Oronasal versus Nasal Masks for Non-Invasive Ventilation in COPD: A Randomized Crossover Trial.

PURPOSE: The impact of oronasal and nasal masks on the quality of nocturnal non-invasive ventilation (NIV) needs to be clarified. This trial was designed to compare the impact of oronasal and nasal masks on the objective quality and subjective acceptance of nocturnal NIV in COPD-patients. PATIENTS AND METHODS: In a randomized crossover trial, 30 COPD-patients with well-established high-intensity NIV (mean inspiratory/expiratory positive airway pressure 26±3/5±1 cmH2O, mean respiratory back-up rate 17±1/min) were ventilated for two consecutive nights on oronasal and nasal masks, respectively. RESULTS: Full polysomnography, nocturnal blood gas measurements, and subjective assessments were performed. There was a tendency towards improved sleep efficiency (primary outcome) when an oronasal mask was worn (+9.9%; 95% CI:-0.2%-20.0%; P=0.054). Sleep stages 3/4 were favored by the oronasal mask (+12.7%; 95% CI: 6.0%-19.3%; P=<0.001). Subjective assessments were comparable with the exception of items related to leakage (P<0.05 in favor of nasal masks). The mean transcutaneous PCO2 value for oronasal masks (47.7±7.4 mmHg) was comparable to that of nasal masks (48.9±6.6 mmHg) (P=0.11). There was considerable diversity amongst individual patients in terms of sleep quality and gas exchange following mask exchange. Subjective mask preference was not associated with sleep quality, but with nocturnal dyspnea. Over 40% of patients subsequently switched to the mask that they were not previously accustomed to. CONCLUSION: In general, oronasal and nasal masks are each similarly capable of successfully delivering NIV in COPD-patients. However, the individual response to different interfaces is extremely heterogeneous, while subjective mask preference is independent from objective measures, but associated with dyspnea. TRIAL REGISTRATION: German Clinical Trials Registry (DRKS00007741).

Impact of home mechanical ventilation on sleep quality.

PURPOSE OF REVIEW: The number of patients receiving home mechanical ventilation (HMV) has dramatically increased in recent years. Although physiological parameters, health-related quality of life and long-term outcomes frequently serve as primary outcomes, only a few studies have primarily addressed sleep quality in patients undergoing HMV. Therefore, this review article summarizes the current knowledge on sleep quality in patients receiving HMV. RECENT FINDINGS: HMV can be performed noninvasively via face masks or invasively via tracheal cannulas. Studies in patients receiving invasive HMV therapy are clearly lacking. Most studies in this field have focused on invasively ventilated patients in the ICU, but the findings are not necessarily applicable to patients undergoing invasive HMV. On the other hand, there are several trials showing that noninvasive ventilation (NIV) has the potential to improve sleep quality in patients with severe sleep disturbances associated with chronic hypercapnic respiratory failure. To this end, both subjectively and objectively assessed sleep qualities by polysomnography are reported to improve after long-term NIV is initiated. SUMMARY: Although HMV has the potential to improve sleep quality in patients with chronic hypercapnic respiratory failure, it can also have a negative impact on sleep quality, particularly in cases of patient-ventilator asynchrony or leakage. Therefore, both subjective and objective polysomnographic assessments of sleep quality should become an integral part of managing patients who receive HMV therapy.

Continuous non-invasive PCO2 monitoring in weaning patients: Transcutaneous is advantageous over end-tidal PCO2.

BACKGROUND AND OBJECTIVE: Continuous partial pressure of carbon dioxide (PCO2 ) assessment is essential for the success of mechanical ventilation (MV). Non-invasive end-tidal PCO2 (PetCO2 ) and transcutaneous PCO2 (PtcCO2 ) measurements serve as alternatives to the gold standard arterial PCO2 (PaCO2 ) method, but their eligibility in critical care is unclear. METHODS: The present study therefore performed methodological comparisons of PaCO2 versus PetCO2 and PtcCO2 , respectively, in weaning patients receiving invasive MV via tracheal cannulas. PetCO2 and PtcCO2 were recorded continuously, while PaCO2 was analysed at baseline, and after 30 and 60 min. Using the Bland-Altman analysis, a clinically acceptable range was defined as a mean difference of ±4 mm Hg between PaCO2 and non-invasive strategies. RESULTS: A total of 60 patients (COPD (n = 30) and non-COPD (n = 30)) completed the protocol. Mean PCO2 values were 42.4 ± 8.6 mm Hg (PaCO2 ), 36.5 ± 7.5 mm Hg (PetCO2 ) and 41.7 ± 8.7 mm Hg (PtcCO2 ). Mean differences between PtcCO2 and PaCO2 were -0.7 ± 3.6 mm Hg (95% CI: -1.6/0.3 mm Hg; 95% limits of agreement: -7.8 to 6.4 mm Hg), and between PetCO2 and PaCO2 -5.9 ± 5.3 mm Hg (95% CI: -7.2/-4.5 mm Hg; 95% limits of agreement: -16.2 to 4.5 mm Hg). Underestimation of PaCO2 by PetCO2 was most pronounced in COPD patients. CONCLUSION: Our data therefore support PtcCO2 as a suitable means for monitoring PCO2 in patients undergoing invasive MV. This is in contrast to PetCO2 , which clearly underestimated PaCO2 , especially in patients with COPD.