Ultrasound evaluation of radial nerve injuries by cortex overlapping screw tips after internal fixation of humeral fractures: a cadaveric study.

PURPOSE: The radial nerve may be painfully irritated or damaged by open reduction and internal fixation (ORIF) of humeral fractures. Secondary radial nerve lesions after ORIF of humeral shaft fractures are described in up to 16%. Not only peripheral nerves but also orthopaedic instruments and osteosynthesis material are well visible by ultrasound. The aim of this study was to evaluate the accuracy of ultrasound in assessing the relation between the bone overlapping screw tips and the radial nerve close to the humeral bone. METHODS: Ultrasound-guided drilling was used to place screws as close as possible to the radial nerve in 8 humeral bones of four cadavers. The relation between the radial nerve and the screw tips was assessed by high-resolution ultrasound, and the overlap of all screw tips over the bone was measured by ultrasound and fluoroscopy. Thereafter, the findings were validated by anatomical dissection. RESULTS: We could correctly identify all screw tips and their relation to the radial nerve by ultrasound. In 7 of 8 cases, the screw tip had direct contact with the radial nerve. The overlaying length of the screw tip was accurately measured by using ultrasound in all cases. In contrast fluoroscopy underestimated this length in 50% of cases. CONCLUSION: With this study, we show that ultrasound can reliable visualize the screw tips and its relation to the radial nerve. Ultrasound is a promising diagnostic tool to evaluate patients with radial nerve irritations or lesions after ORIF of humeral fractures. Furthermore, ultrasound could be an adequate tool to guide drilling.

[Progressive muscle relaxation in postoperative pain therapy]. / Progressive Muskelrelaxation in der postoperativen Schmerztherapie.

BACKGROUND: Early and optimal treatment of postoperative pain based on a multimodal treatment concept is very important so that subsequent chronification can be avoided. OBJECTIVES: This study investigated the influence of progressive muscle relaxation on the sensation of pain and the need for analgesics after orthopedic interventions. MATERIALS AND METHODS: This nonrandomized pilot study tested 104 patients in the Clinic of Orthopedics at the Saarland University Medical Center in Homburg, Germany. The patients underwent total endoprosthesis (TEP) of the or the knee or spine surgery (laminectomy), and they had the option of choosing to use the technique of progressive muscle relaxation. All patients completed a questionnaire on the first, fourth, and ninth postoperative day. Data were collected on the maximum and minimum intensity of pain, duration of strong pain, length of hospital stay, and use of pain medication. These were compared by means of t tests for the group with progressive muscle relaxation and the group without progressive muscle relaxation. RESULTS: No significant difference was observed between the two groups regarding pain sensation analgesic dosage. There was a tendency for the length of hospital stay to be shorter in the group with progressive muscle relaxation. CONCLUSION: The positive effect of progressive muscle relaxation cannot be confirmed on the basis of the study data. Owing to the varying study design and implementation as well as the inclusion of heterogeneous patient groups, no conclusion can be drawn at present regarding the effectiveness of progressive muscle relaxation in common practice; therefore, further research is necessary.

Dobutamine Versus Vasopressin After Mesenteric Ischemia.

BACKGROUND: Gastrointestinal blood flow may be compromised during and after vasopressor support. Endothelin expression may lead to microcirculatory dysfunction. The aim of this study was to analyze the effect of vasopressin and dobutamine after mesenteric ischemia on the gastrointestinal mucosal microcirculation, endothelin expression, and morphologic injury. MATERIALS AND METHODS: Pigs were studied in four groups (six pigs in each group): 1, sham; 2-4 ischemia (1 h superior mesenteric artery occlusion with 30 min reperfusion and 30 min of vehicle [2], dobutamine [3], or vasopressin [4] administration, followed by 30-min break and thiopental-induced hypotension [3, 4]). Blood flow of the gastric, jejunal, and rectosigmoidal mucosa was measured. At the end of the experiment, the mucosal expression of endothelin-1 (ET-1) and its receptor subtypes A (ETA) and B were determined by polymerase chain reaction. Mucosal injury, apoptotic cell death, and leukocytic infiltration were determined by histology and immunohistochemical analysis of cleaved caspase-3 and myeloperoxidase. RESULTS: Mesenteric ischemia increased jejunal mucosal ET-1 gene expression, arterial ET-1, intestinal fatty acid binding protein, and jejunal mucosal injury compared with sham. Dobutamine increased arteriovenous shunting at the cost of the jejunal mucosal blood perfusion. This was associated with an increased expression of ET-1 and ETA and mucosal leukocytic infiltration. In contrast, vasopressin increased postischemic capillary density and tissue blood flow. This was associated with a lower ET-1 gene expression. Vasopressin did not induce jejunal mucosal leukocytic infiltration. CONCLUSIONS: Vasopressin reduces mesenteric ischemia-associated alterations of the microcirculation and tissue integrity, whereas dobutamine does not.

