[Noninvasive ventilation in out-of-hospital emergency medicine]. / Nichtinvasive Beatmung in der präklinischen Notfallmedizin.

BACKGROUND: Noninvasive ventilation is mechanical respiratory support without the use of an artificial airway. There is no need for a tube or analgosedation. There are some advantages in comparison to invasive forms of ventilation. OBJECTIVES: Many patients are treated out of hospital because of acute dyspnea. For these patients, noninvasive ventilation is a therapeutic option. Some prehospital intubations can be avoided, if some kind of noninvasive ventilation is available. CONCLUSIONS: In order to offer noninvasive ventilation to all patients, it also has to be available in the prehospital setting. Modern mechanical ventilators, which are used in emergency medical service, are eligible to provide noninvasive ventilation.

[Preclinical blood gas analysis. 2. Experience with three blood gas analyzers in emergency care]. / Die präklinische Blutgasanalyse. Teil 2: Erfahrungen mit 3 Blutgasanalysegeräten im Notarztdienst.

UNLABELLED: Within the last few years the use of Point-of-Care Analyzers increased. These testing is primarily performed in the emergency room, intensive care units, and in the operating room using small portable analyzers. The fact of being transportable and working with rechargeable or changable batteries and disposable cartridges caused us to use blood gas analysis in the prehospital setting. METHODS: We tested three available blood gas analyzers: AVL OPTI 1, IRMA Blood Analyzer and the i-Stat Portlab System. All analyzers work with single-use cartridges and the calibration procedure is automatic. The AVL OPTI 1 uses a calibration gas and sucks in the blood by itself. The IRMA and the i-Stat system use a containing calibration gel, which must be removed from the sensory by injecting the blood sample. In all analyzers the results appear within 2-4 min on the screen. The OPTI 1 and the IRMA are able to print out the results automatically, the i-Stat uses an additional printer connected over an infrared adapter. RESULTS: During the observation period of 2 years more than 320 prehospital blood gas analyses were performed (200 with the OPTI 1.70 with IRMA and 50 with the i-Stat). All devices served their purpose. The main problems appeared with the application of the blood samples at the IRMA and the i-Stat. Because of this intricate procedures 21.4% and 20% of all tries failed. The time spent on the measurement was 2 to 5 minutes. CONCLUSIONS: All tested devices worked satisfactorily. Relating to the safety, the performance and the use the AVL OPTI 1 has to become the best notes. But this system is much more bigger and heavier than the others, especially the i-Stat Blood analyzer.

[Preclinical blood gas analysis. 1. The value of preclinical blood gas analysis]. / Die präklinische Blutgasanalyse Teil 1: Der Stellenwert der präklinischen Blutgasanalyse.

UNLABELLED: Prehospital blood gas analysis is a new method in out-of-hospital emergency care. In a prospective pilot study we evaluated the feasibility of prehospital compensation of severe acidosis relying on different monitoring systems to evaluate patients oxygen, carbon dioxide or acid-base status, respectively. METHODS: With the help of arterial blood gas checks taken at the site of the emergency, the acid base status of patients undergoing out of hospital cardiopulmonary resuscitation was analysed. The values derived from the first arterial puncture were used to determine the presence and the type of acidosis. The data of the arterial blood gas checks were set into relation with the time elapsed since the beginning of resuscitation and they were compared with end-tidal CO2. RESULTS: During the observation period 26 blood gas analyses from patients who had out-of-hospital resuscitation because of cardiac arrest were done. Twenty three patients had severe acidosis (pH range < 6.9 to 7.31), one had alkalosis (pH 7.51). Only two had an arterial pH within normal range. The pCO2 was variable (range: 24 to 97 mm Hg). The correlation of pH with time from the beginning of resuscitation to arterial puncture was poor (r = 0.407, p < 0.05). There was no correlation between pH and BE (r = 0.267) or pH and pCO2, (r = 0.016) respectively. Prehospital capnometry had a poor correlation with arterial pCO2 in most emergency patients. Only patients with respiratory disturbances of extrapulmonary origin showed a good correlation between end-tidal CO2 and the arterial pCO2. In severely ill patients the arterio-alveolar CO2-difference was unexpectedly high (> 15 mm Hg). In four patients resuscitation was not successful until compensation of an unexpectedly severe acidosis based upon the findings from blood-gas analysis had been performed. CONCLUSIONS: Arterial blood gas analysis proved to be helpful in the optimal management of out of hospital cardiac arrest. The incidence of severe acidosis in patients undergoing cardiopulmonary resuscitation was 80%. The probability of developing acidosis was found to increase slightly depending on the time elapsed since the beginning of CPR. The application of a calculated buffering of acidosis with sodium bicarbonate showed a good outcome in selected cases. In emergency patients alternative methods fail to detect severe disturbances of the patients oxygen and/or carbon dioxide status and the acid-base balance. Management of prehospital cardiac arrest could be optimized by the routine use of blood gas analysis.