Hypothermie bei Traumapatienten

Development and Characterization of Hybrid, Temperature Sensing and Heating Yarns with Color Change

A person's body temperature is an important indicator of their health status. A deviation of that temperature by just 2 °C already has or can lead to serious consequences, such as fever or hypothermia. Hence, the development of a temperature-sensing and heatable yarn is an important step toward enabling and improving the monitoring and regulation of a person's body temperature. This technology offers benefits to several industries, such as health care and sports. This paper focuses on the characterization and development of a hybrid yarn, which can measure and visualize temperature changes through a thermoresistive and thermochromic effect. Moreover, the yarn is able to serve as a flexible heating element by connecting to a power source. The structure of the yarn is designed in three layers. Each layer and component ensures the functionality and flexibility of the yarn and additional compatibility with further processing steps. A flexible stainless steel core was used as the heat-sensitive and heat-conducting material. The layer of polyester wrapped around the stainless steel yarn improves the wearing comfort and serves as substrate material for the thermochromic coating. The resulting hybrid yarn has a reproducible sensory function and changes its resistance by 0.15 Ω between 20 and 60 °C for a length of 30 cm. In addition, the yarn has a uniform and reproducible heating power, so that temperature steps can be achieved at a defined length by selecting certain voltages. The thermochromic color change is clearly visible between 28 and 29 °C. Due to its textile structure, the hybrid sensory and actuating yarn can easily be incorporated into a woven fabric or into a textile by means of joining technology sewing.

An uncommon case of severe accidental hypothermia in an urban setting

Accidental hypothermia is an uncommon presentation in urban settings. Here we present a patient admitted with a core temperature of 26.6°C (80°F) and a serum potassium of 8.5 mmol/l who subsequently went into cardiac arrest. After > 90 min of active cardiopulmonary resuscitation and peak serum potassium of >12 mmol/l, the patient had a spontaneous return of circulation. The patient's hospital course was complicated by compartment syndrome of his forearm; however, he was discharged home without any lasting neurological damage.

Effects of accidental hypothermia on posttraumatic complications and outcome in multiple trauma patients

INTRODUCTION

Accidental hypothermia seems to predispose multiple trauma patients to the development of posttraumatic complications, such as Systemic Inflammatory Response Syndrome (SIRS), sepsis, Multiple Organ Dysfunction Syndrome (MODS), and increased mortality. However, the role of accidental hypothermia as an independent prognostic factor is controversially discussed. The aim of the present study was to evaluate the incidence of accidental hypothermia in multiple trauma patients and its effects on the development of posttraumatic complications and mortality.

PATIENTS AND METHODS

Inclusion criteria for patients in this retrospective study (2005-2009) were an Injury Severity Score (ISS) ≥16, age ≥16 years, admission to our Level I trauma centre within 6h after the accident. Accidental hypothermia was defined as body temperature less than 35°C measured within 2 h after admission, but always before first surgical procedure in the operation theatre. The association between accidental hypothermia and the development of posttraumatic complications as well as mortality was investigated. Statistical analysis was performed with χ(2)-test, Student's t-test, ANOVA and logistic regression. Statistical significance was considered at p<0.05.

RESULTS

310 multiple trauma patients were enrolled in the present study. Patients' mean age was 41.9 (SD 17.5) years, the mean injury severity score was 29.7 (SD 10.2). The overall incidence of accidental hypothermia was 36.8%. The overall incidence of posttraumatic complications was 77.4% (SIRS), 42.9% (sepsis) and 7.4% (MODS), respectively. No association was shown between accidental hypothermia and the development of posttraumatic complications. Overall, 8.7% died during the posttraumatic course. Despite an increased mortality rate in hypothermic patients, hypothermia failed to be an independent risk factor for mortality in multivariate analysis.

CONCLUSIONS

Accidental hypothermia is very common in multiply injured patients. However, it could be assumed that the increase of mortality in hypothermic patients is primarily caused by the injury severity and does not reflect an independent adverse effect of hypothermia. Furthermore, hypothermia was not shown to be an independent risk factor for posttraumatic complications.

[Interruption of the diagnostic algorithm and immediate surgical intervention after major trauma--incidence and clinical relevance. Analysis of the Trauma Register of the German Society for Trauma Surgery]

BACKGROUND

Life-threatening situations after multiple trauma which require interruption of the diagnostic algorithm and immediate surgical treatment after admission are a challenge for the multidisciplinary trauma team. The purpose of this study was to evaluate the incidence, causes, implications and relevance of life-threatening situations for major trauma patients after admission to trauma centers.

PATIENT AND METHODS

Data of 12,971 patients listed in the German Trauma Register of the German Society for Trauma Surgery (DGU, 2002-2007) were analyzed. Patients with an injury severity score (ISS) > 16, no isolated head injury and primary admission to a trauma center were included. Data were allocated according to patients where the diagnostic algorithm in the resuscitation room was interrupted to perform emergency surgery (group Notop, n = 713, 5.5%) and patients who received early surgical care after completed diagnostics (group Frühop, n = 5,515, 42.5%). Comparative parameters were the pattern and severity of injury, physiological state and clinical outcome.

