Critical Care最新文献

Citrate accumulation is a relevant complication of continuous kidney replacement therapy (CKRT). In response to the commentary by Wang and Li, we reassessed findings from a cohort of 911 critically ill patients, in whom bilirubin levels, technical parameters, and CKRT modality were independently associated with citrate accumulation. Continuous venovenous haemodiafiltration (CVVHDF) was associated with a lower risk compared with continuous venovenous haemodialysis (CVVHD). While this difference was initially hypothesised to reflect transmembrane flux and membrane patency, Wang and Li highlighted potential confounding by device-specific citrate concentrations. We acknowledge this limitation, as CVVHDF was delivered exclusively using the Prismaflex system, whereas CVVHD was performed with the multiFiltrate device that both use different citrate regimens. Although multiFiltrate was associated with a higher citrate load, total citrate load was not independently associated with citrate accumulation at therapy initiation or at the time of accumulation. Importantly, treatment modality remained significantly associated with citrate accumulation after multivariable adjustment. These findings suggest that factors beyond citrate load contribute to citrate accumulation, warranting further investigation.

Background: To determine whether lung ultrasound (LUS) may early predict the failure of non-invasive respiratory support (high-flow nasal cannula-HFNC, continuous positive airway pressure-CPAP, non-invasive ventilation-NIV) in hypoxemic patients.

Methods: In this prospective multicenter international observational study, we enrolled patients undergoing non-invasive treatments for hypoxemia (PaO₂/FiO₂ < 300 mmHg). LUS, PaO₂/FiO₂ and ROX index were assessed before (baseline) and 2 h after treatment start. Regional/global LUS aeration scores were computed (4 degrees of loss-of-aeration: 0-normal to 3-severe loss of aeration) in 6 regions per hemithorax (2 anterior, 2 lateral, 2 posterior). Failure was defined as need of respiratory support's escalation within 48 h (HFNC to CPAP to NIV, any support to intubation/ECMO).

Results: We studied 100 patients (age 70 [57-76] years; female sex 39%; supports: 13 HFNC, 68 CPAP, 19 NIV); the overall rate of treatment failure was 22%. At the baseline, clinical and ultrasound parameters were similar in failing and non-failing patients; after 2 h, failing patients had lower PaO₂/FiO₂. (149 mmHg [124-201] vs. 200 [171-243]; p = 0.001), lower ROX index (7.8 [4.9-9.2] vs. 10.9 [7.9-13.8]; p = 0.003) and higher lateral (3.0 [1.0-6.0] vs. 1.5 [0.0-3.0]; p = 0.047), antero-lateral (4.0 [1.0-9.0] vs. 2.0 [0.0-4.0]; p = 0.027) and global (13.0 [8.0-17.0] vs. 10.0 [7.0-13.0]; p = 0.036) LUS aeration scores. No improvement in lung aeration was observed in failing patients within the initial 2 h of treatment (global LUS score variations 0.0 [-2.0-1.0] vs. -3.0 [-5.0 - -2.0]; p < 0.001). ROX index and antero-lateral/global LUS scores' variations were independent predictors of failure. AUCs for treatment failure were: 2-hour ROX index 0.71 [0.58-0.84], 2-hour PaO₂/FiO₂ 0.73 [0.60-0.85], global LUS score variations 0.73 [0.62-0.89]. A combined clinical-ultrasound score (ROX-US) showed AUC of 0.82 [0.73-0.91]. A ROX-US≥1 identified the success of the treatment with sensitivity 95% and specificity 50%; a ROX-US≥2 identified the success of the treatment with sensitivity 45% and specificity 96%.

Conclusions: Changes in LUS aeration scores induced by 2 h of non-invasive respiratory support help early predict the risk of treatment failure. LUS score improved only in responders and was an independent predictor of failure.

Background: Extracorporeal carbon dioxide removal (ECCO₂R), when used as an adjunct to mechanical ventilation in patients with mild to moderate acute respiratory distress syndrome (ARDS), has been proposed as a strategy to control hypercapnic acidosis during ultra-lung-protective ventilation (ULPV). However, no multicenter study has systematically assessed ventilation improvement markers with a standardized protocol using ECCO₂R devices featuring a peristaltic pump design. This prospective, multicenter study conducted in France addresses these gaps by evaluating the performance and safety of PRISMALUNG+, a novel membrane lung specifically developed for ECCO₂R, either as a standalone therapy or combined with continuous renal replacement therapy (CRRT). A specific protocol for ULPV was used to minimize lung stress and mitigate the risk of hypoxemia.

