Thromboembolic events in burn patients: An analysis of risk factors and different anticoagulants.

BACKGROUND: Burn patients are in a state of activated coagulation, putting them at risk for thromboembolic events. Additionally, certain patient-related factors are associated with an increased risk of thrombus formation. This study aimed to evaluate the incidence of thromboembolic events and identify potential risk factors, including patient characteristics, surgical treatment, anticoagulation strategies, and laboratory parameters. METHODS: A single-centre retrospective cohort study was conducted on all patients with burns treated between 2002 and 2020. Medical reports of patients with and without thromboembolic events were descriptively analysed. The association of time to thromboembolic events with total body surface area (TBSA) was assessed by cause-specific Cox models adjusted for different covariates. The association of time to thromboembolic events with type and dosage of anticoagulants was assessed using a cause-specific Cox proportional hazards model with time-dependent covariates, applied to a matched subset of patients. RESULTS: The incidence of thromboembolic events was 8.1% in a cohort of 642 patients. We found a statistically significant increase in the hazard for thromboembolic events by a factor of 1.02 (95% CI 1.00 to 1.03; P ≤ 0.05) per percent increase in TBSA. We identified former alcohol abuse (HR=2.54, CI 1.33 to 4.84, P = 0.005) and higher body mass index (HR=1.06, 95% CI 1.00 to 1.12, P = 0.046) as potential risk factors for the development of thromboembolic events. We further noted inadequate median anti-Factor-X activity levels and elevated C-reactive protein and procalcitonin levels at the time of the event. CONCLUSION: Our results showed a moderate risk of thromboembolic events among burn patients, underlining the importance of close monitoring with regard to thrombus formation. In particular, patients with higher TBSA, alcohol abuse and BMI may be evaluated more regularly for thromboembolic events. Anti-Factor-X activity levels should be determined regularly and therapy should be adjusted if necessary.

Enzymatic debridement for circumferential deep burns: the role of surgical escharotomy.

INTRODUCTION: Circumferential deep burns carry a high risk for a burn induced compartment syndrome. It was recently shown that an enzymatic bromelain-based debridement with Nexobrid® is a safe and efficient procedure to release pressure in deep circumferential extremity burns reducing the need for surgical escharotomy. We therefore herein aimed to analyze the conceptual relation between Nexobrid® and surgical escharotomy. PATIENTS AND METHODS: We conducted a retrospective study on all patients with circumferential deep partial-thickness or full-thickness burns requiring immediate escharotomy that was either performed by surgical incision or Nexobrid®. Medical records of 792 patients that were treated at the burn center of the University Hospital Zurich between 2016 and 2021 were analyzed. RESULTS: Overall, 62 patients with circumferential deep partial-thickness or full-thickness burns who received preventive decompression either by Nexobrid® (N = 29) or surgical escharotomy (N = 33), were included. Whilst distribution of age, sex, BMI and type of injury showed no difference between the groups, the ABSI score, TBSA, percentage of third degree burns and mortality were significantly higher in patients who received a surgical escharotomy. CONCLUSION: While the use of Nexobrid® to prevent burn induced compartment syndrome has steadily increased, surgical escharotomies were predominantly performed in severely burned patients with a high degree of full-thickness burns. Thus, higher mortality in this patient group needs to be considered with caution and is mainly attributed to the higher TBSA. Although evidence is lacking for the use of Nexobrid® for larger body areas exceeding 15%, escharotomy is also the more reliable and faster approach in such critically burned patients.

Heart rate profiles and heart rate variability during scuba diving.

AIMS: The aim of the present study was to describe heart rate profiles and heart rate variability patterns in non-selected scuba divers of different ages under non-experimental real-world conditions. METHODS: We used specially designed silver-loaded polydimethylsiloxane dry electrodes for underwater ECG recordings. With a custom-built setup, heart rate profiles and heart rate variability patterns were documented before submersion, during diving and after resurfacing in 18 separate dives. RESULTS: Heart rates of the divers just before descent were remarkably high (median 114 bpm, interquartile range [IQR] 83-154) with a statistically significant rapid decrease after submersion (median 90 bpm, IQR 70-116; p = 0.008). The percentage heart rate reduction by submersion was individually very variable (median 21%, range 5-39%). We noted a general increase in autonomic nervous system (ANS) activity without predominance of parasympathetic parameters, suggesting a concomitant sympatheticadrenergic activation. CONCLUSIONS: Scuba diving under real-world conditions by non-selected divers is characterised by relatively high heart rates just before submersion, an individually variable but significant bradycardic dive response, and induces an immediate and sustained parallel increase of parasympathetic and sympathetic-adrenergic autonomic nervous system activity. These observations could explain several specific pathophysiological mechanisms of diving incidents (haemodynamic decompensation, arrhythmias, acute coronary syndromes) and underlines the importance of cardiovascular risk stratification in diving eligibility assessment.