Diagnostic Accuracy of Central Venous Catheter Confirmation by Bedside Ultrasound Versus Chest Radiography in Critically Ill Patients: A Systematic Review and Meta-Analysis. (Carroll)

Ablordeppey EA, Drewry AM, Beyer AB, et al. Diagnostic Accuracy of Central Venous Catheter Confirmation by Bedside Ultrasound Versus Chest Radiography in Critically Ill Patients: A Systematic Review and Meta-Analysis. Crit Care Med. 2017 Apr;45(4):715-724.

OBJECTIVE: We performed a systematic review and meta-analysis to examine the accuracy of bedside ultrasound for confirmation of central venous catheter position and exclusion of pneumothorax compared with chest radiography.

DATA SOURCES: PubMed, Embase, Cochrane Central Register of Controlled Trials, reference lists, conference proceedings and ClinicalTrials.gov.

STUDY SELECTION: Articles and abstracts describing the diagnostic accuracy of bedside ultrasound compared with chest radiography for confirmation of central venous catheters in sufficient detail to reconstruct 2 × 2 contingency tables were reviewed. Primary outcomes included the accuracy of confirming catheter positioning and detecting a pneumothorax. Secondary outcomes included feasibility, interrater reliability, and efficiency to complete bedside ultrasound confirmation of central venous catheter position.

DATA EXTRACTION: Investigators abstracted study details including research design and sonographic imaging technique to detect catheter malposition and procedure-related pneumothorax. Diagnostic accuracy measures included pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

DATA SYNTHESIS: Fifteen studies with 1,553 central venous catheter placements were identified with a pooled sensitivity and specificity of catheter malposition by ultrasound of 0.82 (0.77-0.86) and 0.98 (0.97-0.99), respectively. The pooled positive and negative likelihood ratios of catheter malposition by ultrasound were 31.12 (14.72-65.78) and 0.25 (0.13-0.47). The sensitivity and specificity of ultrasound for pneumothorax detection was nearly 100% in the participating studies. Bedside ultrasound reduced mean central venous catheter confirmation time by 58.3 minutes. Risk of bias and clinical heterogeneity in the studies were high.

CONCLUSIONS: Bedside ultrasound is faster than radiography at identifying pneumothorax after central venous catheter insertion. When a central venous catheter malposition exists, bedside ultrasound will identify four out of every five earlier than chest radiography.

Delirium in Critically Ill Children: An International Point Prevalence Study. (Carroll)

Traube C, Silver G, Reeder RW, et al. Delirium in Critically Ill Children: An International Point Prevalence Study. Crit Care Med. 2017 Apr; 45(4) :584-590.

OBJECTIVES: To determine prevalence of delirium in critically ill children and explore associated risk factors.

DESIGN: Multi-institutional point prevalence study.

SETTING: Twenty-five pediatric critical care units in the United States, the Netherlands, New Zealand, Australia, and Saudi Arabia.

PATIENTS: All children admitted to the pediatric critical care units on designated study days (n = 994).

INTERVENTION: Children were screened for delirium using the Cornell Assessment of Pediatric Delirium by the bedside nurse. Demographic and treatment-related variables were collected.

MEASUREMENTS AND MAIN RESULTS: Primary study outcome measure was prevalence of delirium. In 159 children, a final determination of mental status could not be ascertained. Of the 835 remaining subjects, 25% screened positive for delirium, 13% were classified as comatose, and 62% were delirium-free and coma-free. Delirium prevalence rates varied significantly with reason for ICU admission, with highest delirium rates found in children admitted with an infectious or inflammatory disorder. For children who were in the PICU for 6 or more days, delirium prevalence rate was 38%. In a multivariate model, risk factors independently associated with development of delirium included age less than 2 years, mechanical ventilation, benzodiazepines, narcotics, use of physical restraints, and exposure to vasopressors and antiepileptics.

CONCLUSIONS: Delirium is a prevalent complication of critical illness in children, with identifiable risk factors. Further multi-institutional, longitudinal studies are required to investigate effect of delirium on long-term outcomes and possible preventive and treatment measures. Universal delirium screening is practical and can be implemented in pediatric critical care units.

