Continuous improvements in perinatal care have resultedin increased survival of premature infants.Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease(CLD...Continuous improvements in perinatal care have resultedin increased survival of premature infants.Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease(CLD) or bronchopulmonary dysplasia.Strategies to minimize the risk of lung injury have been developed and include improved antenatal management(education,regionalization,steroids,and antibiotics),exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support.The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patientventilator asynchrony that is associated with poor outcome.Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur.This has led to the development of new ventilation modes including neurally adjusted ventilatory assist(NAVA).This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity(Edi) and transmit it to trigger the ventilator in synchrony with the patient's own respiratory efforts.This permits the patient to control peak inspiratory pressure,mean airway pressure and tidal volume.Back up pressure control(PC) is provided when there is no Edi signal and no pneumatic trigger.Compared with standard conventional ventilation,NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants.NAVA is safe mode of ventilation.The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage,pneumothorax,or necrotizing enterocolitis when compared to conventional ventilation.Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive.Most previous studies and trials were not sufficiently large and did not include longterm patient oriented outcomes.Multicenter,randomized,outcome trials are needed to determine whether NAVA is effective in avoiding intubation,facilitating extubation,decreasing time of ventilation,reducing the incidence ofCLD,decreasing length of stay,and improving long-term outcomes such as the duration of ventilation,length of hospital stay,rate of pneumothorax,CLD and other major complications of prematurity.In order to prevent barotrauma,next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA.They should also include an upper limit to the inspiratory time as in conventional ventilation.The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants.Newly developed ventilators should also include leak compensation and high frequency ventilation.A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA.展开更多
Background The recruitment maneuver （RM） has been shown to improve oxygenation in some patients with acute respiratory distress syndrome. But there is a lack of standardization and lack of clinical studies to prove ...Background The recruitment maneuver （RM） has been shown to improve oxygenation in some patients with acute respiratory distress syndrome. But there is a lack of standardization and lack of clinical studies to prove the improvement on clinical outcome. We conducted this study to evaluate the clinical efficacy and safety of the RM in patients with acute respiratory distress syndrome （ARDS） using Iow tidal volume ventilation.Methods We randomly assigned 110 patients with ARDS from 14 Chinese intensive care units （ICUs） at the tertiary teaching hospitals. Patients with PaO2 ≤200 mmHg at FiO2 1.0 and PEEP ≥10 cmH2O were included in the study.Patients were randomized into two groups： control group and RM group. The tidal volume was set to 6-8 mi per kilogram of predicted body weight （PBW） in both groups. RM was performed by continuous positive airway pressure （CPAP） of 40 cmH2O maintained for 40 seconds. RMs was conducted every eight hours for the first five days, or stopped within five days if the patient reached the weaning standard.Results One hundred and ten patients had completed the requirements for the primary study goals, 55 from the RM group and 55 control patients. Baseline characteristics remained similar in the two groups. In the RM group the PaO2/FiO2 was significantly increased compared to baseline at 120 minutes after RM on day one and day two （P=0.007and P=0.001）. There were no significant differences between the RM and control group in hospital mortality （41.8% vs.56.4%, P=0.13）, 28-day mortality （29.1% vs. 43.6%, P=0.11） and ventilator-free days at day 28 （10.8±10.1 vs. 7.4±10.0,P=0.08）. ICU mortality （32.7% vs. 52.7%, P=0.03）, the rate of survival with unassisted breathing for at least 48 consecutive hours at day 28 （58.2% vs. 36.2%, P=0.02）, and nonpulmonary organ failure-free days at day 28 （17.4±11.1vs. 13.0±12.0, P=0.03） favored the RM group. There was no significant difference in mean blood pressure and heart rate before RM and at 30, 60, 120 minutes after RM. There was no incidence of barotraumas.Conclusions RM was safe and useful for improving oxygenation in patients with ARDS who were ventilated with a low tidal volume, with a beneficial impact on their clinical outcome.展开更多
