Herbert Koinig

Ultrasonographic Guidance Improves Sensory Block and Onset Time of Three-in-One Blocks

The use of ultrasound reduces the onset time, improves the quality of sensory block, and minimizes the risks associated with the supraclavicular approach for brachial plexus and stellate ganglion blockade.The present study was designed to evaluate whether ultrasound also facilitates the approach for 3-in-1 blocks. Forty patients (ASA physical status II or III) undergoing hip surgery after trauma were randomly assigned to two groups. In the ultrasound (US) group, 20 mL bupivacaine 0.5% was administered under US guidance, whereas in the control group, the same amount and concentration of local anesthetic was administered with the assistance of a nerve stimulator (NS). After US- or NS-based identification of the femoral nerve, the local anesthetic solution was administered, and the distribution of the local anesthetic solution was visualized and recorded on videotape in the US group. The quality and the onset of the sensory block was assessed by using the pinprick test in the central sensory region of each of the three nerves and compared with the same stimulation on the contralateral leg every 10 min for 60 min. The rating was performed using a scale from 100% (uncompromised sensibility) to 0% (no sensory sensation). Heart rate, noninvasive blood pressure, and oxygen saturation were measured at short intervals for 60 min. The onset of sensory blockade was significantly shorter in Group US compared with Group NS (US 16 +/- 14 min, NS 27 +/- 16 min, P < 0.05). The quality of the sensory block after injection of the local anesthetic was also significantly better in Group US compared with Group NS (US 15% +/- 10% of initial value, NS 27% +/- 14% of initial value, P < 0.05). A good analgesic effect was achieved in 95% of the patients in the US group and in 85% of the patients in the NS group. In the US group, visualization of the cannula tip, the femoral nerve, the major vessels, and the local anesthetic spread was possible in 85% of patients. Incidental arterial puncture (n = 3) was observed only in the NS group. We conclude that an US-guided approach for 3-in-1 block reduces the onset time, improves the quality of the sensory block and minimizes the risks associated with this regional anesthetic technique. Implications: The onset time and the quality of a regional anesthetic technique for the lower extremity is improved by ultrasonographic nerve identification compared with older techniques. (Anesth Analg 1997;85:854-7)

Magnesium sulfate reduces intra- and postoperative analgesic requirements

In a randomized, double-blind study with two parallel groups, we assessed the analgesic effect of perioperative magnesium sulfate administration in 46 ASA physical status I or II patients undergoing arthroscopic knee surgery with total IV anesthesia. The patients received either magnesium sulfate 50 mg/kg preoperatively and 8 mg [center dot] kg-1 [center dot] h-1 intraoperatively or the same volume of isotonic sodium chloride solution IV. Anesthesia was performed with propofol (2 mg/kg for induction, 6-8 mg [center dot] kg- 1 [center dot] h- 1 for maintenance), fentanyl (3 [micro sign]g/kg for induction), and vecuronium (0.1 mg/kg for intubation). Intraoperative pain was defined as an increase of mean arterial blood pressure and heart rate of more than 20% from baseline values after the induction of anesthesia and was treated with bolus fentanyl (1-2 [micro sign]g/kg). Postoperative analgesia was achieved with fentanyl (0.5 [micro sign]g/kg) and evaluated using the pain visual analog scale for 4 h. During the intraoperative and postoperative periods, patients in the magnesium group required significantly less fentanyl than those in the control group (control group 0.089 +/- 0.02 [micro sign]g [center dot] kg-1 [center dot] min-1 versus magnesium group 0.058 +/- 0.01 [micro sign]g [center dot] kg-1 [center dot] min- 1; P < 0.05 and control group 0.021 +/- 0.013 [micro sign]g [center dot] kg-1 [center dot] min-1 and magnesium group 0.0031 +/- 0.0018 [micro sign]g [center dot] kg-1 [center dot] min-1; P < 0.01 for intraoperative and postoperative periods, respectively). We conclude that, in a clinical setting with almost identical levels of surgical stimulation, IV magnesium sulfate administration reduces intraoperative and postoperative analgesic requirements compared with isotonic sodium chloride solution administration. Implications: The perioperative administration of IV magnesium sulfate reduces intra- and postoperative analgesic requirements in patients with almost identical levels of surgical stimulus. Our results demonstrate that magnesium can be an adjuvant to perioperative analgesic management. (Anesth Analg 1998;87:206-10)

Incidence of complications in intrahospital transport of critically ill patients--experience in an Austrian university hospital.

