Dead Space to Tidal Volume Ratio Is Associated With Higher Postextubation Support in Children

Abstract

BACKGROUND: Extubation failure is associated with increased duration of mechanical ventilation, length of hospital stay, and mortality. An elevated dead-space-to-tidal-volume ratio (V D /V T) has been proposed as a predictor of successful extubation in children. We hypothesized that a higher V D /V T value would be associated with extubation failure and higher postextubation respiratory support. METHODS: This was a prospective, observational, cohort study. All subjects were < 18 y old and were extubated in the pediatric multidisciplinary ICU or the cardiac ICU at an academic medical center from June 2016 through March 2017. Using arterial blood gas analysis and mainstream volumetric capnography, daily V D /V T measurements were obtained on intubated subjects using an automated algorithm. Respiratory support upon extubation was based on the clinical team's judgment and defined as low (ie, room air or nasal cannula) or high (ie, high-flow nasal cannula, CPAP, or bi-level positive airway pressure). Subjects were monitored for 48 h after extubation for escalation in respiratory support and need for re-intubation. RESULTS: Of 189 subjects included in the analysis, 166 were successfully extubated and 23 (12%) required re-intubation. There was no significant difference in final V D /V T between those who extubated successfully and those who failed extubation, with a median V D /V T of 0.28 (interquartile range [IQR] 0.20-0.37) vs 0.29 (IQR 0.21-0.33), respectively (P 5 .87). Those who received a high level of support upon extubation had a higher V D /V T than those who received a low level of support, with a median of 0.32 (IQR 0.23-0.39) vs 0.25 (IQR 0.16-0.30), respectively (P < .001). This association remained significant when controlling for age, duration of intubation, and cyanotic congenital heart disease (odds ratio 1.63, 95% CI 1.18-2.24). CONCLUSIONS: There was no significant relationship between V D /V T and extubation success, although V D /V T was associated with the level of respiratory support provided following extubation. Further studies should investigate whether the use of V D /V T can help reduce extubation failure rates with varying levels of postextubation respiratory support.

Tests and Indices Predicting Extubation Failure in Children: A Systematic Review and Meta-analysis

“…Mean age was 2.86 [95% confidence interval (CI) 2.48–3.23] years, I 2 = 98.6% [ 4 , 19 – 23 , 25 – 52 ]. Mean duration of MV prior to extubation attempt was 5.91 (95% CI 4.85–6.97) days, I 2 = 99.5% [ 4 , 20 – 32 , 34 – 38 , 41 – 43 , 46 – 49 , 51 – 54 ]. Out of the studies that presented the indications for intubation (17/41 studies) [ 4 , 19 , 20 , 22 , 23 , 25 – 27 , 39 , 41 , 43 , 46 , 51 – 53 , 55 , 56 ], intubation due to respiratory pathologies were cited to be the most common indication ( n = 3070/4131).…”

“…Mean duration of MV prior to extubation attempt was 5.91 (95% CI 4.85–6.97) days, I 2 = 99.5% [ 4 , 20 – 32 , 34 – 38 , 41 – 43 , 46 – 49 , 51 – 54 ]. Out of the studies that presented the indications for intubation (17/41 studies) [ 4 , 19 , 20 , 22 , 23 , 25 – 27 , 39 , 41 , 43 , 46 , 51 – 53 , 55 , 56 ], intubation due to respiratory pathologies were cited to be the most common indication ( n = 3070/4131). In studies that presented reasons for admissions (22/41 studies) [ 19 – 21 , 23 , 24 , 29 – 35 , 37 , 42 , 44 , 45 , 47 – 50 , 53 , 54 ], respiratory diseases were also the most common reason for PICU admission ( n = 1372/3917).…”

The effect of low molecular weight heparin combined with air pressure in the prevention of lower extremity venous thrombosis after cesarean section: A single-center retrospective study

“…[ 29 ] In addition, LMWH inhibits thrombosis and arteriovenous thrombosis in vitro and in vivo without affecting platelet aggregation and fibrinogen-platelet binding. [ 30 ] It has a low likelihood of causing bleeding while exerting antithrombotic effects. At the recommended dose, LMWH does not prolong bleeding time.…”