[The clinical research on the application of the heating humidifier with heating wire in pipeline in patients with tracheal intubation].

OBJECTIVE: To explore the effect of the heating humidifier with heating wire in pipeline in patients with tracheal intubation. METHODS: The present research was a prospective study. One hundred and twenty patients with tracheal intubation and mechanical ventilation who could not reach the indication of extubation after weaning were randomly divided into two groups. The patients in the control group (n = 60) were treated by routine airway management which was intermittent airway instillation with normal saline to humidify the airway, and those in the experimental group(n = 60) were used heating humidifier with heating wire in pipeline for airway humidification. The temperature and humidity of inhaled gas, sputum viscosity, the number of tracheal catheter with sputum scab after extubation, as well as number of reintubated cases due to tube plugging, and the oxygenation index at different time points after oxygen inhalation were recorded. RESULTS: The temperature and humidity of inhaled gas in experimental group were higher than those in control group [temperature (centigrade): 36.9 ± 0.2 vs. 22.3 ± 2.1, humidity (mg/L): 44.0 ± 2.0 vs. 27.0 ± 4.0, both P < 0.01]. The number of sputum viscosity II (humidification in well) in experimental group was significantly more than that in the control group (49 vs. 15), but the number of sputum viscosity III (humidification in sufficient) in experimental group was significantly less than that in the control group (8 vs. 43, both P < 0.05). The number of tracheal catheter with sputum scab after extubation (5 cases) and reintubation for tracheal catheter plugging (0 case) in experimental group were significantly less than those in the control group (24 cases, 6 cases, P < 0.01). The oxygenation index (mm Hg, 1 mm Hg = 0.133 kPa) in experimental group was increased after oxygen inhalation, and higher than that in control group at 96 hours and 120 hours (96 hours: 349.0 ± 21.3 vs. 290.0 ± 20.7, 120 hours: 354.0 ± 25.6 vs. 309.0 ± 22.6, both P < 0.01). CONCLUSIONS: The humidify of heating humidifier with heating wire in pipeline for airway humidification in patients with tracheal intubation was better than that of intermittent airway instillation with normal saline.

Reduced incidence and severity of acute mountain sickness in Qinghai-Tibet railroad construction workers after repeated 7-month exposures despite 5-month low altitude periods.

The construction of the Qinghai-Tibet railroad provided a unique opportunity to study the relation between intermittent altitude exposure and acute mountain sickness (AMS). For 5 yr, workers spent 7-month periods at altitude interspaced with 5-month periods at sea level; the incidence, severity, and risk factors of AMS were prospectively investigated. Six hundred lowlanders commuted for 5 yr between near sea level and approximately 4500 m and were compared to 600 other lowland workers, recruited each year upon their first ascent to high altitude as newcomers, and to 200 Tibetan workers native to approximately 4500 m. AMS was assessed with the Lake Louise Scoring System. The incidence and severity of AMS in commuters were lower upon each subsequent exposure, whereas they remained similar in newcomers each year. AMS susceptibility was thus lowered by repeated exposure to altitude. Repeated exposure increased resting Sao(2) and decreased resting heart rate. Tibetans had no AMS, higher Sao(2), and lower heart rates. In conclusion, repetitive 7-month exposures increasingly protect lowlanders against AMS, even when interspaced with 5-month periods spent at low altitude, but do not allow attaining the level of adaptation of altitude natives.