Therapeutic temperature modulation is associated with pulmonary complications in patients with severe traumatic brain injury

Abstract

Aim: To examine complications associated with the use of therapeutic temperature modulation (mild hypothermia and normothermia) in patients with severe traumatic brain injury (TBI).

Methods: One hundred and fourteen charts were reviewed. Inclusion criteria were: severe TBI with Glasgow Coma Scale (GCS) < 9, intensive care unit (ICU) stay > 24 h and non-penetrating TBI. Patients were divided into two cohorts: the treatment group received therapeutic temperature modulation (TTM) with continuous surface cooling and indwelling bladder temperature probes. The control group received standard treatment with intermittent acetaminophen for fever. Information regarding complications during the time in the ICU was collected as follows: Pneumonia was identified using a combination of clinical and laboratory data. Pulmonary embolism, pneumothorax and deep venous thrombosis were identified based on imaging results. Cardiac arrhythmias and renal failure were extracted from the clinical documentation. acute respiratory distress syndrome and acute lung injury were determined based on chest imaging and arterial blood gas results. A logistic regression was conducted to predict hospital mortality and a multiple regression was used to assess number and type of clinical complications.

Results: One hundred and fourteen patients were included in the analysis (mean age = 41.4, SD = 19.1, 93 males), admitted to the Jackson Memorial Hospital Neuroscience ICU and Ryder Trauma Center (mean GCS = 4.67, range 3-9), were identified and included in the analysis. Method of injury included motor vehicle accident (n = 29), motor cycle crash (n = 220), blunt head trauma (n = 212), fall (n = 229), pedestrian hit by car (n = 216), and gunshot wound to the head (n = 27). Ethnicity was primarily Caucasian (n = 260), as well as Hispanic (n = 227) and African American (n = 223); four patients had unknown ethnicity. Patients received either TTM (43) or standard therapy (71). Within the TTM group eight patients were treated with normothermia after TBI and 35 patients were treated with hypothermia. A logistic regression predicting in hospital mortality with age, GCS, and TM demonstrated that GCS (Beta = 0.572, P < 0.01) and age (Beta = -0.029) but not temperature modulation (Beta = 0.797, ns) were significant predictors of in-hospital mortality [χ(2) (3) = 22.27, P < 0.01] A multiple regression predicting number of complications demonstrated that receiving TTM was the main contributor and was associated with a higher number of pulmonary complications (t = -3.425, P = 0.001).

Conclusion: Exposure to TTM is associated with an increase in pulmonary complications. These findings support more attention to these complications in studies of TTM in TBI patients.

Keywords: Fever; Head injury; Hypothermia; Pneumonia; Traumatic brain injury.

Figure 1

Complications by group. ARDS: Acute respiratory distress syndrome; ALI: Acute lung injury; PE: Pulmonary embolism; DVT: Deep venous thrombosis. ^aP < 0.05.