Arno Schiferer

A randomized controlled trial of femoral nerve blockade administered preclinically for pain relief in femoral trauma.

BACKGROUND:Analgesia at the location of the accident and on transport for femoral trauma is often delayed or insufficient. In this prospective, randomized, controlled study, we evaluated the preclinical use of femoral nerve blockade for reducing pain and anxiety compared with IV analgesia using metamizol. METHODS:Patients with painful femoral trauma, such as fracture or severe contusion, were randomized to receive at the site of the accident a femoral nerve blockade (n = 31) or IV analgesia with metamizol (n = 31). A visual analog scale (VAS) was used to assess pain and anxiety. Variables were assessed at baseline, during transport and upon arrival at the hospital. RESULTS:In patients receiving the femoral nerve blockade, pain values decreased by half from VAS 86 ± 6 mm at the site of the accident to VAS 41 ± 15 mm during transport. Anxiety decreased by half from VAS 84 ± 11 mm to VAS 39 ± 14 mm. Heart rate decreased by 20 ± 5 bpm. In the metamizol group, pain, anxiety, and heart rate did not decrease (P < 0.001). Time of treatment was 7.4 ± 3.5 min longer in the femoral nerve blockade group. CONCLUSION:Preclinically administered femoral nerve blockade effectively decreases pain, anxiety, and heart rate after femoral trauma. Regional blockade is an option for out-of-hospital analgesia administered by a trained physician.

Femoral nerve blockade administered preclinically for pain relief in severe knee trauma is more feasible and effective than intravenous metamizole: a randomized controlled trial.

BACKGROUND Before clinical treatment and during transportation, the analgesic therapy offered to patients with painful knee trauma may be quite insufficient. We hypothesize that a femoral nerve blockade for analgesia can be administered in a preclinical setting at the injury site and provides better pain relief than intravenous metamizole, whose analgesic effect is comparable with that of opioids. METHODS After an initial clinical investigation, 52 patients were randomized according to computer-generated codes; 26 patients received a femoral nerve blockade and 26 received metamizole. The treatment was started at the injury site and the level of pain on the 100-mm visual analog scale was assessed at the beginning and the end of treatment. RESULTS Pain and anxiety scores were significantly reduced by half in the femoral nerve blockade group; peripheral vasoconstriction was noted in 26 patients at the injury site and dropped to six at the time of arrival at the hospital. Two of 26 patients in the blockade group did not benefit from the treatment. In the metamizole group, pain and anxiety did not decrease significantly; vasoconstriction persisted in all patients. CONCLUSION Patients with painful knee trauma benefited from femoral nerve blockade administered before hospitalization. The treatment can be administered safely in the preclinical setting and provides effective analgesia.

Serological features of antibodies to protamine inducing thrombocytopenia and thrombosis.

Abstract Background: A significant proportion of patients undergoing cardiopulmonary bypass develop anti-protamine antibodies, with or without the association of thromboembolic events. Methods: We extensively investigated the serological features of protamine antibodies, which developed in six patients who were clinically suspected to have heparin-induced thrombocytopenia (HIT). Three patients had thrombotic events. Sera were tested by four different commercially available immunoassays, a heparin-platelet aggregation test, and for their binding properties to heparin, platelet factor 4 (PF4), complex heparin-PF4, protamine, and protamine complex with heparin. Sera from four patients were also tested for the capability to induce platelet activation and the formation of platelet-monocyte heterotypic aggregates. Results: The ELISA assay Zymutest HIA was strongly positive in all cases, the HPIA Asserachrome was borderline, and the gel centrifugation test PaDGIA was positive in two tested patients. Platelet aggregation tests were negative. Using a variation of the Zymutest HIA we demonstrate that IgG antibodies bound only to protamine or protamine complex with heparin, but not to heparin or PF4 only. Sera-induced platelet P-selectin expression and the formation of platelet-monocyte aggregates. Blood samples from one patient proofed positive concomitantly with the thromboembolic event. However, serological characteristics did not differ between antibodies associated with thromboembolic events from those without. Conclusions: These data show that protamine-induced antibodies are specific and may induce platelet activation, which explains their association with thromboembolic events.

Muscle mass, strength and functional outcomes in critically ill patients after cardiothoracic surgery: does neuromuscular electrical stimulation help? The Catastim 2 randomized controlled trial.

