Introduction
Our objective was to identify parameters to identify Amyotrophic Lateral Sclerosis (ALS) patients at risk of acute respiratory failure after enteral feeding tube (EFT) insertion.
Methods
Retrospective single-site, IRB-exempt review of 17 patients identified by procedure code 43246 (Esophagogastroduodenoscopy) and ALS (ICD9-335, ICD10-G12.2) between 2015–2019. Spirometry, pre/post-procedure VC, use of non-invasive ventilation, procedure type and type of sedation were reviewed. Statistical significance determined at P ≤ .05. Cohen’s d effect size was done to address impact of the small sample size.
Results
Procedure selection followed the American Academy of Neurology recommendations using pre-procedure FVC; lowest risk (FVC > 50%) patients were referred for percutaneous enteral gastrostomy (PEG), whereas moderate risk (FVC 30–50%) and high risk (FVC < 30%) patients were referred for radiographically inserted gastrostomy or PEG with endotracheal intubation. Despite appropriate pre-operative risk stratification by FVC, post-procedure vital capacity (VC) acutely and significantly declined in 35% of patients, (mean decline 56%, SD 33), that impacted all procedure types.
Conclusion
In our case series, 35% of ALS patients developed acute respiratory failure with a marked acute drop in VC after enteral feeding tube placement. Pre-procedure FVC risk stratification into low, moderate or high risk did not identify patients who developed acute procedural respiratory failure, as this was not limited to those patients identified pre-operatively as moderate or high-risk. Post-procedure VC and change from pre-procedure measurements did identify patients who needed increased, inpatient post-procedure respiratory support. Implication of these observations drawn from a retrospective review support the need for additional research, to both confirm the initial findings in a larger sample size, difficult in single center trials with a low prevalence disease; further explore the impact of the type of sedation on post procedure respiratory failure, and determine if this is unique to ALS, or more broadly impacts patients with all forms of neuromuscular respiratory insufficiency.