Methods: Between April 2021 and December 2023, 58 patients were treated with ECCO₂R (16 in combination with CRRT). Tidal volume (V_T) was reduced stepwise from 6 mL/kg to 4 mL/kg. Once the partial pressure of carbon dioxide (PaCO₂) exceeded 50 mmHg, sweep gas (100% oxygen at 10 L/min) was initiated to provide ECCO₂R. Outcomes were measured at 8 and 24 h, while safety was monitored until discharge or day 28.

Results: During V_T reduction and before ECCO₂R initiation, peak hypercapnia and respiratory acidosis reached PaCO₂ of 53.0 [50.0-55.0] mmHg and pH of 7.30 [7.24-7.36]. After 24 h of treatment, V_T significantly decreased from 6.0 [6.0-6.1] to 4.0 [4.0-4.30] (p < 0.0001), driving pressure (∆P) from 12.0 [10.0-16.0] cmH₂O to 10.0 [8.0-13.0] cmH₂O (p < 0.0001), ventilatory ratio (VR) from 1.7 [1.5-2.1] to 1.3 [1.0-1.6] (p < 0.0001) and mechanical power from 18.8 [15.0-22.0] J/min to 11.8 [8.8-15.5] J/min (p < 0.0001). PaO₂/FiO₂ did not significantly change over time and respiratory acidosis resolved with treatment, as evidenced by normalization of pH and a reduction in PaCO₂. Importantly, no major bleeding events, intracranial hemorrhages, or hemolysis were reported during the study.

Conclusion: This study demonstrates that hypercapnic acidosis occurring during ultra-low V_T ventilation (ULPV) can be safely mitigated with ECCO₂R in mechanically ventilated patients with mild to moderate ARDS. Moreover, under ULPV, ∆P, VR and mechanical power were improved without inducing hypoxemia.

Trial registration: Clinicaltrials.gov: NCT04617093, Registration date: 30 October 2020.

Introduction: This study aimed to develop and validate a non-breath-holding contrast-enhanced electrical impedance tomography (EIT) method using low-pass filtering for bedside assessment of regional lung perfusion in mechanically ventilated ICU patients.

Methods: This was a randomized cross-over trial. Each patient received two 10 mL 10% NaCl bolus injections via a central venous catheter, performed respectively during an end-expiratory pause (apnea) and during ongoing mechanical ventilation (non-apnea). In the non-apnea method, a 0.17 Hz low-pass filter was used to remove respiratory interference during perfusion analysis. Pixel-wise correlation was assessed using Spearman correlation analysis.

Results: 20 mechanically ventilated ICU patients were included in the final analysis. Pixel-wise perfusion correlation between apnea and non-apnea methods showed good overall consistency (median r = 0.94, IQR 0.90-0.97). Global V/Q match%, dead space%, and shunt% were comparable between the two methods. The impedance drop duration was significantly shorter in the non-apnea method (5.3 s vs. 6.1 s, p = 0.008).

Conclusion: The non-apnea contrast-EIT method provides consistent lung perfusion images with the conventional apnea method, expanding EIT applicability to patients intolerant to apnea and potentially yielding more physiologically realistic results.

Background: Transesophageal echocardiography during out-of-hospital cardiac arrest can be performed during ongoing chest compressions and may improve resuscitation quality, but its prehospital use has not been systematically evaluated. To assess the feasibility, diagnostic yield, and impact of prehospital TEE on resuscitation metrics and advanced life support (ALS) interventions during OHCA.

Methods: We conducted a randomized controlled trial in a physician-staffed two-tiered emergency medical service (EMS). Adults with ongoing non-traumatic OHCA were randomized 1:1 to standard ALS or ALS plus TEE. The primary endpoints were hands-off time and chest compression fraction (CCF) from EMS arrival to return of spontaneous circulation (ROSC) or resuscitation termination. Secondary endpoints included ROSC at hospital admission, survival to hospital discharge, neurological status at hospital discharge, and TEE findings. Analyses followed the intention-to-treat principle.

Results: Of 249 screened patients, 35 were randomized and 32 analyzed (TEE n = 15; control n = 17). Median hands-off time was 4 s in both groups. Mean CCF was higher in the TEE group (96.2%) than the control group (91.6%), with a mean difference of 4.6% (95% confidence interval 2.5-6.7; p < 0.001). Sustained ROSC occurred in 40% (TEE) versus 71% (control; p = 0.083). The control group had an eCPR rate of 41%, compared to 20% in the TEE group. Using TEE, an incorrect area of maximal compression or inadequate depth was identified in 23% and 14%, respectively.

Conclusion: Prehospital TEE during OHCA was feasible without negatively interfering with CPR metrics, and provided clinically relevant diagnostic information and procedural guidance, warranting further evaluation in larger trials.

Trial registration: German Clinical Trials Register DRKS00028695 registered on 28 April 2022.