Surgical treatment of spondylodiscitis in critically ill septic patients.

PURPOSE: Surgical procedures in critically ill patients with spondylodiscitis are challenging and there are several controversies. Here, we present our experience with offering surgical intervention early in critically ill septic patients with spondylodiscitis. METHOD: After we introduced a new treatment paradigm offering early but limited surgery, eight patients with spondylodiscitis complicated by severe sepsis and multiple organ failure underwent urgent surgical treatment over a 10-year period. Outcome was assessed according to the Barthel index at 12-month follow-up and at the last available follow-up (mean 89 months). RESULTS: There were 7 men and 1 woman, with a mean age of 62 years. The preoperative ASA score was 5 in 2 patients, and 4 in 6 patients. Six of them presented with high-grade paresis, and in all of them, spondylodiscitis with intraspinal and/or paravertebral abscesses was evident in MR imaging studies. All patients underwent early surgery (within 24 h after admission). The median time in intensive care was 21 days. Out of the eight patients, seven survived. One year after surgery, five patients had a good outcome (Barthel index: 100 (1); 80 (3); and 70 (1)). At the last follow-up (mean 89 months), 4 patients had a good functional outcome (Barthel index between 60 and 80). CONCLUSION: Early surgical treatment in critically ill patients with spondylodiscitis and sepsis may result in rapid control of infection and can provide favorable long-term outcome. A general strategy of performing only limited surgery is a valid option in such patients who have a relatively high risk for surgery.

Resection of posterior fossa tumors in the semi-sitting position in children younger than 4 years of age.

PURPOSE: The semi-sitting position for resection of posterior fossa tumors is a matter of ongoing debate. Here we report about our experience with this approach in children younger than 4 years of age. METHODS: We retrospectively analyzed data of children younger than 4 years of age operated on in our institution in the semi-sitting position over a 15-year period. Patients were intraoperatively monitored for venous air embolism (VAE) by transthoracic Doppler (TTD) or transesophageal echocardiography (TEE). The severity of VAE was classified according to the Tübingen grading scale. Intraoperative incidents of VAE were recorded and the patients' course was followed postoperatively with a special focus on possible complications. RESULTS: Twenty-four children (18 boys, 6 girls) were operated on in the semi-sitting position (26 operations). Mean age was 2.2 years (± 1.0), range between 0.4 and 3.9 years. External ventricular drains were inserted in 18 children with hydrocephalus preoperatively. VAE was detected in 6 instances during surgery (6/26 (23.1%)). In 3 patients with grade 1 VAE, no additional treatment was necessary. In one patient with grade 2 VAE, intracardiac air suction via the central venous catheter was performed, and in two patients with grade 4 VAE, additional cathecholamine-infusion was administered. No major intraoperative complications occurred. Postoperative CT images showed pneumocephalus in all children. In two children, small asymptomatic impression skull fractures at the site of the Mayfield pin occurred. Revision surgery was necessary in one child with a suboccipital CSF fistula. CONCLUSION: The semi-sitting position for resection of tumors in the posterior fossa in children younger than 4 years of age can be safely performed in experienced centers taking special caution to detect and treat potential complications in an interdisciplinary setting.

Routine postoperative admission to the neurocritical intensive care unit after microvascular decompression: necessary or can it be abandoned?

Postoperative neurocritical intensive care unit (NICU) admission of patients who underwent craniotomy for close observation is common practice. In this study, we performed a comparative analysis to determine if there is a real need for NICU admission after microvascular decompression (MVD) for cranial nerve disorders or whether it may be abandoned. The present study evaluates a consecutive series of 236 MVD surgeries performed for treatment of trigeminal neuralgia (213), hemifacial spasm (17), vagoglossopharyngeal neuralgia (2), paroxysmal vertigo (2), and pulsatile tinnitus (2). All patients were operated by the senior surgeon according to a standard protocol over a period of 12 years. Patients were admitted routinely to NICU during the first phase of the study (phase I), while in the second phase (phase II), only patients with specific indications would go to NICU. While 105 patients (44%) were admitted to NICU postoperatively (phase I), 131 patients (56%) returned to the ward after a short stay in a postanaesthesia care unit (PACU) (phase II). Specific indications for NICU admission in phase I were pneumothorax secondary to central venous catheter insertion (4 patients), AV block during surgery, low blood oxygen levels after extubation, and postoperative dysphagia and dysphonia (1 patient, respectively). There were no significant differences in the distribution of ASA scores or the presence of cardiac and pulmonary comorbidities like congestive heart failure, arterial hypertension, or chronic obstructive pulmonary disease between groups. There were no secondary referrals from PACU to NICU. Our study shows that routine admission of patients after eventless MVD to NICU does not provide additional value. NICU admission can be restricted to patients with specific indications. When MVD surgery is performed in experienced hands according to a standard anaesthesia protocol, clinical observation on a neurosurgical ward is sufficient to monitor the postoperative course. Such a policy results in substantial savings of costs and human resources.

