High altitude trekking after lung transplantation: a prospective study using lung ultrasound to detect comets tails for interstitial pulmonary edema in lung transplant recipients and healthy volunteers

Abstract

Clinical trial registration number: NCT03117686 (clinicaltrials.gov). SUMMARYThe intensity of physical activity which can be tolerated after lung transplantation and the tolerance to prolonged exercise at high altitude are poorly investigated. Lung ultrasound comet tails have been used in the diagnosis of interstitial pulmonary edema and high pulmonary altitude edema. The aim was to assess the number of lung ultrasound comet tails and to monitor changes in the optic nerve sheath diameter (ONSD) during a climb to the top of Mount Kilimanjaro in 10 lung transplant recipients and 10 healthy controls at three different altitude levels: 1360, 3505, 4900 m. Lung transplant recipients showed a constant increase in comet tail scores with altitude, whereas control subjects only showed an increase at the highest measurement point. Differences between groups (transplant versus control) reached significance only after the first ascend: 0.9 (95% CI: À0.41; 2.21) vs. 0.1 (95% CI: À0.12; 0.32) (P = 0.2; 1360 m), 2.33 (95% CI: 0.64; 4.02) vs. 0.3 (95% CI: À0.18; 0.78) (P = 0.04; 3505 m), and 4.11 (95% CI: 0.13; 0.34) vs. 2.9 (95% CI: 0.49; 5.31) (P = 0.15; 4900 m); ONSD increased significantly in both groups from 3.53 (95% CI: 0.34; 0.66) at 1360 m to 4.11 (95% CI: 0.36; 0.71) at 4900 m (P < 0.05). Lungs of transplant recipients are able to adapt to altitude and capable of performing prolonged exercise at high altitude after slow ascend.

Lung Ultrasound in the Assessment of Pulmonary Complications After Lung Transplantation

“…This is the first observational study to investigate LUS in a prospective follow-up design in a cohort of lung transplant recipients with LUS performed at four fixed time points in a post-LTx setting. LUS in the setting of evaluating pre-and post-LTx complications has only been applied in a few studies, and in later stages after LTx [16,18,19]. One case series study on six neurologically diseased donors found that LUS was able to detect abnormalities not identified on a CXR in donor lungs, and thereby potentially able to accelerate possible donor lung intervention such as ex vivo lung perfusion [16].…”

“…Although the benefit of LUS implementation has been widely proven within pulmonology, its application in a clinical post-LTx setting represents a novelty with only a few published studies [16][17][18][19]. Among these, a recent study of 165 lung transplant recipients concluded LUS to be a valid tool to exclude pneumothorax two hours after transbronchial biopsy (TBB) performed in relation to surveillance bronchoscopy when comparing to CXR due to a negative predictive value of 99 % and a sensitivity of 75 % [18].…”

Lung Ultrasound to Phenotype Chronic Lung Allograft Dysfunction in Lung Transplant Recipients. A Prospective Observational Study

“…There is only limited experience with lung ultrasound (LUS) as part of LTx followup. LUS has primarily been used in the early post-operative phase after LTx in order to diagnose and monitor acute complications such as pleural effusion, pneumonia, and atelectasis [17][18][19][20]. In interstitial lung disease (ILD), lung parenchyma and pleura possess an increased tissue density, which can be demonstrated by LUS findings as a significant number of B-line reverberation artifacts as part of the interstitial syndrome (IS), and pleural thickening [21][22][23][24][25][26][27].…”

Cardiopulmonary response to high‐altitude mountaineering in lung transplant recipients—The Jebel Toubkal experience

“…However, poor cardiorespiratory fitness and muscle weakness are commonly persistent despite normalization of pulmonary function 2 . Although high‐altitude trekking has been reported after transplantation, data on the patient's physiological adaptation during prolonged strenuous exercise in a reduced oxygen environment remain scarce 3–5 …”

“…The previous expedition of the Vienna Lung Transplant Program to climb Mount Kilimanjaro in June 2017 proved the feasibility and safety of high‐altitude mountaineering in LuTx recipients 3,5 . A second expedition was planned to expand our understanding of cardiopulmonary changes in lung recipients exposed to altitude, using more sophisticated medical monitoring methods.…”