Is the Duration of Mechanical Ventilation Predictable?

doi:10.1378/chest.112.3.745

Chest

Volume 112, Issue 3, September 1997, Pages 745-751

https://doi.org/10.1378/chest.112.3.745 Get rights and content

Background

Prolonged mechanical ventilation (MV) is associated with high morbidity, mortality, and cost. However, few and limited data are available on the prediction of duration of MV. We conducted an observational cohort study to seek predictive criteria.

Methods

The study was performed in a surgical ICU (SICU) in a university hospital. One hundred ninety-five consecutive unselected patients and 203 episodes of MV were prospectively analyzed to determine if clinical features, physiologic parameters, or multifactor scoring systems, at the time of admission or intubation, could be used as predictors of MV ≥15 days. A univariate statistical analysis and a multiple logistic regression were used. A prospective validation study was then conducted to determine the accuracy of the results.

Results

(1) Univariate statistical analysis indicated that SICU length of stay, emergent endotracheal intubation as opposed to elective intubation, indication for MV, sepsis score at the time of admission and intubation, lung injury score (LIS) at the time of admission and intubation, number of organ system failures at the time of admission and intubation, and serum albumin concentration were significantly different between the two groups. (2) Only the circumstances (emergency) of endotracheal intubation (odds ratio [OR]=3.5, p=0.02) and the LIS (OR=3.7, p=0.004) independently predicted a duration of endotracheal intubation ≥15 days. One hundred twentyeight consecutive patients requiring emergent intubation and MV were included in the prospective validation. The accuracy of the LIS ≥1 used to predict MV ≥15 days was as follows: sensitivity=0.88; specificity=0.28; positive predictive value=0.24; negative predictive value=0.91.

Conclusion

Low incidence of MV ≥15 days was observed (13% and 20%, respectively, in observational cohort study and validation study) in unselected SICU patients. LIS ≥1 at the time of intubation provides excellent negative predictive value (0.93 and 0.91) of duration of MV ≥15 days. These data suggest that tracheotomy should not be considered for patients with LIS <1.

Section snippets

Materials and Methods

The study was conducted in a 12-bed surgical ICU (SICU) at a university hospital. Between November 1991 and December 1992, all patients requiring MV were included in the study. Patients requiring MV for cervical trauma, known subglottic or tracheal abnormality or chronic neuromuscular disease, and patients with noninvasive ventilation were not included. Patients were included only if intubation was performed in our SICU or in the operative room a few hours before SICU admission.

The following

Results

Over a 13-month period with 482 ICU admissions, 195 critically ill patients were studied: 123 male patients (63%), 72 female patients. Two hundred eighty-seven patients were not intubated and thus not included in the study. No patients met medical criteria for noninclusion (ie, neuromuscular disease). Two hundred three episodes of MV were analyzed (6 patients with two episodes and 1 patient with three). Mean age was 59.4±19.7 years (range, 14 to 96 years). The mean duration of endotracheal

Discussion

The first result of our prospective study is that various multiple factors and scores correlate with the duration of MV: serum albumin concentration, emergent endotracheal intubation, indication of MV, SS, LIS, OSFI, and SICU length of stay. The scores (SS, OSFI, LIS) are reliable for the duration of MV on the day of admission and on the day of intubation. However, only emergent endotracheal intubation and LIS on the day of intubation are statistically significant in the multivariate analysis.

Acknowledgment

The authors would like to thank Patricia Leriche for her manuscript assistance.

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Cited by (52)

