title: Effect of phrenic nerve palsy on early postoperative lung function after pneumonectomy: a prospective study.
abstract: BACKGROUND
  The issue of phrenic nerve preservation during pneumonectomy is still an unanswered question. So far, its direct effect on immediate postoperative pulmonary lung function has never been evaluated in a prospective trial.
  
  
  METHODS
  We conducted a prospective crossover study including 10 patients undergoing pneumonectomy for lung cancer between July 2011 and July 2012. After written informed consent, all consecutive patients who agreed to take part in the study and in whom preservation of the phrenic nerve during operation was possible, were included in the study. Upon completion of lung resection, a catheter was placed in the proximal paraphrenic tissue on the pericardial surface. After an initial phase of recovery of 5 days all patients underwent ultrasonographic assessment of diaphragmatic motion followed by lung function testing with and without induced phrenic nerve palsy. The controlled, temporary paralysis of the ipsilateral hemidiaphragm was achieved by local administration of lidocaine 1% at a rate of 3 mL/h (30 mg/h) via the above-mentioned catheter.
  
  
  RESULTS
  Temporary phrenic nerve palsy was accomplished in all but 1 patient with suspected catheter dislocation. Spirometry showed a significant decrease in dynamic lung volumes (forced expiratory volume in 1 second and forced vital capacity; p < 0.05) with the paralyzed hemidiaphragm. Blood oxygen saturation levels did not change significantly.
  
  
  CONCLUSIONS
  Our results show that phrenic nerve palsy causes a significant impairment of dynamic lung volumes during the early postoperative period after pneumonectomy. Therefore, in these already compromised patients, intraoperative phrenic nerve injury should be avoided whenever possible.
authors.affiliation: Division of General Thoracic Surgery, University Hospital of Bern, Bern, Switzerland.
authors.forename: Gregor J
authors.initials: GJ
authors.lastname: Kocher
authors.forename: Karl
authors.initials: K
authors.lastname: Mauss
authors.forename: Giovanni L
authors.initials: GL
authors.lastname: Carboni
authors.forename: Beatrix
authors.initials: B
authors.lastname: Hoksch
authors.forename: Roland
authors.initials: R
authors.lastname: Kuster
authors.forename: Sebastian R
authors.initials: SR
authors.lastname: Ott
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Schmid
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018592:Cross-Over Studies; D003964:Diaphragm / Q000294:innervation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010523:Peripheral Nervous System Diseases / Q000150:complications* / Q000503:physiopathology / Q000517:prevention & control; D010791:Phrenic Nerve / Q000293:injuries* / Q000503:physiopathology; D011013:Pneumonectomy / Q000009:adverse effects*; D011183:Postoperative Complications; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D012133:Respiratory Paralysis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D014797:Vital Capacity
keywords: 11; 6; DLCOcorr; FEV1; FVC; MRI; diffusing lung capacity for carbon monoxide, corrected for hemoglobin; forced expiratory volume in 1 second; forced vital capacity; magnetic resonance imaging