OBJECTIVE: To investigate the relationship between sleep apnea hypopnea syndrome (SAHS) and some cardiovascular abnormalities in elderly snorers, as well as the effectiveness of nasal continuous positive airway pressu...OBJECTIVE: To investigate the relationship between sleep apnea hypopnea syndrome (SAHS) and some cardiovascular abnormalities in elderly snorers, as well as the effectiveness of nasal continuous positive airway pressure on those with SAHS. METHODS: With the use of polysomnography, 73 elderly snorers (older than 60 years) were examined and placed into either the SAHS group or the control group. Using ambulatory electrocardiogram (ECG) and blood pressure measurement, daily nocturnal rhythm of blood pressure, hypertension, heart rate variability, some arrhythmia and angina pectoris of coronary heart disease (CHD) were monitored and compared between the two groups before and after 5 - 7 days of treatment with nasal continuous positive airway pressure on the SAHS group. RESULTS: This study indicated a higher incidence (47.9%) of sleep apnea syndrome in elderly snorers and demonstrated that there was a significantly higher incidence of hypertension, disappearance in daily nocturnal rhythm of blood pressure, poor effectiveness of nitrate on angina pectoris of coronary heart disease, decreased heart rate variability during sleep, increased arrhythmia and lower pulse oxygen saturation (SpO(2)) levels in the SAHS group than in the control group. After nasal continuous positive airway pressure treatment during sleep, snoring control, significantly higher SpO(2) levels and lower index of apnea/hypopnea were achieved in the SAHS group; heart rate variability (HRV) and blood pressure day nocturnal rhythm were returned to normal levels. CONCLUSION: This research suggests that there is a close relationship between the development of sleep apnea syndrome and some cardiovascular diseases. Continuous positive nasal airway pressure is effective not only on SAHS but also on coexisting cardiovascular disorders.展开更多
OBJECTIVE: To investigate the impact of proportional assist ventilation (PAV) on tolerance and breathlessness in ventilated chronic obstructive pulmonary disease (COPD), and to describe the patient-ventilator interact...OBJECTIVE: To investigate the impact of proportional assist ventilation (PAV) on tolerance and breathlessness in ventilated chronic obstructive pulmonary disease (COPD), and to describe the patient-ventilator interaction, hemodynamic state, breathing pattern and work of breath during PAV and pressure support ventilation (PSV). METHODS: Ten intubated COPD patients on weaning from mechanical ventilation were studied. Elastance and resistance were measured by both the inspiratory-hold technique during a brief period of volume control ventilation and runaway technique during PAV. Each assistance level of PAV (80%, 60% and 40%) and PSV was selected randomly. Patients' response, hemodynamics, blood gas and lung mechanics were monitored. RESULTS: Tidal volume and respiratory rate didn't change in a consistent manner as the level of assist was decreased (P > 0.05). With the level of assist increasing, peak inspiratory pressure was increasing significantly (P展开更多
文摘Continuous improvements in perinatal care have resultedin increased survival of premature infants.Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease(CLD) or bronchopulmonary dysplasia.Strategies to minimize the risk of lung injury have been developed and include improved antenatal management(education,regionalization,steroids,and antibiotics),exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support.The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patientventilator asynchrony that is associated with poor outcome.Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur.This has led to the development of new ventilation modes including neurally adjusted ventilatory assist(NAVA).This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity(Edi) and transmit it to trigger the ventilator in synchrony with the patient's own respiratory efforts.This permits the patient to control peak inspiratory pressure,mean airway pressure and tidal volume.Back up pressure control(PC) is provided when there is no Edi signal and no pneumatic trigger.Compared with standard conventional ventilation,NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants.NAVA is safe mode of ventilation.The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage,pneumothorax,or necrotizing enterocolitis when compared to conventional ventilation.Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive.Most previous studies and trials were not sufficiently large and did not include longterm patient oriented outcomes.Multicenter,randomized,outcome trials are needed to determine whether NAVA is effective in avoiding intubation,facilitating extubation,decreasing time of ventilation,reducing the incidence ofCLD,decreasing length of stay,and improving long-term outcomes such as the duration of ventilation,length of hospital stay,rate of pneumothorax,CLD and other major complications of prematurity.In order to prevent barotrauma,next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA.They should also include an upper limit to the inspiratory time as in conventional ventilation.The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants.Newly developed ventilators should also include leak compensation and high frequency ventilation.A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA.
