INTRODUCTION: Use of mechanical ventilation (MV), administered either invas
ively via tracheostomy, or more commonly non-invasively (CPAP, BiPAP), appe
ars to be increasing in ALS. No prospective databases exist that describe t
he behavior of physicians and patients and the criteria for instituting MV
in ALS.
METHODS: 387 placebo patients in a Phase III trial of r-metHuBDNF were foll
owed for 9 months. Although the use of MV was not the primary end-point of
the trial, information was gathered regarding it by cataloging respiratory
adverse events and tracking health resource utilization,
RESULTS: 35 of 387 patients utilized My during the trial. Twenty-eight (7%)
patients received BiPAP, Seven (2%) were tracheotomized without first rece
iving BiPAP. Forced vital capacity (NC): BiPAP patients had a mean (+/- SEM
) FVC% of 71.8 +/-2.8X and ALSFRS of 27.7 +/-1.0 at baseline; non-BiPAP pat
ients had a mean baseline: FVC% of 88,7 +/-1.0%, and an ALSFRS of 30,3 +/-0
.3. Symptom duration at entry was similar for both groups (2.1 +/-0.4 years
vs. 2.1 +/-0,1 years). At the time of first use of BiPAP, average FVC% was
47,5 +/-4.0% and ALSFRS score was 22.4 +/-1.5. The range of FVC% at start
of BiPAP was 15-87. The nine-month survival was 67.9% for BiPAP patients vs
. 86% for non-BiPAP patients. The use of BiPAP varied tremendously among th
e 38 study sites, with some not employing it at all and others using it in
as many as 40% of patients.
CONCLUSIONS: Of the 9% of placebo patients who received MV, BiPAP patients
were more rapidly progressing than non-BiPAP patients, and showed a greater
eventual mortality rate. Patients began MV at a wide range of values of FV
C%, and centers differed in their prescribing practices. Factors influencin
g BiPAP use are complex, and not strictly related to FVC%.