Acute respiratory failure among lung transplant adults requiring intensive care: Changing spectrum of causative organisms and impact of procalcitonin test in the diagnostic workup.

BACKGROUND: The aim was to identify the causing organisms and assess the association of procalcitonin (PCT) with bacterial pneumonia within 24 hours of intensive care unit admission (ICU-A) among lung transplant (LT) adult recipients. METHODS: Secondary analysis from a prospective cohort study. All LT adults admitted to ICU for acute respiratory failure (ARF) over 5 years were included. Patients were followed until hospital discharge or death. RESULTS: Fifty-eight consecutive LT patients were enrolled. The most important cause of ICU-A due to ARF was pneumonia 29 (50%) followed by acute rejection 3 (5.2%) and bronchiolitis obliterans syndrome exacerbation 3 (5.2%). Microorganisms were isolated from 22/29 cases with pneumonia (75.9%): 17 (77.2%) bacterial, 4 (18.2%) viral, 1 (4.5%) Aspergillus fumigates, with Pseudomonas aeruginosa being the most common cause (45.5%) of pneumonia, with 10 patients presenting chronic colonization by P aeruginosa. Median [Interquartile range (IQR)] PCT levels within 24 hours after admission were higher in pneumonia (1.5 µg/L; IQR:0.3-22.0), than in non-pneumonia cases (0.2 µg/L; IQR:0.1-0.7) (P = .019) and PCT levels within 24 hours helped to discriminate bacterial pneumonia (8.2 µg/L; IQR:0.2-43.0) from viral pneumonia and non-pneumonia cases (0.2 µg/L; IQR:0.1-0.7). The overall negative predictive value for bacterial pneumonia was 85.1%, increasing to 91.6% among episodes after 6 months of LT. CONCLUSIONS: Causes of severe pneumonia in LT are changing, with predominant role of P aeruginosa and respiratory viruses. PCT ≤ 0.5 µg/L within 24 hours helps to exclude bacterial pneumonia diagnosis in LT adults requiring ICU-A. A negative PCT test allows antimicrobial de-escalation and requires an alternative diagnostic to bacterial pneumonia.

Intensive Care to Facilitate Organ Donation: A Report on the 4-Year Experience of a Spanish Center With a Multidisciplinary Model to Promote Referrals Out of the Intensive Care Unit.

BACKGROUND: Intensive care to facilitate organ donation (ICOD) has been defined as the initiation or continuation of intensive care measures in patients with a devastating brain injury (DBI) in whom treatment for curative purposes is deemed futile, and who are considered possible organ donors, with the aim of offering donation after brain death (DBD) inside their end-of-life care plans. We describe the effect on the donation and transplantation activity of the implementation of ICOD protocol at a university hospital. METHODS: Retrospective analysis (2015-2018) of demographics and outcomes of all patients with a DBI, in whom ICOD was considered as part of their end-of-life care in Vall d'Hebron University Hospital, Barcelona. RESULTS: Of the 983 possible donors evaluated, ICOD was considered in 206 (21%), of whom 115 (55.8%) were medically unsuitable for donation. Family consent was obtained for 69 (76%) of the remaining patients. Refusal rate was twice as high when nontherapeutic ventilation was required for organ donation (34%) vs patients previously ventilated (13.6%) (P = .02). Patients subject to ICOD died in a median of 2 days (1-3 d) and 88.4% became actual donors (39 after brain death; 22 after circulatory death). Nine (17.6%) donors were finally not utilized. ICOD contributed to 29% (ranging from 27.7% in 2015 to 31.6% in 2018) of the 208 actual donors and 26% of the 603 organs transplanted. CONCLUSIONS: ICOD is well-accepted by families and offers the donation option to an increasing number of patients at our hospital. It provides an important and sustained increment of the organ pool for transplantation.

Pneumonia versus graft dysfunction as the cause of acute respiratory failure after lung transplant: a 4-year multicentre prospective study in 153 adults requiring intensive care admission.

We aimed to assess the main causes of intensive care unit (ICU) readmissions in lung transplant adults and to identify independent predictors of ICU mortality (primary end-point).This Spanish five-centre prospective cohort study enrolled all lung transplant adults with ICU readmissions after post-transplant ICU discharge between 2012 and 2016. Patients were followed until hospital discharge or death.153 lung transplant recipients presented 174 ICU readmissions at a median (interquartile range) of 6 (2-25) months post-transplant. Chronic lung allograft dysfunction was reported in 39 (25.5%) recipients, 13 of whom (all exitus) had restrictive allograft syndrome (RAS). Acute respiratory failure (ARF) (110 (71.9%)) was the main condition requiring ICU readmission. Graft rejection (six (5.4%) acute) caused only 12 (10.8%) readmissions whereas pneumonia (56 (36.6%)) was the main cause (50 admitted for ARF and six for shock), with Pseudomonas aeruginosa (50% multidrug resistant) being the predominant pathogen. 55 (35.9%) and 69 (45.1%) recipients died in the ICU and the hospital, respectively. Bronchiolitis obliterans syndrome (BOS) stage 2 (adjusted OR (aOR) 7.2 (95% CI 1.0-65.7)), BOS stage 3 (aOR 13.7 (95% CI 2.5-95.3)), RAS (aOR >50) and pneumonia at ICU readmission (aOR 2.5 (95% CI 1.0-7.1)) were identified in multivariate analyses as independent predictors of ICU mortality. Only eight (5.2%) patients had positive donor-specific antibodies prior to ICU readmission and this variable did not affect the model.ARF was the main condition requiring ICU readmission in lung transplant recipients and was associated with high mortality. Pneumonia was the main cause of death and was also an independent predictor. RAS should receive palliative care rather than ICU admission.

