Predictors of cardiac arrest in severe accidental hypothermia.

STUDY OBJECTIVE: To indicate predictors of witnessed hypothermic cardiac arrest. METHODS: We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome. RESULTS: Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction. CONCLUSIONS: In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.

Extracorporeal Rewarming Is Associated With Increased Survival Rate in Severely Hypothermic Patients With Preserved Spontaneous Circulation.

Treatment recommendations for rewarming patients in severe accidental hypothermia with preserved spontaneous circulation have a weak evidence due to the absence of randomized clinical trials. We aimed to compare the outcomes of extracorporeal versus less-invasive rewarming of severely hypothermic patients with preserved spontaneous circulation. We conducted a multicenter retrospective study. The patient population was compiled based on data from the HELP Registry, the International Hypothermia Registry, and a literature review. Adult patients with a core temperature <28°C and preserved spontaneous circulation were included. Patients who underwent extracorporeal rewarming were compared with patients rewarmed with less-invasive methods, using a matched-pair analysis. The study population consisted of 50 patients rewarmed extracorporeally and 85 patients rewarmed with other, less-invasive methods. Variables significantly associated with survival included: lower age; outdoor cooling circumstances; higher blood pressure; higher PaCO 2 ; higher BE; higher HCO 3 ; and the absence of comorbidities. The survival rate was higher in patients rewarmed extracorporeally ( p = 0.049). The relative risk of death was twice as high in patients rewarmed less invasively. Based on our data, we conclude that patients in severe accidental hypothermia with circulatory instability can benefit from extracorporeal rewarming without an increased risk of complications.

Impact of rescue collapse on mortality rate in severe accidental hypothermia: A matched-pair analysis.

AIM: To assess the impact of the occurrence of cardiac arrest associated with initial management on the outcome of severely hypothermic patients who were rewarmed with Extracorporeal Life Support (ECLS). METHODS: We collected the individual data of patients in a state of severe accidental hypothermia who were found with spontaneous circulation and rewarmed with ECLS, from cardiac surgery departments. Patients were divided into two groups: those with a subsequent cardiac arrest (RC group); and those with the retained circulation (HT3 group), and compared by using a matched-pair analysis. The mortality rates and the neurological status in survivors were compared as the main outcomes. The difference in the risk of death between the HT3 and RC groups was calculated. RESULTS: A total of 124 patients were included into the study: 45 in the HT3 group and 79 in the RC group. The matched cohorts consisted of 45 HT3 patients and 45 RC patients. The mortality rate in both groups was 24% and 49% (p = 0.02) respectively; the relative risk of death was 2.0 (p = 0.02). ICU length of stay was significantly longer in the RC group (p < 0.001). Factors associated with survival in the HT3 group included patient age, rewarming rate, and blood BE; while in the RC group, patient age and lactate concentration. CONCLUSIONS: The occurrence of rescue collapse is linked to a doubling of the risk of death in severely hypothermic patients. Procedures which are known as potential triggers of rescue collapse should be performed with special attention, including in conscious patients.

Prognostic Factors for Nonasphyxia-Related Cardiac Arrest Patients Undergoing Extracorporeal Rewarming - HELP Registry Study.

OBJECTIVE: Extracorporeal rewarming is the treatment of choice for patients who had hypothermic cardiac arrest, allowing for best neurologic outcome. The authors' goal was to identify factors associated with survival in nonasphyxia-related hypothermic cardiac arrest patients undergoing extracorporeal rewarming. DESIGN: All 38 cardiac surgery departments in Poland were encouraged to report consecutive hypothermic cardiac arrest patients treated with extracorporeal life support. All variables collected were analyzed in order to compare survivor and nonsurvivor groups. The parameters available at the initiation of extracorporeal rewarming were considered as potential predictors of survival in a logistic regression model. The primary outcome was survival to discharge from the intensive care unit. The secondary outcome was neurologic status. SETTING: Multicenter retrospective study. PARTICIPANTS: Ninety-eight cases in the final analysis. INTERVENTIONS: All patients in nonasphyxia-related hypothermic cardiac arrest rewarmed with extracorporeal life support. MEASUREMENTS AND MAIN RESULTS: The survival rate was 53.1%, and 94.2% of survivors had favorable neurologic outcome. The lowest reported core temperature with cerebral performance category scale 1 was 11.8°C. A univariate analysis identified 3 variables associated with survival, namely: age, initial arterial pH, and lactate concentration. In a multivariate analysis, 2 independent predictors of survival were age (0.957; 95% confidence interval [CI] 0.924-0.991) and lactates (0.871; 95% CI 0.789-0.961). The area under the receiver operating characteristics curve for this fitted model was 0.71; 95% CI 0.602-0.817. CONCLUSIONS: Favorable survival with good neurologic outcome in nonasphyxiated hypothermic patients treated with extracorporeal life support was reported. Age and initial lactate level are independently associated with survival.

Preliminary outcome of treatment of postoperative primarily closed sternotomy wounds treated using negative pressure wound therapy.

UNLABELLED: Hospital infections, and in particular infections of the surgical site are a common problem of the procedural departments. Due to continuous progress of surgical techniques and patient population getting older with multiple co-morbidities, multidirectional actions need to be taken to avoid these infections or, if they do occur, achieve optimal treatment outcomes. Vacuum wound therapy is one of the directions that has been developed over the recent years. The aim of the study evaluate wound healing in patients after an off-pump coronary artery bypass grafting procedure, using the internal mammary artery, treated with negative pressure wound therapy system. MATERIAL AND METHODS: This prospective, open label study evaluated healing of postoperative sternotomy wounds after their primary closure with negative pressure wound therapy, using continuous negative pressure of -80 mmHg in 40 patients and 40 patients in a control group in whom conventional dressings were applied in the postoperative period. RESULTS: The number of patients in whom primary wound healing occurred without complications was significantly higher in the negative pressure wound therapy group versus the control group (x2 test =4.50, p=0.0339) and the number of total superficial infections was significantly smaller versus the control group (x2 test =5; p=0.0254). Antibiotic therapy was also initiated significantly less often as compared to the group treated with conventional dressings (x2 test = 4.11; p=0.0425). CONCLUSIONS: Negative pressure wound therapy after primary wound closure reduces the risk of superficial infections in the population with multiple risk factors of complications in the sternotomy wound healing.