Spontaneous breathing trial with pressure support on positive end-expiratory pressure and extensive use of non-invasive ventilation versus T-piece in difficult-to-wean patients from mechanical ventilation: a randomized controlled trial

BACKGROUND

The aim of this study is to assess whether a strategy combining spontaneous breathing trial (SBT) with both pressure support (PS) and positive end-expiratory pressure (PEEP) and extended use of post-extubation non-invasive ventilation (NIV) (extensively-assisted weaning) would shorten the time until successful extubation as compared with SBT with T-piece (TP) and post-extubation NIV performed in selected patients as advocated by guidelines (standard weaning), in difficult-to-wean patients from mechanical ventilation.

METHODS

The study is a single-center prospective open label, randomized controlled superiority trial with two parallel groups and balanced randomization with a 1:1 ratio. Eligible patients were intubated patients mechanically ventilated for more than 24 h who failed their first SBT using TP. In the extensively-assisted weaning group, SBT was performed with PS (7 cmH2O) and PEEP (5 cmH2O). In case of SBT success, an additional SBT with TP was performed. Failure of this SBT-TP was an additional criterion for post-extubation NIV in this group in addition to other recommended criteria. In the standard weaning group, SBT was performed with TP, and NIV was performed according to international guidelines. The primary outcome criterion was the time between inclusion and successful extubation evaluated with a Cox model with adjustment on randomization strata.

RESULTS

From May 2019 to March 2023, 98 patients were included and randomized in the study (49 in each group). Four patients were excluded from the intention-to-treat population (2 in both groups); therefore, 47 patients were analyzed in each group. The extensively-assisted weaning group had a higher median age (68 [58-73] vs. 62 [55-71] yrs.) and similar sex ratio (62% male vs. 57%). Time until successful extubation was not significantly different between extensively-assisted and standard weaning groups (median, 172 [50-436] vs. 95 [47-232] hours, Cox hazard ratio for successful extubation, 0.88 [95% confidence interval: 0.55-1.42] using the standard weaning group as a reference; p = 0.60). All secondary outcomes were not significantly different between groups.

CONCLUSION

An extensively-assisted weaning strategy did not lead to a shorter time to successful extubation than a standard weaning strategy. Trial registration The trial was registered on ClinicalTrials.gov (NCT03861117), on March 1, 2019, before the inclusion of the first patient. https://clinicaltrials.gov/study/NCT03861117 .

Unveiled central hypoventilation after tracheotomy in anti-IgLON5 disease: a case report

Anti-IgLON5 disease is a recently described entity that has been associated with neurological symptoms and sleep disturbances including sleep breathing disorders. Sleep stridor as well as obstructive and less often central sleep apnea have been reported but rarely needing ventilation on tracheotomy. We report the case of a patient in whom obstructive sleep apnea with secondary development of dysphagia and recurrent aspiration pneumonia led to the diagnosis of anti-IgLON 5 disease. Acute respiratory failure due to laryngospasm required intubation and eventually tracheotomy. Yet hypoventilation persisted, and polysomnography demonstrated central sleep apnea alternating with sleep-related tachypnea. Nocturnal ventilation was thus reintroduced. The association of obstructive sleep apnea with dysphagia is a potential red flag for anti-IgLON5 disease, which remains an overlooked diagnosis. Breathing disorders can be complex in this context, with a mixed obstructive and central pattern whose central component can be unveiled after tracheotomy. This highlights the importance of closely monitoring sleep and respiration even after tracheotomy.

CITATION

Tankéré P, Le Cam P, Folliet L, et al. Unveiled central hypoventilation after tracheotomy in anti-IgLON5 disease: a case report. J Clin Sleep Med. 2023;19(9):1701-1704.

Response to PEEP in COVID-19 ARDS patients with and without extracorporeal membrane oxygenation. A multicenter case–control computed tomography study

Background

PEEP selection in severe COVID-19 patients under extracorporeal membrane oxygenation (ECMO) is challenging as no study has assessed the alveolar recruitability in this setting. The aim of the study was to compare lung recruitability and the impact of PEEP on lung aeration in moderate and severe ARDS patients with or without ECMO, using computed tomography (CT).

Methods

We conducted a two-center prospective observational case–control study in adult COVID-19-related patients who had an indication for CT within 72 h of ARDS onset in non-ECMO patients or within 72  h after ECMO onset. Ninety-nine patients were included, of whom 24 had severe ARDS under ECMO, 59 severe ARDS without ECMO and 16 moderate ARDS.