Porcine Liver Transplantation Without Veno-venous Bypass As an Extended Criteria Donor Model.

Liver transplantation is regarded as the gold standard for the treatment of a variety of fatal hepatic diseases. However, unsolved issues of chronic graft failure, ongoing organ donor shortages, and the increased use of marginal grafts call for the improvement of current concepts, such as the implementation of organ machine perfusion. In order to evaluate new methods of graft reconditioning and modulation, translational models are required. With respect to anatomical and physiological similarities to humans and recent progress in the field of xenotransplantation, pigs have become the main large animal species used in transplantation models. After the initial introduction of a porcine orthotopic liver transplant model by Garnier et al. in 1965, several modifications have been published over the past 60 years. Due to specifies-specific anatomical traits, a veno-venous bypass during the anhepatic phase is regarded as a necessity to reduce intestinal congestion and ischemia resulting in hemodynamic instability and perioperative mortality. However, the implementation of a bypass increases the technical and logistical complexity of the procedure. Furthermore, associated complications such as air embolism, hemorrhage, and the need for a simultaneous splenectomy have been reported previously. In this protocol, we describe a model of porcine orthotopic liver transplantation without the use of a veno-venous bypass. The engraftment of donor livers after static cold storage of 20 h - simulating extended criteria donor conditions - demonstrates that this simplified approach can be performed without significant hemodynamic alterations or intraoperative mortality and with regular uptake of liver function (as defined by bile production and liver-specific CYP1A2 metabolism). The success of this approach is ensured by an optimized surgical technique and a sophisticated anesthesiologic volume and vasopressor management. This model should be of special interest for workgroups focusing on the immediate postoperative course, ischemia-reperfusion injury, associated immunological mechanisms, and the reconditioning of extended criteria donor organs.

Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor.

BACKGROUND: Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures. METHODS: Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anaesthesia a blood sample was taken (T1). The patients then received 1 g-kg-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate®) and PFA-100® tests. RESULTS: No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate®, neither in the adenosinediphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100® closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosindiphosphate (COL/ADP) test 79s [70/99] and 91s [81/109]; p=0.002); collagen/epinephrine (COL/EPI) test 109s [92/129] and 122s [94/159]; p=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatine solution had a significant prolongation. COL/ADP: 78s [70/98] and 91s [82/133]; p=0.0004). COL/EPI: test 111s [92/128] and 127s [103/146]; p=0.0026). Except for individual outliers, the measured values were in the normal range. CONCLUSIONS: In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.

Structured evaluation of stress triggers in prehospital emergency medical care : An analysis by questionnaire regarding the professional groups.

