Critical Care Medicine最新文献

Objectives: Hyperkalemia is a common life-threatening condition causing severe electrophysiologic derangements and arrhythmias. The beneficial effects of calcium (Ca 2+ ) treatment for hyperkalemia have been attributed to "membrane stabilization," by restoration of resting membrane potential (RMP). However, the underlying mechanisms remain poorly understood. Our objective was to investigate the mechanisms underlying adverse electrophysiologic effects of hyperkalemia and the therapeutic effects of Ca 2+ treatment.

Design: Controlled experimental trial.

Setting: Laboratory investigation.

Subjects: Canine myocytes and tissue preparations.

Interventions and measurements: Optical action potentials and volume averaged electrocardiograms were recorded from the transmural wall of ventricular wedge preparations ( n = 7) at baseline (4 mM potassium), hyperkalemia (8-12 mM), and hyperkalemia + Ca 2+ (3.6 mM). Isolated myocytes were studied during hyperkalemia (8 mM) and after Ca 2+ treatment (6 mM) to determine cellular RMP.

Main results: Hyperkalemia markedly slowed conduction velocity (CV, by 67% ± 7%; p < 0.001) and homogeneously shortened action potential duration (APD, by 20% ± 10%; p < 0.002). In all preparations, this resulted in QRS widening and the "sine wave" pattern observed in severe hyperkalemia. Ca 2+ treatment restored CV (increase by 44% ± 18%; p < 0.02), resulting in narrowing of the QRS and normalization of the electrocardiogram, but did not restore APD. RMP was significantly elevated by hyperkalemia; however, it was not restored with Ca 2+ treatment suggesting a mechanism unrelated to "membrane stabilization." In addition, the effect of Ca 2+ was attenuated during L-type Ca 2+ channel blockade, suggesting a mechanism related to Ca 2+ -dependent (rather than normally sodium-dependent) conduction.

Conclusions: These data suggest that Ca 2+ treatment for hyperkalemia restores conduction through Ca 2+ -dependent propagation, rather than restoration of membrane potential or "membrane stabilization." Our findings provide a mechanistic rationale for Ca 2+ treatment when hyperkalemia produces abnormalities of conduction (i.e., QRS prolongation).

Objectives: To assess the effects of antibiotics delivered via the respiratory tract in preventing ventilator-associated pneumonia (VAP).

Data sources: We searched PubMed, Scopus, the Cochrane Library, and ClinicalTrials.gov for studies published in English up to October 25, 2023.

Study selection: Adult patients with mechanical ventilation of over 48 h and receiving inhaled or instilled antibiotics (with control group) to prevent VAP were included.

Data extraction: Two independent groups screened studies, extracted the data, and assessed the risk of bias. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess the certainty/quality of the evidence. Results of a random-effects model were reported for overall and predefined subgroup meta-analyses. The analysis was primarily conducted on randomized controlled trials, and observational studies were used for sensitivity analyses.

Data synthesis: Seven RCTs with 1445 patients were included, of which six involving 1283 patients used nebulizers to deliver antibiotics. No obvious risk of bias was found among the included RCTs for the primary outcome. Compared with control group, prophylactic antibiotics delivery via the respiratory tract significantly reduced the risk of VAP (risk ratio [RR], 0.69 [95% CI, 0.53-0.89]), particularly in subgroups where aminoglycosides (RR, 0.67 [0.47-0.97]) or nebulization (RR, 0.64 [0.49-0.83]) were used as opposed to other antibiotics (ceftazidime and colistin) or intratracheal instillation. No significant differences were observed in mortality, mechanical ventilation duration, ICU and hospital length of stay, duration of systemic antibiotics, need for tracheostomy, and adverse events between the two groups. Results were confirmed in sensitivity analyses.

Conclusions: In adult patients with mechanical ventilation for over 48 h, prophylactic antibiotics delivered via the respiratory tract reduced the risk of VAP, particularly for those treated with nebulized aminoglycosides.

Objectives: To quantify the frequency and patterns of clinicians' use of choice frames when discussing preference-sensitive care with surrogate decision-makers in the ICU.

Design: Secondary sequential content analysis.

