Purpose
To estimate the severity of flow limitation in patients with OSA, the number of breaths with flattened inspiratory flow curves should be identified. Attempts to do a quantitative analysis of ...the flattening degree for all breaths in a nighttime recording have failed up to now.
Methods
SOMNOmedics (Randersacker, Germany) developed an automated flattening analysis parameter called the obstructive coefficient (OC). Polysomnographic measurement including esophageal manometry was done in 25 subjects (10 healthy, 9 patients with mild OSA, and 6 with severe OSA). For each breath, the data couple of OC and esophageal pressure (EP) was used for analysis.
Results
Data couples of OC and EP were recorded for 104,608 breaths. Airway patency histogram profiles for each study group showed no remarkable differences between each other. Increase in EP with increasing RDI was identified as the only marker of OSA severity. A strong shift was observed in N3 breaths from maximum OC/lowest EP values in healthy subjects to low OC values in association with maximum EP values in OSA.
Conclusion
The OC enables quantification of all breaths of a nighttime recording according to their degree of flattening. The relation of strong limited to less strong limited breaths is the same across the three study groups. The analysis of the corresponding EP to a given OC value for each study group identified the EP that is necessary to cause a given flow as the only parameter that discriminates degrees of severity of OSA.
The trial registration number is DRKS00018095 from 2019 to 10-09.
Pandemic scenarios like the current Corona outbreak show the vulnerability of both globalized markets and just-in-time production processes for urgent medical equipment. Even usually cheap personal ...protection equipment becomes excessively expensive or is not deliverable at all. To avoid dangerous situations especially to medical professionals, but also to affected patients, 3D-printer and maker-communities have teamed up to develop and print shields, masks and adapters to help the medical personnel. In this study, we investigate three home-made respiratory masks for filter and protection efficacy and discuss the results and legal aspects. A home-printed respiratory mask with a commercial filter, a scuba-diving mask with a commercial filter and a mask sewn from a vacuum cleaner bag were investigated with 99mTc-labeled NaCl-aerosol, and the respective filter-efficacy was measured under a scintigraphic camera. The sewn mask from a vacuum cleaner bag had a filter efficacy of 69.76%, the 3D-printed mask of 39.27% and the scuba-diving mask of 85.07%. Home-printed personal protection equipment can be a-yet less efficient-alternative against aerosol in case professional masks are not available, but legal aspects of their use and distribution have to be kept in mind in order to avoid compensation claims.
Abstract Background The optimal treatment for central sleep apnea (CSA) depends on the underlying pathophysiology and should consider the potential for hemodynamic impairment when using positive ...airway pressure devices. While the long-term effects on overall cardiovascular outcome have been investigated for different device settings, the immediate hemodynamic consequences are not well understood. This is mainly due to a lack of hemodynamic monitoring during routine polysomnographic assessment. The application of most monitoring devices is either restricted by their invasiveness, e.g. in thermodilution, or cannot be used continuously like in echocardiography. Impedance cardiography (ICG), however, enables physicians to implement a continuous non-invasive monitoring of different hemodynamic parameters which can be useful in various clinical scenarios. In sleep medicine, the hemodynamic effect of initiating positive airway pressure treatment in patients with pre-existing heart failure should be of special concern. Case presentation In this case report, we compare the efficacy of three different treatment modalities in a patient with CSA related to chronic heart failure considering the resolution of respiratory events on polysomnography (PSG). In addition, we outline the hemodynamic effects of each treatment device using ICG for non-invasive hemodynamic monitoring. Regarding the reduction of respiratory central events, long-term oxygen treatment (LTOT) and adaptive servoventilation (ASV) proved to be more efficient compared with automatic positive airway pressure (APAP). Hemodynamically, substantial differences of the cardiac performance were observed between the treatment devices. This especially applied to ASV which led to a pronounced drop in cardiac output. Conclusion Our case report indicates that treatment of CSA may induce significant changes of hemodynamic parameters which would remain undetected during routine polysomnographic assessment. We conclude that non-invasive hemodynamic monitoring may be considered when positive airway pressure treatment is initiated in patients at risk of hemodynamic impairment.
