Obesity Hypoventilation Syndrome

The Association of Body Mass Index and Outcomes in Adult Patients with Chest Wall Injuries

BACKGROUND

Thoracic injury secondary to rib fractures following motor vehicle collisions (MVCs) significantly contribute to morbidity and mortality. While obesity has reached epidemic proportions, little is known regarding how BMI impacts outcomes in MVCs. The aim of this study was to examine how BMI impacts outcomes in MVC patients with rib fractures.

METHODS

The ACS-TQIP Database was utilized to evaluate adult MVC patients with ≥3 rib fractures. Patients with a non-thoracic AIS ≥3 were excluded, to focus on chest injuries. Patients were sorted according to the presence or absence of flail chest injuries and BMI into groups with a low (<15), intermediate (15-24), or severe (≥25) ISS.

RESULTS

Overweight and obese patients in the non-flail cohort had decreased odds of pneumothorax in all ISS groups (P < 0.05). Overweight (P = 0.049) and obese (P = 0.011) patients in the low ISS non-flail cohort had decreased odds of splenic laceration. In the non-flail cohort, obese patients with a low and intermediate ISS had decreased odds of pulmonary contusion (P < 0.01). Obese patients in the low and intermediate ISS non-flail cohorts had increased odds of PE (P < 0.05). In both the flail and non-flail cohorts, obese patients with an intermediate ISS had decreased odds of liver laceration (P < 0.05), as well as a longer HLOS, ICU-LOS, and mechanical ventilation time (P < 0.01).

CONCLUSION

Obesity affects associated injuries, complications, and hospital outcomes in a complex way after MVC related chest wall trauma. Thus, the effect of BMI should be taken into consideration when assessing and treating obese MVC trauma patients.

A network meta-analysis of different positive airway pressure interventions in obesity hypoventilation syndrome

Continuous positive airway pressure (CPAP) and different types of non-invasive ventilation (NIV) have been studied in obesity hypoventilation syndrome such as bi-level PAP with back-up rate (BPAP-BUR), BPAP without BUR, and the new hybrid devices that target a pre-set volume by adjustment of pressure support (VT-PS). Although several studies have compared one PAP intervention with the other, none has compared all four in a head-to-head design, which formed the basis of this network meta-analysis. PubMed and Web of Science were searched for potentially includable randomised active comparator trials. Changes in partial pressure of carbon dioxide (PaCO₂ ) and Epworth Sleepiness Score (ESS) were the primary outcomes of interest. Network meta-analysis was done in R program using the 'frequentist' framework. A total of seven trials were included. Only VT-PS and BPAP-BUR showed statistically significant reductions in PaCO₂ compared to control, with no significant inter-PAP differences except for the comparison between VT-PS and CPAP. Only VT-PS showed a statistically significant improvement in ESS as compared to control, with no other significant inter-PAP differences. P-score ranking (based on effect size and standard errors) and Hasse diagram ranked VT-PS and BPAP as superior to other PAPs for both primary outcomes. There were no significant differences between the different PAP interventions for hospital or emergency department admissions. The results of this network meta-analysis suggest superiority of VT-PS and BPAP over other PAP interventions at least for daytime hypercapnia and subjective daytime somnolence.

Pulmonary embolism in obesity-hypoventilation syndrome

INTRODUCTION

Obesity-hypoventilation syndrome occurs with alveolar hypoventilation during sleeping and daytime. Obesity may be a risk factor for venous thromboembolism. However, the venous thromboembolism in the obesity-hypoventilation syndrome is not well characterized.

OBJECTIVE

This case series aimed to investigate the presence and clinical features of venous thromboembolism in patients with the obesity-hypoventilation syndrome.

METHODS

Data of eight case reports were collected. Ages ranged from 36 to 73 years.

RESULTS

All patients had mosaic perfusion and enlarged main pulmonary artery, two had signs of infarction and mostly segmental and subsegmental filling defects. On the basis of this information some conclusions can be drawn carefully.