BACKGROUND: Emergency medical services work in the environment of high responsibility teams and have to act under unpredictable working conditions. Stress occurs and has potential of negative effects on tasks, teamwork, prioritization processes and cognitive control. Stress is not exclusively dictated by the situation-the individuals rate the situation of having the necessary skills that a particular situation demands. There are different occupational groups in the emergency medical services in Germany. Training, tasks and legal framework of these groups vary. OBJECTIVE: The aim of this study was to identify professional group-specific stressors for emergency medical services. These stress situations can be used to design skills building tools to enable individuals to cope with these stressors. MATERIAL AND METHODS: The participants were invited to the study via posters and social media. An expert group (minimum 6 months of experience) developed a set of items via a two-step online Delphi survey. The experts were recruited from all professional groups represented in the German emergency medical service. We evaluated the resulting parameters for relevance and validity in a larger collective. Lastly, we identified stress factors that could be grouped in relevant scales. In total 1017 participants (paramedics, physicians) took part in the final validation survey. RESULTS: After validation, we identified a catalogue of stressors with 7 scales and 25 items for EMT (Emergency Medical Technician) paramedics (KMO [Kayser-Meyer-Olkin criterion] 0.81), 6 scales and 24 items for advanced paramedics (KMO 0.82) and 6 scales and 24 items for EMS (Emergency Medical Service) physicians (KMO 0.82). For the professional group of EMT basic, the quality parameters did not allow further processing of the items. Professional group-specific scales for EMT paramedics are "professional limitations", "organizational framework", "expectations" and "questions of meaning". For advanced paramedics "appreciation", "exceptional circumstances" and "legal certainty" were identified. The EMT physicians named "handling third parties", "tolerance to ambiguity", "task management" and "pressure to act". A scale that is representative for all professional groups is "teamwork". Organizational circumstances occur in all groups. The item "unnecessary missions" for EMT paramedics and "legal concerns with the application of methods" for advanced paramedics are examples. DISCUSSION: Different stressors are relevant for the individual professional groups in the German emergency medical service. The developed catalogue can be used in the future to evaluate the subjective stress load of emergency service professionals. There are stressors that are inherent in the working environment (e.g. pressure to act) and others that can be improved through training (teamwork). We recommend training of general resistance as well as training of specific items (e.g., technical, nontechnical skills). All professionals mentioned items with respect to organizational factors. The responsible persons can identify potential for improvement based on the legal and organizational items. The EMT basic requires further subdivision according to task areas due to its variable applicability.

Analysis of risk factors for venous air embolism in the semisitting position and its impact on outcome in a consecutive series of 740 patients.

OBJECTIVE: Routine use of the semisitting position, which offers several advantages, remains a matter of debate. Venous air embolism (VAE) is a potentially serious complication associated with the semisitting position. In this study, the authors aimed to investigate the safety of the semisitting position by analyzing data over a 20-year period. METHODS: The incidence of VAE and its perioperative management were analyzed retrospectively in a consecutive series of 740 patients who underwent surgery between 1996 and 2016. The occurrence of VAE was defined by detection of bubbles on transthoracic Doppler echocardiography (TTDE) or transesophageal echocardiography (TEE) studies, a decrease of end-tidal CO2 (ETCO2) by 4 mm Hg or more, and/or an unexplained drop in systolic arterial blood pressure (≥ 10 mm Hg). From 1996 until 2013 TTDE was used, and from 2013 on TEE was used. The possible risk factors for VAE and its impact on surgical performance were analyzed. RESULTS: There were 404 women and 336 men with a mean age at surgery of 49 years (range 1-87 years). Surgery was performed for infratentorial lesions in 709 patients (95.8%), supratentorial lesions in 17 (2.3%), and cervical lesions in 14 (1.9%). The most frequent pathology was vestibular schwannoma. TEE had a higher sensitivity than TTDE. While TEE detected VAE in 40.5% of patients, TTDE had a detection rate of 11.8%. Overall, VAE was detected in 119 patients (16.1%) intraoperatively. In all of these patients, VAE was apparent on TTDE or TEE. Of those, 23 patients also had a decrease of ETCO2, 18 had a drop in blood pressure, and 23 had combined decreases in ETCO2 and blood pressure. VAE was detected in 24% of patients during craniotomy before opening the dura mater, in 67% during tumor resection, and in 9% during wound closure. No risk factors were identified for the occurrence of VAE. Two patients had serious complications due to VAE. Surgical performance in vestibular schwannoma surgery was not affected by the presence of VAE. CONCLUSIONS: This study shows that the semisitting position is overall safe and that VAE can be managed effectively. Persistent morbidity is very rare. The authors suggest that the semisitting position should continue to have a place in the standard armamentarium of neurological surgery.

Noninvasive continuous arterial pressure monitoring during anesthesia induction in patients undergoing cardiac surgery.