文摘Background The recruitment maneuver （RM） has been shown to improve oxygenation in some patients with acute respiratory distress syndrome. But there is a lack of standardization and lack of clinical studies to prove the improvement on clinical outcome. We conducted this study to evaluate the clinical efficacy and safety of the RM in patients with acute respiratory distress syndrome （ARDS） using Iow tidal volume ventilation.Methods We randomly assigned 110 patients with ARDS from 14 Chinese intensive care units （ICUs） at the tertiary teaching hospitals. Patients with PaO2 ≤200 mmHg at FiO2 1.0 and PEEP ≥10 cmH2O were included in the study.Patients were randomized into two groups： control group and RM group. The tidal volume was set to 6-8 mi per kilogram of predicted body weight （PBW） in both groups. RM was performed by continuous positive airway pressure （CPAP） of 40 cmH2O maintained for 40 seconds. RMs was conducted every eight hours for the first five days, or stopped within five days if the patient reached the weaning standard.Results One hundred and ten patients had completed the requirements for the primary study goals, 55 from the RM group and 55 control patients. Baseline characteristics remained similar in the two groups. In the RM group the PaO2/FiO2 was significantly increased compared to baseline at 120 minutes after RM on day one and day two （P=0.007and P=0.001）. There were no significant differences between the RM and control group in hospital mortality （41.8% vs.56.4%, P=0.13）, 28-day mortality （29.1% vs. 43.6%, P=0.11） and ventilator-free days at day 28 （10.8±10.1 vs. 7.4±10.0,P=0.08）. ICU mortality （32.7% vs. 52.7%, P=0.03）, the rate of survival with unassisted breathing for at least 48 consecutive hours at day 28 （58.2% vs. 36.2%, P=0.02）, and nonpulmonary organ failure-free days at day 28 （17.4±11.1vs. 13.0±12.0, P=0.03） favored the RM group. There was no significant difference in mean blood pressure and heart rate before RM and at 30, 60, 120 minutes after RM. There was no incidence of barotraumas.Conclusions RM was safe and useful for improving oxygenation in patients with ARDS who were ventilated with a low tidal volume, with a beneficial impact on their clinical outcome.
文摘OBJECTIVE: To investigate the relationship between sleep apnea hypopnea syndrome (SAHS) and some cardiovascular abnormalities in elderly snorers, as well as the effectiveness of nasal continuous positive airway pressure on those with SAHS. METHODS: With the use of polysomnography, 73 elderly snorers (older than 60 years) were examined and placed into either the SAHS group or the control group. Using ambulatory electrocardiogram (ECG) and blood pressure measurement, daily nocturnal rhythm of blood pressure, hypertension, heart rate variability, some arrhythmia and angina pectoris of coronary heart disease (CHD) were monitored and compared between the two groups before and after 5 - 7 days of treatment with nasal continuous positive airway pressure on the SAHS group. RESULTS: This study indicated a higher incidence (47.9%) of sleep apnea syndrome in elderly snorers and demonstrated that there was a significantly higher incidence of hypertension, disappearance in daily nocturnal rhythm of blood pressure, poor effectiveness of nitrate on angina pectoris of coronary heart disease, decreased heart rate variability during sleep, increased arrhythmia and lower pulse oxygen saturation (SpO(2)) levels in the SAHS group than in the control group. After nasal continuous positive airway pressure treatment during sleep, snoring control, significantly higher SpO(2) levels and lower index of apnea/hypopnea were achieved in the SAHS group; heart rate variability (HRV) and blood pressure day nocturnal rhythm were returned to normal levels. CONCLUSION: This research suggests that there is a close relationship between the development of sleep apnea syndrome and some cardiovascular diseases. Continuous positive nasal airway pressure is effective not only on SAHS but also on coexisting cardiovascular disorders.
文摘OBJECTIVE: To investigate the impact of proportional assist ventilation (PAV) on tolerance and breathlessness in ventilated chronic obstructive pulmonary disease (COPD), and to describe the patient-ventilator interaction, hemodynamic state, breathing pattern and work of breath during PAV and pressure support ventilation (PSV). METHODS: Ten intubated COPD patients on weaning from mechanical ventilation were studied. Elastance and resistance were measured by both the inspiratory-hold technique during a brief period of volume control ventilation and runaway technique during PAV. Each assistance level of PAV (80%, 60% and 40%) and PSV was selected randomly. Patients' response, hemodynamics, blood gas and lung mechanics were monitored. RESULTS: Tidal volume and respiratory rate didn't change in a consistent manner as the level of assist was decreased (P > 0.05). With the level of assist increasing, peak inspiratory pressure was increasing significantly (P
