Phrenic nerve dysfunction after heart-lung and lung transplantation

Abstract

The incidence and consequences (ventilator days and ICU length of stay(ICU LOS)) of phrenic nerve dysfunction (PND) was studied by retrospective chart review of 27 heart-lung (HLTX) and 111 lung transplantations (LTX) for the period from 1991 to 6/2001 in our institution. On clinical suspicion of diaphramatic dysfunction a phrenic nerve conduction study( (1) MacLean I.C. et al. Arch Phys Med Rehab. 1981; 62: 71 Google Scholar ) was performed, completed with a needle electromyography (EMG) of the diaphragm( (2) Bolton C.F. et al. Muscle and Nerve. 1992; 15: 678 Crossref PubMed Scopus (115) Google Scholar ), when the nerve conduction study was not conclusive. PND is defined as an uni- or bilateral abnormal EMG of the phrenic nerve(s) or signs of denervation on the needle EMG of the diaphragm. Data are presented as mean +/-1 standard deviation. The incidence of PND in 21 evaluable HLTX patients was 42,8 % (9 patients), resulting in significantly more ventilator days (PND 37,6 +/-36,3 days(d) vs non-PND 5,3+/-3d,p<0,05) and a prolonged ICU LOS (PND 46,8+/-33d vs non-PND 9,8+/-4,9d,p<0.05). Thirteen out of the 42 phrenic nerves at risk developed PND (25%). In the 97 evaluable LTX patients 9 (9,3%) developed PND involving 12 of the 142 phrenic nerves at risk (8.45 %). This resulted in a significantly higher number of ventilator days (PND 30,6+/-14,8d vs non-PND 7,9+/-14,8d,p<0,05) and a longer ICU LOS (PND 37,9+/-18,7d vs non-PND 12,1+/-17,8d,p<0.05). In LTX patients suffering from PND more tracheostomies were performed (PND 4/9 patients or 44,4% vs non-PND 4/88 patients or 4,5%,p<0,005) and 8 out of 9 LTX PND patients had a sequential single LTX. The needle EMG of the diaphragm revealed denervation of the diaphragm in 1 HLTX and in 4 LTX.