Objective: In this study we compared noninvasive arterial pressure measurement using ClearSight™ vascular-unloading-technique (Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurement during induction of anesthesia undergoing mayor cardiac surgery. Design: Prospective, monocentric. Setting: University hospital. Participants: 54 patients undergoing mayor cardiac surgery. Interventions: During induction all patients were simultaneously monitored with invasive (reference method) and noninvasive arterial pressure measurement (test-method) over a mean time period of 27 minutes. Measurements and Main Results: We observed slightly lower systolic and mean arterial pressures noninvasive than invasive. For systolic arterial pressure the mean of the differences was -18,05 mmHg (p < 0,05, SD ±16,78 mmHg), the mean arterial pressure MAP -5,47 mmHg (p < 0,05, SD ±11,08 mmHg) and for diastolic pressure -1,09 mmHg (p < 0,05, SD±11,15 mmHg),. The mean of the differences in heartrate was 1,15 (p < 0,05, SD±6,9 mmHg). When considering all measured values of the invasively measured MAP and the ClearSight ™ -MAP at the same timestamp over the recording interval, an almost identical progress can be seen that indicates a sufficient mapping of the hemodynamic changes. The percentage error for mean arterial, systolic and diastolic pressure measured by ClearSight™ amounts to 25,95 %, 26,77 % and 34,16 %, respectively. Conclusions: We conclude that ClearSight ™ is a good option for hemodynamic monitoring during induction of anesthesia. Taking into account the limitations, non-invasive arterial blood pressure measurement offers sufficient security to safely initiate anesthesia, especially when MAP is of particular interest. The use of non-invasive arterial blood pressure measurement with ClearSight ™ during induction of anesthesia in patients scheduled for major cardiac surgery is reliable and easy to use.

Albumin combined with Mannitol impairs whole blood coagulation and platelet function in vitro.

BACKGROUND: The indication of hydroxyethyl starch is currently under critical discussion and albumin 5% (ALB) has an increasing use in the operating theatre. Therefore, ALB is routinely used in neurosurgical procedures and often combined with mannitol 20% (MAN). Purpose of this in-vitro study was to determine the influence of the combination of MAN and ALB on blood coagulation and platelet function. METHODS: Twenty-two healthy volunteers were included into this study and 21 analyzed. Blood was obtained and diluted into five groups: 1) 7% dilution with MAN; 2) 10% dilution with ALB; 3) 17% dilution with isotonic balanced electrolyte solution; 4) 17% dilution with MAN+ALB; and 5) undiluted blood as control group (CON). Rotational thrombelastometry via ROTEM® (EXTEM™/FIBTEM™ Test; SABIC, Riyad, Saudi Arabia) and thrombocyte aggregometry via Multiplate® (Roche Diagnostics, Grenzach-Wyhlen, Germany) (ASPI, ADP and TRAP-test) were used to detect differences within the intervention groups and compared to the control group. RESULTS: The maximum clot firmness in the FIBTEM™ Test (SABIC) decreased under the normal range with the combination of MAN+ALB: 8 mm (5.5-11) compared to CON: 15 mm (12.5-20), P<0.05. Platelet function (ADP test) showed significant decreases for ALB: 51 AUC (40-84) and MAN+ALB: 54 AUC (41-68) compared to CON: 92 AUC (75-101), P<0.05. Except in clotting time all other EXTEM™ tests (SABIC) of MAN+ALB subgroup showed significant impairment on blood coagulation compared to the control group. CONCLUSIONS: In this in-vitro study clinically relevant dilutions of MAN+ALB showed a significant inhibition of blood coagulation and platelet function. Further in-vivo studies are necessary to confirm these results.

Training of airway management for anesthesia teams - Measurement of transfer into daily work routine by questionnaire.