Halving the Volume of AnaConDa: Evaluation of a New Small-Volume Anesthetic Reflector in a Test Lung Model.

BACKGROUND: Volatile anesthetics are increasingly used for sedation in intensive care units. The most common administration system is AnaConDa-100 mL (ACD-100; Sedana Medical, Uppsala, Sweden), which reflects volatile anesthetics in open ventilation circuits. AnaConDa-50 mL (ACD-50) is a new device with half the volumetric dead space. Carbon dioxide (CO2) can be retained with both devices. We therefore compared the CO2 elimination and isoflurane reflection efficiency of both devices. METHODS: A test lung constantly insufflated with CO2 was ventilated with a tidal volume of 500 mL at 10 breaths/min. End-tidal CO2 (EtCO2) partial pressure was measured using 3 different devices: a heat-and-moisture exchanger (HME, 35 mL), ACD-100, and ACD-50 under 4 different experimental conditions: ambient temperature pressure (ATP), body temperature pressure saturated (BTPS) conditions, BTPS with 0.4 Vol% isoflurane (ISO-0.4), and BTPS with 1.2 Vol% isoflurane. Fifty breaths were recorded at 3 time points (n = 150) for each device and each condition. To determine device dead space, we adjusted the tidal volume to maintain normocapnia (n = 3), for each device. Thereafter, we determined reflection efficiency by measuring isoflurane concentrations at infusion rates varying from 0.5 to 20 mL/h (n = 3), for each device. RESULTS: EtCO2 was consistently greater with ACD-100 than with ACD-50 and HME (ISO-0.4, mean ± standard deviations: ACD-100, 52.4 ± 0.8; ACD-50, 44.4 ± 0.8; HME, 40.1 ± 0.4 mm Hg; differences of means of EtCO2 [respective 95% confidence intervals]: ACD-100 - ACD-50, 8.0 [7.9-8.1] mm Hg, P < .001; ACD-100 - HME, 12.3 [12.2-12.4] mm Hg, P < .001; ACD-50 - HME, 4.3 [4.2-4.3] mm Hg, P < .001). It was greatest under ATP, less under BTPS, and least with ISO-0.4 and BTPS with 1.2 Vol% isoflurane. In addition to the 100 or 50 mL "volumetric dead space" of each AnaConDa, "reflective dead space" was 40 mL with ACD-100 and 25 mL with ACD-50 when using isoflurane. Isoflurane reflection was highest under ATP. Under BTPS with CO2 insufflation and isoflurane concentrations around 0.4 Vol%, reflection efficiency was 93% with ACD-100 and 80% with ACD-50. CONCLUSIONS: Isoflurane reflection remained sufficient with the ACD-50 at clinical anesthetic concentrations, while CO2 elimination was improved. The ACD-50 should be practical for tidal volumes as low as 200 mL, allowing lung-protective ventilation even in small patients.

Establishment of Predictive Models for Nonocclusive Mesenteric Ischemia Comparing 8,296 Control with 452 Study Patients.

OBJECTIVE: The aim of this study was to develop clinical preoperative, intraoperative, and postoperative scores for early identification of patients who are at risk of nonocclusive mesenteric ischemia (NOMI). DESIGN: A retrospective analysis. SETTING: Single center. PARTICIPANTS: From January 2008 to December 2014, all patients from the Department of Thoracic and Cardiovascular Surgery were included on the basis of the hospital database. INTERVENTIONS: All mesenteric angiographically identified NOMI patients were compared with non-NOMI patients. MEASUREMENTS AND MAIN RESULTS: The study population of 8,748 patients was randomized into a cohort for developing the scores (non-NOMI 4,214 and NOMI 235) and a cohort for control (non-NOMI 4,082 and NOMI 217). Risk factors were identified using forward and backward Wald test and were included in the predictive scores for the occurrence of NOMI. C statistic showed that the scores had a high discrimination for the prediction of NOMI preoperatively (C statistic 0.79; p < 0.001), intraoperatively (C statistic 0.68; p < 0.001), and postoperatively (C statistic 0.85; p < 0.001). A combination of the preoperative, intraoperative, and postoperative risk scores demonstrated the highest discrimination (C statistic 0.87; p < 0.001). The combined score included the following risk factors: renal insufficiency (preoperative); use of cardiopulmonary bypass and intra-aortic balloon pump support (intraoperative); and reexploration for bleeding, renal replacement therapy, and packed red blood cells ≥ 4 units (postoperative). The results were similar in the control group. CONCLUSIONS: These scores could be useful to identify patients at risk for NOMI and promote a rapid diagnosis and therapy.

