Associations With Extubation Failure and Predictive Value of Risk Analytics Algorithms With Extubation Readiness Tests Following Congenital Cardiac Surgery

Factors Associated With Successful Extubation Readiness Testing in Children With Congenital Heart Disease

BACKGROUND

In children with congenital heart disease, extubation readiness testing (ERT) is performed to evaluate the potential for liberation from mechanical ventilation. There is a paucity of data that suggests what mechanical ventilation parameters are associated with successful ERT. We hypothesized that ERT success would be associated with certain mechanical ventilator parameters.

METHODS

Data on daily ERT assessments were recorded as part of a quality improvement project. In accordance with our respiratory therapist-driven ventilator protocol, patients were assessed daily for ERT eligibility and tested daily, if eligible. Mechanical ventilation parameters were categorized a priori to evaluate the differences in levels of respiratory support. The primary outcome was ERT success.

RESULTS

A total of 780 ERTs from 320 subjects (median [interquartile range] age 2.5 [0.6-6.5] months and median weight [interquartile range] 4.2 [3.3-6.9] kg) were evaluated. A total of 528 ERTs (68%) were passed, 306 successful ERTs (58%) resulted in extubation, and 30 subjects (9.4%) were re-intubated. There were statistically significant differences in the ERT pass rate for ventilator mode, peak inspiratory pressure, Δ pressure, PEEP, mean airway pressure ([Formula: see text]), and dead-space-to-tidal-volume ratio (all P < .001) but not for [Formula: see text]. ERT success decreased with increases in peak inspiratory pressure, Δ pressure, PEEP, [Formula: see text], and dead-space-to-tidal-volume ratio. Logistic regression revealed neonates, Δ pressure ≥ 11 cm H2O, and [Formula: see text] > 10 cm H2O were associated with a decreased odds of ERT success, whereas children ages 1-5 years and an [Formula: see text] of 0.31-0.40 had increased odds of ERT success.

CONCLUSIONS

ERT pass rates decreased as ventilator support increased; however, some subjects were able to pass ERT despite high ventilator support. We found that [Formula: see text] was associated with ERT success and that protocols should consider using [Formula: see text] instead of PEEP thresholds for ERT eligibility. Cyanotic lesions were not associated with ERT success, which suggests that patients with cyanotic heart disease can be included in ERT protocols.

Higher Cumulative Dose of Opioids and Other Sedatives are Associated with Extubation Failure in Norwood Patients

BACKGROUND

The primary purpose of this study is to evaluate the relationship between sedation usage and extubation failure, and to control for the effects of hemodynamic, oximetric indices, clinical characteristics, ventilatory settings pre- and post-extubation, and echocardiographic (echo) findings in neonates with hypoplastic left heart syndrome (HLHS) post-Norwood procedure.

METHODS

Single-center, retrospective analysis of Norwood patients during their first extubation post-surgery from January 2015 to July 2021. Extubation failure was defined as reintubation within 48 h of extubation. Demographics, clinical characteristics, ventilatory settings, echo findings (right ventricular function, tricuspid regurgitation), and cumulative dose of sedation medications before extubation were compared between patients with successful or failed extubation.

RESULTS

The analysis included 130 patients who underwent the Norwood procedure with 121 (93%) successful and 9 (7%) failed extubations. Univariate analyses showed that vocal cord anomaly (p = 0.05), lower end-tidal CO2 (p < 0.01), lower pulse-to-respiratory quotient (p = 0.02), and ketamine administration (p = 0.04) were associated with extubation failure. The use of opioids, benzodiazepines, dexmedetomidine, and ketamine are mutually correlated in this cohort. On multivariable analysis, the vocal cord anomaly (OR = 7.31, 95% CI 1.25-42.78, p = 0.027), pre-extubation end-tidal CO2 (OR = 0.80, 95% CI 0.65-0.97, p = 0.025), and higher cumulative dose of opioids (OR = 10.16, 95% CI 1.25-82.43, p = 0.030) were independently associated with extubation failure while also controlling for post-extubation respiratory support (CPAP/BiPAP/HFNC vs NC), intubation length, and echo results.

CONCLUSION

Higher cumulative opioid doses were associated with a greater incidence of extubation failure in infants post-Norwood procedure. Therefore, patients with higher cumulative doses of opioids should be more closely evaluated for extubation readiness in this population. Low end-tidal CO2 and low pulse-to-respiratory quotient were also associated with failed extubation. Consideration of the pulse-to-respiratory quotient in the extubation readiness assessment can be beneficial in the Norwood population.

Failed Extubation in Neonates After Cardiac Surgery: A Single-Center, Retrospective Study

OBJECTIVES

To describe factors associated with failed extubation (FE) in neonates following cardiovascular surgery, and the relationship with clinical outcomes.

DESIGN

Retrospective cohort study.

SETTING

Twenty-bed pediatric cardiac ICU (PCICU) in an academic tertiary care children's hospital.

