Daniel Heise

Comparison of urinary neutrophil glucosaminidase-associated lipocalin, cystatin C, and α1-microglobulin for early detection of acute renal injury after cardiac surgery

OBJECTIVE Acute renal injury is a frequent complication after cardiac surgery that necessitates additional treatment and increases mortality. To apply measures for optimizing renal function in a well-directed and effective way, it is most important to detect acute kidney injury at an early stage. The present study compares three markers of renal tubular function for detection of acute renal injury according to the acute kidney injury (Acute Kidney Injury Network (AKIN)) criteria. METHODS Urinary concentration of the tubular markers neutrophil glucosaminidase-associated lipocalin (NGAL), α1-microglobulin (α1MG), and cystatin C (CysC) were measured in 50 patients after elective cardiac surgery. Samples were taken once preoperatively and postoperatively every 12 h for up to 5 days. Based on the highest recorded postoperative AKIN score, patients were divided into two groups (AKIN 0 and AKIN 1-3). Statistical analysis was done for marker concentrations at three time points: preoperative, after admission to the intensive care unit (ICU), and at the highest postoperative AKIN level. In addition, all concentrations of marker proteins were multiplied by the ratio of creatinine concentrations in serum and urine; these products were also analyzed statistically. In this way, we were able to eliminate the influence of varying degrees of diuresis on marker concentrations. RESULTS As early as at admission to the ICU, all marker proteins showed significantly higher concentrations compared with preoperative values. However, differences in concentrations between the groups AKIN 0 and AKIN 1-3 were only statistically significant for NGAL. Using receiver operating characteristic (ROC) analysis, we found that only NGAL concentrations were suitable for detecting acute kidney injury with adequate sensitivity and specificity (area under the curve (AUC)=0.773). Levels of α1MG yielded a comparable accuracy when urinary concentrations were multiplied by the serum/urine creatinine ratio (AUC=0.712). CONCLUSION An increase in urinary NGAL is an early sign of acute kidney injury after cardiac surgery. After multiplication by the serum/urine creatinine ratio, urinary α1MG is also suitable for detection of acute kidney injury at an early stage.

Validation of a clinical score to determine the risk of acute renal failure after cardiac surgery

OBJECTIVE Preoperative assessment of risk factors for postoperative acute renal failure (ARF) is a key point in the management of cardiac surgery patients. A reliable evaluation of individual risk permits the efficient application of prophylactic and therapeutic measures to patients with increased risk of ARF. In 2005, Thakar published a scoring system to determine the ARF risk prior to surgery. The score allowed calculation of the incidence of postoperative ARF requiring dialysis (ARF-D) with a high level of precision. METHODS In order to examine the reproducibility of the results on different patient populations, we retrospectively applied the scoring system to 3,508 cardiac surgery patients at the Goettingen University Hospital. RESULTS We found a qualitative correlation between the score value and ARF-D, but prognostic significance, when judged by the area under the receiver operating characteristic (ROC) curve, was considerably reduced. Also, the incidence of ARF-D in the Goettingen population was remarkably higher than the incidence shown by Thakar for patients with the same score. CONCLUSIONS The correlation between score values and incidence of ARF-D shows that the Thakar score is qualitatively transferable to cardiac surgery patients from other centres. Though the score allows the discrimination between patients with higher or lower risks of ARF-D within the Goettingen collective, it was not suitable to estimate the real incidence of postoperative ARF-D with sufficient precision.

Recombinant activated factor VII (Novo7®) in patients with ventricular assist devices: Case report and review of the current literature

Postoperative bleeding might become a serious problem in the management of cardiac surgical patients, with marked medical and economic impact. In these life-threatening situations, massive haemorrhage represents frequently a combination of surgical and coagulopathic bleeding. Surgical bleeding results from a definite source at the operation site and can be corrected using surgical standard techniques. Acute coagulopathies, in contrast, result from impaired thrombin formation, and require optimized therapeutical strategies. Effective pharmacological treatment will be complicated by the presence of ventricular assist devices (VAD), which necessarily imply effective anticoagulation.In episodes of uncontrolled coagulopathic bleeding, the application of recombinant activated factor VII (rFVIIa) as a effective haemostatic agent has become more and more popular. However, only very few data are available on its use in patients with VAD in place.We researched the PubMed-database for case reports about the use of rFVIIa in patients with VAD and summarized them. In addition, we report a case from our hospital. In all cases cessation of bleeding without any thrombembolic complications could be achieved. In cases of uncontrollable, non-surgical bleeding rFVIIa seems to be a therapeutical option even for patients with VAD.

The effect of a novel extracorporeal cytokine hemoadsorption device on IL-6 elimination in septic patients: A randomized controlled trial.

