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

BACKGROUND: The 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. METHODS: In 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. RESULTS: NMES 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. CONCLUSIONS: NMES 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 REGISTRATION: Clinicaltrials.gov identifier NCT02391103. Registered on 7 March 2015.

Serum Creatinine Back-Estimation in Cardiac Surgery Patients: Misclassification of AKI Using Existing Formulae and a Data-Driven Model.

BACKGROUND AND OBJECTIVES: A knowledge of baseline serum creatinine (bSCr) is mandatory for diagnosing and staging AKI. With often missing values, bSCr is estimated by back-calculation using several equations designed for the estimation of GFR, assuming a "true" GFR of 75 ml/min per 1.73 m(2). Using a data set from a large cardiac surgery cohort, we tested the appropriateness of such an approach and compared estimated and measured bSCr. Moreover, we designed a novel data-driven model (estimated serum creatinine [eSCr]) for estimating bSCr. Finally, we analyzed the extent of AKI and mortality rate misclassifications. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data for 8024 patients (2833 women) in our cardiac surgery center were included from 1997 to 2008. Measured and estimated bSCr were plotted against age for men and women. Patients were classified to AKI stages defined by the Kidney Disease Improving Global Outcomes (KDIGO) group. Results were compared with data from another cardiac surgery center in Zurich, Switzerland. RESULTS: The Modification of Diet in Renal Disease and the Chronic Kidney Disease Epidemiology Collaboration formulae describe higher estimated bSCr values in younger patients, but lower values in older patients compared with the measured bSCr values in both centers. The Pittsburgh Linear Three Variables formula correctly describes the increasing bSCr with age, however, it underestimates the overall bSCr level, being in the range of the 25% quantile of the measured values. Our eSCr model estimated measured bSCr best. AKI stage 1 classification using all formulae, including our eSCr model, was incorrect in 53%-80% of patients in Vienna and in 74%-91% in Zurich; AKI severity (according to KDIGO stages) and also mortality were overestimated. Mortality rate was higher among patients falsely classified into higher KDIGO stages by estimated bSCr. CONCLUSIONS: bSCr values back-estimated using currently available eGFR formulae are inaccurate and cannot correctly classify AKI stages. Our model eSCr improves the prediction of AKI but to a still inadequate extent.

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.

[Intensive care treatment of patients with left ventricular assist devices]. / Intensivbehandlung von Kranken mit Linksherzersatz.

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.

Serological features of antibodies to protamine inducing thrombocytopenia and thrombosis.

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.

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.

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.

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.

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.