Setting: One hundred one audio-recorded and transcribed conferences between surrogates and clinicians of incapacitated, critically ill adults from a prospective, multicenter cohort study.

Subjects: Surrogate decision-makers and clinicians.

Interventions: None.

Measurements and main results: Four coders identified preference-sensitive decision episodes addressed in the meetings, including topics such as mechanical ventilation, renal replacement, and overall goals of care. Prior critical care literature provided specific topics identified as preference-sensitive specific to the critical care context. Coders then examined each decision episode for the types of choice frames used by clinicians. The choice frames were selected a priori based on decision science literature. In total, there were 202 decision episodes across the 101 transcripts, with 20.3% of the decision episodes discussing mechanical ventilation, 19.3% overall goals of care, 14.4% renal replacement therapy, 14.4% post-discharge care (i.e., discharge location such as a skilled nursing facility), and the remaining 32.1% other topics. Clinicians used default framing, in which an option is presented that will be carried out if another option is not actively chosen, more frequently than any other choice frame (127 or 62.9% of decision episodes). Clinicians presented a polar interrogative, or a "yes or no question" to accept or reject a specific care choice, in 43 (21.3%) decision episodes. Clinicians more frequently presented options emphasizing both potential losses and gains rather than either in isolation.

Conclusions: Clinicians frequently use default framing and polar questions when discussing preference-sensitive choices with surrogate decision-makers, which are known to be powerful nudges. Future work should focus on designing interventions promoting the informed use of these and the other most common choice frames used by practicing clinicians.

Objectives: This study aimed to systematically assess the methodological quality and key recommendations of the guidelines for the diagnosis and treatment of liver failure (LF), furnishing constructive insights for guideline developers and equipping clinicians with evidence-based information to facilitate informed decision-making.

Data sources: Electronic databases and manual searches from January 2011 to August 2023.

Study selection: Two reviewers independently screened titles and abstracts, then full texts for eligibility. Fourteen guidelines were included.

Data extraction and synthesis: Two reviewers extracted data and checked by two others. Methodological quality of the guidelines was appraised using the Appraisal of Guidelines for Research and Evaluation II tool. Of the 14 guidelines, only the guidelines established by the Society of Critical Care Medicine and the American College of Gastroenterology (2023) achieved an aggregate quality score exceeding 60%, thereby meriting clinical recommendations. It emerged that there remains ample room for enhancement in the quality of the guidelines, particularly within the domains of stakeholder engagement, rigor, and applicability. Furthermore, an in-depth scrutiny of common recommendations and supporting evidence drawn from the 10 adult LF guidelines unveiled several key issues: controversy exists in the recommendation, the absence of supporting evidence and confusing use of evidence for recommendations, and a preference in evidence selection.

Conclusions: There are high differences in methodological quality and recommendations among LF guidelines. Improving these existing problems and controversies will benefit existing clinical practice and will be an effective way for developers to upgrade the guidelines.

Objectives: Despite the recommendation for lung-protective mechanical ventilation (LPMV) in pediatric acute respiratory distress syndrome (PARDS), there is a lack of robust supporting data and variable adherence in clinical practice. This study evaluates the impact of an LPMV protocol vs. standard care and adherence to LPMV elements on mortality. We hypothesized that LPMV strategies deployed as a pragmatic protocol reduces mortality in PARDS.

Design: Multicenter prospective before-and-after comparison design study.

Setting: Twenty-one PICUs.

Patients: Patients fulfilled the Pediatric Acute Lung Injury Consensus Conference 2015 definition of PARDS and were on invasive mechanical ventilation.

Interventions: The LPMV protocol included a limit on peak inspiratory pressure (PIP), delta/driving pressure (DP), tidal volume, positive end-expiratory pressure (PEEP) to F io2 combinations of the low PEEP acute respiratory distress syndrome network table, permissive hypercarbia, and conservative oxygen targets.

