[Apnea test for assessment of brain death under extracorporeal life support]. / Apnoetest beim irreversiblen Hirnfunktionsausfall unter extrakorporaler Zirkulation.

BACKGROUND: The fourth edition of the German guideline for the assessment of brain death, published in 2015 by the German Medical Council (Bundesärztekammer), emphasizes the importance of an apnea test. It is also now required under all circumstances of extracorporeal life support. OBJECTIVES: This article is an instruction for the guideline-conforming performance of an apnea test in general and also in cases of extracorporeal life support in different configurations. MATERIALS AND METHODS: A literature review was performed. CONCLUSIONS: The apnea test is an essential part of the bedside examination for the clinical diagnosis of brain death. It is required for all kinds of extracorporeal life support and can be easily performed without endangering the patient. More accurate recommendations for its performance should be considered for the next version of the German guideline for brain death assessment.

[Functional separation of the lungs. Ventilation strategy for unilateral blunt force thoracic trauma]. / Funktionelle Trennung der Lungen. Beatmungsstrategie bei einseitigem stumpfem Thoraxtrauma.

Independent lung ventilation was performed in a patient with severe hypoxemia (oxygenation ratio p(a)O2/F(I)O2 61 mmHg) due to unilateral blunt chest trauma and consecutive consolidation of the injured lung. Recruitment and immobilization of the consolidated lung was achieved by functional separation of both lungs with application of a mean airway pressure (p(mean)) of 28 mbar in combination with low frequency ventilation (4/min) of the injured lung. Adequate ventilation was maintained via the normal lung (p(mean) 14 mbar). This ventilation strategy stabilized oxygenation and ventilation by preventing overinflation and ventilator-induced lung injury.

Ventilation with low tidal volumes during upper abdominal surgery does not improve postoperative lung function.

BACKGROUND: Prolonged postoperative decrease in lung function is common after major upper abdominal surgery. Evidence suggests that ventilation with low tidal volumes may limit the damage during mechanical ventilation. We compared postoperative lung function of patients undergoing upper abdominal surgery, mechanically ventilated with high or low tidal volumes. METHODS: This was a double-blind, prospective, randomized controlled clinical trial. One hundred and one patients (age ≥ 50 yr, ASA ≥ II, duration of surgery ≥ 3 h) were ventilated with: (i) high [12 ml kg(-1) predicted body weight (PBW)] or (ii) low (6 ml kg(-1) PBW) tidal volumes intraoperatively. The positive end-expiratory pressure was 5 cm H(2)O in both groups and breathing frequency adjusted to normocapnia. Time-weighted averages (TWAs) of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) until 120 h after operation were compared (P<0.025 considered statistically significant). Secondary outcomes were oxygenation, respiratory and non-respiratory complications, length of stay and mortality. RESULTS: The mean (sd) values of TWAs of FVC and FEV(1) were similar in both groups: FVC: 6 ml group 1.8 (0.7) litre vs 12 ml group 1.6 (0.5) litre (P=0.12); FEV(1): 6 ml group 1.4 (0.5) litre vs 12 ml group 1.2 (0.4) litre (P=0.15). FVC and FEV(1) at any single time point and secondary outcomes did not differ significantly between groups. CONCLUSIONS: Prolonged impaired lung function after major abdominal surgery is not ameliorated by low tidal volume ventilation.

Risk factors associated with bleeding during and after percutaneous dilational tracheostomy.

We evaluated the effect of pre-operative coagulation status on the incidence of acute and chronic bleeding in 415 consecutive patients undergoing percutaneous dilational tracheostomy. The incidence of acute bleeding was independent of the coagulation variables tested. The risk of chronic bleeding was higher with an activated partial thromboplastin time above 50 s (OR 3.7 (95% CI 1.1-12.7); NNT 18.4 (95% CI 9.0-infinity); p = 0.04), a platelet count below 50 x 10(9) l(-1) (OR 5.0 (95% CI 1.4-17.2); NNT 12.3 (95% CI 6.2-833.3); p = 0.01) and in the presence of two or more abnormal coagulation variables (OR 9.5 (95% CI 2.3-34.7); NNT 6.2 (95% CI 3.2-68); p = 0.002). Low-dose heparin treatment did not significantly increase the risk of chronic bleeding.

ACE I/D but not AGT (-6)A/G polymorphism is a risk factor for mortality in ARDS.