Racial and Ethnic Variation in Pediatric Cardiac Extracorporeal Life Support Survival. (Carroll)

Chan T, et al. Racial and Ethnic Variation in Pediatric Cardiac Extracorporeal Life Support Survival. Crit Care Med. 2017 Apr; 45(4):670-678.

OBJECTIVES: Previous studies have suggested an association between nonwhite race and poor outcomes in small subsets of cardiac surgery patients who require extracorporeal life support. This study aims to examine the association of race/ethnicity with mortality in pediatric patients who receive extracorporeal life support for cardiac support.

DESIGN: Retrospective analysis of registry data.

SETTING: Prospectively collected multi-institutional registry data.

SUBJECTS: Data from all North American pediatric patients in the Extracorporeal Life Support International Registry who received extracorporeal life support for cardiac support between 1998 and 2012 were analyzed. Multivariate regression models were constructed to examine the association between race/ethnicity and hospital mortality, adjusting for demographics, diagnosis, pre-extracorporeal life support care, extracorporeal life support variables, and extracorporeal life support-related complications.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Of 7,106 patients undergoing cardiac extracorporeal life support, the majority of patients were of white race (56.9%) with black race (16.7%), Hispanic ethnicity (15.8%), and Asian race (2.8%) comprising the other major race/ethnic groups. The mortality rate was 53.9% (n = 3,831). After adjusting for covariates, multivariate analysis identified black race (relative risk = 1.10; 95% CI, 1.04-1.16) and Hispanic ethnicity (relative risk = 1.08; 95% CI, 1.02-1.14) as independent risk factors for mortality.

CONCLUSIONS: Black race and Hispanic ethnicity are independently associated with mortality in children who require cardiac extracorporeal life support.

Partial Neuromuscular Blockade during Partial Ventilatory Support in Sedated Patients with High Tidal Volumes. (Stulce)

Doorduin J, Nollet JL, Roesthuis LH, et al. Partial Neuromuscular Blockade during Partial Ventilatory Support in Sedated Patients with High Tidal Volumes. Am J Respir Crit Care Med. 2017 Apr 15;195(8):1033-1042.

RATIONALE: Controlled mechanical ventilation is used to deliver lung-protective ventilation in patients with acute respiratory distress syndrome. Despite recognized benefits, such as preserved diaphragm activity, partial support ventilation modes may be incompatible with lung-protective ventilation due to high Vt and high transpulmonary pressure. As an alternative to high-dose sedatives and controlled mechanical ventilation, pharmacologically induced neuromechanical uncoupling of the diaphragm should facilitate lung-protective ventilation under partial support modes.

OBJECTIVES: To investigate whether partial neuromuscular blockade can facilitate lung-protective ventilation while maintaining diaphragm activity under partial ventilatory support.

METHODS: In a proof-of-concept study, we enrolled 10 patients with lung injury and a Vt greater than 8 ml/kg under pressure support ventilation (PSV) and under sedation. After baseline measurements, rocuronium administration was titrated to a target Vt of 6 ml/kg during neurally adjusted ventilatory assist (NAVA). Thereafter, patients were ventilated in PSV and NAVA under continuous rocuronium infusion for 2 hours. Respiratory parameters, hemodynamic parameters, and blood gas values were measured.

MEASUREMENTS AND MAIN RESULTS: Rocuronium titration resulted in significant declines of Vt (mean ± SEM, 9.3 ± 0.6 to 5.6 ± 0.2 ml/kg; P < 0.0001), transpulmonary pressure (26.7 ± 2.5 to 10.7 ± 1.2 cm H2O; P < 0.0001), and diaphragm electrical activity (17.4 ± 2.3 to 4.5 ± 0.7 μV; P < 0.0001), and could be maintained under continuous rocuronium infusion. During titration, pH decreased (7.42 ± 0.02 to 7.35 ± 0.02; P < 0.0001), and mean arterial blood pressure increased (84 ± 6 to 99 ± 6 mm Hg; P = 0.0004), as did heart rate (83 ± 7 to 93 ± 8 beats/min; P = 0.0004).

CONCLUSIONS: Partial neuromuscular blockade facilitates lung-protective ventilation during partial ventilatory support, while maintaining diaphragm activity, in sedated patients with lung injury.