Cardiac intensivists frequently assess patient readiness to wean off mechanical ventilation with an extubation readiness trial despite it being no more effective than clinician judgement alone. We evaluated the utility of high-frequency physiologic data and machine learning for improving the prediction of extubation failure in children with cardiovascular disease.

This was a retrospective analysis of clinical registry data and streamed physiologic extubation readiness trial data from one paediatric cardiac ICU (12/2016-3/2018). We analysed patients’ final extubation readiness trial. Machine learning methods (classification and regression tree, Boosting, Random Forest) were performed using clinical/demographic data, physiologic data, and both datasets. Extubation failure was defined as reintubation within 48 hrs. Classifier performance was assessed on prediction accuracy and area under the receiver operating characteristic curve.

Of 178 episodes, 11.2% (N = 20) failed extubation. Using clinical/demographic data, our machine learning methods identified variables such as age, weight, height, and ventilation duration as being important in predicting extubation failure. Best classifier performance with this data was Boosting (prediction accuracy: 0.88; area under the receiver operating characteristic curve: 0.74). Using physiologic data, our machine learning methods found oxygen saturation extremes and descriptors of dynamic compliance, central venous pressure, and heart/respiratory rate to be of importance. The best classifier in this setting was Random Forest (prediction accuracy: 0.89; area under the receiver operating characteristic curve: 0.75). Combining both datasets produced classifiers highlighting the importance of physiologic variables in determining extubation failure, though predictive performance was not improved.

Physiologic variables not routinely scrutinised during extubation readiness trials were identified as potential extubation failure predictors. Larger analyses are necessary to investigate whether these markers can improve clinical decision-making.

For CHD patients undergoing corrective surgery utilising cardiopulmonary bypass, post-operative inhaled nitric oxide has been administered to alleviate pulmonary hypertension. We performed a systematic review and meta-analyses to determine the effect of inhaled nitric oxide on haemodynamics, gas exchange, and hospitalisation characteristics in children immediately after cardiopulmonary bypass.

A systematic review of the literature was performed to identify full-text manuscripts in English. PubMed, EMBASE, and the Cochrane databases were queried. Once manuscripts were identified for inclusion, a list of all the endpoints in each manuscript was created. Endpoints with data present from two or more studies were then kept for pooled analyses. All endpoints included were continuous variables and so mean and standard deviation were utilised as the effect data for comparison.

A total of eight studies were deemed appropriate for inclusion. There were significant differences with decreases in mean pulmonary artery pressure of −6.82 mmHg, left atrial pressure of −1.16 mmHg, arteriovenous oxygen difference of −1.63, arterial carbon dioxide concentration of −2.41 mmHg, mechanical ventilation duration of −8.56 hours, and length of cardiac ICU stay duration of −0.91 days. All significant variables achieved p < 0.001.

Inhaled nitric oxide in children immediately after cardiopulmonary bypass decreases mean pulmonary artery pressure significantly and decreases the arterial carbon dioxide concentration significantly without significantly altering other haemodynamic parameters. This results in a statistically shorter duration of mechanical ventilation and cardiac ICU length of stay without altering overall hospital length of stay.

Percutaneous, transtracheal jet ventilation (percutaneous transtracheal jet ventilation) is an effective way to ventilate both adults and children. However, some authors suggest that a resuscitation bag can be utilized to ventilate through a cannula placed into the trachea.

Percutaneous transtracheal ventilation (percutaneous transtracheal ventilation) through a 14-gauge catheter is ineffective when attempted using a resuscitation bag.

Eight insufflation methods were studied. A 14-gauge intravenous catheter was attached to an adult resuscitation bag, a pediatric resuscitation bag, wall-source (wall) oxygen, portable-tank oxygen with a regulator, and a jet ventilator (JV) at two flow rates. The resuscitation bags were connected to the 14-gauge catheter using a 7 mm adult endotracheal tube adaptor connected to a 3 cc syringe barrel. The wall and tank oxygen were connected to he 14-gauge catheter using a three-way stopcock. The wall oxygen was tested with the regulator set at 15 liters per minute (LPM) and with the regulator wide open. The tank was tested with the regulator set at 15 and 25 LPM. The JV was connected directly to the 14-gauge catheter using JV tubing supplied by the manufacturer. Flow was measured using an Ohmeda 5420 Volume Monitor. A total of 30 measurements were taken, each during four seconds of insufflation, and the results averaged (milliliters (ml) per second (sec)) for each device.

Flow rates obtained using both resuscitation bags, tank oxygen, and regulated wall oxygen were extremely low (adult 215 ±20 ml/sec; pediatric 195 ±19 ml/sec; tank 358 ±13 ml/sec; wall at 15 l/min 346 ±20 ml/sec). Flow rates of 1,394 ±13 ml were obtained using wall oxygen with the regulator wide open. Using the JV with the regulator set at 50 pounds per square inch (psi), a flow rate of 1,759 ±40 was obtained.These were the only two methods that produced flow rates high enough to provide an adequate tidal volume to an adult.

Resuscitation bags should not be used to ventilate adult patients through a 14-gauge, transtracheal catheter. Jet ventilation is needed when percutaneous transtracheal ventilation is attempted. If jet ventilation is attempted using oxygen supply tubing, it must be connected to an unregulated oxygen source of at least 50 psi.