Results

Non-inflated lung at PEEP 5 cmH₂O was significantly greater in ECMO than in non-ECMO patients. Recruitment induced by increasing PEEP from 5 to 15 cmH₂O was not significantly different between ECMO and non-ECMO patients, while PEEP-induced hyperinflation was significantly lower in the ECMO group and virtually nonexistent. The median [IQR] fraction of recruitable lung mass between PEEP 5 and 15 cmH₂O was 6 [4–10]%. Total superimposed pressure at PEEP 5 cmH₂O was significantly higher in ECMO patients and amounted to 12 [11–13] cmH₂O. The hyperinflation-to-recruitment ratio (i.e., a trade-off index of the adverse effects and benefits of PEEP) was significantly lower in ECMO patients and was lower than one in 23 (96%) ECMO patients, 41 (69%) severe non-ECMO patients and 8 (50%) moderate ARDS patients. Compliance of the aerated lung at PEEP 5 cmH₂O corrected for PEEP-induced recruitment (C_{BABY LUNG}) was significantly lower in ECMO patients than in non-ECMO patients and was linearly related to the logarithm of the hyperinflation-to-recruitment ratio.

Conclusions

Lung recruitability of COVID-19 pneumonia is not significantly different between ECMO and non-ECMO patients, with substantial interindividual variations. The balance between hyperinflation and recruitment induced by PEEP increase from 5 to 15 cmH₂O appears favorable in virtually all ECMO patients, while this PEEP level is required to counteract compressive forces leading to lung collapse. C_{BABY LUNG} is significantly lower in ECMO patients, independently of lung recruitability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04076-z.

Prevalence and risk factors of hemodynamic instability associated with preload-dependence during continuous renal replacement therapy in a prospective observational cohort of critically ill patients

Background

Hemodynamic instability is a frequent complication of continuous renal replacement therapy (CRRT). Postural tests (i.e., passive leg raising in the supine position or Trendelenburg maneuver in the prone position) combined with measurement of cardiac output are highly reliable to identify preload-dependence and may provide new insights into the mechanisms involved in hemodynamic instability related to CRRT (HIRRT). We aimed to assess the prevalence and risk factors of HIRRT associated with preload-dependence in ICU patients.

We conducted a single-center prospective observational cohort study in ICU patients with acute kidney injury KDIGO 3, started on CRRT in the last 24 h, and monitored with a PiCCO® device. The primary endpoint was the rate of HIRRT episodes associated with preload-dependence during the first 7 days after inclusion. HIRRT was defined as the occurrence of a mean arterial pressure below 65 mmHg requiring therapeutic intervention. Preload-dependence was assessed by postural tests every 4 h, and during each HIRRT episode. Data are expressed in median [1st quartile–3rd quartile], unless stated otherwise.

Results

42 patients (62% male, age 69 [59–77] year, SAPS-2 65 [49–76]) were included 6 [1–16] h after CRRT initiation and studied continuously for 121 [60–147] h. A median of 5 [3–8] HIRRT episodes occurred per patient, for a pooled total of 243 episodes. 131 episodes (54% [CI_95% 48–60%]) were associated with preload-dependence, 108 (44%, [CI_95% 38–51%]) without preload-dependence, and 4 were unclassified. Multivariate analysis (using variables collected prior to HIRRT) identified the following variables as risk factors for the occurrence of HIRRT associated with preload-dependence: preload-dependence before HIRRT [odds ratio (OR) = 3.82, p < 0.001], delay since last HIRRT episode > 8 h (OR = 0.56, p < 0.05), lactate (OR = 1.21 per 1-mmol L⁻¹ increase, p < 0.05), cardiac index (OR = 0.47 per 1-L min⁻¹ m⁻² increase, p < 0.001) and SOFA at ICU admission (OR = 0.91 per 1-point increase, p < 0.001). None of the CRRT settings was identified as risk factor for HIRRT.

Conclusions

In this single-center study, HIRRT associated with preload-dependence was slightly more frequent than HIRRT without preload-dependence in ICU patients undergoing CRRT. Testing for preload-dependence could help avoiding unnecessary decrease of fluid removal in preload-independent HIRRT during CRRT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00883-9.

