Legionnaires Disease in Solid Organ Transplant Recipients: A Decade-Long Nationwide Study in France.

BACKGROUND: Legionnaires disease (LD) is a rare, life-threatening opportunistic bacterial infection that poses a significant risk to patients with impaired cell-mediated immunity such as solid organ transplant recipients. However, the epidemiologic features, clinical presentation, and outcomes of LD in this population are poorly described. RESEARCH QUESTION: What are the clinical manifestations, radiologic presentation, risk factors for severity, treatment, and outcome of LD in solid organ transplant recipients? STUDY DESIGN AND METHODS: In this 10-year multicenter retrospective cohort study in France, where LD notification is mandatory, patients were identified by hospital discharge databases. Diagnosis of LD relied on positive culture findings from any respiratory sample, positive urinary antigen test (UAT) results, positive specific serologic findings, or a combination thereof. Severe LD was defined as admission to the ICU. RESULTS: One hundred one patients from 51 transplantation centers were eligible; 64 patients (63.4%) were kidney transplant recipients. Median time between transplantation and LD was 5.6 years (interquartile range, 1.5-12 years). UAT results were positive in 92% of patients (89/97). Among 31 patients with positive culture findings in respiratory samples, Legionella pneumophila serogroup 1 was identified in 90%. Chest CT imaging showed alveolar consolidation in 98% of patients (54 of 57), ground-glass opacity in 63% of patients (36 of 57), macronodules in 21% of patients (12 of 57), and cavitation in 8.8% of patients (5 of 57). Fifty-seven patients (56%) were hospitalized in the ICU. In multivariate analysis, severe LD was associated with negative UAT findings at presentation (P = .047), lymphopenia (P = .014), respiratory symptoms (P = .010), and pleural effusion (P = .039). The 30-day and 12-month mortality rates were 8% (8 of 101) and 20% (19 of 97), respectively. In multivariate analysis, diabetes mellitus was the only factor associated with 12-month mortality (hazard ratio, 3.2; 95% OR, 1.19-8.64; P = .022). INTERPRETATION: LD is a late and severe complication occurring in solid organ transplant recipients that may present as pulmonary nodules on which diabetes impacts its long-term prognosis.

Changes in pulse pressure variation to assess preload responsiveness in mechanically ventilated patients with spontaneous breathing activity: an observational study.

BACKGROUND: Pulse pressure variation (PPV) is not reliable in predicting preload responsiveness in patients receiving mechanical with spontaneous breathing (SB) activity. We hypothesised that an increase in PPV after a tidal volume (VT) challenge (TVC) or a decrease in PPV during passive leg raising (PLR) can predict preload responsiveness in such cases. METHODS: This prospective observational study was performed in two ICUs and included patients receiving mechanical ventilation with SB, for whom the treating physician decided to test preload responsiveness. Transthoracic echocardiography was used to measure the velocity-time integral (VTI) of the left ventricular outflow tract. Patients exhibiting an increase in VTI ≥12% during PLR were defined as PLR+ patients (or preload responders). Then, a TVC was performed by increasing VT by 2 ml kg-1 predicted body weight (PBW) for 1 min. PPV was recorded at each step. RESULTS: Fifty-four patients (Simplified Acute Physiology Score II: 60 (25) ventilated with a VT of 6.5 (0.8) ml kg-1 PBW, were included. Twenty-two patients were PLR+. The absolute decrease in PPV during PLR and the absolute increase in PPV during TVC discriminated between PLR+ and PLR- patients with area under the receiver operating characteristic (AUROC) curve of 0.78 and 0.73, respectively, and cut-off values of -1% and +2%, respectively. Those AUROC curve values were similar but were significantly different from that of baseline PPV (0.61). CONCLUSION: In patients undergoing mechanical ventilation with SB activity, PPV does not predict preload responsiveness. However, the decrease in PPV during PLR and the increase in PPV during a TVC help discriminate preload responders from non-responders with moderate accuracy. CLINICAL TRIAL REGISTRATION: NCT04369027 (ClinicalTrials.gov).

Increase in Central Venous Pressure During Passive Leg Raising Cannot Detect Preload Unresponsiveness.

OBJECTIVE: By analogy with the classical central venous pressure rules to assess a fluid challenge, we hypothesized that an increase in central venous pressure greater than or equal to 5 cm H2O (i.e., 4 mm Hg) during passive leg raising can predict preload unresponsiveness diagnosed by the absence of increase in velocity-time integral of the left ventricular outflow tract greater than or equal to 10% during the test (negative passive leg raising test). DESIGN AND SETTINGS: Velocity-time integral was measured by transthoracic echocardiography. Central venous pressure and velocity-time integral were measured before and during passive leg raising. PATIENTS: Critically ill patients for whom the physician decided to test preload responsiveness by passive leg raising were prospectively included. MEASUREMENT AND MAIN RESULTS: Fifty-seven set of measurements were performed in 50 patients. Preload unresponsiveness (negative passive leg raising test) was observed in 32 cases. The changes in central venous pressure during passive leg raising did not differ between positive passive leg raising cases (positive passive leg raising test) and negative passive leg raising test cases (3 ± 2 vs 3 ± 2 mm Hg, respectively) and thus did not predict preload unresponsiveness (area under the receiver-operating characteristic curve of 0.59). An increase in central venous pressure greater than or equal to 4 mm Hg during passive leg raising was observed in 10 cases of positive passive leg raising test and in 11 cases of negative passive leg raising test. Taking an increase in central venous pressure greater than or equal to 3 or greater than or equal to 5 mm Hg rather than greater than or equal to 4 mm Hg during passive leg raising did not better allow one to identify negative passive leg raising test. CONCLUSIONS: Marked increase in central venous pressure during passive leg raising cannot identify negative passive leg raising test cases and thus preload unresponsiveness. Measurements of cardiac output (or its surrogates) during passive leg raising are, thus, mandatory to appropriately interpret this test.