BackgroundThe effects of neuromuscular electrical stimulation (NMES) in critically ill patients after cardiothoracic surgery are unknown. The objectives were to investigate whether NMES prevents loss of muscle layer thickness (MLT) and strength and to observe the time variation of MLT and strength from preoperative day to hospital discharge.MethodsIn this randomized controlled trial, 54 critically ill patients were randomized into four strata based on the SAPS II score. Patients were blinded to the intervention. In the intervention group, quadriceps muscles were electrically stimulated bilaterally from the first postoperative day until ICU discharge for a maximum of 14 days. In the control group, the electrodes were applied, but no electricity was delivered. The primary outcomes were MLT measured by ultrasonography and muscle strength evaluated with the Medical Research Council (MRC) scale. The secondary functional outcomes were average mobility level, FIM score, Timed Up and Go Test and SF-12 health survey. Additional variables of interest were grip strength and the relation between fluid balance and MLT. Linear mixed models were used to assess the effect of NMES on MLT, MRC score and grip strength.ResultsNMES had no significant effect on MLT. Patients in the NMES group regained muscle strength 4.5 times faster than patients in the control group. During the first three postoperative days, there was a positive correlation between change in MLT and cumulative fluid balance (r = 0.43, P = 0.01). At hospital discharge, all patients regained preoperative levels of muscle strength, but not of MLT. Patients did not regain their preoperative levels of average mobility (P = 0.04) and FIM score (P = 0.02) at hospital discharge, independent of group allocation.ConclusionsNMES had no effect on MLT, but was associated with a higher rate in regaining muscle strength during the ICU stay. Regression of intramuscular edema during the ICU stay interfered with measurement of changes in MLT. At hospital discharge patients had regained preoperative levels of muscle strength, but still showed residual functional disability and decreased MLT compared to pre-ICU levels in both groups.Trial registrationClinicaltrials.gov identifier NCT02391103. Registered on 7 March 2015.

Lack of donor and recipient age interaction in cardiac transplantation

BACKGROUND The proportion of older donors and recipients is constantly rising in heart transplantation (HTX). The impact of age on different outcomes after HTX has been studied; however, effects of interaction between donor and recipient age remain elusive. METHODS This retrospective cohort study comprised 1,190 patients who underwent HTX between 1984 and 2011 at the Medical University Vienna. Multivariable models consisted of a basic set that included donor age, recipient age, and transplant eras and were adjusted for 2 sets of 6 possible confounders and 3 mediator variables. Cox models were used to estimate the risk of death. To search for age-related effects on the development of cardiac allograft vasculopathy (CAV), we applied cause-specific Cox models and proportional sub-distribution hazard models for competing risk data. RESULTS Survival was 80%, 77%, 69%, and 56% after 1, 2, 5, and 10 years, respectively. Donor age (hazard ratio [HR], 1.1; 95% confidence interval [CI], 1.0-1.2), recipient age (HR, 1.1; 95% CI, 1.0-1.2), admission from intensive care unit to HTX (HR, 1.5; 95% CI, 1.2-1.9), and diabetes (HR, 1.4; 95% CI, 1.1-1.7) were identified as significant independent risk factors for death. Significant risk factors for CAV were donor age (HR, 1.4; 95% CI, 1.3-1.5) and male recipient sex (HR, 1.5; 95% CI, 1.0-2.2). Recipient age was inversely associated with initiation of CAV (HR, 0.8; 95% CI, 0.8-1.0). Analysis of the interaction between donor and recipient age was not significant for death (p = 0.8) or CAV (p = 0.6). CONCLUSIONS We found no interaction between donor and recipient age negatively affecting mortality and CAV. The identified independent risk factors may have implications for allocation strategies in elderly recipients.

Acute Kidney Injury and Outcome After Heart Transplantation: Large Differences in Performance of Scoring Systems.