Measurements and main results: There were 285 of 693 (41·1%) and 408 of 693 (58·9%) patients treated with and without the LPMV protocol, respectively. Median age and oxygenation index was 1.5 years (0.4-5.3 yr) and 10.9 years (7.0-18.6 yr), respectively. There was no difference in 60-day mortality between LPMV and non-LPMV protocol groups (65/285 [22.8%] vs. 115/406 [28.3%]; p = 0.104). However, total adherence score did improve in the LPMV compared to non-LPMV group (57.1 [40.0-66.7] vs. 47.6 [31.0-58.3]; p < 0·001). After adjusting for confounders, adherence to LPMV strategies (adjusted hazard ratio, 0.98; 95% CI, 0.97-0.99; p = 0.004) but not the LPMV protocol itself was associated with a reduced risk of 60-day mortality. Adherence to PIP, DP, and PEEP/F io2 combinations were associated with reduced mortality.

Conclusions: Adherence to LPMV elements over the first week of PARDS was associated with reduced mortality. Future work is needed to improve implementation of LPMV in order to improve adherence.

Objectives: In sepsis treatment, antibiotics are crucial, but overuse risks development of antibiotic resistance. Recent guidelines recommended the use of procalcitonin to guide antibiotic cessation, but solid evidence is insufficient. Recently, concerns were raised that this strategy would increase recurrence. Additionally, optimal protocol or difference from the commonly used C-reactive protein (CRP) are uncertain. We aimed to compare the effectiveness and safety of procalcitonin- or CRP-guided antibiotic cessation strategies with standard of care in sepsis.

Data sources: A systematic search of PubMed, Embase, CENTRAL, Igaku Chuo Zasshi, ClinicalTrials.gov , and World Health Organization International Clinical Trials Platform.

Study selection: Randomized controlled trials involving adults with sepsis in intensive care.

Data extraction: A systematic review with network meta-analyses was performed. The Grading of Recommendations, Assessments, Developments, and Evaluation method was used to assess certainty.

Data synthesis: Eighteen studies involving 5023 participants were included. Procalcitonin-guided and CRP-guided strategies shortened antibiotic treatment (-1.89 days [95% CI, -2.30 to -1.47], -2.56 days [95% CI, -4.21 to -0.91]) with low- to moderate-certainty evidence. In procalcitonin-guided strategies, this benefit was consistent even in subsets with shorter baseline antimicrobial duration (7-10 d) or in Sepsis-3, and more pronounced in procalcitonin cutoff of "0.5 μg/L and 80% reduction." No benefit was observed when monitoring frequency was less than half of the initial 10 days. Procalcitonin-guided strategies lowered mortality (-27 per 1000 participants [95% CI, -45 to -7]) and this was pronounced in Sepsis-3, but CRP-guided strategies led to no difference in mortality. Recurrence did not increase significantly with either strategy (very low to low certainty).

Conclusions: In sepsis, procalcitonin- or CRP-guided antibiotic discontinuation strategies may be beneficial and safe. In particular, the usefulness of procalcitonin guidance for current Sepsis-3, where antimicrobials are used for more than 7 days, was supported. Well-designed studies are needed focusing on monitoring protocol and recurrence.

Objectives: Catheter malposition after subclavian venous catheterization (SVC) is not uncommon and can lead to serious complications. This study hypothesized that the left access is superior to the right access in terms of catheter malposition after ultrasound-guided infraclavicular SVC due to the asymmetry of the bilateral brachiocephalic veins.

Design: Parallel-armed randomized controlled trial.

Setting: A tertiary referral hospital in Korea.

Patients: Patients 20-79 years old who were scheduled to undergo SVC under general anesthesia.

Interventions: Patients were randomly assigned to either the left ( n = 224) or right ( n = 225) SVC group. The primary outcome measure was the overall catheter malposition rate. The secondary outcome measures included catheter malposition rates into the ipsilateral internal jugular and contralateral brachiocephalic veins, other catheterization-related complications, and catheterization performance.

Measurements and main results: The catheter malposition rate was lower (10 [4.5%] vs. 31 [13.8%], p = 0.001), especially in the ipsilateral internal jugular vein (9 [4.0%] vs. 24 [10.7%], p = 0.007), in the left SVC group than in the right SVC group. In the left SVC group, catheterization success rates on the first pass (88 [39.3%] vs. 65 [28.9%], p = 0.020) and first-catheterization attempt (198 [88.4%] vs. 181 [80.4%], p = 0.020) were higher whereas times for vein visualization (30 s [18-50] vs. 20 s [13-38], p < 0.001) and total catheterization (134 s [113-182] vs. 132 s [103-170], p = 0.034) were longer. There were no significant differences in other catheterization performance and catheterization-related complications between the two groups.

