Elevated risk of venous thromboembolism in patients undergoing therapeutic hypothermia after cardiac arrest

Sedation, temperature and pressure after cardiac arrest and resuscitation-The STEPCARE trial: A statistical analysis plan

BACKGROUND

Basic management for patients who have suffered a cardiac arrest and are admitted to an intensive care unit (ICU) after resuscitation includes setting targets for blood pressure and managing sedation and temperature. However, optimal targets and management are unknown.

METHODS

The STEPCARE (Sedation, Temperature and Pressure after Cardiac Arrest and Resuscitation) trial is a multicenter, parallel-group, randomized, factorial, superiority trial in which sedation, temperature, and blood pressure strategies will be studied in three separate comparisons (SED-CARE, TEMP-CARE, and MAP-CARE). The trial population will be adults admitted to intensive care who are comatose after resuscitation from out-of-hospital cardiac arrest. The primary outcome will be all-cause mortality, and the secondary outcomes will be poor functional outcome (modified Rankin Scale 4-6), Health-Related Quality of Life using EQ-VAS, and specific serious adverse events in the intensive care unit predefined for each trial. All outcomes will be assessed at 6 months after randomization. The prognosticators, outcome assessors, statisticians, data managers, steering group, and manuscript writers will be blinded to treatment allocation. This statistical analysis plan includes a comprehensive description of the statistical analyses, handling of missing data, and assessments of underlying statistical assumptions. Analyses will be conducted according to the intention-to-treat principle, that is, all randomized participants with available data will be included. The analyses will be performed independently by two statisticians following the present plan.

CONCLUSION

This statistical analysis plan describes the statistical analyses for the STEPCARE trial in detail. The aim of this predefined statistical analysis plan is to minimize the risk of analysis bias.

Hypothermia During Microsurgical Head and Neck Reconstruction and Incidence of Venous Thromboembolism

Importance

Venous thromboembolism (VTE) is a severe complication after microsurgical free tissue transfer (FTT) to the head and neck. Hypothermia during surgery is a modifiable risk factor, and avoiding it may reduce the postoperative VTE rate.

Objective

To assess the association between hypothermia (temperature <36 °C) and postoperative VTE and free flap pedicle thrombosis rates after head and neck reconstruction with FTT.

Design, Setting, and Participants

This retrospective cohort study in a tertiary academic referral center used prospective and retrospective database and medical record data collected for patients who underwent head and neck reconstruction with FTT between January 1, 2012, and August 31, 2023. Temperature over time was classified as normothermia (temperature ≥36 °C), hypothermia (<36 °C) for more than 30 minutes and less than 120 minutes, and hypothermia for 120 minutes or more.

Exposure

Venous thromboembolism.

Main Outcomes and Measures

The study outcomes were VTE events and thrombosis of the free flap pedicle that required revision surgery. Univariable and multivariable regressions were used to test the association between the outcomes and clinical factors.

Results

A total of 1078 patients (mean [SD] age, 61.3 [12.6] years; 724 males [67.2%]; mean [SD] Caprini score, 6.4 [2.1]) were included. The VTE and pedicle thrombosis rates were 3.2% (35 patients) and 2.2% (24 patients), respectively. In a multivariable model controlled for Caprini score and chemoprophylaxis, VTE was associated with hypothermia of more than 30 minutes and less than 120 minutes (odds ratio [OR], 3.82; 95% CI, 0.99-14.07) and hypothermia of 120 minutes or longer (OR, 3.55; 95% CI, 1.05-11.95). Free flap pedicle thrombosis was not associated with hypothermia (OR, 0.61; 95% CI, 0.26-1.43).

Conclusions and Relevance

These findings suggest that preventing hypothermia during microsurgical FTT to the head and neck may decrease the postoperative rate of VTE. Future studies should explore the optimal intraoperative body temperature range that may prevent the development of VTE without compromising patient safety.

Hypothermia: Beyond the Narrative Review-The Point of View of Emergency Physicians and Medico-Legal Considerations

Hypothermia is a widespread condition all over the world, with a high risk of mortality in pre-hospital and in-hospital settings when it is not promptly and adequately treated. In this review, we aim to describe the main specificities of the diagnosis and treatment of hypothermia through consideration of the physiological changes that occur in hypothermic patients. Hypothermia can occur due to unfavorable environmental conditions as well as internal causes, such as pathological states that result in reduced heat production, increased heat loss or ineffectiveness of the thermal regulation system. The consequences of hypothermia affect several systems in the body-the cardiovascular system, the central and peripheral nervous systems, the respiratory system, the endocrine system and the gastrointestinal system-but also kidney function, electrolyte balance and coagulation. Once hypothermia is recognized, prompt treatment, focused on restoring body temperature and supporting vital functions, is fundamental in order to avert preventable death. It is important to also denote the fact that CPR has specificities related to the unique profile of hypothermic patients.