Presepsin and Inflammatory Markers Correlate With Occurrence and Severity of Nonocclusive Mesenteric Ischemia After Cardiovascular Surgery.

OBJECTIVES: To prospectively evaluate the relationship of established inflammatory markers and presepsin on nonocclusive mesenteric ischemia and to correlate presepsin levels to the occurrence and severity of nonocclusive mesenteric ischemia. DESIGN: Patients were prospectively enrolled and blood samples taken, followed by a retrospective evaluation of laboratory values and angiographic findings. The study was ethics committee approved. SETTINGS: Patients with clinical suspicion of nonocclusive mesenteric ischemia underwent catheter angiography of the superior mesenteric artery. Images were assessed by two experienced radiologists on consensus basis using a previously published standardized reporting system (Homburg-Nonocclusive Mesenteric Ischemia-Score). Two groups were formed according to the severity of nonocclusive mesenteric ischemia, mild and severe, patients without clinical signs of nonocclusive mesenteric ischemia formed the reference group. These data were correlated to inflammatory blood markers assessed pre- and postoperatively: C-reactive protein, leucocytes, procalcitonin, and presepsin as well as outcome data. PATIENTS: Between January 2010 and March 2011, a total of 839 patients undergoing cardiovascular surgery participated in this study. MEASUREMENTS AND MAIN RESULTS: Mild nonocclusive mesenteric ischemia was diagnosed in 4.5%, and severe nonocclusive mesenteric ischemia in 3.2%. Median postoperative presepsin concentrations were significantly greater in mild and severe nonocclusive mesenteric ischemia than in non-nonocclusive mesenteric ischemia. Statistics showed that postoperative presepsin better discriminated mild and severe nonocclusive mesenteric ischemia than any other tested biomarker. CONCLUSIONS: Elevated postoperative plasma presepsin concentrations are an independent predictor of mild and severe nonocclusive mesenteric ischemia. The established inflammatory blood markers significantly correlate with the development and severity of nonocclusive mesenteric ischemia.

Prolonged Catheter Use and Infection in Regional Anesthesia: A Retrospective Registry Analysis.

BACKGROUND: Prolonged catheter use is controversial because of the risk of catheter-related infection, but the extent to which the risk increases over time remains unknown. We thus assessed the time-dependence of catheter-related infection risk up to 15 days. METHODS: Our analysis was based on the German Network for Regional Anesthesia, which includes 25 centers. We considered 44,555 patients who had surgery between 2007 and 2014 and had continuous regional anesthesia as well as complete covariable details. Cox regression analysis was performed and adjusted for confounding covariables to examine the relationship between catheter duration and probability of infection-free catheter use. RESULTS: After adjustment for confounding factors, the probability of infection-free catheter use decreases with each day of peripheral and epidural catheter use. In peripheral catheters, it was 99% at day 4 of catheter duration, 96% at day 7, and 73% at day 15. In epidural catheters, it was 99% at day 4 of catheter duration, 95% at day 7, and 73% at day 15. Only 31 patients (0.07%) had severe infections that prompted surgical intervention. Among these were five catheters that initially had only mild or moderate signs of infection and were left in situ; all progressed to severe infections. CONCLUSIONS: Infection risk in catheter use increases over time, especially after four days. Infected catheters should be removed as soon as practical. VISUAL ABSTRACT: An online visual overview is available for this article at http://links.lww.com/ALN/B683.

Risks and Benefits of Ultrasound, Nerve Stimulation, and Their Combination for Guiding Peripheral Nerve Blocks: A Retrospective Registry Analysis.