THEORY: Problems in airway management are rare in anesthesia but when they occur, they have serious consequences for the patient. For this reason, training is recommended for professionals involved in anesthetic care. Here we investigated, if a newly developed technical/ non-technical hybrid airway training would be relevant for daily practice in a tertiary referral hospital. HYPOTHESES: We hypothesized that: (a) both parts of the validated questionnaires meet the quality criteria for the application in anesthesia teams, (b) even though the team regularly deals with airway management, airway management training is relevant to all professions and (c) contents of the developed training can be integrated into the behaviour of the teams. METHOD: In this observational study, 104 professionals took part in a one-day technical/non-technical hybrid airway training programme. Participants received a questionnaire six months after training, based on selected scales of the validated tools; "Training Evaluation Inventory" and "Transfer Climate Questionnaire". RESULTS: The scales of "perceived usefulness", "task cues" and "positive reinforcement" showed good internal consistency and all were rated higher than 3.9 on a 5-point Likert scale (1=complete rejection; 5=fullest approval). The scale "negative reinforcement and punishment" showed satisfactory internal consistency for physicians (rated 2.75 ± 0.8). By removing an item in each case, the scales "attitude towards training" (rated 4.93 ± 0.2) and "extinction" (rated 3.02 ± 0.8) showed satisfactory internal consistency for nurses and anesthetic technicians. "Social Cues" did not meet qualitative criteria. There was no difference in the assessment by the professional groups. CONCLUSIONS: The presented training course was perceived as useful by both professional groups equally, which supported the interprofessional concept. The content was positively reinforced in practice six months after training and is relevant for professionals who are regularly confronted with the topic "airway management". Scales which meet qualitative criteria for only one profession and the scale "social cues" should be reconsidered in the context of an interprofessional team.

[Complications and success rates of subclavian vein catheterization depending on experience]. / Komplikationen und Erfolgsraten des Vena-subclavia-Katheters in Abhängigkeit der Erfahrung.

BACKGROUND: The infraclavicular puncture of the subclavian vein is a standard procedure for anesthetists. Meanwhile the literature and recommendations are clear and the use of real-time ultrasound guidance is the standard procedure; however, anesthetists will always get into special circumstances were they have to use the landmark technique, so this competence must be preserved. Feared complications of infraclavicular subclavian vein puncture are pneumothorax and arterial puncture. Up to now there is no clear learning curve for the infraclavicular subclavian vein puncture in the landmark technique performed by anesthetists. OBJECTIVE: The aim of this study was to examine the influence of the puncture experience on the success rate and mechanical complications, such as pneumothorax and arterial puncture in patients who received an infraclavicular subclavian vein puncture with the landmark technique. Three levels of experience were defined for comparison: inexperienced 0-20 punctures, moderately experienced 21-50 and experienced over 50 punctures. MATERIAL AND METHODS: Post hoc analysis of a previously published noninferiority study to examine the influence of ventilation on the pneumothorax rate in the subclavian vein puncture using the landmark technique. This analysis included 1021 anesthetized patients who were included in the original study between August 2014 and October 2017. Demographic data as well as the number of puncture attempts, puncture success, the overall rate of mechanical complications, pneumothorax rate and arterial puncture rates were calculated. RESULTS: The overall rate of mechanical complications (pneumothorax + arterial puncture) was significantly higher in the inexperienced group (0-21) compared to the experienced group (>50, 15% vs. 8.5%, respectively, p = 0.023). This resulted in an odds ratio of 0.52 (confidence interval, CI: 0.32-0.85, p = 0.027). Likewise, the rate of puncture attempts in the group of inexperienced (0-20) with 1.85 ± 1.12 was significantly higher than in the group of experienced (>50, 1.58 ± 0.99, p = 0.004) and resulted in an odds ratio of 0.59 (CI: 0.31-0.96, p = 0.028). Although the puncture attempts of the moderately experienced (21-50) compared to the inexperienced (0-20) was not significant lower, we found an odds ratio of 0.69 (CI: 0.48-0.99, p = 0.042). The rate of successful puncture was 95.1% in the experienced group versus 89.3% in the inexperienced group (p = 0.001), which resulted in an odds ratio of 2.35 (CI: 1.28-4.31, p = 0.018). When viewed individually, no significant differences were found for pneumothorax and arterial puncture. CONCLUSION: In this post hoc analysis of the puncture of the subclavian vein using the landmark technique, we found a significant reduction of puncture attempts and overall mechanical complications. At least 50 punctures seem to be necessary to achieve the end of the learning curve; however, the landmark technique should only be used under special circumstances, when real-time ultrasound is not available. Anesthetists who want to complete their repertoire and learn the landmark technique should always perform a static ultrasound examination before starting the puncture in order to reduce complications due to anatomical variations or thrombosis.