Effect of Noninvasive Ventilation After Unplanned Extubation.

BACKGROUND: Our study set out to test the effect of noninvasive ventilation (NIV) performed after unplanned extubation. METHODS: Retrospective analysis of prospectively collected data in a university-affiliated mixed ICU of 12 beds during a 5-y period (January 2013 to December 2017). Unplanned extubation was defined as the occurrence of an unplanned removal of the endotracheal tube, whether deliberate or accidental. NIV after an unplanned extubation was not protocolized and was decided by the physician in charge on an individual basis. RESULTS: A total of 121 subjects (median [25th-75th percentile] age, 62.1 [43.3-73.6] y; median [25th-75th percentile] Simplified Acute Physiology Score II, 45 [36-54]) experienced 131 unplanned extubation episodes. Re-intubation was deemed necessary in 35 subjects (28.9%). NIV was used in 24 subjects (19.8%) (prophylactic NIV, n = 10; rescue NIV, n = 14). The re-intubation rates were 25.8%, 10%, and 64.3% in the no NIV, prophylactic, and rescue NIV subgroups, respectively. The median (25th-75th percentile) time to re-intubation was longer for subjects on NIV (9.1 [3.5-49.2] vs 0.46 [0.25-1] h, P = .001). The median (25th-75th percentile) ICU length of stay and duration of mechanical ventilation were longer in the subjects who underwent NIV (14.5 [7-24.5] vs 6 [3-14] d, respectively, P = .004; and 9 [3-22] vs 3 [1-7.3] d, respectively, P = .003). CONCLUSIONS: NIV after unplanned extubation had uncertain efficacy, especially when provided as rescue management of postextubation respiratory failure.

Constipation in critical care patients: both timing and duration matter.

OBJECTIVE: Most of the studies have defined constipation as a period without stool after ICU admission. We aimed to test the impact of both duration and timing of infrequent defecation in critical care patients. PATIENTS AND METHODS: We performed a prospective, bi-center, observational study. Patients were divided into three subgroups: 'not constipated', '3-5 days', and 'at least 6 days' (longest period without stool passage, respectively, shorter than 3 days, 3-5 days, and ≥6 days). Furthermore, 'early' constipated patients were defined as those for whom the longest time to stool passage occurred just after ICU admission, whereas for 'late' constipated patients the longest period without stool occurred later during ICU stay. RESULTS: A total of 182 patients were included: the mean age was 67.2 years (54.4-78.9 years), 80 were women, and simplified acute physiology score II was 42 (34-52). In all, 42 (23.1%), 82 (45.1%), and 58 (31.8%) belonged to the nonconstipated, 3-5 days, or greater than or equal to 6 days subgroup of patients, respectively. Time spent under mechanical ventilation and ICU length of stay was longer in the greater than or equal to 6 days subgroups as compared with both other subgroups. ICU stay was longer in the 3-5 days subgroup as compared with the not constipated patients. Furthermore, the late patients of the greater than or equal to 6 days subgroups exhibited worse survival as compared with all other patients. CONCLUSION: Both timing and duration of infrequent defecation seem to have an impact on critical care patient's outcome, and should therefore be included in the diagnostic criteria.

Assessment of changes in blood glucose concentration with intravascular microdialysis.

Blood glucose and its variability of is a major prognostic factor associated with morbidity. We hypothesized that intravenous microdialysis incorporated in a central venous catheter (CVC) would be interchangeable with changes in blood glucose measured by the reference method using a blood gas analyzer. Microdialysis and central venous blood glucose measurements were simultaneously recorded in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression and the Bland-Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in blood glucose measurement were evaluated by four-quadrant plot and trend interchangeability methods (TIM). In the 23 patients analyzed, the CVC was used as part of standard care with no complications. The correlation coefficient for absolute values (N = 99) was R = 0.91 (P < 0.001). The bias, precision and limits of agreement were - 9.1, 17.4 and - 43.2 to 24.9 mg/dL, respectively. The concordance rate for changes in blood glucose measurements (N = 77) was 85% with the four-quadrant plot. The TIM showed that 14 (18%) changes of blood glucose measurements were uninterpretable. Among the remaining 63 (82%) interpretable changes, 23 (37%) were interchangeable, 13 (20%) were in the gray zone, and 27 (43%) were not interchangeable. Microdialysis using a CVC appears to provide imprecise absolute blood glucose values with risk of insulin misuse. Moreover, only one third of changes in blood glucose measurements were interchangeable with the reference method using the TIM.