BACKGROUND: Ultrasound, nerve stimulation, and their combination are all considered acceptable ways to guide peripheral nerve blocks. Which approach is most effective and associated with the fewest complications is unknown. We therefore used a large registry to analyze whether there are differences in vascular punctures, multiple skin punctures, and unintended paresthesia. METHODS: Twenty-six thousand seven hundred and thirty-three cases were extracted from the 25-center German Network for Regional Anesthesia registry between 2007 and 2016 and grouped into ultrasound-guided puncture (n = 10,380), ultrasound combined with nerve stimulation (n=8173), and nerve stimulation alone (n = 8180). The primary outcomes of vascular puncture, multiple skin punctures, and unintended paresthesia during insertion were compared with conditional logistic regression after 1:1:1 propensity score matching. Results are presented as odds ratios and 95% CIs. RESULTS: Propensity matching successfully paired 2508 patients with ultrasound alone (24% of 10,380 patients), 2508 patients with a combination of ultrasound/nerve stimulation (31% of 8173 patients), and 2508 patients with nerve stimulation alone (31% of 8180 patients). After matching, no variable was imbalanced (standardized differences <0.1). Compared with ultrasound guidance alone, the odds of multiple skin punctures (2.2 [1.7-2.8]; P < .001) and vascular puncture (2.7 [1.6-4.5]; P < .001) were higher with nerve stimulation alone, and the odds for unintended paresthesia were lower with nerve stimulation alone (0.3 [0.1-0.7]; P = .03). The combined use of ultrasound/nerve stimulation showed higher odds of multiple skin punctures (1.5 [1.2-1.9]; P = .001) and lower odds of unintended paresthesia (0.4 [0.2-0.8]; P = .007) compared with ultrasound alone. Comparing the combined use of ultrasound/nerve stimulation with ultrasound alone, the odds for vascular puncture (1.3 [0.7-2.2]; P = .4) did not differ significantly. Systemic toxicity of local anesthetics was not observed in any patient with ultrasound guidance alone, in 1 patient with the combined use of ultrasound and nerve stimulation, and in 1 patient with nerve stimulation alone. CONCLUSIONS: Use of ultrasound alone reduced the odds of vascular and multiple skin punctures. However, the sole use of ultrasound increases the odds of paresthesia.

Efficient application of volatile anaesthetics: total rebreathing or specific reflection?

The circle system has been in use for more than a 100 years, whereas the first clinical application of an anaesthetic reflector was reported just 15 years ago. Its functional basis relies on molecular sieves such as zeolite crystals or activated carbon. In a circle system, the breathing gas is rebreathed after carbon dioxide absorption; a reflector on the other hand specifically retains the anaesthetic during expiration and resupplies it during the next inspiration. Reflection systems can be used in conjunction with intensive care ventilators and do not need the permanent presence of trained qualified staff. Because of easy handling and better ventilatory capabilities of intensive care ventilators, reflection systems facilitate the routine use of volatile anaesthetics in intensive care units. Until now, there are three reflection systems commercially available: the established AnaConDa™ (Sedana Medical, Uppsala, Sweden), the new smaller AnaConDa-S™, and the Mirus™ (Pall Medical, Dreieich, Germany). The AnaConDa consists only of a reflector which is connected to a syringe pump for infusion of liquid sevoflurane or isoflurane. The Mirus represents a technical advancement; its control unit includes a gas and ventilation monitor as well as a gas dispensing unit. The functionality, specific features, advantages and disadvantages of both systems are discussed in the text.

Volumetric and reflective device dead space of anaesthetic reflectors under different conditions.

Inhalation sedation is increasingly performed in intensive care units. For this purpose, two anaesthetic reflectors, AnaConDa™ and Mirus™ are commercially available. However, their internal volume (100 ml) and possible carbon dioxide reflection raised concerns. Therefore, we compared carbon dioxide elimination of both with a heat moisture exchanger (HME, 35 ml) in a test lung model. A constant flow of carbon dioxide was insufflated into the test lung, ventilated with 500 ml, 10 breaths per minute. HME, MIRUS and AnaConDa were connected successively. Inspired (insp-CO2) and end-tidal carbon dioxide concentrations (et-CO2) were measured under four conditions: ambient temperature pressure (ATP), body temperature pressure saturated (BTPS), BTPS with 0.4 Vol% (ISO-0.4), and 1.2 Vol% isoflurane (ISO-1.2). Tidal volume increase to maintain normocapnia was also determined. Insp-CO2 was higher with AnaConDa compared to MIRUS and higher under ATP compared to BTPS. Isoflurane further decreased insp-CO2 and abolished the difference between AnaConDa and MIRUS. Et-CO2 showed similar effects. In addition to volumetric dead space, reflective dead space was determined as 198 ± 6/58 ± 6/35 ± 0/25 ± 0 ml under ATP/BTPS/ISO-0.4/ISO-1.2 conditions for AnaConDa, and 92 ± 6/25 ± 0/25 ± 0/25 ± 0 ml under the same conditions for MIRUS, respectively. Under BTPS conditions and with the use of moderate inhaled agent concentrations, reflective dead space is small and similar between the two devices.

