[Quality of emergency ventilation. A prospective study of trauma patients]

The prehospitaly initiated endotracheal intubation and controlled ventilation, is especially in multi-system-trauma cases, recognized to be the "gold standard". Thus especially in view of the increasing demands being placed upon the quality of prehospital emergency treatment in general, the quality of such prehospital induced ventilation, is becoming of increasing importance. Thereby we must take into consideration the limited possabilities, which are afflicted with a high degree of uncertainess, which we have at our disposal to effectively evaluate the efficiency of emergency ventilation. The purpose of our study within a collective of severely traumatized patients, was to determine the quality of prehospitaly induced ventilation with regards to the adequacy of oxygenation and ventilation and as a result of our findings, to identify areas for procedural optimization.

The prospective study over an one year period involved n = 104 trauma cases (male: 79; female: 25/age: 39.8 +/- 20.8 years/ISS: 28.1 +/- 15.3) whose prehospital emergency treatment required and included endotracheal intubation and controlled ventilation. All patients were subject to a prehospital pulse oxymetric monitoring, whereas none were subject to an objectivating apparatus monitoring of ventilation: 94.2% of the patients were upon admission adequately oxygenated (paO2 > 80 mmHg); only one patient was hypoxemic (paO2 < 60 mmHg). 46.2% were adequately ventilated (paCO2: 35-45 mmHg), 43.2% however were hyperventilated (paCO2 < 35 mmHg), and 10.6% hypoventilated (paCO2 > 45 mmHg). A statistical significant relation between hyper-/hypoventilation and the degree of severity of trauma as well as to the individual injury pattern was not evident. However with reference to age: The group of > 60 years of age were significantly more frequently hyperventilated (paCO2 < 30 mmHg: 31.2%; p < 0.05). A noteworthy accumulation of hypoventilation was experienced amongst the group of patients, who during the prehospital treatment phase were hemodynamic instable (shock index > 1).

In summary it is evident, that as a rule, even very severe traumatized patients can prehospitaly be adequately oxygenated and that such oxygenation can with the assistance of pulse oxymetric monitoring be effectively controlled. Remaining problem is the emergency physicians ability to evaluate and control ventilation. The prehospital determination of minute volume (MV) in accordance with the presently valid recommendation: MV = 100-150 ml/kg body weight, in the majority of trauma cases results in inadequate ventilation. The introduction of an objectifying monitoring method is therefore urgently required.