Physiological effects of intravenous fructose 1.6-diphosphate on diaphragmatic function in malnourished patients with COPD.
BACKGROUND
A low body mass index is one of the strongest predictors of mortality in Chronic Obstructive Pulmonary Disease (COPD) patients. Under-nutrition is often associated with skeletal muscle wasting and hypophosphatemia.


OBJECTIVE
In a pilot, randomised, double-blind placebo-controlled study, we assessed the physiological effects of phosphorous administration in 17 stable undernourished COPD patients, on diaphragmatic function, breathing pattern, neuromuscular drive (P0.1) and dyspnea score. Fructose 1.6-diphosphate (FDP) or placebo was administered i.v. for 7 consecutive days.


RESULTS
FDP administration was associated with a marked increase in inspiratory time (Ti) that induced a significant rise (p < 0.05) in the Pressure Time Product of the diaphragm per breath (PTPdi/b). However, since breathing frequency also decreased, the Pressure Time Product per minute of the diaphragm (PTPdi/min), index of diaphragmatic energy expenditure was markedly reduced. The efficiency of the respiratory pump in clearing CO2 was also improved, although not significantly, in the FDP group (p = 0.09) as well as the maximal transdiaphragmatic pressure during the sniff manoeuvre (Pdi,sniff).


CONCLUSIONS
This pilot physiological study showed that phosphorus replacement in undernourished, stable COPD patients, may be associated with a complex modification in respiratory pattern and diaphragmatic functions, leading to a marked although not significant reduction in PTPdi/min.
Nava
S
S
Respiratory Unit Fondazione S. Maugeri, I.R.C.C.S. Istituto Scientifico di Pavia, Italy. snava@fsm.it
Fuccella
L M
LM
Viglianti
B
B
D000368:Aged; D000369:Aged, 80 and over; D003964:Diaphragm / Q000187:drug effects / Q000503:physiopathology*; D004311:Double-Blind Method; D005260:Female; D005635:Fructosediphosphates / Q000008:administration & dosage*; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008297:Male; D044342:Malnutrition / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D009119:Muscle Contraction / Q000187:drug effects*; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D013147:Spirometry
D005635:Fructosediphosphates; D007155:Immunologic Factors; C029063:fructose-1,6-diphosphate