J. Rathgeber

Severe accidental hypothermia : rewarming strategy using a veno-venous bypass system and a convective air warmer

Objective: To study a rewarming strategy for patients with severe accidental hypothermia using a simple veno-venous bypass in combination with a convective air warmer. Setting: Eighteen beds in a university hospital intensive care unit. Patients: Four adults admitted with a core temperature less than 30 °C. Hypothermia was caused by alcoholic intoxication in three patients and by drug overdose in one patient. Measurements and main results: All patients were rewarmed by a veno-venous bypass and in three cases a convective air warmer was also used. At a bypass flow rate of 100–300 ml/min the mean increase in core temperature was 1.15 °C/h (Range: 1.1–1.2 °C/h). One patient died 2 days after rewarming as a consequence of a reactivated pancreatitis. The other three patients survived without neurological sequelae. Conclusion: This rewarming technique seems safe and effective and allowed the controlled rewarming of our patients who suffered from severe accidental hypothermia

Airway humidification in mechanically ventilated neonates and infants: A comparative study of a heat and moisture exchanger vs. a heated humidifier using a new fast-response capacitive humidity sensor

OBJECTIVE To study the efficiency of a heated humidifier and a heat and moisture exchanger in mechanically ventilated neonates and infants. DESIGN Prospective, controlled, clinical study. SETTING University pediatric intensive care unit. PATIENTS Forty neonates and infants who needed mechanical ventilation were enrolled in the study. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A heat and moisture exchanger and active airway humidification were alternately used in the same patients to exclude interindividual differences in airway humidification. Airway humidity was measured by a new fast-response capacitive humidity sensor which measures airway humidity with an acquisition rate of 20 Hz throughout the respiratory cycle. The humidity sensor was placed at the endotracheal tube adapter. Measurements were done at the beginning and at the end of three consecutive sessions of passive, active, and again passive airway humidification, each session lasting 6 hrs. There was no significant difference between mean inspiratory airway humidity with the heated humidifier (33.8 +/- 2.9 mg/L) and with the heat and moisture exchanger (34.0 +/- 2.6 mg/L). Moreover, the mode of airway humidification did not significantly influence body temperature or PCO2. No serious side effects such as endotracheal tube occlusion were observed. CONCLUSIONS Passive airway humidification by a heat and moisture exchanger is effective in mechanically ventilated neonates and infants over a 6-hr period. However, the performance and safety of a heat and moisture exchanger in prolonged mechanical ventilation remain to be proven.

Determination of airway humidification in high-frequency oscillatory ventilation using an artificial neonatal lung model : Comparison of a heated humidifier and a heat and moisture exchanger

Objective: Thus far only few data are available on airway humidification during high-frequency oscillatory ventilation (HFOV). Therefore, we studied the performance and efficiency of a heated humidifier (HH) and a heat and moisture exchanger (HME) in HFOV using an artificial lung model. Methods: Experiments were performed with a pediatric high-frequency oscillatory ventilator. The artificial lung contained a sponge saturated with water to simulate evaporation and was placed in an incubator heated to 37 °C to prevent condensation. The airway humidity was measured using a capacitive humidity sensor. The water loss of the lung model was determined gravimetrically. Results: The water loss of the lung model varied between 2.14 and 3.1 g/h during active humidification; it was 2.85 g/h with passive humidification and 7.56 g/h without humidification. The humidity at the tube connector varied between 34.2 and 42.5 mg/l, depending on the temperature of the HH and the ventilator setting during active humidification, and between 37 and 39.9 mg/l with passive humidification. Conclusion: In general, HH and HME are suitable devices for airway humidification in HFOV. The performance of the ventilator was not significantly influenced by the mode of humidification. However, the adequacy of humidification and safety of the HME remains to be demonstrated in clinical practice.

Oxygen cost of breathing for assisted spontaneous breathing modes: Investigation into three states of pulmonary function

AbstractObjectiveWe investigated the effects of continuous positive airway pressure (CPAP) and pressure support ventilation (PSV) on the oxygen cost of breathing (

Infection prevention during anaesthesia ventilation by the use of breathing system filters (BSF): Joint recommendation by German Society of Hospital Hygiene (DGKH) and German Society for Anaesthesiology and Intensive Care (DGAI).

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Causes of failure and dangers in the use of motor driven infusion pumps. Accidental closure of the infusion system

O2resp) for different states of pulmonary function. Additionally

[Is reduction of intraoperative heat loss and management of hypothermic patients with anesthetic gas climate control advisable? Heat and humidity exchangers vs. active humidifiers ina functional lung model].

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