Effects of Reinstitution of Prolonged Mechanical Ventilation on the Outcomes of 370 Patients in a Long-Term Acute Care Hospital

Prolonged weaning from mechanical ventilation: who, what, when and how?

Weaning from invasive mechanical ventilation is an important part of the management of respiratory failure patients. Patients can be classified into those who wean on the first attempt (simple weaning), those who require up to three attempts (difficult weaning) and those who require more than three attempts (prolonged weaning). The process of weaning includes adequately treating the underlying cause of respiratory failure, assessing the readiness to wean, evaluating the response to a reduction in ventilatory support, and eventually liberation from mechanical ventilation and extubation or decannulation. Post-extubation respiratory failure is a contributor to poorer outcomes. Identifying and addressing modifiable risk factors for post-extubation respiratory failure is important; noninvasive ventilation and high-flow nasal cannulae may be useful bridging aids after extubation. Factors to consider in the pathophysiology of prolonged mechanical ventilation include increased respiratory muscle load, reduced respiratory muscle capacity and reduced respiratory drive. Management of these patients involves a multidisciplinary team, to first identify the cause of failed weaning attempts, and subsequently optimise the patient's physiology to improve the likelihood of being successfully weaned from invasive mechanical ventilation.

Automatic tube compensation for liberation from prolonged mechanical ventilation in tracheostomized patients: A retrospective analysis

BACKGROUND

To analyze the predictability of an automatic tube compensation (ATC) screening test compared with the conventional direct liberation test performed before continuous oxygen support for MV liberation.

METHODS

This retrospective study analyzed tracheostomized patients with prolonged MV in a weaning unit of a medical center in Taiwan. In March 2020, a four-day ATC test to screen patient eligibility for ventilator liberation was implemented, intended to replace the direct liberation test. We compared the predictive accuracy of these two screening methods on the relevant outcomes in the two years before and one year after the implementation of this policy.

RESULTS

Of the 403 cases, 246 (61%) and 157 (39%) received direct liberation and ATC screening tests, respectively. These two groups had similar outcomes: successful weaning upon leaving the Respiratory Care Center (RCC), success on day 100 of MV, success at hospital discharge, and in-hospital survival. Receiver operating characteristic curve analysis showed that the ATC screening test had better predictive ability than the direct liberation test for RCC weaning, discharge weaning, 100-day weaning, and in-hospital survival.

CONCLUSION

This closed-circuit ATC screening test before ventilator liberation is a feasible and valuable method for screening PMV patients undergoing ventilator liberation in the pandemic era. Its predictability for a comparison with the open-circuit oxygen test requires further investigation.

Development of a Nomogram Model for Predicting the Risk of In-Hospital Death in Patients with Acute Kidney Injury

OBJECTIVE

To analyze the risk factors of in-hospital death in patients with acute kidney injury (AKI) in the intensive care unit (ICU), and to develop a personalized risk prediction model.

METHODS

The clinical data of 137 AKI patients hospitalized in the ICU of Anhui provincial hospital from January 2018 to December 2020 were retrospectively analyzed. Patients were divided into two groups: those that survived to discharge ("survival" group, 100 cases) and those that died while in hospital ("death" group, 37 cases), and risk factors for in-hospital death analyzed.

RESULTS

The in-hospital mortality of AKI patients in the ICU was 27.01% (37/137). A multivariate logistic regression analysis indicated age, mechanical ventilation and vasoactive drugs were significant risk factors for in-hospital death in AKI patients, and a nomogram risk prediction model was developed. The Harrell's C-index of the nomogram model was 0.891 (95% CI: 0.837-0.945), and the area under the receiver operating characteristic (ROC) curve was 0.886 (95% CI: 0.823-0.936) after internal validation, indicating that the nomogram model had good discrimination. The Hosmer-Lemeshow goodness of fit test and calibration curve indicated the predicted probability of the nomogram model was consistent with the actual frequency of death in ICU patients with AKI. The decision curve analysis (DCA) showed that the clinical net benefit level of the nomogram model is highest when the probability threshold of AKI is between 0.01 and 0.75.

