Efficacy of abdominal thrusts and back blows for patients with foreign body airway obstruction: MOCHI registry analysis.

Aim: This study aimed to evaluate the effectiveness of abdominal thrusts and back blows as initial bystander interventions compared to the absence of bystander intervention in patients with foreign body airway obstruction (FBAO). Methods: This was a prospective, observational study conducted at 25 hospitals in Japan (April 2020-March 2023), including patients aged ≥ 18 years presenting emergency departments with FBAO. The primary outcome was a favorable neurological outcome at 30 days, defined as a Cerebral Performance Category 1 or 2. Secondary outcomes were 30-day survival and success of obstruction relief. We used propensity scores with inverse probability of treatment weighting (IPTW) to adjust for confounding. Logistic regression and Cox proportional hazards models were applied for outcome analysis. Results: Among 407 patients, 24 received abdominal thrusts, 76 received back blows, and 175 received no bystander intervention. Median age was 81. After IPTW adjustment, favorable neurological outcomes were significantly more frequent in patient receiving abdominal thrusts (38% vs. 16%; difference 22%, 95% CI 14%-31%) and back blows (31% vs. 16%; difference 15%, 95% CI 8%-23%) compared to no intervention. Back blows were also associated with higher survival (adjusted HR 0.52, 95% CI, 0.35-0.78), while abdominal thrusts were not (adjusted HR 0.73, 95% CI, 0.40-1.35). Conclusion: Abdominal thrusts and back blows were both associated with significantly favorable neurological outcomes compared to no intervention. Back blows were additionally associated with higher survival.