaesthesia is advocated even in very small infants.

Heparin-induced thrombocytopenia type II: perioperative management using danaparoid in a coronary artery bypass patient with renal failure.

An 84-year-old patient with heparin-induced thrombocytopenia (HIT), global cardiac decompensation, and acute renal failure underwent a cardiosurgical intervention using an extracorporeal circuit. For systemic anticoagulation danaparoid (Orgaran) was applied as a heparin substitute preoperatively and maintained for systemic anticoagulation during ECC despite it being eliminated by the kidney. The postoperative recovery was prolonged due to bleeding complications. During cardiopulmonary bypass (216 min) the target level of anti-factor Xa was 1.5 UI/ml. This required continuous infusion and an occasional bolus of danaparoid. Coagulation in the extracorporeal circuit was observed twice at plasma levels below 1.4 IU/ml. There were no thromboembolic or neurologic events. We did not retransfuse blood from the extracorporeal circuit or the cardiotomy reservoir after bypass, but because elimination of danaparoid was impaired in this patient and there is no neutraliser available antifactor Xa postoperatively exceeded 0.6 IU/ml for 30 hours. Diffuse bleeding with tamponade resulted. Weaning the patient from the respirator was achieved 12 hours after the last re-exploration. From the 4th postoperative day 750 IU of danaparoid were administered twice daily subcutaneously for thrombosis prevention. On the 6th postoperative day discharge from the ICU was possible. We conclude that the application of danaparoid for cardiopulmonary bypass in patients suffering from acute renal failure may be complicated by hemorrhage.