Atelectasis in primary graft dysfunction survivors after lung transplantation

Respiratory compliance related to prognostic of lung transplant patients with veno‑venous extracorporeal membrane oxygenation support

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) plays an important role in the perioperative care of critically ill lung transplant patients. However, the factors predicting prognosis are unclear. This study assessed the association between static respiratory compliance (Crs) and outcomes of lung transplant patients receiving VV-ECMO in terms of 90-day mortality. Data were retrospectively collected for patients that underwent lung transplantation with VV-ECMO support during 2022-2023. Patients were divided into two groups according to the early postoperative Crs: lower Crs (Crs < 25 ml/cmH2O) and higher Crs (Crs ≥ 25 ml/cmH2O). Differences in patient characteristics and prognosis were then compared between the two groups. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of Crs for predicting 90-day mortality and univariate Cox proportional hazard model analysis was performed to estimate risk of Crs. Data were available for a total of 85 patients, including 50 (58.8%) patients in the higher Crs group and 35 (41.2%) patients in the lower Crs group. A lower Crs was significantly associated with a longer postoperative ECMO duration (hours, 42 vs. 24; P = 0.022), longer postoperative ventilator time (days, 3.7 vs. 2.0; P = 0.003), higher application of continuous renal replacement therapy (CRRT) (20.0% vs. 6.0%; P = 0.049), higher incidence of pneumonia (42.9% vs. 20.0%; P = 0.023), and higher 90-day mortality (22.9% vs. 6.0%; P = 0.023). The area under the curve of Crs for predicting 90-day mortality was 0.661 (P = 0.034). A higher Crs was a protective factor (hazard ratio = 0.925 [0.870-0.984)] P = 0.014). For lung transplant patients receiving VV-ECMO support, Crs < 25 ml/cmH2O is associated with more complications and higher 90-day mortality. As Crs is easily obtained at the bedside, it may be useful for predicting prognosis and guiding patient management.

Driving pressure association with mortality in post-lung transplant patients: A prospective observational study

OBJECTIVE

To investigate the association between driving pressure (ΔP) and 90-day mortality in patients following lung transplantation (LTx) in patients who developed primary graft dysfunction (PGD).

METHODS

This prospective, observational study involved consecutive patients who, following LTx, were admitted to our intensive care unit (ICU) from January 2022 to January 2023. Patients were separated into two groups according to ΔP at time of admission (i.e., low, ≤15 cmH2O or high, >15 cmH2O). Postoperative outcomes were compared between groups.

RESULTS

In total, 104 patients were involved in the study, and of these, 69 were included in the low ΔP group and 35 in the high ΔP group. Kaplan-Meier analysis of 90-day mortality showed a statistically significant difference between groups with survival better in the low ΔP group compared with the high ΔP group. According to Cox proportional regression model, the variables independently associated with 90-day mortality were ΔP and pneumonia. Significantly more patients in the high ΔP group than the low ΔP group had PGD grade 3 (PGD3), pneumonia, required tracheostomy, and had prolonged postoperative extracorporeal membrane oxygenation (ECMO) time, postoperative ventilator time, and ICU stay.

CONCLUSIONS

Driving pressure appears to have the ability to predict PGD3 and 90-day mortality of patients following LTx. Further studies are required to confirm our results.

Baseline lung allograft dysfunction in primary graft dysfunction survivors after lung transplantation

BACKGROUND

Primary graft dysfunction (PGD) after lung transplantation has previously been associated with increased risk of death and chronic lung allograft dysfunction (CLAD), but the relationship to baseline lung allograft dysfunction (BLAD), where graft function fails to normalize, is not known.

METHODS

We reviewed all double lung transplant recipients transplanted in our program 2004-2016. We defined PGD and CLAD as per recent consensus definitions and BLAD as failure to achieve both FEV1 and FVC ≥80% predicted on 2 consecutive tests ≥3 weeks apart. We used logistic and proportional hazards regression to test the association between severe high-grade PGD (PGD3) with BLAD and CLAD respectively, adjusting for known and identified confounders.

RESULTS

446 patients met inclusion criteria and 76 (17%) developed PGD3 at 48- or 72-h post-transplant. PGD3 occurred more frequently in patients with interstitial lung disease or pulmonary vascular disease, those with higher BMIs and recipients of older donors. PGD3 was associated with more frequent (58% vs. 36%; p = 0.0008) and more severe BLAD (p < 0.0001) and increased BLAD risk in an adjusted model (OR 2.00 [95% CI 1.13-3.60]; p = 0.0182). PGD3 was not associated with CLAD frequency, severity or time to CLAD onset in an adjusted model (HR 1.10 (95% CI 0.64-1.78), p = 0.7226).

CONCLUSION

Severe PGD was associated with increased risk and severity of BLAD but not CLAD. The mechanisms via which PGD may mediate baseline function warrant further investigation.