Protracted viral shedding and viral load are associated with ICU mortality in Covid-19 patients with acute respiratory failure

Background

Protracted viral shedding is common in hospitalized patients with COVID-19 pneumonia, and up to 40% display signs of pulmonary fibrosis on computed tomography (CT) after hospital discharge. We hypothesized that COVID-19 patients with acute respiratory failure (ARF) who die in intensive care units (ICU) have a lower viral clearance in the respiratory tract than ICU patients discharged alive, and that protracted viral shedding in respiratory samples is associated with patterns of fibroproliferation on lung CT. We, therefore, conducted a retrospective observational study, in 2 ICU of Lyon university hospital.

Results

129 patients were included in the study, of whom 44 (34%) died in ICU. 432 RT-PCR for SARS-CoV-2 were performed and 137 CT scans were analyzed. Viral load was significantly higher in patients deceased as compared to patients alive at ICU discharge (p < 0.001), after adjustment for the site of viral sampling and RT-PCR technique. The median time to SARS-CoV-2 negativation on RT-PCR was 19 days [CI_95 %:15–21] in patients alive at ICU discharge and 26 days [CI_95 %:17-infinity] in non-survivors at ICU discharge. Competitive risk regression identified patients who died in ICU and age as independent risk factors for longer time to SARS-CoV-2 negativation on RT-PCR, while antiviral treatment was independently associated with shorter time. None of the CT scores exploring fibroproliferation (i.e., bronchiectasis and reticulation scores) were significantly associated with time to SARS-CoV-2 negativation.

Conclusions

Viral load in respiratory samples is significantly lower and viral shedding significantly shorter in ICU survivors of COVID-19 associated acute respiratory failure. Protracted viral shedding is unrelated to occurrence of fibrosis on lung CT.

Quantitative-analysis of computed tomography in COVID-19 and non COVID-19 ARDS patients: A case-control study

PURPOSE

The aim of this study was to assess whether the computed tomography (CT) features of COVID-19 (COVID+) ARDS differ from those of non-COVID-19 (COVID-) ARDS patients.

MATERIALS AND METHODS

The study is a single-center prospective observational study performed on adults with ARDS onset ≤72 h and a PaO₂/FiO₂ ≤ 200 mmHg. CT scans were acquired at PEEP set using a PEEP-FiO₂ table with VT adjusted to 6 ml/kg predicted body weight.

RESULTS

22 patients were included, of whom 13 presented with COVID-19 ARDS. Lung weight was significantly higher in COVID- patients, but all COVID+ patients presented supranormal lung weight values. Noninflated lung tissue was significantly higher in COVID- patients (36 ± 14% vs. 26 ± 15% of total lung weight at end-expiration, p < 0.01). Tidal recruitment was significantly higher in COVID- patients (20 ± 12 vs. 9 ± 11% of VT, p < 0.05). Lung density histograms of 5 COVID+ patients with high elastance (type H) were similar to those of COVID- patients, while those of the 8 COVID+ patients with normal elastance (type L) displayed higher aerated lung fraction.

Lung cancer may increase serum procalcitonin level

INTRODUCTION

Serum procalcitonin (PCT) is a biomarker used routinely to diagnose infections. Some malignancies are usual false positives for PCT. However, its value and behavior in the setting of lung cancers are poorly known. The objective of this study was to assess PCT positivity in a lung cancer cases series.

METHOD

Between November 2011 and September 2012, all cases of newly diagnosed lung cancer with a pre-antineoplastic PCT assay and no patent signs of infection were included in the study. All PCT levels were assessed by immunofluorescent assay in a single laboratory.

RESULTS

Eighty-nine patients were included (70.8% male; mean age 62; small-cell cancer 20.2%; stage IV cancer 60.7%). Overall, PCT was positive in 42%. A neuroendocrine component, having 2 or more metastatic sites, having a pleura or a liver metastasis, and being positive for CRP were all significantly associated with positive PCT in univariate analysis. In multivariate analysis, only the presence of a neuroendocrine component remained strongly associated with a positive PCT (AOR=7.24 [CI=95% 1.91-27.51]; P=0.004). Finally, baseline PCT levels <0.5 µg/l were found in 43% of NSCLC with a neuroendocrine component, vs. 9% of cancers with other histology (P=0.0001).

CONCLUSION

Lung cancer may cause false positives for procalcitonin, particularly in cases of neuroendocrine cancers or in the presence of multiple metastases. These results should be taken into account for PCT-based decisional algorithms.