Objective We report on the effect of hemoadsorption therapy to reduce cytokines in septic patients with respiratory failure. Methods This was a randomized, controlled, open-label, multicenter trial. Mechanically ventilated patients with severe sepsis or septic shock and acute lung injury or acute respiratory distress syndrome were eligible for study inclusion. Patients were randomly assigned to either therapy with CytoSorb hemoperfusion for 6 hours per day for up to 7 consecutive days (treatment), or no hemoperfusion (control). Primary outcome was change in normalized IL-6-serum concentrations during study day 1 and 7. Results 97 of the 100 randomized patients were analyzed. We were not able to detect differences in systemic plasma IL-6 levels between the two groups (n = 75; p = 0.15). Significant IL-6 elimination, averaging between 5 and 18% per blood pass throughout the entire treatment period was recorded. In the unadjusted analysis, 60-day-mortality was significantly higher in the treatment group (44.7%) compared to the control group (26.0%; p = 0.039). The proportion of patients receiving renal replacement therapy at the time of enrollment was higher in the treatment group (31.9%) when compared to the control group (16.3%). After adjustment for patient morbidity and baseline imbalances, no association of hemoperfusion with mortality was found (p = 0.19). Conclusions In this patient population with predominantly septic shock and multiple organ failure, hemoadsorption removed IL-6 but this did not lead to lower plasma IL-6-levels. We did not detect statistically significant differences in the secondary outcomes multiple organ dysfunction score, ventilation time and time course of oxygenation.

Conductive warming and insulation reduces perioperative hypothermia

BackgroundPerioperative hypothermia is rather common after head and neck surgery.MethodsIn this prospective, randomised controlled study with 40 patients, we tested the hypothesis that the use of a new conductive warming system (PerfecTemp™, The Laryngeal Mask Company Limited, St. Helier, Jersey) in combination with insulation of 1.29 clo (treatment group) is better in reducing the incidence of hypothermia during and after head and neck surgery than insulation only (control group).ResultsRepeated-measures analysis of variance (ANOVA) and post hoc Scheffé’s test identified a significantly higher core temperature in the treatment group at 45, 60, 75, 90, 105 and 120 min (p < 0.05). Furthermore, Fisher’s exact test confirmed a lower incidence of intraoperative (3 vs. 9 patients; p = 0.03) and postoperative hypothermia (0 vs. 6 patients; p = 0.008).ConclusionIn conclusion, the combination of good thermal insulation and conductive warming is effective in preventing perioperative hypothermia during head and neck surgery. Level of Evidence: 1b

Intraoperative full-thickness pressure ulcer in a patient after transapical aortic valve replacement using a novel underbody forced-air warming blanket

To the Editor: Intraoperativepressureulcers in patients undergoing cardiac surgery are a common but potentially preventable incident [1,2]. Full-thickness pressure ulcers interfere with functional recovery and are complicated by pain and infection. In some patients, this situation may cause premature mortality [3]. Transapical aortic valve replacement is an alternative to open aortic valve replacement in high-risk patients with severe aortic stenosis and multiple co-morbidities. A case in which transapical aortic valve replacement was complicated by a full-thickness pressure ulcer from a novel forced-air warming underbody blanket is presented. A 76 year-old, 70 kgwoman, with severe aortic stenosis, left ventricular (LV) hypertrophy, and atrial fibrillation was scheduled for transapical aortic valve replacement. To prevent perioperativehypothermia,shewasplacedonanovelunderbody forced-airwarmingblanket (UNIVERSALII;Moeck&Moeck, Hamburg, Germany). This blanket incorporates a light-weight, 10 mm, strong supporting structure designed to minimize pressure on the patients backwithout interrupting the supply of warmair.Itwasdevelopedespeciallyforcardiacsurgeryandmay be used in patients weighing up to 150 kg. The manufacturer declares that theweightof thepatient isdistributedevenly,so that the riskof a pressure ulcer is greatly reducedwithout theneed for additional pressure reducing devices on the operating table. After induction of anesthesia, the patient was actively warmed using the underbody forced-air warming blanket and the corresponding blower (TWINWARM; Moeck & Moeck). The temperature of the blower was set to 43°C. A left anteriolateral mini-thoracotomy was performed; the pericardium was opened; and epicardial pacingwires were placed. After the introducer shealth was placed in the LV apex, a guidewire was advanced across the aortic valve into the ascending aorta. Then the ballon-tipped valvuloplasty catheter was introduced and valvuloplasty was performed during rapid ventricular pacing. The prosthetic valve was then placed within the aortic valve annulus. After reinitiating rapid ventricular pacing, the prosthetic valve was deployed. Prosthetic valve position and function were assessed by fluoroscopy and transesophageal echocardiography (TEE). The delivery system was removed from the apex during rapid pacing and the apex of the LV was closed. Duration of the procedurewas about 60minutes. During skin closure, the patient suddenly developed hypotension and bradycardia. Within minutes, cardiopulmonary resuscitation (CPR) was initiated. After several minutes of CPR, an emergency median sternotomy was performed; after injection of heparin, the ascending aorta and the right atrium were cannulated. Cardiopulmonary bypass (CPB) was started 20 minutes after circulatory deterioration. Diagnostic heart catheterization ruled out closure of a coronary artery ostium and a second TEE ruled out malfunction of the aortic valve. After a perfusion time of 140 minutes, the patient was weaned from CPB using DDD-pacing and moderate doses of epinephrine, norepinephrine, and the phosphodiesterase III inhibitor, enoximone. After sternal closure, the patient was transferred to the intensive care unit (ICU). The entire operative procedure lasted 4 hours and 32 minutes. During that time, the patient was continuously warmed with the underbody forced-air blanket. Her blood pressure and heart rate stabilized during the next severalhours;hertracheawasextubated15hoursafterherarrival in the ICU. She was fully awake and there were no neurologic sequelae. On the first postoperative day, a large full-thickness pressure ulcer with purple and grey discolored, skin induration, and subcutaneous necrosis were seen on the buttocks. On the 5th postoperative day, the patient vomited several times, her lactate levels were increasing, and she developed severe septic shock. Emergency laparotomy showed ischemia of the small intestine with ischemic perforation. Despite all measures, the patient died of septic shock with multiorgan failure on the same day. Although the incidence of grade 1 intraoperative pressure ulcers in patients undergoing cardiac surgery is high [4], fullthickness pressure ulcers appearing immediately after cardiac surgery are uncommon. Our patient was at high risk for development of an intraoperative pressure ulcer: peripheral perfusion was restricted because of low cardiac output due to severe aortic valve stenosis and peripheral vascular disease. It was further compromised during the procedure, especially during CPR and CPB. During CPR, passive movements of the patient may have caused sliding of her body on the operation table, leading to tearing and folding of the tissues. Such shear forces exert a parallel force that occludes capillary blood flow while pressure exerts a perpendicular force on the soft tissues, which is another well-known cause of pressure ulcers [5]. It is