CONCLUSION

Present cases indicate that pulmonary embolism are also very common in patients with obesity-hypoventilation syndrome, anticoagulant therapy is at least as important as the treatment of the current disease. Clinicians will frequently be faced with patients with obesity-hypoventilation syndrome suspected of PE.

Risk of Readmission and Mortality Following Hospitalization with Hypercapnic Respiratory Failure

PURPOSE

Hypercapnic respiratory failure (HRF) is a frequent cause of hospitalization and a common comorbidity in hospitalized patients. There are few studies addressing what factors might predict poor outcomes in this patient population. The purpose of the current study was to investigate characteristics and outcomes of patients hospitalized with HRF.

METHODS

A study of patients ≥ 18 years admitted with HRF in a 1-year period. Patients with limited life expectancy related to other conditions, and those with a non-respiratory cause of HRF, were excluded.

RESULTS

202 subjects met eligibility criteria: 24% had a diagnosis of obstructive sleep apnea, 6% obesity hypoventilation, 46% chronic obstructive pulmonary disease, and 10% asthma. Fifteen (7%) died during the index admission. Forty-one patients (23%) were readmitted within 30 days: peripheral vascular disease [adjusted odds ratio (aOR) 4.78, CI 1.45-15.74] and tachycardia (aOR 2.97, CI 1.22-7.26) were associated with an increased risk of readmission. Sixty-six patients (36%) died after discharge. Risk of death was increased in older patients (aOR 1.32, CI 1.13-1.54 per 5 years), those with peripheral vascular disease (aOR 12.56, CI 2.35-67.21), higher Charlson co-morbidity index (aOR 1.39, CI 1.09-1.76), use of home oxygen (aOR 4.03, CI 1.89-8.57), and those who had been readmitted (aOR 3.07, CI 1.46-6.43).

CONCLUSIONS

Hospitalization for HRF is associated with a high morbidity and mortality. Our observation that home oxygen use was associated with increased mortality suggests that oxygen use could be a risk factor for death in patients with HRF.

Efficacy of bilevel ventilatory support in the treatment of stable patients with obesity hypoventilation syndrome: systematic review and meta-analysis

OBJECTIVE

To systematically review the effects of bilevel ventilatory support (BVS) in patients with Obesity Hypoventilation Syndrome (OHS).

METHODS

A search of databases (MEDLINE accessed by PubMed, Cochrane CENTRAL, EMBASE and LILACS) was conducted from inception to June 2018. Randomized trials comparing BVS to other therapeutic modalities such as lifestyle counseling, continuous positive airway pressure (PAP) or BVS with average volume assured pressure support for the treatment of patients with OHS were included. The primary outcome was a change in daytime arterial carbon dioxide levels (PaCO₂). Secondary outcome measures included arterial partial pressure of oxygen (PaO₂), blood bicarbonate (HCO₃), percentage of total sleep time (TST) with oxygen saturation <90%, transcutaneous pressure of carbon dioxide (PtcCO₂), Epworth Sleepiness Scale (ESS), Medical Outcome Survey Short Form (SF36), Functional Outcomes of Sleep Questionnaire (FOSQ), Severe Respiratory Insufficiency Questionnaire (SRI), compliance with treatment, and weight loss.

RESULTS

Of 176 articles identified, seven studies were included. When BVS was compared to lifestyle counseling, the intervention was superior in improving PaCO₂ (-2.90 mmHg; 95%CI -4.28 to -1.52), PaO₂ (2.89 mmHg; 95%CI 0.33 to 5.46), HCO₃ (-2.55 mmol/L; 95%CI -3.28 to -1.81), percentage of TST<90% (-30.55%; 95%CI -37.98 to -23.12), ESS (-2.52; 95%CI -4.16 to -0.88) and FOSQ (6.33; 95%CI 1.78 to 10.88). However, when BVS was compared to other PAP modalities, there was no difference in any of the outcomes evaluated.

CONCLUSIONS

Treatment using BVS therapy is superior to lifestyle counseling. Different PAP modalities appear to be equally effective in improving outcomes. CRD42017065326.