PATIENTS

Neonates admitted to the PCICU following cardiac surgery between July 2015 and June 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients who experienced FE were compared with patients who were successfully extubated. Variables associated with FE ( p < 0.05) from univariate analysis were considered for inclusion in multivariable logistic regression. Univariate associations of FE with clinical outcomes were also examined. Of 240 patients, 40 (17%) experienced FE. Univariate analyses revealed associations of FE with upper airway (UA) abnormality (25% vs 8%, p = 0.003) and delayed sternal closure (50% vs 24%, p = 0.001). There were weaker associations of FE with hypoplastic left heart syndrome (25% vs 13%, p = 0.04), postoperative ventilation greater than 7 days (33% vs 15%, p = 0.01), Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category 5 operations (38% vs 21%, p = 0.02), and respiratory rate during spontaneous breathing trial (median 42 vs 37 breaths/min, p = 0.01). In multivariable analysis, UA abnormalities (adjusted odds ratio [AOR] 3.5; 95% CI, 1.4-9.0), postoperative ventilation greater than 7 days (AOR 2.3; 95% CI, 1.0-5.2), and STAT category 5 operations (AOR 2.4; 95% CI, 1.1-5.2) were independently associated with FE. FE was also associated with unplanned reoperation/reintervention during hospital course (38% vs 22%, p = 0.04), longer hospitalization (median 29 vs 16.5 d, p < 0.0001), and in-hospital mortality (13% vs 3%, p = 0.02).

CONCLUSIONS

FE in neonates occurs relatively commonly following cardiac surgery and is associated with adverse clinical outcomes. Additional data are needed to further optimize periextubation decision-making in patients with multiple clinical factors associated with FE.

The Inadequate Oxygen Delivery Index and Its Correlation with Venous Saturation in the Pediatric Cardiac Intensive Care Unit

Continuous monitoring software, T3, has an integrated index called the inadequate oxygen delivery index 50% (IDO2-50) which displays a probability that the mixed venous saturation is below a user-selected threshold of 30-50%. The primary aim of this study was to determine the correlation of the IDO2-50 with a measured venous saturation. The secondary aim of this study was to characterize the hemodynamic factors that contributed to the IDO2-50. This single-center, retrospective study aimed to characterize the correlation between IDO2-50 and inferior vena cava (IVC) saturation. A Bayesian Pearson correlation was conducted to assess the correlation between the collected variables of interest, with a particular interest in the correlation between the IDO2-50 and the IVC saturation. Receiver operator curve (ROC) analysis to assess the ability of the IDO2-50 to identify when the venous saturation was less than 50%. Bayesian linear regression was done with the IDO2-50 (dependent variable) and other independent variables. A total of 113 datasets were collected across 15 unique patients. IDO2-50 had moderate correlation with the IVC saturation (correlation coefficient - 0.569). The IDO2-50 had a weak but significant correlation with cerebral near-infrared spectroscopy (NIRS) values, a weak but significant correlation with heart rate, and a moderate and significant correlation with arterial saturation. ROC analysis demonstrated that the IDO2-50 had a good ability to identify a venous saturation below 50%, with an area under the curve of 0.797, cutoff point of 24.5 with a sensitivity of 81%, specificity of 66%, positive predictive value of 44%, and negative predictive value of 91%. Bayesian linear regression analysis yielded the following model: 237.82 + (1.18 × age in months) - (3.31 × arterial saturation) - (1.92 × cerebral NIRS) + (0.84 × heart rate). The IDO2 index has moderate correlation with IVC saturation. It has good sensitive and negative predictive value. Cerebral NIRS does appear to correlate better with the underlying venous saturation than the IDO2 index.

Association Between Pressure Support During Extubation Readiness Testing and Time to First Extubation in Children With Congenital Heart Disease

BACKGROUND

Extubation readiness testing (ERT) is often performed in children with congenital heart disease prior to liberation from mechanical ventilation. The ideal ERT method in this population is unknown. We recently changed our ERT method from variable (10, 8, or 6 cm H2O, depending on endotracheal tube size) to fixed (5 cm H2O) pressure support (PS). Our study assessed the association between this change and time to first extubation and need for re-intubation.

METHODS

We studied 2 temporally distinct cohorts, one where ERT was conducted with variable PS and another using PS fixed at 5 cm H2O. Data were prospectively collected as part of a quality improvement project. The primary outcome was time to first extubation. Secondary outcomes were need for re-intubation and percentage of successful ERTs. We performed Poisson regression or logistic regression for the association between PS during ERT and time to first extubation or re-intubation, respectively.

RESULTS

We included 320 subjects, 186 in the variable PS group and 152 in fixed PS group. In unadjusted analysis, median time to first extubation was longer in the fixed PS group compared to the variable PS group (4.1 [2.0-7.1] d vs 3.1 [1.1-5.9] d, P = .02), and there was no difference in re-intubation rate (11% vs 8%, P = .34). Subjects in the fixed PS group were significantly more likely to be mechanically ventilated after cardiac arrest, have a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category of 4 or 5, be extubated on day shift, receive enteral feeds at extubation, have higher respiratory support at extubation, and higher dead-space-to-tidal-volume ratio. After controlling for these variables in multivariable regression, we found no association between the choice of PS and time to first extubation or re-intubation.

CONCLUSIONS

The use of a fixed PS of 5 cm H2O instead of variable PS during ERT was not associated with longer time to first extubation or extubation failure.