Background Kidney function is an important aspect for patient outcome after heart transplantation (HTX). Acute kidney injury (AKI) is defined by changes in serum creatinine (SCr) and diuresis with risk/injury/failure/loss/end stage (RIFLE), acute kidney injury network (AKIN), or kidney disease: improving global outcomes (KDIGO) scores. Methods We investigated the effect of perioperative AKI on 1-year mortality after HTX over a period of 10 years at a single-center university hospital. Multivariable Cox proportional-hazards regression analyzed the association between 1-year mortality and potential risk factors. Receiver operating curves for 1-year mortality were calculated to determine sensitivity and specificity of scores. Results Sixty of 346 patients (17%) died within the first year. Acute kidney injury was a predictor of mortality only in the high-risk AKI groups of all scores: Hazard ratios (95% confidence interval) for RIFLE F: 7.164 (3.307-15.523); KDIGO/AKIN stage 3: 3.492 (2.006-6.081). Within each score, we identified patient groups, which had no elevated risk for an adverse outcome despite their allocation to the milder forms of AKI. In multivariable regression analysis, primary graft dysfunction was the predominant perioperative risk factor for 1-year mortality. Conclusions In contrast to other patient cohorts, mild forms of perioperative AKI are of subordinate influence on patient outcome in HTX.

Impact of preoperative serum creatinine on short- and long-term mortality after cardiac surgery: a cohort study

BACKGROUND Preoperative renal insufficiency is an important predictor of mortality after cardiac surgery. This retrospective cohort study was designed to identify the optimal cut-off for baseline serum creatinine (bSCr) and estimated glomerular filtration rate (eGFR) to predict survival. Furthermore, we investigated the potential confounding effect of other perioperative risk indicators on short- and long-term survival. METHODS Data of 9490 cardiac surgical patients were prospectively collected between 1997 and 2008 (follow up to 2010) at the Medical University Vienna. We identified bSCr cut-off values and calculated uni- and multivariate hazard models for short- and long-term survival and compared the results with a validation set from Zurich. The estimated survival curves defined a distinct period of increased mortality until 150 days. RESULTS Cut-off values of >115 µmol litre(-1) for bSCr and ≤50 ml min(-1) for eGFR were identified. Increased bSCr, associated with higher mortality [hazard ratio (HR) 2.61, 95% confidence interval (CI) 2.43-2.80, P<0.0001], was present in 19.5% of patients and remained predictive for short- (HR 1.59, 95% CI 1.38-1.83, P=0.0027) and long-term survival (HR 1.46, 95% CI 1.32-1.62, P<0.0001) in the multivariate hazard models. A cut-off of >120 µmol litre(-1) for bSCr was determined for the validation set. Decreased eGFR was present in 23.6% (HR 2.86, 95% CI 2.67-3.06, P<0.0001). CONCLUSIONS In our patients, increased bSCr was an independent predictor of mortality, which may critically influence risk evaluation and perioperative treatment guidance.

A prospective analysis of invasive candidiasis following cardiac surgery: Severity markers are predictive

AIM Invasive Candida infections (ICI) in intensive care unit (ICU) patients are associated with high mortality. A 2-year prospective study was performed to improve clinical decision making in long-term ICU patients after cardiac surgery. METHODS Demographic, clinical and physiological data, the incidence of ICI and Candida colonisation scores were analysed. To assess severity of illness the new simplified acute physiology score (SAPS II score), the European system for cardiac operative risk evaluation (EuroSCORE) and the sequential organ failure assessment (SOFA) score were calculated. To define independent risk factors univariate and multivariate Cox-regression analyses with time-dependent covariates were calculated. RESULTS One hundred and sixty-nine cardiac surgery patients with ICU admittance ≥ 4 days out of 513 admittances were enrolled. Ten patients had proven ICI. In the multivariate analysis the SOFA score (HR = 1.29, p = 0.009) was associated with proven ICI. In 71 patients receiving empiric antifungal therapy for presumptive but unproven ICI the SOFA score (HR = 1.18, p = 0.029) and corrected Candida colonisation index (HR 11.08; p = 0.030) were significantly associated to ICI. Neither SAPS II score nor EuroScore were associated with ICI in either patient group. The mortality rate of patients receiving empiric antifungal therapy was significantly lower compared to that of patients with proven ICI (36.6% vs. 80%, respectively). CONCLUSION Time-associated SOFA score assessing acute organ failure was the only independent risk factor for proven ICI. Cardiovascular procedures did not confer risk to develop ICI. Empiric antifungal therapy may be warranted in severely ill cardiac surgery patients.

