Mouthpiece Ventilation Research Articles

Inhalable liposomal formulation for vasoactive intestinal peptide

Inhalation of vasoactive intestinal peptide (VIP) was suggested as promising treatment option of various lung diseases like asthma and pulmonary hypertension. However, the medical use of peptides is limited by their short half-life due to rapid enzymatic degradation in the airways. For that reason, we recently developed unilamellar nano-sized VIP-loaded liposomes (VLL). Now we investigated their applicability for inhalation purposes. After nebulisation by a mouthpiece ventilation inhaler we found the particle size almost unaffected, being in a size range appropriate for bronchiolar deposition; we observed no peptide release due to nebulisation. The VIP release kinetics from VLL were tested by an ex vivo vasorelaxation model. Exposure to target organs revealed an immediate response, which was significantly retarded for VLL as compared to free VIP ( p = 0.001). Using vasorelaxation as endpoint, we observed a sustained release and an extended pharmacological effect compared to equimolar free VIP. The liposomes have the potential to improve VIP inhalation therapy by providing a “dispersible peptide depot” in the bronchi. Thereby, the release of VIP from liposomes may be triggered by exposure to cells, i.e. directly by ligand–receptor interactions.

Diurnal ventilation via mouthpiece: survival in end-stage Duchenne patients

The present study aimed to assess the impact of diurnal mouthpiece intermittent positive pressure ventilation (MIPPV) as the extension of the nasal intermittent positive pressure ventilation (NIPPV) in Duchenne muscular dystrophy (DMD). In total, 42 DMD patients aged 15-33 yrs, normocapnic at night with NIPPV and receiving MIPPV since end-diurnal hypercapnia, were studied. Transcutaneous CO2 tension (Pt,CO2) was prospectively monitored at the end of the day, before and after MIPPV initiation. Vital capacity (VC), breathing pattern and maximal inspiratory strength were measured. Patients were asked to score the presence (1 point) or absence (0 point) of seven respiratory-linked symptoms before and after MIPPV establishment. Survival rates reached 88, 77, 58 and 51% after 1, 3, 5 and 7 yrs, respectively. The mean survival rate was 31 yrs. VC stabilised during 5 yrs with MIPPV. Symptom scores significantly decreased and Pt,CO2 normalised during the day (8.17 +/- 2.22 to 5.78 +/- 0.73 kPa). No accident and minor side-effects were observed in this 184 cumulated patient-yrs study. In conclusion, daytime mouthpiece ventilation is safe, prolongs survival and stabilises vital capacity in Duchenne muscular dystrophy patients. It is recommended on the condition that patients are equipped with a self-supporting harness.