[A humidification system for CPAP therapy in obstructive sleep apnea--evaluation of the effectiveness in changing climatic environmental conditions]. / Ein Befeuchtersystem für die CPAP-Therapie bei obstruktiver Schlafapnoe--Evaluierung der Leistungsfähigkeit bei wechselnden klimatischen Umgebungsbedingungen.

OBJECTIVE: Upper airway dryness is a frequent side-effect of nasal continuous positive airway pressure (nCPAP) therapy in obstructive sleep apnoea syndrome (OSA). In this situation, heated humidification is often used. Therefore, the present study aimed to investigate the humidification performance--defined as the maximum achievable humidity in the tube system of the CPAP device--of a heated humidifier (HH) offered as CPAP accessories, as a function of ambient air conditions (humidity and temperature). PATIENTS AND METHODS: In 30 patients (22 male, 8 female, mean age 56.4 +/- 11.7 years) with OSA undergoing CPAP treatment, temperature (T) and relative humidity (RH) in the CPAP tube system were measured, with and without the HH Somnowave, until a steady state was achieved. At the same time, ambient T and RH in the examination room were recorded. T and RH were used to calculate the absolute humidity (AH). RESULTS: The conditions of the examination room during the examination nights were as follows: T = 21.9 +/- 2.8 degrees C (15.2-26.9), RH 46.5 +/- 11.9% (21.7-69.1) and AH 9.2 +/- 3.2 g/m3 (3.7-16.7). The steady state AH without HH was 9.6 +/- 3.0 g/m3 (4.1-15.4), that with HH (humidification performance) 23.2 +/- 2.8 g/m3 (19.1-29.9) (p < 0.001). CONCLUSION: Under the ambient conditions of humidity and temperature, commonly found in European bedrooms, the HH demonstrate a high humidification performance. Thus, it would appear that the HH is suitable for the treatment of dry upper airways under nCPAP therapy.

System performance of multislice spiral computed tomography.

Multislice spiral CT offers many new possibilities for clinical CT imaging. Drastically increased scan speeds and z-resolution, respectively, as well as applications such as cardiac CT that have become feasible for the first time in routine clinical use. The concept of multiple simultaneously acquired slices yields image quality equivalent or better than single-slice spiral CT. Especially, there is no dependence on spiral pitch, neither with regard to noise nor to slice sensitivity. The reconstructed slice width can be chosen freely and retrospectively, which offers additional flexibility when evaluating optimal protocols for various kinds of examinations. Three-dimensional isotropic resolution can be achieved routinely with examinations fast enough to scan in a single breath hold (Fig. 9). Without any drawbacks in image quality, MSCT in combination with online tube current modulation can reduce patient dose. In some body regions, dose is decreased to 50% compared to a scan with constant tube current. One of the most promising new applications is the dedicated ECG-gated cardiac interpolation 180 degrees MCI, which allows four-dimensional (4-D) imaging of the heart. The complete beating heart can be reconstructed in well-defined phases of the heart cycle, thereby adding high temporal resolution to isotropic 3-D spatial resolution (for more examples refer to http://www.imp.uni-erlangen.de/e/research/cardio/).