ZusammenfassungHINTERGRUND: Im letzten Jahrzehnt gab es gewaltige Fortschritte beim Transport von kritisch kranken Patienten im Krankenhaus. Obwohl der innerklinische Transport heutzutage als Kontinuum der Intensivbetreuung angesehen wird, stellt dieser immer noch ein spezielles Risiko für die Patienten dar. METHODIK: Diese prospektive Beobachtungsstudie hatte das Ziel, die Häufigkeit von transportassoziierten Komplikationen zu eruieren und zusätzliche Quellen für ein erhöhtes Komplikationsrisiko herauszufiltern. In einem Zeitraum von 8 Monaten wurden alle innerklinischen Transporte von Erwachsenen und Kindern von anästhesiologischen Intensivstationen beobachtet und analysiert. RESULTATE: Ingesamt wurden 452 Transporte an 226 Patienten durchgeführt. Die Gesamtrate an kritischen Zwischenfällen war niedrig (4,2%) und es konnte kein direkter Zusammenhang zwischen Mortalität und dem Transportprozess festgestellt werden. Neben bekannten Risikofaktoren wie Beatmung mit positiv endexspiratorischem Druck und Katecholaminbedarf des Patienten, stellte sich der akut indizierte Transport als signifikanter Risikofaktor heraus. SCHLUSSFOLGERUNG: Verbessertes Management solcher Transporte hat erheblich zur Risikominimierung beigetragen, obwohl nach wie vor besonders im Zusammenhang mit der Schwere der Erkrankung und der Dringlichkeit des Transports ein erhöhtes Restrisiko besteht.SummaryBACKGROUND: During the past decade, considerable changes and advances have been made in intrahospital transport of critically ill patients. Despite the fact that intrahospital transport is nowadays regarded an extension of the intensive care continuum, it still poses a risk for the patient. MATERIALS AND METHODS: This prospective, observational study was designed to determine the occurrence rate of transport-related complications in the altered setting of intrahospital transports and to identify possible confounding sources of increased risk. In an eight-month period, adults and infants from anesthesiologic intensive care units were analyzed. RESULTS: A total of 226 patients underwent 452 intrahospital transports. The overall rate of critical incidents was low (4.2%) and no direct association between mortality and intrahospital transport was observed. In addition to the known risk factors of ventilatory support with positive end-expiratory pressure and requirement for catecholamine support, the necessity for intrahospital transport in the acute vs. elective situation was found to significantly increase the risk of complications. CONCLUSIONS: We conclude that advances in the management of intrahospital transport of critically ill patients have led to an overall decrease of complications. However, an undeniable risk remains, especially in relation to disease severity and the urgency of such transports.

Performance of supraglottic airway devices and 12 month skill retention: A randomized controlled study with manikins

PURPOSE Airway management for successful ventilation by laypersons and inexperienced healthcare providers is difficult to achieve. Bag-valve mask (BVM) ventilation requires extensive training and is performed poorly. Supraglottic airway devices (SADs) have been successfully introduced to clinical resuscitation practice as an alternative. We evaluated recently introduced (i-gel™ and LMA-Supreme™) and established SADs (LMA-Unique™, LMA-ProSeal™) and BVM used by laypeople in training sessions on manikins. METHODS In this randomized controlled study, 267 third-year medical students participated with informed consent and IRB approval. After brief standardized training, each participant applied all devices in a randomized order. Success of device application and ventilation was recorded. Without further training, skill retention was assessed in the same manner 12 months later. Outcome parameters were the number of application attempts, application time, tidal volume and gastric inflation rate recorded at successful attempts, and subjective ease-of-use rating by the participants. RESULTS i-gel™ and LMA-Supreme™ were the most successful in the first attempt at both assessments and in the subjective ease-of-use rating. The shortest application time was found with BVM (8 ± 5s in 2008 vs. 9 ± 5s in 2009) and i-gel (10 ± 3s vs. 12 ± 5s). Tidal volumes were disappointing with no device reaching 50% volume within the recommended range (0.4-0.6L). Gastric inflation rate was highest with BVM (18% vs. 20%) but significantly lower with all SADs (0.4-6%; p < 0.001 for 2008 and 2009). CONCLUSION SADs showed clear advantages over BVM. Compared with LMA-Unique™ and LMA-ProSeal™, i-gel™ and LMA-Supreme™ led to higher first-attempt success rates and a shorter application time.