Halving the volume of AnaConDa: initial clinical experience with a new small-volume anaesthetic reflector in critically ill patients-a quality improvement project.

AnaConDa-100 ml (ACD-100, Sedana Medical, Uppsala, Sweden) is well established for inhalation sedation in the intensive care unit. But because of its large dead space, the system can retain carbon dioxide (CO2) and increase ventilatory demands. We therefore evaluated whether AnaConDa-50 ml (ACD-50), a device with half the internal volume, reduces CO2 retention and ventilatory demands during sedation of invasively ventilated, critically ill patients. Ten patients participated in this cross-over protocol. After sedation with isoflurane via ACD-100 for 24 h, the 5-h observation period started. During the first hour, ACD-100 was used; for the next 2 h, ACD-50; and for the last 2 h, ACD-100 was used again. Sedation was titrated to Richmond Agitation and Sedation Scale (RASS) score - 3 to - 4 and a processed electroencephalogram (Narcotrend Index, Narcotrend-Gruppe, Hannover, Germany) was recorded. Minute ventilation, CO2 elimination, and isoflurane consumption were compared. All patients were deeply sedated (Narcotrend Index, mean ± SD: 38 ± 10; RASS scores - 3 to - 5) and breathed spontaneously with pressure support throughout the observation period. Infusion rates of isoflurane and opioid, either remifentanil or sufentanil, as well as ventilator settings were unchanged. Minute ventilation and end-tidal CO2 were significantly reduced with the ACD-50, respiratory rate remained unchanged, and tidal volume decreased by 66 ± 43 ml. End-tidal isoflurane concentrations were also slightly reduced while haemodynamic measures remained constant. The ACD-50 reduces the tidal volume needed to eliminate carbon dioxide without augmenting isoflurane consumption.

Evaluating the efficiency of desflurane reflection in two commercially available reflectors.

With the AnaConDa™ and the MIRUS™ system, volatile anesthetics can be administered for inhalation sedation in intensive care units. Instead of a circle system, both devices use anesthetic reflectors to save on the anesthetic agent. We studied the efficiency of desflurane reflection with both devices using different tidal volumes (VT), respiratory rates (RR), and 'patient' concentrations (CPat) in a bench study. A test lung was ventilated with four settings (volume control, RR × VT: 10 × 300 mL, 10 × 500 mL, 20 × 500 mL, 10 × 1000 mL). Two different methods for determination of reflection efficiency were established: First (steady state), a bypass flow carried desflurane into the test lung (flowin), the input concentration (Cin) was varied (1-17 vol%), and the same flow (flowex, Cex) was suctioned from the test lung. After equilibration, CPat was stored online and averaged; efficiency [%] was calculated [Formula: see text]. Second (washout), flowin and flowex were stopped, the decline of CPat was measured; efficiency was calculated from the decay constant of the exponential regression equation. Both measurement methods yielded similar results (Bland-Altman: bias: -0.9 %, accuracy: ±5.55 %). Efficiencies higher than 80 % (>80 % of molecules exhaled are reflected) could be demonstrated in the clinical range of CPat and VT. Efficiency inversely correlates with the product of CPat and VT which can be imagined as the volume of anesthetic vapor exhaled by the patient in one breath, but not with the respiratory frequency. Efficiency of the AnaConDa™ was higher for each setting compared with the MIRUS™. Desflurane is reflected by both reflectors with efficiencies high enough for clinical use.

Use of the MIRUS™ system for general anaesthesia during surgery: a comparison of isoflurane, sevoflurane and desflurane.

The MIRUS™ system enables automated end-expired control of volatile anaesthetics. The device is positioned between the Y-piece of the breathing system and the patient's airway. The system has been tested in vitro and to provide sedation in the ICU with end-expired concentrations up to 0.5 MAC. We describe its performance in a clinical setting with concentrations up to 1.0 MAC. In 63 ASA II-III patients undergoing elective hip or knee replacement surgery, the MIRUS™ was set to keep the end-expired desflurane, sevoflurane, or isoflurane concentration at 1 MAC while ventilating the patient with the PB-840 ICU ventilator. After 1 h, the ventilation mode was switched from controlled to support mode. Time to 0.5 and 1 MAC, agent usage, and emergence times, work of breathing, and feasibility were assessed. In 60 out of 63 patients 1.0 MAC could be reached and remained constant during surgery. Gas consumption was as follows: desflurane (41.7 ± 7.9 ml h-1), sevoflurane (24.3 ± 4.8 ml h-1) and isoflurane (11.2 ± 3.3 ml h-1). Extubation was faster after desflurane use (min:sec): desflurane 5:27 ± 1:59; sevoflurane 6:19 ± 2:56; and isoflurane 9:31 ± 6:04. The support mode was well tolerated. The MIRUS™ system reliable delivers 1.0 MAC of the modern inhaled agents, both during mechanical ventilation and spontaneous (assisted) breathing. Agent usage is highest with desflurane (highest MAC) but results in the fastest emergence. Trial registry number: Clinical Trials Registry, ref.: NCT0234509.

