Anesthetic Management of Patients with Transplanted Lung Undergoing Non-Transplant Surgery

Abstract

A variety of physiologic changes occur following lung transplantation; some affect all lung transplant recipients, while others may be dependent on the type of lung transplant surgery performed SLT,BLT,HLT and LDLT or on the pre-transplant diagnosis, when donor lungs are harvested, one of the interrupted nerves is the afferent limb of the cough reflex; coughing can be stimulated from a remaining native lung or sites proximal to the airway anastomosis, but may be blunted, as a consequence of gastroesophageal dysmotility, aspiration of gastric and bile acids may occur and contribute to bronchiolitis obliterans syndrome. Diaphragmatic strength improves after lung transplantation in most patients with COPD, however diaphragmatic paralysis may occur in 3 to 30 percent of transplant recipients, FVC and FEV1 usually improve over first 3 months following SLT and BLT. Following BLT or HLT for PAH, cardiac index, mean pulmonary artery pressure, and pulmonary vascular resistance usually return to normal. After SLT for PAH, mean pulmonary artery pressure and pulmonary vascular resistance decrease significantly, but cardiac index is less likely to improve. Preoperative assessment of lung transplant patients does not differ greatly from what is required for the general population, for proper systematic preoperative assessment anesthesiologist must put in mind beside usual preoperative assessment for any patient, transplanted patient and specific transplanted organ, in lung transplanted patient we should focus in assessment of graft function, manifestation of rejection or infection, effect of immunosuppressive therapy directly by interaction with anesthesia drugs and indirectly by organs affection, don’t forget disease of native lung for which transplantion was taken on , systemic disease already present before transplantion and at last the common indication and type of the surgical procedure after lung transplantion so an excellent assessment of this patient will be obtained if we fulfill this points(Reginald et al.,2004). Intraoperative management similar to that for all other patients is usually suitable for most uncomplicated lung recipients Because these patients are extremely anxious and fearful about perioperative outcome, premedication is recommended, Intraoperative monitoring is, as usual, dictated by the severity of preoperative clinical conditions and the type of planned surgery. Any type of anesthesia may be safely used in a stable, compensated recipient The choice of anesthetic technique in these individuals (regional vs general vs combined general plus regional) should be made in accordance with the surgical procedure and the patient's physical status, taking in consideration risk of technical difficults, risk of infection, coagulopathy and crystalloid or colloid preloading. If general anesthesia is planned difficult intubation must be expected and all equipment for difficult intubation prepared. Intraoperative ventilation double-lung transplants usually do not present marked differences in compliance between the lungs, which are thus not very difficult to ventilate. The difference in compliance between the native and grafted lung is sometimes significant enough to determine intraoperative mediastinal shift. Differential ventilation via a DLT and two mechanical ventilators with different settings may be used to prevent hypoventilation of the graft and possible hemodynamic derangement