Failure factors of non-invasive mechanical ventilation in the treatment of community acquired pneumonia / 中华急诊医学杂志

Objective To investigate the failure factors of no-invasive ventilation (NIV) as an initial ventilation mode for the treatment of community acquired pneumonia (CAP).Methods Totally 237 cases of CAP patients with NIV as initial ventilation were analyzed retrospectively in the emergency department of Beijing Chaoyang Hospital.According to the failure of NIV,patients were divided into two groups.General clinical data and acute physiological and chronic health score (APACHE Ⅱ),physiological parameters,pulmonary infection and the prognosis of the patients were recorded,and were compared between the two groups.The risk factors of NIV 1 hour and 3 hours later were analyzed by multivariate logistic regression.Results Compared with the NIV failure group,the mortality of the patients in the NIV successful group (17.6 and 35.6,P＜ 0.01) was significantly lower.The risk factors for the NIV1 hour failure of the patients included the APACHE Ⅱ score(OR=l.352,95％CI:l.132-3.015,P=0.035),the hemodynamic support (OR=9.826,95％CI:2.525-86.377,P=0.002) and the severity of the pulmonary infection,and the risk factors for the physiological index of the failure of NIV3 hours included hemodynamic support(OR=6.365,95％CI:2.552-28.316,P=0.004),respiratory frequency and pH value.Conclusions Hemodynamic support is the most important risk factor for the failure of NIV in CAP patients.During the NIV treatment,the patients' respiratory frequency,oH and blood pressure should be closely monitored to ensure the success and safety of the treatment.

Research on the respiratory frequency changes of 4DCT reconstructed image / 中华放射肿瘤学杂志

Objective To study the impact of respiratory frequency and amplitude of patients with the thoracic or abdomen tumor on 4DCT' s reconstructed image.Methods 75 thoracic or abdomen tumor patients who performed a scanning with belly belt-type respiratory gating on 4DCT between November 2012 to March 2013 in our hospital were retrieved.Reviewed their respiratory frequency,amplitude and fault distance of 4DCT' s reconstructed image and analyzed the correlation fault distance of the reconstructed image.The correlation analysis was used by bivariate Spearman method.Results Among these reconstructed images,fault distance more than 6 mm could be seen in 11 cases,fault distance ranging from 3 mm to 6 mm could be found in 46 cases,and distance less than 3 mm could be detected in 18 case.Respiratory frequency correlated significantly with the amplitude (rs =0.369,P =0.000);the respiratory rate had a tight association with the fault distance of the reconstructed image (r,=0.273,P=0.018);and respiratory amplitude was associated obviously with the fault distance of the reconstructed image (r,=0.696,P=0.000).Conclusions Both 4DCT reconstructed image and respiratory amplitude are significantly correlated to the continuity of the respiratory frequency.The smaller the respiratory frequence and amplitude change are,the better continuity will be.

Study on the limitation for detecting anaerobic threshold by respiratory frequency. Under the condition of exercise-entrained breathing is minimized / 体力科学

Under the condition that entrainment between breathing rate and exercise rhythm was minimized. The limitation for deciding anaerobic threshold (AT) by respiratory frequency (f) was studied. Ten healthy subjects (5 male and 5 female) have volunteered to take part in two incremental cycle exercises (male : 30 watt/2 min, 50 rpm ; female : 20 watt/2 min, 50 rpm) . The subjects were either sedentary or active and performed tests under two different condi-tions. The different conditions are explained below.<BR>1) Condition M : Use a metronome to maintain pedalling frequency so entrainment would easily occur.<BR>2) Condition S : Use a tachometer to maintain pedalling frequency so entrainment would not easily occur.<BR>Oxygen uptake (VO<SUB>2</SUB>) at AT were determined by two different methods. The first method was to detect the point of non-linear increase in minute ventilation (VE) and carbon dioxide output (VCO<SUB>2</SUB>) and then to increase detection in the ventilatory equivalent for O<SUB>2</SUB> (VE/VO<SUB>2</SUB>) without increasing the ventilatory equivalent for CO<SUB>2</SUB> (VE/VCO<SUB>2</SUB>) (AT-V) . The second method was to detect inflection in f by multisegment linear regression (AT-CF) . There were no significant differences between AT-V (condition M : 26.0±6.2, condition S : 26.4±6.0 m<I>l</I>/kg/ min) and AT-CF (condition M : 31.6±10.2, condition S : 24.7±10.0 m<I>l</I>/kg/min) . A significant positive correlation between AT-V and AT-CF was observed in condition S (r=0.850, p< 0.05), but not in condition M (r=0.563, p>0.05) . The error between AT-V and AT-CF had individual variations. An error within±5% was observed in only 4 out of 10 subjects. These results suggested that even though the ability to detect AT using f is superior in condition S, f is an inadequate indicator for the AT, though the exercise entrained breathing is minimized.