Regional vs. General Anesthesia for Total Knee and Hip Replacement: An Analysis of Postoperative Pain Perception from the International PAIN OUT Registry.

BACKGROUND: Total hip and knee replacements are common surgeries, and an optimal pain treatment is essential for early rehabilitation. Since data from randomized controlled trials on the use of regional anesthesia in joint replacements of the lower extremities are conflicting, we analyzed the international PAIN OUT registry for comparison of regional anesthesia vs. general anesthesia regarding pain and morphine consumption on the first postoperative day. METHODS: International Classification of Diseases-9 (ICD-9) codes were used to identify 2,346 cases of knee arthroplasty and 2,315 cases of hip arthroplasty between 2010 and 2016 from the PAIN OUT registry. Those were grouped according to anesthesia provided (general, regional, and a combination of both). On the first day after surgery, pain levels and opioid consumption were compared. Adjusted odds ratios (ORs [and 95% confidence intervals (CIs)]) were calculated with logistic regression, and propensity matching was used as a sensitivity analysis. RESULTS: After adjustment for confounders, regional anesthesia was associated with reduced opioid consumption (OR 0.20 [95% CI 0.13 to 0.30], P < 0.001) and less pain (OR 0.53 [95% CI 0.36 to 0.78], P = 0.001) than was general anesthesia in knee surgery. In hip surgery, regional anesthesia was only associated with reduced opioid consumption (OR 0.17 [95% CI 0.11 to 0.26], P < 0.001), whereas pain was comparable (OR 1.23 [95% CI 0.94 to 1.61], P = 0.1). Results from a propensity-matched sensitivity analysis were similar. CONCLUSION: In total knee arthroplasty, regional anesthesia was associated with less pain and lower opioid consumption. In total hip arthroplasty, regional anesthesia was associated with lower opioid consumption, but not with reduced pain levels.

Presepsin (sCD14-ST) Is a Novel Marker for Risk Stratification in Cardiac Surgery Patients.

BACKGROUND: Presepsin (soluble cluster-of-differentiation 14 subtype [sCD14-ST]) is a humoral risk stratification marker for systemic inflammatory response syndrome and sepsis. It remains unknown whether presepsin can be used to stratify risk in elective cardiac surgery. The authors therefore determined the usefulness of presepsin for risk stratification in patients having elective cardiac surgery. METHODS: Eight hundred fifty-six cardiac surgical patients were prospectively studied. Preoperative plasma concentrations of presepsin, procalcitonin, N-terminal pro-hormone natriuretic peptide, cystatin C, and the additive European System of Cardiac Operative Risk Evaluation 2 were compared to mortality at 30 days (primary outcome), 6 months, and 2 yr. Discrimination was assessed with C statistic. Logistic regression analysis was used to calculate univariable and multivariable odds ratios. RESULTS: Thirty-day mortality was 3.2%, 6-month mortality was 6.1%, and 2-yr mortality was 10.4% across the population. Median preoperative presepsin concentrations were significantly greater in 30-day nonsurvivors than in survivors: 842 pg/ml (interquartile range, 306 to 1,246) versus 160 pg/ml (interquartile range, 122 to 234); difference, 167 pg/ml (interquartile range, 92 to 301; P < 0.001). The results were similar for 6-month and 2-yr mortality. Compared to the European System of Cardiac Operative Risk Evaluation 2, presepsin concentration provided better discrimination for postoperative mortality at all follow-up periods, including 30 days (C statistic 0.88 vs. 0.74), 6 months (0.87 vs. 0.76), and 2 yr (0.81 vs. 0.74). Presepsin also provided better discrimination than cystatin C, N-terminal pro-hormone natriuretic peptide, or procalcitonin. Elevated presepsin remained an independent risk predictor after adjustment for potential confounding factors. CONCLUSIONS: Elevated preoperative plasma presepsin concentration is an independent predictor of postoperative mortality in elective cardiac surgery patients and is a stronger predictor than several other commonly used assessments.

Inhaled Sedation in Patients With Acute Respiratory Distress Syndrome Undergoing Extracorporeal Membrane Oxygenation.