[Anaesthesia in Patients after Transplantation of Solid Abdominal Organs]. / Anästhesie für Patienten nach Transplantation abdomineller Organe.

An ever-evolving and successful transplantation medicine is providing a large number of living patients after solid organ transplantation. Anaesthetists should therefore be prepared to come into contact with such a patient. In addition to the preoperative assessment of the pre-existing diseases, including the function of the transplanted organ, immunosuppression also plays an important role. Immunosuppression must always be continued perioperatively. Strict adherence to all hygienic regulations is essential in these patients due to immunosuppression and the associated increased risk of infection and sepsis. This includes the strict risk-benefit assessment of all invasive procedures.There are no significant differences between the anaesthetic approaches and agents in transplant and non-transplant patients. However, in the first group, homeostasis of all organ systems should be more focused on.

Changes of collective orientation through a medical student's anaesthesia simulation course - simulation-based training study with non-technical skills debriefing versus medical debriefing.

BACKGROUND: Non-technical skills (NTS) are known to have a positive impact on quality of medical care. The team performance enhancing behaviour, as an example for NTS, is termed "Collective Orientation" (CO). In this study, we investigated the effect of a simulator-based anaesthesia training upon student's CO in relation to medical and TeamGAINS (guided team self-correction, advocacy-inquiry and systemic-constructivist techniques) debriefing. We hypothesized (a) the scale collective orientation, as demonstrated in other team setting, is applicable to fourth year German medical students, (b) collective orientation increases by a four-hour anaesthesia simulation course, (c) the change in collective orientation can be influenced by type of debriefing. METHOD: All classes of an anaesthesia module (4th year medical students) were randomized into two groups. Students took part in a four-hour simulation course with team scenarios, supported by a simulated nurse. In group one the trainer focused on a debriefing on medical problems and in group two, a debriefing according to the specifications of the TeamGAINS concept was conducted. The primary outcome was the mean difference between the collective orientation measured (via questionnaires) immediately before (T1) and after (T2) training. RESULTS: Cronbach's alpha for all scales and measurement points was higher than 0.72. The scale "affiliation" decreases in the group medical debriefing MD = 0.1 (p = 0.008; r = 0.31) and was unchanged in the group TeamGAINS. "Dominance" increases in both groups. The values were MD = 0.19 (p = 0.003; r = 0.25) for medical debriefing and MD = 0.22 (p = 0.01; r = 0.40) for TeamGAINS debriefing. CONCLUSION: The collective orientation questionnaire can be applied to fourth year medical students. Simulation courses influence the attitude towards teamwork. The influence is negatively to the subscale "affiliation" by a "medical debriefing" and independently regardless of the nature of the debriefing for the subscale "dominance". We recommend a debriefing for medical students using the TeamGAINS approach to clarify the connection between the individual performance and non-technical skills. Anaesthesia simulation courses have the potential being a part of a longitudinal education curriculum for teaching non-technical skills.

Mannitol and the Combination of Mannitol and Gelatin Impair Whole Blood Coagulation and the Platelet Function In Vitro.

OBJECTIVE: Mannitol 20% and succinylated gelatin 4% are routinely used in neurosurgical procedures. The aim of this in vitro study was to explore the influence of both agents on blood coagulation and platelet function. METHODS: Blood from 21 healthy volunteers was obtained and then diluted so as to form five groups: (1) 7% dilution with mannitol; (2) 10% dilution with gelatin; (3) 17% dilution with isotonic balanced electrolyte solution; (4) 17% dilution with mannitol+gelatin; and (5) undiluted blood. The extrinsic thrombelastometry (EXTEM) and fibrin thrombelastometry (FIBTEM) tests were examined by rotational thrombelastometry via ROTEM®, and thrombocyte aggregometry with the aspirin inhibiting- (ASPI), adenosine diphosphate- (ADP), and thrombin-activating protein (TRAP) tests performed by Multiplate. RESULTS: In the EXTEM test clot formation time, the alpha angle, and maximum clot firmness were significantly reduced by mannitol and the combination of mannitol with gelatin. The platelet function tested in the ADP test was also significantly reduced with this combination. CONCLUSION: In this in vitro study, clinically relevant dilutions of mannitol and gelatin showed a significant inhibition of whole blood coagulation and the platelet function, which could be detrimental in neurosurgical settings.