Early risk factors for prolonged mechanical ventilation in patients with severe blunt thoracic trauma: A retrospective cohort study
2024, Injury
A significant proportion of patients with severe chest trauma require mechanical ventilation (MV). Early prediction of the duration of MV may influence clinical decisions. We aimed to determine early risk factors for prolonged MV among adults suffering from severe blunt thoracic trauma.
This retrospective, single-center, cohort study included all patients admitted between January 2014 and December 2020 due to severe blunt chest trauma. The primary outcome was prolonged MV, defined as invasive MV lasting more than 14 days. Multivariable logistic regression was performed to identify independent risk factors for prolonged MV.
The final analysis included 378 patients. The median duration of MV was 9.7 (IQR 3.0–18.0) days. 221 (58.5 %) patients required MV for more than 7 days and 143 (37.8 %) for more than 14 days. Male gender (aOR 3.01, 95 % CI 1.63–5.58, p < 0.001), age (aOR 1.40, 95 % CI 1.21–1.63, p < 0.001, for each category above 30 years), presence of severe head trauma (aOR 3.77, 95 % CI 2.23–6.38, p < 0.001), and transfusion of >5 blood units on admission (aOR 2.85, 95 % CI 1.62–5.02, p < 0.001) were independently associated with prolonged MV. The number of fractured ribs and the extent of lung contusions were associated with MV for more than 7 days, but not for 14 days. In the subgroup of 134 patients without concomitant head trauma, age (aOR 1.63, 95 % CI 1.18–2.27, p = 0.004, for each category above 30 years), respiratory comorbidities (aOR 9.70, 95 % CI 1.49–63.01, p = 0.017), worse p/f ratio during the first 24 h (aOR 1.55, 95 % CI 1.15–2.09, p = 0.004), and transfusion of >5 blood units on admission (aOR 5.71 95 % CI 1.84–17.68, p = 0.003) were independently associated with MV for more than 14 days.
Several predictors have been identified as independently associated with prolonged MV. Patients who meet these criteria are at high risk for prolonged MV and should be considered for interventions that could potentially shorten MV duration and reduce associated complications. Hemodynamically stable, healthy young patients suffering from severe thoracic trauma but no head injury, including those with extensive lung contusions and rib fractures, have a low risk of prolonged MV.
When To Do a Tracheostomy?
2021, Encyclopedia of Respiratory Medicine, Second Edition
The precise indication and optimal timing of tracheostomy in acute respiratory failure is still a matter of debate. An early tracheostomy may allow to shorten the weaning process by reducing the work of breathing (WOB) and decreasing the risks associated with prolonged intubation. However, it may unnecessarily expose some patients to potential complications related to the procedure. The question of the best timing for tracheostomy is closely related to the question of the early detection of patients who will experience difficult weaning.
Preadmission tracheostomy is associated with better outcomes in patients with prolonged mechanical ventilation in the postintensive care respiratory care setting
2017, Journal of the Formosan Medical Association
Citation Excerpt :
Similarly, it is difficult to predict the need for PMV early in the course of critical illness. Although a number of predictors have been identified,19–21 the investigations are heterogeneous in the study population and the results cannot be extrapolated to the general critically ill population. In this regard, it is impractical to anticipate a trial on the issue we explored in this study.
Prolonged mechanical ventilation (PMV) is the most common situation where tracheostomy is indicated for intensive care unit (ICU) patients. However, it is unknown if this procedure confers survival benefits on PMV patients in a post-ICU setting.
Patients who were admitted to the specialized weaning unit from 2005 to 2008 and received PMV were included in this study. On admission, data pertaining to patient characteristics, physiologic status, and type of artificial airway (tracheostomy vs. no tracheostomy) were obtained. Outcomes of tracheostomized and nontracheostomized patients were evaluated using multivariate Cox proportional hazards and propensity score-matching models. The primary outcome of interest was 1-year survival.
A total of 401 patients (mean age 74.4 years, 204 male) were identified. In multivariate analyses, higher Acute Physiology and Chronic Health Evaluation II score [hazard ratio (HR) = 1.061, 95% confidence interval (CI) = 1.016–1.107] and presence of comorbidities, including congestive heart failure (HR = 1.562, 95% CI = 1.119–2.181), malignancy (HR = 1.942, 95% CI = 1.306–2.885), and liver cirrhosis (HR = 2.373, 95% CI = 1.015–5.544), were independently associated with 1-year mortality. An association between having tracheostomy and a better 1-year outcome was observed (HR = 0.625, 95% CI = 0.453–0.863). The matched cohort study also demonstrated a favorable 1-year survival for tracheostomized patients, and these patients had significantly lower in-hospital mortality (24% vs. 36%, p = 0.049) and risk of ventilator-associated pneumonia (10% vs. 20%, p = 0.030) than nontracheostomized ones.
Preadmission tracheostomy may be associated with better outcomes of PMV patients in a post-ICU respiratory care setting. The findings suggest that this procedure should be recommended before PMV patients are transferred to specialized weaning units.
Predicting Which Patients will Likely Benefit from Subglottic Secretion Drainage Endotracheal Tubes: A Retrospective Study
2016, Journal of Emergency Medicine
Subglottic secretion drainage endotracheal tubes (SSD ETTs) have been shown to decrease ventilator-associated pneumonia and are recommended for patients intubated > 48 h or 72 h. However, it is difficult to determine which patients will be intubated > 48 h or 72 h at the time of intubation.
We attempted to determine which patient characteristics were associated with intubations ≥ 48 h or 72 h in order to guide proper placement of SSD ETTs.