RESULTS

Patients receiving emergency surgery showed an average ISS score of 39 ± 15 points, whereas patients receiving early surgery showed an average ISS of 31 ± 12 points. On admission patients in the emergency surgery group (44%) suffered from hemodynamic shock considerably more often than patients in the early surgery care group (15%, p < 0.001). This was indicated by the significant differences in systolic blood pressure on admission, amount of preclinical substituted volume, base excess on admission and substituted erythrocyte concentrates in early clinical course. Mortality was 46% in the emergency surgery group and 13% in the early surgical care group (p < 0.001). Severe injuries (AIS ≥ 4) of the thorax, abdomen and extremities (including the pelvis) were encountered considerably more often in the emergency surgery group. There was no statistical difference in occurrence of severe head injuries between the groups. Emergency surgery consisted of 50.5% laparatomy, 19.8% craniotomy, 10.0% thoracotomy and 9.3% pelvic surgery.

CONCLUSION

Life-threatening situations after major trauma which require immediate surgical intervention in the resuscitation room rarely occur in Germany. Nevertheless, they are associated with a high mortality and prolonged and complex clinical course if primarily survived. Indications and decision-making processes of these challenging situations have to be practiced with standardized algorithms and should be considered for the future education of orthopedic surgeons in Germany.

Early modifiable factors associated with fatal outcome in patients with severe traumatic brain injury: a case control study

OBJECTIVE

Survival of patients with severe traumatic brain injury may be improved by minimizing secondary brain injury. We aimed to identify potentially modifiable contributors to secondary brain injury that may persist and adversely affect patient outcome.

DESIGN

Retrospective case control study. Nonsurviving patients with traumatic brain injury were selected and matched 1:1 for age, Glasgow Coma Scale score, Abbreviated Injury Scale: Head (AISHEAD), Revised Trauma Score, and Injury Severity Score with survivors. Potentially modifiable contributors to secondary brain injury were examined and compared in both groups.

SETTING

A level I trauma center in Melbourne, Australia.

PATIENTS

Patients with traumatic brain injury caused by blunt trauma with an AISHEAD >or=4 were identified from a prospective intensive care database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between January 1, 1999, and July 30, 2000, 74 patients, including 37 nonsurvivors, were identified. By design, the groups were well matched for injury severity and baseline conditions. In nonsurvivors, mean arterial pressure was similar to that of survivors at hospital arrival but was lower at 4 hrs after arrival (71 +/- 16 vs. 80 +/- 15 mm Hg, p = .016). A mean arterial pressure <or=65 mm Hg during this 4-hr period was associated with a four-fold increase in the odds of nonsurvival (95% confidence interval, 1.25-12.8). Intracranial pressure monitoring and intensive care unit admission tended to be initiated later in nonsurvivors, potentially delaying recognition and management of inadequate cerebral perfusion pressure. In nonsurvivors, hypothermia did not normalize during the first 24 hrs after injury.

CONCLUSIONS

In patients with severe traumatic brain injury, lower blood pressure in the first 4 hrs after admission was associated with mortality and may have increased the rate of secondary brain injury. Outcomes of patients with severe traumatic brain injury may potentially be improved by early targeting of the higher mean arterial pressure observed in survivors (mean arterial pressure 80 mm Hg), which may facilitate improved cerebral perfusion. Slower initiation of intracranial pressure monitoring and of intensive care unit admission may also have adversely affected outcomes, whereas persistent hypothermia was associated with nonsurvival.

Pathophysiologic changes and effects of hypothermia on outcome in elective surgery and trauma patients

Generally, hypothermia is defined as a core temperature <35 degrees C. In elective surgery, induced hypothermia has beneficial effects. It is recommended to diminish complications attributable to ischemia reperfusion injury. Experimental studies have shown that hypothermia during hemorrhagic shock has beneficial effects on outcome. In contrast, clinical experience with hypothermia in trauma patients has shown accidental hypothermia to be a cause of posttraumatic complications. The different etiology of hypothermia might be one reason for this disparity because induced therapeutic hypothermia, with induction of poikilothermia and shivering prevention, is quite different from accidental hypothermia, which results in physiological stress. Other studies have shown evidence that this contradictory effect is related to the plasma concentration of high-energy phosphates (e.g., adenosine triphosphate [ATP]). Induced hypothermia preserves ATP storage, whereas accidental hypothermia causes depletion. Hypothermia also has an impact on the immunologic response after trauma and elective surgery by decreasing the inflammatory response. This might have a beneficial effect on outcome. Nevertheless, posttraumatic infectious complications may be higher because of an immunosuppressive profile. Further studies are needed to investigate the impact of induced hypothermia on outcome in trauma patients.

Anaesthetic care of the injured child

Paediatric trauma care is complex and diverse. Paediatric trauma care systems have proven difficult to evaluate, and further work is required to assess their usefulness. Furthermore, head injury is a major component of paediatric trauma and its management is becoming increasingly multifactorial. As its pathophysiology continues to unfold there is much opportunity for ongoing research in this area.