Impact of the laryngeal tube as supraglottic airway device on blood flow of the internal carotid artery in patients undergoing general anaesthesia.

INTRODUCTION: Laryngeal tubes (LT) are supraglottic airway devices routinely used in emergency airway management. During cardiac arrest in a swine model, the carotid artery blood flow is reduced after insertion of a LT. A compression of the internal carotid (ICA) artery by the inflated cuff was shown. Up to now there is no information if the LT has similar effects in humans with possible negative implications for use of the LT in case of cardiac arrest. OBJECTIVE: We hypothesized that the use of a LT in humans significantly reduces the blood flow in the ICA compared facemask ventilation. A significant reduction was defined as a 25% reduction from baseline values. MATERIAL AND METHODS: After induction of general anaesthesia and reaching a haemodynamic steady state (stable heart rate >50/min and mean arterial pressure >60 mmHg), blood flow within the ICA was measured via doppler sonography during pressure-controlled ventilation with facemask-, laryngeal tube- and laryngeal mask. RESULTS: We found no differences in the carotid blood flow. Neither between the facemask ventilation (right side 419 ± 159 ml min-1, left side 355 ± 120 ml min-1) and the laryngeal tube ventilation (right side 400 ± 131 ml min-1, left side 384 ± 124 ml min-1. p = 0.86 and p = 0.12), nor the facemask-ventilation and the laryngeal mask ventilation (right ICA 415 ± 150 ml min-1, left ICA 485 ± 274 ml min-1, p = 0.49 and 0.26). CONCLUSIONS: In humans the LT does not impair blood flow of the internal carotid artery during ventilation in general anaesthesia. Further studies are needed to confirm our findings under the conditions of cardiac arrest.

Venous air embolism in the sitting position in cranial neurosurgery: incidence and severity according to the used monitoring.

BACKGROUND: There is an ongoing debate about the sitting position (SP) in neurosurgical patients. The SP provides a number of advantages as well as severe complications such as commonly concerning venous air embolism (VAE). The best monitoring system for the detection of VAE is still controversial. METHODS: In this retrospective analysis we compared 208 patients. Transesophageal echocardiography (TEE) or transthoracic Doppler (TTD) were used as monitoring devices to detect VAE; 101 cases were monitored with TEE and 107 with TTD. RESULTS: The overall incidence of VAE was 23% (TTD: 10%; TEE: 37%), but the incidence of clinically relevant VAE (drop in end-tidal carbon dioxide above 3 mmHg) was higher in the TTD group (9 out of 17 VAE, 53%) compared to the TEE group (19 out of 62 VAE, 31%). None of the patients with recorded VAE had clinically significant sequelae. CONCLUSIONS: In this small sample we found more VAE events in the TEE group, but the incidence of clinically relevant VAE was rare and comparable to other data. There is no consensus in the definition of clinically relevant VAE.

[Anesthesia and hemodynamic management in the sitting position]. / Anästhesie in der Orthopädie†/†Unfallchirurgie - Narkoseführung und Kreislauf-management in sitzender Position.

Every year thousands of patients are operated in the sitting position. The most common position is the beach chair position. Due to case reports with deleterious neurologic outcome, the safety of the beach chair position in combination with general anesthesia is discussed controversially. In this review article the possible complications according to the beach chair position are explained and practical advice is given for the daily anesthetic routine.

[Anaesthesia in patients after transplantation]. / Management von Organspendern und Organempfängern - Narkoseführung bei transplantierten Patienten.