The medical records of 2,159 ventilated patients at a single institution were retrospectively reviewed for intubation duration, age, sex, race, body mass index, weight, intubation reason, whether the intubation was emergent, operative status, intensive care unit (ICU) diagnosis, intubation location, ICU location, comorbidities (e.g., congestive heart failure, chronic obstructive pulmonary disorder, coronary artery disease, dementia, and liver disease), acute kidney injury (AKI), and chronic renal injury. A multivariate regression analysis was then performed with all reliable data.
The following were associated with intubation ≥ 48 h: neuroscience critical care unit (NCCU) admission (risk ratio [RR] = 1.85; 95% confidence interval [CI] 1.34–2.56), emergent intubation (RR = 1.97; 95% 1.28–3.03), comorbid dementia (RR = 2.31; 95% 1.28–4.18), nonoperative intubation (RR = 1.77; 95% 1.28–4.18), and AKI (RR = 3.32; 95% 2.56–4.3). The following were independently associated with intubation ≥ 72 h: NCCU admission (RR = 2.2; 95 CI 1.57–3.08), nonoperative intubation (RR = 3.38; 95% CI 2.63–4.35), comorbid dementia (RR = 3.03; 95% CI 1.67–5.48), and AKI (RR = 3.11; 95% CI 2.38–4.07).
Nonoperative intubation, emergent intubation, history of dementia, admission to NCCU and AKI all appear to be independently associated with increased RRs for either ≥ 48 h or 72 h of ventilation.
Predictive models of prolonged mechanical ventilation yield moderate accuracy
2015, Journal of Critical Care
Citation Excerpt :
An accurate objective tool to assist with this prediction would therefore be very useful but does not currently exist. Studies that aimed at developing such a tool have yielded models with low accuracy but have not accounted for early deaths [9–11]. Regarding this latter limitation, it is important to note that mechanical ventilation may be “not prolonged” when it is discontinued by means of clinical improvement and successful liberation, or alternatively by early death while it is still ongoing.
To develop a model to predict prolonged mechanical ventilation within 48 hours of its initiation.
In 282 general intensive care unit patients, multiple variables from the first 2 days on mechanical ventilation and their total ventilation duration were prospectively collected. Three models accounting for early deaths were developed using different analyses: (a) multinomial logistic regression to predict duration > 7 days vs duration ≤ 7 days alive vs duration ≤ 7 days death; (b) binary logistic regression to predict duration > 7 days for the entire cohort and for survivors only, separately; and (c) Cox regression to predict time to being free of mechanical ventilation alive.
Positive end-expiratory pressure, postoperative state (negatively), and Sequential Organ Failure Assessment score were independently associated with prolonged mechanical ventilation. The multinomial regression model yielded an accuracy (95% confidence interval) of 60% (53%-64%). The binary regression models yielded accuracies of 67% (61%-72%) and 69% (63%-75%) for the entire cohort and for survivors, respectively. The Cox regression model showed an equivalent to area under the curve of 0.67 (0.62-0.71).
Different predictive models of prolonged mechanical ventilation in general intensive care unit patients achieve a moderate level of overall accuracy, likely insufficient to assist in clinical decisions.
Predicting the need of tracheostomy amongst patients admitted to an intensive care unit: A multivariate model
2013, American Journal of Otolaryngology - Head and Neck Medicine and Surgery
Patients requiring prolonged invasive mechanical ventilation are prone to complications, such as infections, tracheal stenosis and death. It has been proposed that early tracheostomy could have a role in preventing these outcomes, but the proper identification of patients at risk can be difficult.
The aim of this study was to develop a multivariate model that allows the early detection of patients that will require prolonged ventilatory support.
A retrospective cohort study was undertaken in the intensive care unit of the Hospital Naval Almirante Nef, Chile, between June 2011 and June 2012. The charts of all intubated patients were reviewed in search for early predictors of prolonged intubation (> 7 days). Multivariate logistic regression analysis was used to detect statistically significant associations and to assess potential confounders.
A total of 349 patients were admitted to the intensive care unit during the study period and 142 (40.7%) required invasive mechanical ventilation. Most of them were male (60.5%), with a mean age of 65.8 ± 16.7 years. Thirty-five patients (24%) required to be ventilated for 7 days or more, and 16 (46%) were tracheostomized for this reason. The regression model showed that older age (p = 0.026), a Pa/Fi ratio of less than 200 (p = 0.046), and the presence of chronic pulmonary disease (p = 0.035) or hypernatremia (p = 0.012) on intubation day were significantly associated with the requirement of prolonged intubation.
Invasive mechanical ventilation is a common reason for admittance to the ICU. The abovementioned predictors can be of assistance when selecting patients that could benefit from early tracheostomies, and are in agreement with earlier reports. Although the model's discriminating capacity was good, it is necessary to formally validate it before recommending its widespread use.

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Chest

Clinical Investigations in Critical CareIs the Duration of Mechanical Ventilation Predictable?

Background

Methods

Results

Conclusion

Section snippets

Materials and Methods

Results

Discussion

Acknowledgment

Chest

Chest

Am J Med

Chest

Lancet

Chest

Chest

Resolution of laryngeal injury following translaryngeal intubation

Am Rev Respir Dis

Early tracheostomy for primary airway management in the surgical critical care setting

Surgery

The role of early tracheostomy in blunt, multiple organ trauma

Am Surg

Timing of tracheotomy in mechanically ventilated patients

Am Rev Respir Dis

Clinical Investigations in Critical Care
Is the Duration of Mechanical Ventilation Predictable?