Bulbar impairment score predicts noninvasive volume-cycled ventilation failure during an acute lower respiratory tract infection in ALS.

UNLABELLED: Amyotrophic lateral sclerosis (ALS) patients can suffer episodes of lower respiratory tract infections (LRTI) leading to an acute respiratory failure (ARF) requiring noninvasive ventilation (NIV).

AIM: To determine whether clinical or functional parameters can predict noninvasive management failure during LRTI causing ARF in ALS.

MATERIAL AND METHOD: A prospective study involving all ALS patients with ARF requiring NIV in a Respiratory Care Unit. NIV was provided with volume-cycled ventilators.

RESULTS: 63 ALS patients were included (APACHE II: 14.93±3.56, Norris bulbar subscore (NBS): 18.78±9.68, ALSFRS-R: 19.90±6.98, %FVC: 40.01±18.07%, MIC: 1.62±0.74L, PCF 2.51±1.15L/s, PImax -34.90±19.44cmH2O, PEmax 51.20±28.84cmH2O). In 73.0% of patients NIV was successful in averting death or endotracheal intubation. Differences were found between the success and failure in the NBS (22.08±6.15 vs 8.66±3.39, p<0.001), ALSFRS (22.08±6.11 vs 12.71±4.39, p<0.001), PCFMI-E (3.85±0.77 vs 2.81±0.91L/s, p=0.007) and ALS onset (spinal/bulbar 33/13 vs 7/10, p=0.03). The predictor of NIV failure was the NBS (OR 0.53, 95% CI 0.31-0.92, p 0.002) with a cut-off point of 12 (S 0.93; E 0.97; PPV 0.76; NPV 0.97).

CONCLUSIONS: NBS can predict noninvasive management failure during LRTI in ALS.