[Accidental hypothermia in trauma patients. Is it relevant to preclinical emergency treatment?].

Trauma patients are at great risk of accidental hypothermia (body temperature [BT] < 36 degrees C). Hypothermia influences the functioning of all organ systems and can lead to pathological changes, which in turn additionally complicate the trauma. Furthermore, hypothermia can, e.g., by influencing blood coagulation (reduction of thrombocyte aggregation, increased fibrinolysis) have a markedly unfavourable impact upon the in-hospital surgical treatment of the trauma patient. In a prospective study involving 302 trauma patients treated during primary helicopter rescue missions over a 1-year period, we studied the following factors: (1) incidence and degree of severity of hypothermia; (2) seasonal influence; (3) possibility of individual risk groups within the study group; (4) changes in BT during the prehospital treatment phase; and (5) their consequences for emergency treatment. METHOD. BT was taken upon commencement of emergency treatment and upon release of the patient to the receiving hospital. To avoid possible damage to the patient's tympanic membrane by the thermometer probe, we excluded all patients under 16 years of age and those with an indication of an ear or temporal-bone injury. In all cases standardized patient positioning was applied. The statistical evaluation was performed utilizing descriptive presentations and the Mann-Whitney U test and chi-square test. RESULTS. During study period, a total of 302 trauma patients were treated. On 228 of these, prehospital temperature monitoring was performed (151 males and 77 females, average age 41.8 years). Because of the established criteria for exceptions and equipment malfunction, no monitoring was performed on 74 patients. Traffic accidents (69%) were the major cause of injury (Table 2), predominantly the group with NACA III (32%), followed by NACA IV (22%) and NACA V (18%) (Table 3); 27% had multi-system trauma. BT monitoring disclosed that 49.6% or almost every second trauma patient, had hypothermia. The proportion of hypothermia II degrees (BT 34 degrees-30 degrees C) versus hypothermia III degrees (BT < 30 degrees C) was 6.6% to 0.5%. Our statistical evaluation did not disclose any significant connection between season of the year and frequency of accidental hypothermia. Special risk factors in regard to frequency and degree of severity turned out to be "entrapment" (98.1% of patients with an entrapment trauma [ET] versus 34.5% without such; P < 0.001) and age (56.8% of patients > 65 years of age without ET and 100% with ET; P < 0.001) (Figs. 2, 3). No significant changes in BT were noted during the prehospital treatment phase. Clinical symptoms pointing to hypothermia or other indicators, i.e., shivering, were only noted in 4.4% of the cases where the patients BT was below normal. CONCLUSION. Based upon our findings, accidental hypothermia poses a relevant problem in the prehospital treatment of trauma patients. It is not limited to a special season of the year. The variability or total absence of definite diagnostic symptoms underlines the necessity for prehospital BT monitoring, whereby tympanic-membrane thermometry has proven to be a worthwhile method.