Six patients suffering from acute respiratory distress syndrome with the need for extracorporeal membrane oxygenation (ECMO) therapy in deep sedation were included. Isoflurane sedation with the AnaConDa system was initiated within 24 hours after initiation of ECMO therapy and resulted in a satisfactory sedation (Richmond Agitation-Sedation Scale -4 to -5). Despite deep sedation, spontaneous breathing was possible in 6 of 6 patients. We observed a reduced need for vasopressor therapy and improved lung function (PaO2, PaCO2, delta P, and tidal volume) during isoflurane sedation. Opioid consumption could be reduced, and only very low doses of isoflurane were needed (1-3 mL/h). This small case series supports the feasibility of sedation using inhaled anesthetics concurrently with venovenous ECMO.

Single-dose Antibiotic Prophylaxis in Regional Anesthesia: A Retrospective Registry Analysis.

BACKGROUND: Catheter-related infection is a serious complication of continuous regional anesthesia. The authors tested the hypothesis that single-dose antibiotic prophylaxis is associated with a lower incidence of catheter-related infections. METHODS: Our analysis was based on cases in the 25-center German Network for Regional Anesthesia database recorded between 2007 and 2014. Forty thousand three hundred sixty-two surgical patients who had continuous regional anesthesia were grouped into no antibiotic prophylaxis (n = 15,965) and single-dose antibiotic prophylaxis (n = 24,397). Catheter-related infections in each group were compared with chi-square test after 1:1 propensity-score matching. Odds ratios (ORs [95% CI]) were calculated with logistic regression and adjusted for imbalanced variables (standardized difference more than 0.1). RESULTS: Propensity matching successfully paired 11,307 patients with single-dose antibiotic prophylaxis (46% of 24,397 patients) and with 11,307 controls (71% of 15,965 patients). For peripheral catheters, the incidence without antibiotics (2.4%) was greater than with antibiotic prophylaxis (1.1%, P < 0.001; adjusted OR, 2.02; 95% CI, 1.49 to 2.75, P < 0.001). Infections of epidural catheters were also more common without antibiotics (5.2%) than with antibiotics (3.1%, P < 0.001; adjusted OR, 1.94; 95% CI, 1.55 to 2.43, P < 0.001). CONCLUSIONS: Single-dose antibiotic prophylaxis was associated with fewer peripheral and epidural catheter infections.

Survival after long-term isoflurane sedation as opposed to intravenous sedation in critically ill surgical patients: Retrospective analysis.

BACKGROUND: Isoflurane has shown better control of intensive care sedation than propofol or midazolam and seems to be a useful alternative. However, its effect on survival remains unclear. OBJECTIVE: The objective of this study is to compare mortality after sedation with either isoflurane or propofol/midazolam. DESIGN: A retrospective analysis of data in a hospital database for a cohort of consecutive patients. SETTING: Sixteen-bed interdisciplinary surgical ICU of a German university hospital. PATIENTS: Consecutive cohort of 369 critically ill surgical patients defined within the database of the hospital information system. All patients were continuously ventilated and sedated for more than 96 h between 1 January 2005 and 31 December 2010. After excluding 169 patients (93 >79 years old, 10 <40 years old, 46 mixed sedation, 20 lost to follow-up), 200 patients were studied, 72 after isoflurane and 128 after propofol/midazolam. INTERVENTIONS: Sedation with isoflurane using the AnaConDa system compared with intravenous sedation with propofol or midazolam. MAIN OUTCOME MEASURES: Hospital mortality (primary) and 365-day mortality (secondary) were compared with the Kaplan-Meier analysis and a log-rank test. Adjusted odds ratios (ORs) [with 95% confidence interval (95% CI)] were calculated by logistic regression analyses to determine the risk of death after isoflurane sedation. RESULTS: After sedation with isoflurane, the in-hospital mortality and 365-day mortality were significantly lower than after propofol/midazolam sedation: 40 versus 63% (P = 0.005) and 50 versus 70% (P = 0.013), respectively. After adjustment for potential confounders (coronary heart disease, chronic obstructive pulmonary disease, acute renal failure, creatinine, age and Simplified Acute Physiology Score II), patients after isoflurane were at a lower risk of death during their hospital stay (OR 0.35; 95% CI 0.18 to 0.68, P = 0.002) and within the first 365 days (OR 0.41; 95% CI 0.21 to 0.81, P = 0.010). CONCLUSION: Compared with propofol/midazolam sedation, long-term sedation with isoflurane seems to be well tolerated in this group of critically ill patients after surgery.

