Annop Piriyapatsom

Tracheal tube obstruction in mechanically ventilated patients assessed by high-resolution computed tomography

Background:Tracheal intubation compromises mucus clearance and secretions accumulate inside the tracheal tube (TT). The aim of this study was to evaluate with a novel methodology TT luminal obstruction in critically ill patients. Methods:This was a three-phase study: (1) the authors collected 20 TTs at extubation. High-resolution computed tomography (CT) was performed to determine cross-sectional area (CSA) and mucus distribution within the TT; (2) five TTs partially filled with silicone were used to correlate high-resolution CT results and increased airflow resistance; and (3) 20 chest CT scans of intubated patients were reviewed for detection of secretions in ventilated patients’ TT. Results:Postextubation TTs showed a maximum CSA reduction of (mean ± SD) 24.9 ± 3.9% (range 3.3 to 71.2%) after a median intubation of 4.5 (interquartile range 2.5 to 6.5) days. CSA progressively decreased from oral to lung end of used TTs. The luminal volume of air was different between used and new TTs for all internal diameters (P < 0.01 for new vs. used TTs for all studied internal diameters). The relationship between pressure drop and increasing airflow rates was nonlinear and depended on minimum CSA available to ventilation. Weak correlation was found between TT occlusion and days of intubation (R2 = 0.352, P = 0.006). With standard clinical chest CT scans, 6 of 20 TTs showed measurable secretions with a CSA reduction of 24.0 ± 3.9%. Conclusions:TT luminal narrowing is a common finding and correlates with increased airflow resistance. The authors propose high-resolution CT as a novel technique to visualize and quantify secretions collected within the TT lumen.

Prospective Observational Study of Predictors of Re-Intubation Following Extubation in the Surgical ICU

BACKGROUND: Re-intubation is associated with high morbidity and mortality. There is limited information regarding the risk factors that predispose patients admitted to the surgical ICU to re-intubation. We hypothesized that preoperative comorbidities, acquired muscular weakness, and renal dysfunction would be predictors of re-intubation in the surgical ICU population. METHODS: This was a prospective observational study in 2 surgical ICUs of a large tertiary hospital. All patients who were extubated during their surgical ICU stay were included. Demographic and clinical data were collected before and after extubation. The primary outcome was re-intubation within 72 h. Using multivariate logistic regression analysis, independent risk factors of re-intubation were determined, and a prediction score was developed. RESULTS: Between December 1, 2012, and January 31, 2014, we included 764 consecutive subjects. Of these, 65 subjects (8.5%) required re-intubation. Independent risk factors of re-intubation were blood urea nitrogen level of >8.2 mmol/L (odds ratio [OR] 3.66, 95% CI 1.97–6.80), hemoglobin level of <75 g/L (OR 2.10, 95% CI 1.23–3.61), and muscle strength of ≤3 (OR 2.03, 95% CI 1.16–3.55). The presence of all 3 risk factors was associated with an estimated probability for re-intubation of 26.8%. CONCLUSIONS: In noncardiac surgery, surgical ICU subjects, elevated blood urea nitrogen level, low hemoglobin level, and muscle weakness were identified as independent risk factors for re-intubation. The presence of these risk factors can potentially aid clinicians in making informed decisions regarding optimal airway management in patients considered for an extubation attempt. (ClinicalTrials.gov registration NCT01967056.)

Endotracheal Tubes Cleaned With a Novel Mechanism for Secretion Removal: A Randomized Controlled Clinical Study

INTRODUCTION: Intubation compromises mucus clearance, allowing secretions to accumulate inside the endotracheal tube (ETT). The purpose of this trial was to evaluate a novel device for ETT cleaning. We hypothesized that its routine use would reduce tube occlusion due to mucus accumulation, while decreasing airway bacterial colonization. METHODS: Subjects were randomized to either the use of the device every 8 h, or the institutional standard of care (blind tracheal suction) only. ETTs were collected at extubation and analyzed with high-resolution computed tomography (HRCT) for quantification of mucus volume. Microbiological testing was performed on biofilm samples. Vital signs and ventilatory settings were collected at the bedside. In-hospital follow-up was conducted, and a final evaluation survey was completed by respiratory therapists. RESULTS: Seventy-four subjects expected to remain intubated for longer than 48 h were enrolled (77 ETTs, 37 treatment vs 40 controls). Treated tubes showed reduced mucus accumulation (0.56 ± 0.12 vs 0.71 ± 0.28 mL; P = .004) and reduced occlusion (6.3 ± 1.7 vs 8.9 ± 7.6%; P = .039). The HRCT slice showing the narrowest lumen within each ETT exhibited less occlusion in cleaned tubes (10.6 ± 8.0 vs 17.7 ± 13.4%, 95% CI: 2–12.1; P = .007). Data on microbial colonization showed a trend in the treatment group toward a reduced ETT-based biomass of bacteria known to cause ventilator-associated pneumonia. No adverse events were reported. The staff was satisfied by the overall safety and feasibility of the device. CONCLUSION: The endOclear is a safe and effective device. It prevents luminal occlusion, thereby better preserving ETT nominal function.

Sedation and Paralysis

Sedation is used almost universally in the care of critically ill patients, especially in those who require mechanical ventilatory support or other life-saving invasive procedures. This review will focus on the sedation strategies for critically ill patients and the pharmacology of commonly used sedative agents. The role of neuromuscular blocking agents in the ICU will be examined and the pharmacology of commonly used agents is reviewed. Finally a strategy for rational use of these sedative and neuromuscular blocking agents in critically ill patients will be proposed.

Lumbar skeletal muscle index derived from routine computed tomography exams predict adverse post-extubation outcomes in critically ill patients

Purpose: To evaluate the effect of a skeletal muscle index derived from a routine CT image at the level of vertebral body L3 (L3SMI) on outcomes of extubated patients in the surgical intensive care unit. Materials and methods: 231 patients of a prospective observational trial (NCT01967056) who had undergone CT within 5 days of extubation were included. L3SMI was computed using semi‐automated segmentation. Primary outcomes were pneumonia within 30 days of extubation, adverse discharge disposition and 30‐day mortality. Secondary outcomes included re‐intubation within 72 h, total hospital costs, ICU length of stay (LOS), post‐extubation LOS and total hospital LOS. Outcomes were analyzed using multivariable regression models with a priori‐defined covariates height, gender, age, APACHE II score and Charlson Comorbidity Index. Results: L3SMI was an independent predictor of pneumonia (aOR 0.96; 95% CI 0.941–0.986; P = 0.002), adverse discharge disposition (aOR 0.98; 95% CI 0.957–0.999; P = 0.044) and 30‐day mortality (aOR 0.94; 95% CI 0.890–0.995; P = 0.033). L3SMI was significantly lower in re‐intubated patients (P = 0.024). Secondary analyses suggest that L3SMI is associated with total hospital costs (P = 0.043) and LOS post‐extubation (P = 0.048). Conclusion: The lumbar skeletal muscle index, derived from routine abdominal CT, is an objective prognostic tool at the time of extubation. HighlightsLumbar skeletal muscle index is an objective prognostic tool in ICU patients.L3SMI independently predicts pneumonia, adverse discharge and 30‐day mortality.L3SMI can be derived from a single axial CT image with minimal training.Simplified model including only L3SMI and age predicts primary outcomes.CT metrics add clinically useful prognostic information without additional cost.