RESUMO
BACKGROUND: Prone positioning has become a standard therapy in acute respiratory distress syndrome to improve oxygenation and decrease mortality. However, little is known about prone positioning in lung transplant recipients. This large, singe-center analysis investigated whether prone positioning improves gas exchange after lung transplantation. METHODS: Clinical data of 583 patients were analyzed. Prone position was considered in case of impaired gas exchange Pao2/fraction of oxygen in inhaled air (<250), signs of edema after lung transplantation, and/or evidence of reperfusion injury. Patients with hemodynamic instability or active bleeding were not proned. Impact of prone positioning (n = 165) on gas exchange, early outcome and survival were determined and compared with patients in supine positioning (n = 418). RESULTS: Patients in prone position were younger, more likely to have interstitial lung disease, and had a higher lung allocation score. Patients were proned for a median of 19 hours (interquartile range,15-26) hours). They had significantly lower Pao2/fraction of oxygen in inhaled air (227 ± 96 vs 303 ± 127 mm Hg, P = .004), and lower lung compliance (24.8 ± 9.1 mL/mbar vs 29.8 ± 9.7 mL/mbar, P < .001) immediately after lung transplantation. Both values significantly improved after prone positioning for 24 hours (Pao2/fraction of oxygen ratio: 331 ± 91 mm Hg; lung compliance: 31.7 ± 20.2 mL/mbar). Survival at 90 days was similar between the 2 groups (93% vs 96%, P = .105). CONCLUSIONS: Prone positioning led to a significant improvement in lung compliance and oxygenation after lung transplantation. Prospective studies are needed to confirm the benefit of prone positioning in lung transplantation.
RESUMO
Recent research has linked sphingolipid (SL) metabolism with cystic fibrosis transmembrane conductance regulator (CFTR) activity, affecting bioactive lipid mediator sphingosine-1-phosphate (S1P). We hypothesize that loss of CFTR function in cystic fibrosis (CF) patients influenced plasma S1P levels. Total and unbound plasma S1P levels were measured in 20 lung-transplanted adult CF patients and 20 healthy controls by mass spectrometry and enzyme-linked immunosorbent assay (ELISA). S1P levels were correlated with CFTR genotype, routine laboratory parameters, lung function and pathogen colonization, and clinical symptoms. Compared to controls, CF patients showed lower unbound plasma S1P, whereas total S1P levels did not differ. A positive correlation of total and unbound S1P levels was found in healthy controls, but not in CF patients. Higher unbound S1P levels were measured in ΔF508-homozygous compared to ΔF508-heterozygous CF patients (p = 0.038), accompanied by higher levels of HDL in ΔF508-heterozygous patients. Gastrointestinal symptoms were more common in ΔF508 heterozygotes compared to ΔF508 homozygotes. This is the first clinical study linking plasma S1P levels with CFTR function and clinical presentation in adult CF patients. Given the emerging role of immunonutrition in CF, our study might pave the way for using S1P as a novel biomarker and nutritional target in CF.