Awake, sedated or anaesthetised for regional anaesthesia block placements?: A retrospective registry analysis of acute complications and patient satisfaction in adults.

BACKGROUND: Whether adults should be awake, sedated or anaesthetised during establishment of regional anaesthesia is still debated and there is little information on the relative safety of each. In paediatric practice, there is often little choice but to use sedation or anaesthesia as otherwise the procedures would be too distressing and patient movement would be hazardous. OBJECTIVE(S): The objective of this study was to evaluate complications related to central and peripheral regional block and patient satisfaction in awake, sedated and anaesthetised adult patients. DESIGN: A retrospective registry analysis. SETTING: The German Network of Regional Anaesthesia database was analysed between 2007 and 2012. PATIENTS: We included data of 42 654 patients and defined three groups: group I awake (n = 25 004), group II sedated (n = 15 121) and group III anaesthetised (n = 2529) for block placement. MAIN OUTCOME MEASURES: Odds ratios [OR; 95% confidence interval (CI)] were calculated with logistic regression analysis and adjusted for relevant confounders to determine the risk of block-related complications in sedated or anaesthetised patients compared with awake patients. RESULTS: Rates of local anaesthetic systemic toxicity were comparable between the groups [awake 0.02% (95% CI: 0.002 to 0.0375), sedated 0.02% (0.003 to 0.042) and anaesthetised 0% (0 to 0.12%)], as were the rates of pneumothorax [awake 0.035% (0 to 0.074), sedated 0% (0 to 0.002) and anaesthetised 0.2% (0 to 0.56)]. Considering peripheral nerve blocks, sedated patients had a decreased risk for multiple skin puncture [adjusted OR: 0.78 (95% CI: 0.71 to 0.85), premature termination [0.45 (0.22 to 0.91)], primary failure [0.58 (0.40 to 0.83)] and postoperative paraesthesia [0.35 (0.28 to 0.45)], but an increased risk for a bloody tap [1.82 (1.50 to 2.21)]. General anaesthesia increased the risk of a bloody tap [adjusted OR: 1.33 (95% CI: 1.01 to 1.78)] and multiple skin puncture [1.28 (1.12 to 1.46)], but decreased the risk for postoperative paraesthesia [0.16 (0.06 to 0.38)]. In neuraxial sites, sedation increased the risk for multiple skin puncture [adjusted OR: 1.18 (95% CI: 1.09 to 1.29)], whereas block placement under general anaesthesia decreased the risk for multiple skin puncture [0.53 (0.39 to 0.72)] and bloody tap but significantly increased the risk for postoperative paraesthesia related to a catheter [2.45 (1.19 to 5.02)]. Sedation was associated with a significant improvement in patient satisfaction. CONCLUSION: Sedation may improve safety and success of peripheral nerve block placement. Block placement under general anaesthesia in adults should be reserved for experienced anaesthesiologists and special situations.

Vasopressin aggravates cardiopulmonary bypass-induced gastric mucosal ischemia.

BACKGROUND/AIM: Upper gastrointestinal bleeding (UGIB) is one of the most frequent gastrointestinal complications after cardiac surgery with cardiopulmonary bypass (CPB). Endothelin expression and microcirculatory dysfunction have been shown to be involved in UGIB. The aim of this study was to analyze the effect of vasopressin during CPB on the gastric mucosal microcirculation and the involvement of the endothelin system. METHODS: Eighteen pigs were randomized into three groups (n = 6 each): group I = sham, group II = CPB (1-hour CPB) and group III = CPB + vasopressin (1-hour CPB and vasopressin administration during CPB to maintain baseline arterial pressure). All animals were observed for a further 90 min after termination of CPB. Systemic hemodynamics as well as blood flow and oxygen saturation of the gastric mucosa were measured continuously. At the end of the experiment, the gastric mucosal expressions of endothelin-1 (ET-1) and its receptor subtypes A (ET(A)) and B (ET(B)) were determined by polymerase chain reaction. Gastric mucosal injury, apoptotic cell death and leukocytic infiltration were determined by histology and immunohistochemical analyses of cleaved caspase-3 and myeloperoxidase. RESULTS: CPB decreased gastric microvascular perfusion, which was associated with an increased expression of ET-1 and ET(A). Vasopressin aggravated the CPB-associated malperfusion, whereas it completely abrogated the upregulation of ET-1 and ET(A). Interestingly, vasopressin did not induce gastric mucosal morphologic injury, leukocytic infiltration or apoptotic cell death. CONCLUSION: Vasopressin aggravates CPB-associated microvascular malperfusion of the gastric mucosa but does not induce gastric mucosal injury.