A prospective observational cohort study was conducted at our 24-bed medical and surgical ICU to study the outcomes of patients who had undergone CABG surgery. Patients undergoing mixed valve surgery and CABG surgery were excluded. The institutional review board waived the need for informed consent because the variables included in the ICURSS model (Fig 1) had already been used for clinical purposes. These variables were recorded along with other demographic and clinical variables once patients arrived in the ICU from the operating room (OR).
Airway and ventilatory management was carried out according to a standard extubation protocol based on the clinical judgment of the ICU medical team. Basically, patients met standard extubation criteria if they were hemodynamically stable (ie, normotension, heart rate of 5 mL/kg at a positive end-expiratory pressure level of 5 cm H2O rendered a Pao2 of > 80 mm Hg and a Paco2 of < 45 mm Hg at fraction of inspired oxygen of 0.4, with a spontaneous respiratory rate < 30 breaths/min. The criteria used for deciding whether to extubate were mainly supported by clinical judgment regarding the ability of the patient to tolerate the change from intermittent positive-pressure ventilation to pressure support ventilation modes, and further decreases of pressure support levels along with hemodynamic stability and lack of major complications. Finally a T-piece was placed 15 to 30 min before extubation, and muscle strength, spontaneous ventilation, and level of consciousness were assessed again in each patient before deciding whether to extubate. When patients had a T-piece placed, the decision to extubate had been already made. The T-trial was mainly used to confirm this decision, and this maneuver was aborted only in those cases where it was unsuccessful, with the patient again receiving mechanical ventilation as a result.
Attending physicians shared similar criteria and aimed to extubate the patient as early as was clinically possible, but they were kept blind to the goals of the study at that time. Pain control was continued after leaving the OR by means of the titrated continuous IV infusion of fentanyl or, more recently, remifen-tanil. Once in the ICU, IV analgesia was usually continued until after extubation.
Occasionally, patients were managed by means of epidural analgesia. In these cases, the potential effects on either the central or the muscular control of respiratory function were carefully monitored, as well as the hemodynamic effects (hypotension). If they were present in any case, the infusion would be stopped as a result. Heart is motor of human’s body. But what may damage its life? The answer you may find on Canadian Neighbor Pharmacy with the latest medical news.
In rare instances, patients arrived in the ICU after they had been extubated in the OR. In such cases, the time of intubation was computed as equal to 0 h, and the patient was considered to have been successfully extubated if reintubation was not needed at another time. Those patients who remained intubated within the first 8 h after ICU admission and were judged as being unable to be extubated at that time were designated as having EEF. The next evaluations were carried out at 16, 24, 48, 72, and 96 h after ICU admission. Thus, patients who remained intubated after 16 h were designated as having a prolonged intubation period (PIP). After the first 24 h, the situation was defined as PMV, and different time cutoffs that were used to define this condition at 24, 48, 72, and 96 h.
We defined patients who died during the evaluation period (ie, 0 to 96 h) would be considered as having extubation failure for every cut point, independently of the moment of death and the number of hours of intubation received. Additionally, in every patient needing reintubation, the time of intubation was computed as a continuum from ICU admission to the last successful extubation. Although these subgroups may add up to only a few cases, this approach might skew the outcomes, and the results obtained including and not including data for these patients could differ. As a result, the data were analyzed and compared both including and not including the data for these patients.
The dependent variable was the dichotomous condition of successful extubation (ie, yes or no) present at each one of the six different time cutoffs listed above. Each outcome variable was matched against the ICURSS values that were calculated in every patient after ICU admission. The predictive ability for extubation failure of the ICURSS model at the six different cutoff points was calibrated using the Hosmer-Lemeshow (HL) goodness-of-fit test. To use the HL statistic, the expected number of events in most groups must exceed five, and none of the groups have expected values of 0.8), “moderate” (AUC, 0.6 to 0.8), or “poor” (AUC, < 0.6).
Statistical analyses were performed using a statistical software package (SPSS, version 12.0.1 for Windows; SPSS Inc; Chicago, IL). The data are presented as the median and the mean ± SD. To compare continuous variables between two groups, median (interquartile range), Student t test, and Mann-Whitney test were used. A p value of < 0.05 was considered to be statistically significant.