Procalcitonin accurately predicts lung transplant adults with low risk of pulmonary graft dysfunction and intensive care mortality.

PURPOSE: We evaluated the association of procalcitonin (PCT), IL-6-8-10 plasma levels during the first 72h after lung transplantation (LT) with ICU-mortality, oxygenation, primary graft dysfunction (PGD), and one-year graft function after LT. MATERIAL AND METHODS: Prospective, observational study. PCT and IL-6-8-10 plasma levels were measured at 24h, 48h and 72h after LT from 100 lung transplant recipients (LTr). Patients were followed until one year after LT. End-points were ICU survival, grade 3 PGD at 72h and one-year graft function. RESULTS: Higher PCT at 24h was associated with lower PaO2/FIO2 ratio and Grade 3 PGD over the first 72h after LT (p<0.05). PCT at 24h was higher in the 9 patients who died (2.90 vs 1.47ng/mL, p<0.05), with AUC=0.74 for predicting ICU-mortality. All patients with PCT<2ng/mL at 24h following LT, survived in the ICU (p<0.05). PCT and IL-10 at 48h were correlated with FEV1 (rho=-0.35) and FVC (rho=-0.29) one year after LT. (p<0.05). CONCLUSIONS: A breakpoint of PCT<2ng/mL within 24h has a high predictive value to exclude grade 3 PGD at 72h and for ICU survival. Moreover, both PCT and IL-10 within 48h were associated with significantly better graft function one year after surgery.

Dilution Factor of Quantitative Bacterial Cultures Obtained by Bronchoalveolar Lavage in Patients with Ventilator-Associated Bacterial Pneumonia.

Ventilator-associated bacterial pneumonia (VABP) is a difficult therapeutic problem. Considerable controversy exists regarding the optimal chemotherapy for this entity. The recent guidelines of the Infectious Diseases Society of America and the American Thoracic Society recommend a 7-day therapeutic course for VABP based on the balance of no negative impact on all-cause mortality, less resistance emergence, and fewer antibiotic treatment days, counterbalanced with a higher relapse rate for patients whose pathogen is a nonfermenter. The bacterial burden causing an infection has a substantial impact on treatment outcome and resistance selection. We describe the baseline bronchoalveolar lavage (BAL) fluid burden of organisms in suspected VABP patients screened for inclusion in a clinical trial. We measured the urea concentrations in plasma and BAL fluid to provide an index of the dilution of the bacterial and drug concentrations in the lung epithelial lining fluid introduced by the BAL procedure. We were then able to calculate the true bacterial burden as the diluted colony count times the dilution factor. The median dilution factor was 28.7, with the interquartile range (IQR) being 11.9 to 53.2. Median dilution factor-corrected colony counts were 6.18 log10(CFU/ml) [IQR, 5.43 to 6.46 log10(CFU/ml)]. In a subset of patients, repeat BAL on day 5 showed a good stability of the dilution factor. We previously showed that large bacterial burdens reduce or stop bacterial killing by granulocytes. (This study has been registered at ClinicalTrials.gov under registration no. NCT01570192.).

Prone positioning as a bridge to recovery from refractory hypoxaemia following lung transplantation.

OBJECTIVES: Refractory hypoxaemia is the leading cause of mortality in the postoperative period after lung transplantation. The role of prone positioning as a rescue therapy in this setting has not been assessed. We evaluated its effects in lung transplant recipients presenting refractory hypoxaemia following the surgery. METHODS: Prospectively collected data from 131 consecutive adult patients undergoing lung transplantation between January 2013 and December 2014 were evaluated. Twenty-two patients received prone position therapy. Indications, associated complications, time to initiation and duration of the manoeuvre were analysed and the effects of prone position on gas exchange were evaluated. Finally, outcomes in this cohort were compared against the rest of lung transplant recipients. RESULTS: Prone positioning was more frequently implemented within the first 72 h (68.2%) and its main indication was primary graft dysfunction. The manoeuvre was maintained during a median of 21 h. After prone position, the pressure of arterial oxygen/fraction of inspired oxygen ratio significantly increased from 81.0 mmHg [interquartile range (IQR) 71.5-104.0] to 220.0 (IQR 160.0-288.0) (P < 0.001). No complications related with the technique were reported. Patients who underwent the manoeuvre had longer hospital stay [50.0 days (IQR 36.0-67.0) vs 30.0 (IQR 23.0-56.0), P = 0.006] than the rest of the population. No differences were found comparing either 1-year mortality (9.1% vs 15.6%; P = 0.740) or 1-year graft function [forced expiratory volume in 1 second of 70.0 (IQR 53.0-83.0) vs 68.0 (IQR 53.5-80.5), P = 0.469]. CONCLUSIONS: Prone positioning is safe and significantly improves gas exchange in patients with refractory hypoxaemia after lung transplantation. It should be considered as a possible treatment in these patients.