The intrapulmonary renin-angiotensin system via tissue concentration of angiotensin II or bradykinin may have multiple effects on pulmonary pathophysiology. Therefore, it was investigated whether the presence of the D allele of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism or the A allele of angiotensinogen (AGT) promoter polymorphism (-6)A/G are independent risk factors for 30-day survival in acute respiratory distress syndrome (ARDS) patients. In a prospective study, adults (Germans of Caucasian ethnicity) with ARDS (n = 84) were recruited from the current authors' intensive care unit and genotyped for the ACE I/D and the AGT (-6)A/G polymorphisms, as were 200 healthy Caucasian controls. Mortality was increased in the ACE DD genotype compared with the I allele, and the ACE I/D polymorphism was an independent prognostic factor for 30-day survival. Patients with a homozygous DD genotype were at highest risk for death (hazard ratio 5.7; 95% confidence interval 1.7-19.2) compared with the II genotype. In contrast, the AGT (-6)A/G polymorphism was neither associated with an increased risk for development of ARDS nor with outcome. In patients with acute respiratory distress syndrome, the angiotensin-converting enzyme insertion/deletion polymorphism but not the angiotensinogen (-6)A/G promoter polymorphism is an independent risk factor with a pronounced effect on 30-day survival.

[Difficult placement of a pulmonary artery catheter due to a persistent left vena cava superior]. / Erschwerte Anlage eines Pulmonaliskatheters durch eine persistierende linke V. cava superior.

The incidental detection of a persistent left vena cava superior during insertion of a pulmonary artery catheter in a patient with acute respiratory distress syndrome (ARDS) prior to extracorporeal membrane oxygenation (ECMO) therapy is reported. A persistent left vena cava superior is the most frequent thoracic malformation and can be associated with other malformations such as congenital heart disease. Therefore, further diagnostic evaluation is needed especially in pulmonary hypertension and ARDS. Anaesthesiologists should be aware of the specific aspects associated with a persistent left vena cava superior.

Muscle force and fatigue in patients with sepsis and multiorgan failure.

INTRODUCTION: Neuromuscular abnormalities are found frequently in sepsis and multiorgan failure (MOF). Surprisingly, however, there are no data on maximum skeletal muscle force and fatigue in these patients. OBJECTIVES: To test the research hypotheses that adductor pollicis (AP) force would be lower in patients with sepsis, whereas fatigue would not differ between patients and immobilized but not infected volunteers. DESIGN AND SETTING: Prospective study; university intensive care unit and laboratory. PATIENTS: Patients with sepsis and MOF (sequential organ failure assessment (SOFA) score >10) and healthy volunteers. INTERVENTIONS: Fatigue was evoked during 20[Symbol: see text]min of intermittent tetanic ulnar nerve stimulation achieving 50% of maximum AP muscle force. MEASUREMENTS AND RESULTS: We measured evoked AP muscle force and fatigue, and compound muscle action potential (CMAP), and performed standard electrophysiological tests in 13 patients, and in 7 volunteers before and after immobilization. Maximum force (20+/-16 vs 65+/-19N; p<0.01) and CMAP (3.6+/-2.5 vs 10+/-2.5 mV; p<0.05) were markedly decreased in patients; however, fatigue and ulnar nerve conduction velocity did not differ from volunteers, and a decrement of CMAP was not observed with nerve stimulation frequencies up to 40 Hz. All patients with critical illness polyneuropathy, and an additional 50% of those without, had significant muscle weakness. CONCLUSION: Peripheral muscle force is markedly decreased in sepsis, without evidence for an increased fatigability. Muscle weakness was most likely due to a sepsis-induced myopathy and/or axonal neuropathy, and was not the result of an immobilization atrophy.

Does perioperative administration of rofecoxib improve analgesia after spine, breast and orthopaedic surgery?

BACKGROUND AND OBJECTIVE: Data on the effectiveness of cyclooxygenase 2 inhibitors in postoperative pain therapy vary widely. We tested in a prospective, placebo-controlled, randomized, double-blind trial the hypotheses that perioperative (i.e. preoperative and postoperative) administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after spine, breast and orthopaedic surgery. METHODS: Five hundred and forty patients scheduled for spine, breast or orthopaedic surgery were randomly assigned to receive in combination with postoperative morphine via patient controlled analgesia pump for 4 days either rofecoxib 50 mg administered perioperatively, rofecoxib 50 mg administered only postoperatively, or placebo. Primary outcome criteria were pain score at rest (numeric rating scale 0-4) and morphine consumption. RESULTS: Perioperative rofecoxib significantly decreased pain score 0 (0-1) vs. 1 (0-2) (median (interquartile range)), and morphine consumption 18 (6-33) vs. 22.5 (12-38) compared with placebo. In contrast, rofecoxib when administered only postoperatively did not significantly improve analgesic effects or side-effects at time of assessment of the main criteria (24 h after skin closure), but during the follow-up period at 48 h and 72 h after skin closure pain scores and morphine consumption were improved compared to placebo. The analgesic effects of rofecoxib were independent from the type of surgery. CONCLUSIONS: Perioperative administration of the cyclooxygenase 2 inhibitor rofecoxib decreases pain scores and morphine consumption after orthopaedic, breast and spine surgery. However, the benefit of preoperative administration of the cyclooxygenase 2 inhibitor seems to be only moderate, suggesting that early postoperative administration may be a useful alternative approach. There is no evidence that the type of surgery influences analgesic effects of cyclooxygenase 2 inhibitors.