Postoperative Analgesia with Remifentanil in Patients Undergoing Cardiac Surgery

Remifentanil, a short-acting opioid, is commonly used in cardiac anesthesia. In this study we sought to demonstrate the feasibility of pain treatment and to determine the remifentanil dose necessary for adequate analgesia in tracheally extubated patients after cardiac surgery. Thirty patients undergoing elective cardiac surgery were included in this study. After surgery, the intraoperatively administered remifentanil was initially continued at 0.05 &mgr;g · kg−1 · min−1. Before tracheal extubation, a nonsteroidal antiinflammatory drug was administered and remifentanil was reduced to 0.035 &mgr;g · kg−1 · min−1. Pain assessment using a visual analog scale (VAS) was performed after tracheal extubation, in 2-min intervals for 10 min, every 10 min until the end of the first hour and every 30 min during the ensuing 5 h. A VAS score ≥30 or a respiratory rate <10 breaths/min was followed by an increase or decrease in the remifentanil dose by 0.005 &mgr;g · kg−1 · min−1, respectively. For rapid dose adaptation during the first 10 min, remifentanil was increased twice by 0.005 &mgr;g · kg−1 · min−1 and then 3 times by 0.01 &mgr;g · kg−1 · min−1. With a mean remifentanil dose of 0.051 &mgr;g · kg−1 · min−1 VAS decreased to 26 ± 14 after 30 min. Sufficient analgesia was achieved with remifentanil doses ranging from 0.03 to 0.09 &mgr;g · kg−1 · min−1. A maximum mean remifentanil dose of 0.057 &mgr;g · kg−1 · min−1 was reached after 4 h. The combination of remifentanil with a nonsteroidal antiinflammatory drug provided adequate analgesia in 73% of patients 30 min after tracheal extubation. Rapid dose titration was necessary during the first 10 min in 50% of patients. Increasing the initial remifentanil dose could shorten the titration period but may be associated with respiratory complications.

Urinary Output Predicts Survival in Patients Undergoing Extracorporeal Membrane Oxygenation Following Cardiovascular Surgery.

Objectives:Extracorporeal membrane oxygenation represents a valuable and rapidly evolving therapeutic option in patients with severe heart or lung failure following cardiovascular surgery. However, survival remains poor and accurate risk stratification challenging. Therefore, we evaluated the predictive value of urinary output within 24 hours after extracorporeal membrane oxygenation initiation on mortality in patients undergoing venoarterial extracorporeal membrane oxygenation support following cardiovascular surgery and aimed to improve established risk prediction models. Design:Single-center, observational registry. Setting:University-affiliated tertiary care center. Patients:We included 205 patients undergoing veno-arterial extracorporeal membrane oxygenation therapy following cardiovascular surgery at a university-affiliated tertiary-care center into our single-centre registry. Interventions:None. Measurements and Main Results:During a median follow-up time of 35 months (interquartile range, 19–69), 64% of patients died. Twenty-four–hour urinary output was the strongest predictor of outcome among renal function variables with an adjusted hazard ratio per 1 SD of 0.55 (95% CI, 0.40–0.76; p < 0.001) for 30-day mortality and of 0.65 (95% CI, 0.53–0.86; p = 0.002) for 2-year long-term mortality. Most remarkably, 24-hour urinary output showed additional prognostic value beyond that achievable with the simplified acute physiology score-3 and sequential organ failure assessment score indicated by improvements in the category-free net reclassification index for 30-day mortality (simplified acute physiology score-3: 36%, p = 0.015; sequential organ failure assessment score: 36%, p = 0.02), as well as for 2-year mortality (simplified acute physiology score-3: 33%, p = 0.02; sequential organ failure assessment score: 43%, p = 0.005). Conclusions:We identified 24-hour urinary output as a strong and easily available predictor of mortality in patients undergoing extracorporeal membrane oxygenation therapy following cardiovascular surgery. Implementation of 24-hour urinary output leads to a substantial improvement of established risk prediction models in this vulnerable patient population. These results are particularly compelling because measurement of urinary output is inexpensive and routinely performed in all critical care units.