CONCLUSION

Patients in the ICU with AKI had high in-hospital mortality and were affected by a variety of risk factors. The nomogram prediction model based on the risk factors of AKI showed good prediction efficiency and clinical applicability, which could help medical staff in the ICU to identify AKI patients with high-risk, allowing early prevention, detection and intervention, and reducing the risk of in-hospital deaths in ICU patients with AKI.

Maximal expiratory pressure is associated with reinstitution of mechanical ventilation after successful unassisted breathing trials in tracheostomized patients with prolonged mechanical ventilation

Objective

Reinstitution of mechanical ventilation (MV) for tracheostomized patients after successful weaning may occur as the care setting changes from critical care to general care. We aimed to investigate the occurrence, consequence and associated factors of MV reinstitution.

Methods

We analyzed the clinical data and physiological measurements of tracheostomized patients with prolonged MV discharged from the weaning unit to general wards after successful weaning to compare between those with and without in-hospital MV reinstitution within 60 days.

Results

Of 454 patients successfully weaned, 116 (25.6%) reinstituted MV at general wards within 60 days; at hospital discharge, 42 (36.2%) of them were eventually liberated from MV, 51 (44.0%) remained MV dependent, and 33 (28.4%) died. Of the 338 patients without reinstitution within 60 days, only 3 (0.9%) were later reinstituted with MV before discharge (on day 67, 89 and 136 at general wards, respectively), and 322 (95.2%) were successfully weaned again at discharge, while 13 (3.8%) died. Patients with MV reinstitution had a significantly lower level of maximal expiratory pressure (P_Emax) before unassisted breathing trial compared to those without reinstitution. Multivariable Cox regression analysis showed fever at RCC discharge (hazard ratio [HR] 14.00, 95% confidence interval [CI] 3.2–61.9) chronic obstructive pulmonary disease (HR 2.37, 95% CI 1.34–4.18), renal replacement therapy at the ICU (HR 2.29, 95% CI 1.50–3.49) and extubation failure before tracheostomy (HR 1.76, 95% CI 1.18–2.63) were associated with increased risks of reinstitution, while P_Emax > 30 cmH₂O (HR 0.51, 95% CI 0.35–0.76) was associated with a decreased risk of reinstitution.

Conclusions

The reinstitution of MV at the general ward is significant, with poor outcomes. The P_Emax measured before unassisted breathing trial was significantly associated with the risk of reinstituting MV at the general wards.

Chronic Comorbid Illnesses Predict the Clinical Course of 866 Patients Requiring Prolonged Mechanical Ventilation in a Long-Term, Acute-Care Hospital

OBJECTIVE

To determine whether burdens of chronic comorbid illnesses can predict the clinical course of prolonged mechanical ventilation (PMV)patients in a long-term, acute-care hospital (LTACH).

METHODS

Retrospective study of 866 consecutive PMV patients whose burdens of chronic comorbid illnesses were quantified using the Cumulative Illness Rating Scale (CIRS). Based on increasing CIRS scores, 6 groups were formed and compared: group A (≤25; n = 97), group B (26-28; n = 105), group C (29-31; n = 181), group D (32-34; n = 208), group E (35-37; n = 173), and group F (>37; n = 102).

RESULTS

As CIRS scores increased from group A to group F, rates of weaning success, home discharges, and LTACH survival declined progressively from 74% to 17%, 48% to 0%, and 79% to 21%, respectively (all P < .001). Negative correlations between the mean score of each CIRS group and correspondent outcomes also supported patients' group allocation and an accurate prediction of their clinical course (all P < .01). Long-term survival progressively declined from a median survival time of 38.9 months in group A to 3.2 months in group F (P < .001). Compared to group A, risk of death was 75% greater in group F (P = .03). Noteworthy, PMV patients with CIRS score <25 showed greater ability to recover and a low likelihood of becoming chronically critically ill. Diagnostic accuracy of CIRS to predict likelihood of weaning success, home discharges, both LTACH and long-term survival was good (area under the curves ≥0.71; all P <.001).

CONCLUSIONS

The burden of chronic comorbid illnesses was a strong prognostic indicator of the clinical course of PMV patients. Patients with lower CIRS values showed greater ability to recover and were less likely to become chronically critically ill. Thus, CIRS can be used to help guide clinicians caring for PMV patients in transfer decisions to and from postacute care setting.