More than 17000 patients currently live in Germany who have had organ transplants. The implications of this for the anaesthetists are that they are very likely to be confronted by such a patient at some point during their active career. Besides the preoperative assessment which includes that of the function of the transplanted organ, appropriate immunosuppression poses a particular challenge. Close collaboration with both patients and their transplant specialists is essential to preempt the perioperative consequences and plan continuation of immunosuppression. Strictly aseptic measures are mandatory as well as detailed evaluation of the risk-benefit balance of all invasive procedures.There are no significant differences between the anaesthetic approaches and agents in transplant and non-transplant patients. However, in the latter group, homeostasis of all organ systems should be more focused on.

Milrinone combined with vasopressin improves cardiac index after cardiopulmonary resuscitation in a pig model of myocardial infarction.

BACKGROUND: Milrinone used for acute cardiac insufficiency could be of interest during cardiopulmonary resuscitation because of its positive inotropic effects. In this study, the combination of milrinone-vasopressin was compared with epinephrine and vasopressin, as well as with the combination of epinephrine-vasopressin, in reference to hemodynamics. METHODS: Thirty-two pigs underwent ligation of the circumflex coronary artery and induction of ventricular fibrillation lasting for 4 min. Cardiopulmonary resuscitation was performed after randomization to one of four groups: epinephrine (30-microg/kg bolus), vasopressin (0.4-U/kg bolus), epinephrine-vasopressin (15-microg/kg epinephrine bolus, 0.2-U/kg vasopressin bolus), or milrinone-vasopressin (0.4-U/kg vasopressin bolus, 50-microg/kg milrinone bolus over 5 min and a continuous infusion of 0.4 microg.kg.min). The hemodynamic variables were measured before cardiopulmonary resuscitation as well as 4, 8, 15, and 30 min after return of spontaneous circulation. RESULTS: All animals were resuscitated successfully. The animals of the milrinone-vasopressin group displayed significantly (P<0.05) higher cardiac index values (30 min after return of spontaneous circulation: epinephrine, 65.8+/-13.2; vasopressin, 70.7+/-18.3; epinephrine-vasopressin, 69.1+/-36.2; milrinone-vasopressin, 120.7+/-34.8 ml.min.kg) without a decrease in mean arterial pressure or coronary perfusion pressure. CONCLUSIONS: The combination of vasopressin-milrinone as compared with epinephrine during cardiopulmonary resuscitation leads to an improved cardiac index without relevant decrease of mean arterial pressure or coronary perfusion pressure.

Low-flow perfusion via the innominate artery during aortic arch operations provides only limited somatic circulatory support.

BACKGROUND: Aortic arch operations in pediatric patients using low-flow perfusion techniques have been standardized to a certain degree, but some of the often-stated beneficial effects have never been proven. Especially, the existence or efficacy of any subdiaphragmal perfusion still remains unclear. METHODS: Twenty-six newborn male piglets (10-15 kg) underwent aortic arch surgery under general anesthesia using either low-flow perfusion via the innominate artery (LF, 30 ml/(kg min), 25 degrees C, n=12) or conventional deep hypothermic circulatory arrest (DHCA, 20 degrees C, n=14). Cortical somatosensory-evoked potentials (SSEPs), carotid, and subdiaphragmal blood flows were measured. The animals of both groups have been randomized to either pH-stat or alpha-stat management on cardiopulmonary bypass (CPB). RESULTS: During low-flow perfusion via the innominate artery only negligible flows of maximum 1-3 ml/min in the femoral arteries were detected, whereas the right carotid artery flow doubled. During reperfusion, serum-lactate and aspartate amino-transferase (AST) levels were significantly higher compared to the circulatory arrest group, whereas alanine amino-transferase (ALT), gamma-glutamyl transpeptidase (gamma-GT), AP, and creatinine did not show any significant differences. Cortical SSEP returned to preoperative values in all but two low-flow animals. There was no return of SSEP in all piglets operated under deep hypothermic circulatory arrest (p<0.01). CONCLUSION: Compared to DHCA, low-flow perfusion via the innominate artery provides superior neuroprotection despite higher tissue temperatures. Although collateral blood flow via the subclavian artery and the circulus arteriosus willisii has often been presumed, only 'trickle-flow' with some protective potential was detectable in the femoral arteries during low-flow perfusion. Origin of elevated lactate and AST levels seems to be the lower limbs.