Thoracoabdominal Aortic Aneurysm Repair: Reducing Adverse Outcome with Left Heart Bypass, Selective Visceral Perfusion and Renal Protection:

Objective: To report our experience with left heart bypass and selective visceral perfusion for prevention of permanent spinal cord injury and distal organ failure in patients undergoing thoracoabdominal aortic aneurysm repair. Methods: From April 2001 to March 2002 seven patients were electively operated on with left heart bypass and selective perfusion of the visceral and renal organs at the University Clinic of Vienna, Austria. There were four males (57%) and two females (43%) with a mean age of 70 ± 6 years. Etiology of the aneurysm was a chronic dissection in one patient and athereosclerotic in the remaining five. Crawford classification was I in one patient (14%), II in five patients (86%) and III in one patient (14%). Existing comorbidities were hypertension in all seven patients, coronary artery disease in two patients (29%), chronic pulmonary obstructive disease in two patients (29%), and lung cancer resection and peripheral artery occlusive disease in one patient (14%) each. Two patients had a history of prior aortic aneurysm repair, namely elective repair of the ascending thoracic aorta 2 months before the thoracoabdominal aortic aneurysm repair, and replacement of the infrarenal aorta 12 years previously in another patient. Results: All patients survived the operation and were discharged after a mean hospital stay of 25 ± 13 days. Adverse outcome occurred in three out of seven patients. One patient with Crawford classification 11 developed acute renal insufficiency, and two patients with class 11 and III showed signs of transient paraparesis, respectively. Mean intraoperative blood loss was 3315 ± 701 ml. On average, 6.7 ± 2.8 units of packed red cells, 10 units of fresh frozen plasma, and 1 unit of platelets were given during the operation. Intensive care unit stay ranged from 2 to 16 days. Conclusions: The combined usage of left heart bypass, selective visceral perfusion, and renal protection can be recommended as a useful and effective technique in order to minimize adverse outcome in patients undergoing repair of the thoracoabdominal aorta.

Asystole during endovascular embolization of a dural arterio-venous fistula in the brain.

ndovascular embolization has become a conve-nient and reliable technique in the treatment ofcerebrovascular malformations in the neurologi-cal and neuroradiological field (1–8). Despite the op-tion to reach almost every region of the brain withoutcraniotomy, numerous complications have been de-scribed (3,5–10). We report a case of asystole duringendovascular embolization of a dural arteriovenousfistula (d-AVF) in the brain.

ASSOCIATION OF VENOARTERIAL EXTRA-CORPOREAL MEMBRANE OXYGENATION CANNULATION SITE WITH WEANING TIME AND SURVIVAL

Venoarterial extracorporeal membrane oxygenation (ECMO) is a life-saving measure in patients with refractory heart failure after cardiac surgery. However, femoral-femoral cannulation is associated with distal limb ischemia, poor upper body oxygenation and may lead to a rise of left ventricular

BENEFICIAL EFFECTS OF LEVOSIMENDAN ON SURVIVAL IN PATIENTS UNDERGOING EXTRACORPOREAL MEMBRANE OXYGENATION FOLLOWING CARDIOVASCULAR SURGERY

The impact of levosimendan treatment on clinical outcome in patients undergoing extracorporeal membrane oxygenation (ECMO) support following cardiovascular (CV) surgery is unknown. It is tempting to speculate that the benefical effects of levosimendan are more efficiently translated into improved