Determinants of time-to-weaning in a specialized respiratory care unit

Standard spontaneous breathing trial parameters may not predict unplanned reintubation for trauma patients

BACKGROUND

The applicability of spontaneous breathing trial (SBT) factors such as negative inspiratory force (NIF) and rapid shallow breathing index (RSBI) as predictors of reintubation in trauma patients (TPs) is unclear. This study aimed to identify predictors of unplanned reintubation (UR) in TPs.

METHODS

A single center, retrospective (1/2017-12/2023) study of TPs ≥18 years-old extubated from endotracheal mechanical ventilation was performed. Patients with UR during admission were compared to patients without UR. A multivariable logistic regression was performed to identify risk factors associated with UR.

RESULTS

39 of 424 ​TPs (9.2 ​%) had UR. UR patients were older (median: 55 vs 39 years-old, p ​= ​0.012) and more often had congestive heart failure (10.3 ​% vs 1.6 ​%, p ​< ​0.001), cirrhosis (7.7 ​% vs 1.9 ​%, p ​= ​0.025), end stage renal disease (7.7 ​% vs 1.6 ​%, p ​= ​0.044), and a higher injury severity scores (ISS) (median: 27 vs 18, p ​< ​0.001). UR patients had increased ventilator days (median: 6 vs 2, p ​< ​0.001) prior to extubation, whereas RSBI and NIF were similar (median: 36 vs 32, p ​= ​0.508) and (median: -24.0 vs -27.0 ​cm ​H2O, p ​= ​0.190). On multivariable analysis, RSBI <50 or <105 and NIF ​< ​-20 were not associated with UR. Age (OR 1.03, CI 1.01-1.05, p ​= ​0.006) and ISS (OR 1.04, CI 1.01-1.08, p ​= ​0.022) were independently associated with increased risk of UR.

CONCLUSIONS

SBT parameters (RSBI and NIF) were not associated with UR. Age and ISS were independently associated with UR. This suggests additional patient-specific factors should help guide extubation decisions for TPs.

Reported roles of care partners in a specialized weaning centre-perspectives of patients, care partners, and health care providers

Background

Care partners are individuals chosen by a person with an illness to support their care during hospitalization. Patients with persistent critical illness have longer than average critical care admission and often other conditions including dysphagia, communication vulnerability, severe physical deconditioning, the need for an artificial airway, and difficulty weaning from invasive mechanical ventilation. Family presence has been identified as important for patients experiencing persistent critical illness in specialized weaning centers. Despite this, the role of care partners in clinical settings for patients with persistent critical illness has not been fully characterized, particularly from the perspectives of patients, care partners, and health care providers. The aim of this study was to gain insights into the roles of care partners during persistent critical illness from the perspectives of patients, care partners, and health care providers.

Methods

We used qualitative descriptive methodology including semi-structured interviews and content analysis. Interviews were audio recorded and transcribed verbatim. Included participants (n = 30) were patient survivors (n = 7), care partners of patient survivors (n = 9), and professionally diverse health care providers (n = 14) of adult patients with persistent critical illness from two specialized units in one community academic hospital in Toronto, Canada.

Results

Participants across all groups described care partner roles that included physical, mental health, cognitive, social, and spiritual support of the patient, including the perceived role of safeguarding the multiple dimensions of care for the patient who is experiencing persistent critical care in specialized care settings.

Discussion

The results of this study are being used to co-design, implement, and evaluate a sustainable care partner program that is acceptable, appropriate, and feasible to implement in clinical settings where the care of patients with persistent critical illness occurs.

Reporting method

Consolidated criteria for reporting qualitative studies (COREQ).

Clinician-perceived barriers and facilitators for the provision of actionable processes of care important for persistent or chronic critical illness

AIM

To explore clinician-perceived barriers to and facilitators for the provision of actionable processes of care important for patients with persistent or chronic critical illness.

DESIGN

Qualitative descriptive interview study.

METHODS

Secondary analysis of semi-structured telephone interviews (December 2018 - February 2019) with professionally diverse clinicians working with adults experiencing persistent or chronic critical illness in Canadian intensive care units. We used deductive content analysis informed by the Social-Ecological Model.