Conclusions: These findings strengthen the rationale for choosing the left access over the right access for ultrasound-guided infraclavicular SVC.

Objectives: International guidelines recommend IV crystalloid as the primary fluid for sepsis resuscitation, with 5% human albumin solution (HAS) as the second line. However, it is unclear which fluid has superior clinical effectiveness. We conducted a trial to assess the feasibility of delivering a randomized controlled trial comparing balanced crystalloid against 5% HAS as sole early resuscitation fluid in patients with sepsis presenting to hospital.

Design: Multicenter, open, parallel-group randomized feasibility trial.

Setting: Emergency departments (EDs) in 15 U.K. National Health Service (NHS) hospitals.

Patients: Adult patients with sepsis and a National Early Warning Score 2 greater than or equal to five requiring IV fluids withing one hour of randomization.

Interventions: IV fluid resuscitation with balanced crystalloid or 5% HAS for the first 6 hours following randomization.

Measurements and main results: Primary feasibility outcomes were recruitment rate and 30-day mortality. We successfully recruited 301 participants over 12 months. Mean ( sd ) age was 69 years (± 16 yr), and 151 (50%) were male. From 1303 participants screened; 502 participants were potentially eligible and 300 randomized to receive trial intervention with greater than 95% of participants receiving the intervention. The median number of participants per site was 19 (range, 1-63). Thirty-day mortality was 17.9% ( n = 53). Thirty-one participants died (21.1%) within 30 days in the 5% HAS arm, compared with 22 participants (14.8%) in the crystalloid arm (adjusted odds ratio, 1.50; 95% CIs, 0.84-2.83).

Conclusions: Our results suggest it is feasible to recruit critically ill patients to a fluid resuscitation trial in U.K. EDs using 5% HAS as a primary resuscitation fluid. There was lower mortality in the balanced crystalloid arm. Given these findings, a definitive trial is likely to be deliverable, but the point estimates suggest such a trial would be unlikely to demonstrate a significant benefit from using 5% HAS as a primary resuscitation fluid in sepsis.

Objectives: To study the impact of social determinants of health (SDoH) on pediatric extracorporeal membrane oxygenation (ECMO) outcomes.

Design, setting, and patients: Retrospective study of children (< 18 yr) supported on ECMO (October 1, 2015 to March 1, 2021) using Pediatric Health Information System (44 U.S. children's hospitals). Patients were divided into five diagnostic categories: neonatal cardiac, pediatric cardiac, neonatal respiratory, pediatric respiratory, and sepsis. SDoH included the Child Opportunity Index (COI; higher indicates social advantage), race, ethnicity, payer, and U.S. region. Children without COI were excluded. Diagnostic category-specific clinical variables related to baseline health and illness severity were collected.

Interventions: None.

Measurements and main results: Children supported on ECMO experienced a 33% in-hospital mortality (2863/8710). Overall, children with lower COI, "other" race, Hispanic ethnicity, public insurance and from South or West regions had greater mortality. Associations between SDoH and ECMO outcomes differed between diagnostic cohorts. Bivariate analyses found that only pediatric cardiac patients had an association between COI or race and mortality. Multivariable logistic regression analyses examined relationships between SDoH, clinical variables and mortality within diagnostic categories. Pediatric cardiac patients had 5% increased odds of death (95% CI, 1.01-1.09) for every 10-point decrement in COI, while Hispanic ethnicity was associated with higher survival (adjusted odds ratio [aOR] 0.72 [0.57-0.89]). Children with heart disease from the highest COI quintile had less cardiac-surgical complexity and earlier cannulation. Independent associations with mortality were observed in sepsis for Black race (aOR 1.62 [1.06-2.47]) and other payer in pediatric respiratory patients (aOR 1.94 [1.23-3.06]).

Conclusions: SDoH are statistically associated with pediatric ECMO outcomes; however, associations differ between diagnostic categories. Influence of COI was observed only in cardiac patients while payer, race, and ethnicity results varied. Further research should investigate differences between diagnostic cohorts and age groups to understand drivers of inequitable outcomes.