Invasive mechanical ventilation of hypoxaemic coronavirus disease 2019 (COVID-19) patients is associated with mortality rates of >50%. We evaluated clinical outcome data of two hospitals that agreed ...on a predefined protocol for restrictive use of invasive ventilation where the decision to intubate was based on the clinical presentation and oxygen content rather than on the degree of hypoxaemia.
Data analysis was carried out of patients with positive PCR-testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), typical history, and symptoms and pulmonary infiltrates who exhibited oxygen saturation values of <93%.
We identified 78 patients who met the inclusion criteria. The oxygen saturation nadir was 84.4±6.5% for the whole group. 53 patients (68%) received nasal oxygen (group 1), 17 patients (22%) were treated with nasal high-flow continuous positive airway pressure (CPAP), noninvasive ventilation or a combination thereof (group 2), and eight patients (10%) were intubated (group 3). The Horovitz index was 216±8 for group 1, 157±13 for group 2 and 106±15 for group 3. Oxygen content was 14.5±2.5, 13.4±1.9 and 11.6±2.6 mL O
·dL
for the three respective groups. Overall mortality was 7.7%; the mortality of intubated patients was 50%. Overall, 93% of patients could be discharged on room air.
Permissive hypoxaemia where decisions for the level of respiratory therapy were based on the clinical presentation and oxygen content resulted in low intubation rates, low overall mortality and a low number of patients who require oxygen after discharge.
Asymptomatic patients with hemoglobin (Hb) variants can be detected by low oxygen levels in pulse oximetry (SpO₂).
Depending on the type of Hb variant, low SpO₂ values are either falsely low, with ...corresponding normal arterial oxygen saturation (SaO₂), or truly low, with low SaO₂ values, as observed in Hb variants with low oxygen binding affinity. In this context, attention must be paid to the method of determining SaO₂.
Low oxygen affinity Hb variants such as Hb Rothschild (HbR) might compensate for low oxygen loading in the lung through unloading more oxygen in peripheral tissues. This is the first case report to illustrate that maximal oxygen uptake and the workload are unimpaired in HbR variant patients.
Background
Intensive care unit-acquired weakness syndrome (ICUAWS) can be a consequence of long-term mechanical ventilation. Despite recommendations of early patient mobilisation, little is known ...about the feasibility, safety and benefit of interval training in early rehabilitation facilities (ERF) after long-term invasive ventilation.
Methods and Results
We retrospectively analysed two established training protocols of bicycle ergometry in ERF patients after long-term (> 7 days) invasive ventilation (
n
= 46). Patients conducted moderate continuous (MCT,
n
= 24, mean age 70.3 ± 10.1 years) or high-intensity interval training (HIIT,
n
= 22, mean age 63.6 ± 12.6 years). The intensity of training was monitored with the BORG CR10 scale (intense phases ≥ 7/10 and moderate phases ≤ 4/10 points). The primary outcome was improvement (∆-values) of six-minute-walk-test (6 MWT), while the secondary outcomes were improvement of vital capacity (VC
max
), forced expiratory volume in 1 s (FEV
1
), maximal inspiratory pressure (PI
max
) and functional capabilities (functional independence assessment measure, FIM/FAM and Barthel scores) after 3 weeks of training. No adverse events were observed. There was a trend towards a greater improvement of 6 MWT in HIIT than MCT (159.5 ± 64.9 m vs. 120.4 ± 60.4 m;
p
= .057), despite more days of invasive ventilation (39.6 ± 16.8 days vs. 26.8 ± 16.2 days;
p
= .009). VC
max
(∆0.5l ± 0.6 vs. ∆0.5l ± 0.3;
p
= .462), FEV
1
(∆0.2l ± 0.3 vs. ∆0.3l ± 0.2;
p
= .218) PI
max
(∆0.8 ± 1.1 kPa vs. ∆0.7 ± 1.3pts;
p
= .918) and functional status (FIM/FAM: ∆29.0 ± 14.8pts vs. ∆30.9 ± 16.0pts;
p
= .707; Barthel: ∆28.9 ± 16.0 pts vs. ∆25.0 ± 10.5pts;
p
= .341) improved in HIIT and MCT.
Conclusions
We demonstrate the feasibility and safety of HIIT in the early rehabilitation of ICUAWS patients. Larger trials are necessary to find adequate dosage of HIIT in ICUAWS patients.
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