Screening and treatment of pre-bariatric surgical patients with obesity related sleep disordered breathing.

Background: There is a significant burden of sleep disordered breathing (SDB) in patients living with severe and complex obesity undergoing pre-bariatric surgery assessment. This longitudinal observational study evaluated the burden of obesity hypoventilation syndrome (OHS) in this cohort of patients and the therapeutic compliance of patients commenced on positive airway pressure treatment. Methods: All pre-bariatric surgery patients referred to the sleep clinic for review after an abnormal screening study between 2018 and 2022 were included. We collected data on their sleep study results, anthropometrics, co-morbid medical conditions, clinical observations, spirometry and arterial blood gas (ABG). Patients commenced on therapy were followed-up longitudinally and compliance data collected via remote monitoring. Results: A total of 116 patients were included [age: mean ± standard deviation (SD) 48.8±10.8 years; body mass index (BMI) 49.2±8.5 kg/m2; Epworth Sleepiness Scale (ESS) 8.7±5.1 points]. Fifteen patients (12.9% of cohort) were diagnosed with hypercapnic respiratory failure (pH 7.40±0.02; pO2 11.00±1.04 kPa; pCO2 6.15±0.08 kPa). Compared to eucapnic obstructive sleep apnoea (OSA) patients, they were older (51.1 vs. 48.5 years; P=0.311), had a higher BMI (51.5 vs. 48.9 kg/m2; P=0.266), more likely to be female (66.7% vs. 53.5%; P=0.275) and had a higher ESS score (10.4 vs. 8.5 points; P=0.177). On binomial regression analysis insulin dependent diabetes was the only patient characteristic of significance with prevalence increased in patients with OHS (26.7% vs. 8.9%; P=0.042). Forced vital capacity (FVC) and oxygen saturation (SpO2) cut-offs demonstrated high specificity (96.8%) but low sensitivity (13.3%) to diagnosed hypercapnia. Fifty percent of the patients with hypercapnia required bi-level ventilation. On follow-up 44.9% of patients were compliant with therapy (>4 hours usage/night). Conclusions: In minimally symptomatic patients living with severe and complex obesity who have an abnormal overnight oximetry, over 1 in 10 demonstrated chronic respiratory failure. Clinic spirometry and daytime SpO2 excluded those with hypercapnia. Overall adherence to prescribed therapy is low. Screening, appropriate pre-operative optimisation and peri-operative planning are important in preventing complications in this patient cohort.

Pre-operative screening for sleep disordered breathing: obstructive sleep apnoea and beyond.

Sleep disordered breathing describes an important group of conditions that causes abnormal nocturnal gas exchange, with important implications in the peri-operative management plan. An understanding of the pathophysiology behind obstructive sleep apnoea and other disorders that may lead to hypoventilation can help to prevent complications. Patients with these disorders may be minimally symptomatic and it requires careful screening in the pre-operative assessment process for a diagnosis to be made. Decisions regarding initiation of therapy, such as positive airway pressure, and delay of the operation need to be carefully weighed up against the urgency of the surgical intervention. Planning of the peri-operative care, including the use of positive airway pressure therapy and appropriate post-operative monitoring, can help to avoid respiratory and cardiovascular morbidities and improve clinical outcomes. Educational aims: To review different types of sleep disordered breathing and available screening methods in pre-operative assessment.To understand the pathophysiology behind sleep disordered breathing and how it can lead to complications in the peri-operative setting.To review the planning and treatment strategies that should be considered as part of peri-operative management.

Prolonged Ventilatory Support for Patients Recovering From Guillain-Barré Syndrome.

BACKGROUND: Recovery from Guillain-Barré syndrome (GBS) may be protracted, and patients may need prolonged ventilatory support. We present clinical data from a tertiary referral weaning center managing patients with GBS requiring prolonged ventilatory support. METHODS: A retrospective review of patients managed in a 34-bed specialist ventilator weaning facility in London, United Kingdom, between 2006 and 2017. Data including demographics, initial presentation, and ventilatory support were collected. Functional recovery and outcome data were collected between 12 months and 3 years following disease onset. RESULTS: Twenty-nine patients with severe GBS requiring prolonged ventilation were included. In several patients, coexisting conditions or complications affected the course. Seventy-six percent (n = 22) were successfully weaned from invasive ventilation with a median time to tracheostomy decannulation of 193 days (range: 49-527 days). Use of noninvasive ventilation (NIV), as part of the weaning program, was applied in 59% (13/22), with 14% (3/22) requiring long-term nocturnal NIV. Twenty-four percent (7/29) were not decannulated, with 14% (4/29) supported on long-term invasive ventilation. Forty-five percent (10/22) weaned from invasive ventilation were able to achieve short distance-assisted ambulation. Mortality at 36 months was 17% (5/29), with 3 of these deaths occurring in patients invasively ventilated during their acute admission. CONCLUSIONS: GBS with severe respiratory muscle weakness and bulbar dysfunction may require prolonged invasive ventilation. However, there is potential for complete weaning from invasive mechanical ventilatory support with associated function recovery. These data highlight the importance of maintaining ongoing support and rehabilitation for patients with GBS requiring prolonged ventilation.

Time-to-death in chronic respiratory failure on home mechanical ventilation: A cohort study.

BACKGROUND AND OBJECTIVE: Home mechanical ventilation (HMV) is used in heterogeneous conditions underlying chronic hypercapnic respiratory failure, but there are sparse data on long-term clinical outcomes. The aim was to systematically analyse the time and the circumstances of death on HMV. METHODS: All-cause mortality data of HMV patients were prospectively collected between 2008 and 2018 in a large tertiary centre. Data were categorised into diagnostic groups including neuromuscular disease (NMD), chest wall disease (CWD), chronic obstructive pulmonary disease (COPD), obesity hypoventilation syndrome (OHS), overlap syndrome of COPD and OSA (overlap) and other group. The primary outcome was time-to-death from initiation of HMV. RESULTS: 1210 deaths were recorded over a 10-year period. Median time-to-death was 19.5 [6-55] months and differed between groups (Kruskal Wallis p < 0.001). CWD (98.5 [23.5-120] months) and slowly progressive NMD (64.5 [28-120] months) had the longest time-to-death on HMV, while OHS (33 [13-75] months) and overlap syndrome (30.5 [14.5-68.5] months) had a longer median time-to-death than COPD (19.5 [7-42.5] months) and motor neurone disease (7 [3-14] months). Daily adherence to HMV of greater than 4 h/night was associated with better outcomes (10 [3-24] vs. 30 [10-76] months; p < 0.001). 43% with confirmed location of death died outside the hospital. CONCLUSIONS: The time-to-death on home mechanical ventilation varies widely across disease groups with chronic respiratory failure and seems to be associated with daily usage time. TRIAL REGISTRATION: researchregistry.com UIN: researchregistry4122.