[Infections of the deep neck spaces with accompanying mediastinitis]. / Infekte der tiefen Halsweichteile mit begleitender Mediastinitis.

BACKGROUND: Infections of the deep neck spaces with accompanying mediastinitis are still a therapeutic problem with a high mortality. PATIENTS: We report on three patients with deep neck space infections and accompanying mediastinitis who have been treated in the Departments of Otorhinolaryngology at the Universities of Bochum and Essen in the past 2 years. In two patients the infection originated from a peritonsillar abscess and in one patient from an odontogenic infection. THERAPY: One patient was successfully treated by a tonsillectomy and drainage of the parapharyngeal abscess in conjunction with a thoracotomy because of a mediastinal abscess and bilateral pneumothorax. The second patient was cured by a tonsillectomy, wide cervical drainage und cervical mediastinotomy. The third patient with pre-existent alcohol abuse died because of multiorgan failure despite wide cervical und mediastinal drainage. CONCLUSION: In every deep neck infection a mediastinal involvement has to be taken into account. Fast diagnosis and treatment are essential for the prognosis of this life-threatening disease.

A new system for regional citrate anticoagulation in continuous venovenous hemodialysis (CVVHD).

BACKGROUND: CVVHD is an established renal replacement therapy in hemodynamically unstable ICU patients. Various methods for regional citrate anticoagulation have been developed to minimize bleeding complications. Metabolic alkalosis, the risk of severe hypocalcemia and need for continuous calcium substitution as well as treatment-associated hypernatremia have limited the success of systems employed so far. We have developed a new technique for regional citrate anticoagulation in CVVHD to overcome these deficiencies and have performed a validation study. METHODS: One hundred and thirty-three filters with an overall treatment duration of 3,324 hours were used in 19 critically ill patients with bleeding complications. We used a calcium-containing dialysate (1.81 mmol/l Ca) to avoid mandatory systemic calcium supplementation. Sodium bicarbonate was added to the dialysate in variable concentrations (13 - 34 mmol/l) to control acid-base status and prevent hypernatremia. The resulting dialysate sodium concentrations were between 121 and 140 mmol/l. Blood flow was set at 75 ml /min. Infusion of a solution containing trisodium citrate and citric acid with an overall citrate concentration of 113 mmol/l was started at 250 ml/h. Primary endpoints were pre- and post-filter ionized calcium (Ca(i)) concentrations, base excess and serum sodium. Filter life was assessed as a secondary end-point. RESULTS: Control of electrolyte balance and azotemia was excellent (prefilter serum Ca(i) 1.06 +/- 0.012 mmol/l (+/- SEM), post-filter Ca(i) 0.23 +/- 0.01 mmol/l, base excess -0.39 +/- 0.4 mmol/l, serum sodium 137 +/- 4 mmol/l, mean serum creatinine 1.8 +/- 0.07 mg/dl). Normal base excess was achieved with a mean dialysate bicarbonate concentration of 26 mmol/l at a mean citrate infusion rate of 266 +/- 4 ml/h. After 48 hours, 25% of filters were still patent, mean filter life was 26 +/- 1.6 hours. No patient developed serious CVVHD-related adverse events. CONCLUSION: The new regional citrate anticoagulation system for CVVHD is safe, feasible and can avoid major complications of previously described methods, especially hypocalcemia, alkalosis and hypernatremia.

Clinical experience with quinupristin-dalfopristin as rescue treatment of critically ill patients infected with methicillin-resistant staphylococci.

OBJECTIVES: To describe the efficacy and safety of quinupristin-dalfopristin (Q-D) as rescue therapy in critically ill patients with severe infections caused by methicillin-resistant staphylococci unresponsive to vancomycin treatment. DESIGN: Observational study in the context of the compassionate use programme for Q-D. METHODS: Twelve mechanically ventilated patients suffering from severe staphylococcal infections, pretreated unsuccessfully with vancomycin despite in vitro sensitivity, were included. Patients received, intravenously, Q-D 7.5 mg/kg body weight 3 times daily. The duration of Q-D therapy averaged 11.8 days (range: 1-26 days). The outcome variables were clinical efficacy and bacteriological eradication. RESULTS: Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE) were isolated in three patients each, and both bacteria were isolated from six patients. Eradication of pathogen(s) was achieved in 7 of 12 patients (66%). Five patients (42%) died due to severe co-morbidity. Adverse events related to Q-D were not observed and neither renal nor liver function was adversely affected. CONCLUSIONS: Quinupristin-dalfopristin appears to be an efficient and safe antimicrobial drug for the rescue treatment of staphylococcal infections in critically ill patients. It may be considered as a treatment option in cases of vancomycin treatment failure.