Propofol up2date – Teil 1: Geschichte und pharmakologische Charakteristika

Propofol is a common hypnotic agent in anaesthesiology and intensive care medicine and for procedural sedation as well. Despite the intensive usage the full potential, pharmacokinetic and -dynamic abilities, interactions and side effects of the substance may not be realized by all providers. Additionally there is dispute and unwarranted myth about the substance. Propofol is a highly potent hypnotic with a wide range of (un)desired effects. This article is reviewing the diversity of the substance in clinical practice.

Propofol up2date – Teil 2: Patientengruppen, unerwünschte Wirkungen und die Nachfolgesubstanz Fospropofol

Propofol is a common hypnotic agent in anaesthesiology and intensive care medicine and for procedural sedation as well. Despite the intensive usage the full potential, pharmacokinetic and -dynamic abilities, interactions and side effects of the substance may not be realized by all providers. Additionally there is dispute and unwarranted myth about the substance. Propofol is a highly potent hypnotic with a wide range of (un)desired effects. This article is reviewing the diversity of the substance in clinical practice.

Modifying a kidney injury score by including perioperative data Comparison of three predictive scores

AbstractAt present, several scores have been developed to assess the risk of acute kidney injury (AKI) after cardiac surgery, and every score represents a compromise between the completeness of the factors and the early evaluation of the AKI risk. This study examined whether the predictive reliability of an AKI risk score can be significantly improved by applying not only preoperative risk factors but also intraoperative and postoperative parameters for the calculation of the score.Materials and methodsThree scores were deduced from the data of 662 patients undergoing cardiac surgery; these were based on preoperative (score 1), pre- and intraoperative (score 2) or on pre-, intra- and postoperative parameters (score 3). Sensitivity and specificity for the prediction of an AKI were determined from a validation population comprising 529 additional patients.ResultsAKI occurred in 455 patients (38.2%). Sensitivity and specificity of the scores were 60.9% and 67.6% (score 1), 60.4% and 68.2% (score 2) and 66.8% and 64.8% (score 3).ConclusionThe inclusion of intra- and postoperative parameters into a predictive model does not significantly improve the ability to identify patients at risk of AKI. As scores based on preoperative parameters allow for the earliest possible risk stratification, they should be preferred in clinical practice.

Retrospective Validation of New Simulation Software to Prevent Perioperative Hypothermia in Major Urologic Abdominal Surgery

Background. Perioperative hypothermia is still a major problem. Therefore, it would be useful to predict which warming method would prevent perioperative hypothermia in a particular patient. Methods. The simulation software “ThermoSim Vers. 5.07” was validated using the data of two prospective, randomized, and controlled studies. The diagnostic effectiveness was assessed by calculating sensitivity and specificity, positive predictive value (PPV), and negative predictive value (NPV) in the detection of perioperative hypothermia. Results. Sensitivity of the software was 100% (Study 1) and 94% (Study 2), specificity was 67% (Study 1) and 38% (Study 2), PPV was 60% (Study 1) and 50% (Study 2), and NPV was 100% (Study 1) and 90% (Study 2). Conclusions. The software is helpful in predicting which warming method is necessary to prevent perioperative hypothermia. Thermal treatment based on the prediction of the software will lead to some overtreatment, but will prevent perioperative hypothermia reliably.