From clinical reasoning to effective clinical decision making—new training methods

Identification of causes and immediate adjustment to treatment of acute thrombocytopenia occurring in patients in the intensive care unit is required to avoid imminent complications. Hence it is important to train awareness and clinical decision making of students in the medical curriculum. Therefore, real-life cases were transferred into an interactive eLearning platform comprising the steps of patient assessment and therapeutic decisions. Heparin-induced platelet count decrease is an immune-mediated prothrombotic disorder, resulting from an adverse drug reaction (Kelton and Warkentin, 2008). After cardiac surgery antibodies against circulating heparin—platelet factor (PF) four complexes develop in up to 50%. Patients experience a risk of 1–5% to acquire clinical symptoms of heparin-induced thrombocytopenia (HIT) (Warkentin et al., 2000; Linkins et al., 2012). Due to complications, mortality rates are high and amount to 5–10% (Kelton and Warkentin, 2008; Kelton et al., 2013). As clinical teaching case a 59-year-old male patient is presented, who was admitted to the intensive care unit (ICU) of the General Hospital of Vienna on extracorporeal life support (ECMO). The man underwent bypass surgery six days ago in a peripheral hospital and is concomitantly suffering from an active infection. On the fourth day at ICU a platelet count decrease has been noticed.

Intensive care treatment of patients with left ventricular assist devices

ZusammenfassungDer Linksherzersatz durch ein Unterstützungssystem [„left ventricular assist device“ (LVAD)] ist, abgesehen von der Herztransplantation, die einzig etablierte chirurgische Behandlung des therapierefraktären Endstadiums der Linksherzinsuffizienz. Das individuelle intensivmedizinische Management dieser Patienten ist vom Aufnahmegrund abhängig und bedarf einer Vorstellung von der spezifischen Hämodynamik und den Eigenheiten der derzeit am häufigsten implantierten Kunstherzen mit nichtpulsatilem Flussmuster. Hierzu gehören Kenntnisse des hämodynamischen Monitorings, der Pumpenspezifika, des Managements von Antikoagulation und Hämostase sowie der Bewältigung von Problemen wie Rechtsherzversagen, Aortenklappeninsuffizienz und Infektionen. Die Behandlung eines bewusstlosen LVAD-Patienten stellt eine klinische Herausforderung dar, die versierte Kenntnisse in der transthorakalen und transösophagealen Echokardiographie, eine gezielte Labordiagnostik und pathophysiologisches Wissen zur differenzialdiagnostischen Abklärung erfordert. Unumgänglich sind zudem eine professionelle, interdisziplinäre Zusammenarbeit sowie der Austausch aktueller kritischer Informationen.AbstractApart from heart transplantation, implantation of a left ventricular assist device (LVAD) is the only established surgical treatment for therapy-refractory terminal left heart failure, The specific intensive care unit (ICU) management of these patients depends on the reason for the ICU admission and requires understanding of the characteristic hemodynamics of non-pulsatile LVADs as well as of the inherent problems. Knowledge about the specific features in hemodynamic monitoring, understanding of pump characteristics, management of anticoagulation and hemostasis and the handling of problems, such as right heart failure, aortic valve insufficiency and infections is essential. The management of unconscious LVAD patients can be challenging. It requires a sophisticated transthoracic and transesophageal echocardiography (TTE/TEE) examination, targeted laboratory diagnostics and consideration of possible alternative diagnoses. Professional interdisciplinary cooperation and exchange of current knowledge is crucial.Apart from heart transplantation, implantation of a left ventricular assist device (LVAD) is the only established surgical treatment for therapy-refractory terminal left heart failure, The specific intensive care unit (ICU) management of these patients depends on the reason for the ICU admission and requires understanding of the characteristic hemodynamics of non-pulsatile LVADs as well as of the inherent problems. Knowledge about the specific features in hemodynamic monitoring, understanding of pump characteristics, management of anticoagulation and hemostasis and the handling of problems, such as right heart failure, aortic valve insufficiency and infections is essential. The management of unconscious LVAD patients can be challenging. It requires a sophisticated transthoracic and transesophageal echocardiography (TTE/TEE) examination, targeted laboratory diagnostics and consideration of possible alternative diagnoses. Professional interdisciplinary cooperation and exchange of current knowledge is crucial.