RESULTS

We recruited 31 participants from intensive care units across nine Canadian provinces. Reported intrapersonal level barriers to the provision of actionable processes of care included lack of training, negative emotions and challenges prioritizing these patients. Facilitators included establishment of positive relations and trust with patients and family. Interpersonal barriers included communication difficulties, limited access to physicians and conflict. Facilitators included communication support, time spent with the patient/family and conflict management. Institutional barriers comprised inappropriate care processes, inadequate resources and disruptive environmental conditions. Facilitators were regular team rounds, appropriate staffing and employment of a primary care (nurse and/or physician) model. Community-level barriers included inappropriate care location and insufficient transition support. Facilitators were accessed to alternate care sites/teams and to formalized transition support. Public policy-level barriers included inadequacy of formal education programs for the care of these patients; knowledge implementation for patient management was identified as a facilitator.

CONCLUSION

Our results highlighted multilevel barriers and facilitators to the delivery of actionable processes important for quality care for patient/family experiencing persistent or chronic critical illness.

IMPACT

Using the Social-Ecological Model, the results of this study provide intra and interpersonal, institutional, community and policy-level barriers to address and facilitators to harness to improve the care of patients/family experiencing persistent or chronic critical illness.

REPORTING METHOD

Consolidated criteria for reporting qualitative studies.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

The effect of threshold inspiratory muscle training on the duration of weaning in intensive care unit-admitted patients: A randomized clinical trial

Background

The purpose of this study was to evaluate the effect of threshold inspiratory muscle training (IMT) on the duration of weaning in intensive care unit (ICU)-admitted patients.

Materials and Methods

This randomized clinical trial enrolled 79 ICU-admitted, mechanically ventilated patients in 2020-2021 in Imam Reza Hospital, Mashhad. Patients were randomly divided into intervention (n = 40) and control (n = 39) groups. The intervention group received threshold IMT and conventional chest physiotherapy, while the control group only received conventional chest physiotherapy once a day. Before and after the end of the intervention, the strength of inspiratory muscles and the duration of weaning were measured in both the groups.

Results

The duration of weaning was shorter in the intervention group (8.4 ± 1.1 days) versus the control group (11.2 ± 0.6 days) (P < 0.001). The rapid shallow breathing index decreased by 46.5% in the intervention group and by 27.3% in the control group after the intervention (both P < 0.001), and the between-group comparison showed a significantly higher reduction in the intervention group than control group (P < 0.001). The patients' compliance after the intervention compared to the 1^st day increased to 16.2 ± 6.6 in the intervention group and 9.6 ± 6.8 in the control group (both P < 0.001), and the between-group comparison showed a significantly higher increase in the intervention group than control group. The maximum inspiratory pressure increased by 13.7 ± 6.1 in the intervention group and by 9.1 ± 6.0 in the control group (P < 0.001). Furthermore, the weaning success was 54% more probable in the intervention group than control group (P < 0.05).

Conclusion

The results of this study showed the positive effect of IMT with threshold IMT trainer on increased strength of respiratory muscles and reduced weaning duration.

Plasma concentrations of NOX4 are predictive of successful liberation from mechanical ventilation and 28-day mortality in intubated patients

Background

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) enzymes play important roles in generating reactive oxygen species (ROS); in particular, NOX4 plays a distinct role in regulating lung inflammation and apoptosis.

Methods

We determined whether plasma NOX4 level can be used as a prognostic biomarker to guide weaning from mechanical ventilation and to predict mortality in intubated patients. Plasma levels of NOX4 were measured at days 1 (NOX4 D1) and 7 (NOX4 D7) after initiation of mechanical ventilation in 184 patients.

Results

With increase in day 7 NOX4 quartile, the success of weaning tended to decrease and 28-day mortality tended to increase. On multivariate logistic regression, Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) [odds ratio (OR): 1.10; 95% CI, 1.02–1.18], duration of mechanical ventilation (OR: 1.12; 95% CI: 1.06–1.18), and NOX4 D7 levels >18.2 ng/mL (OR: 4.40; 95% CI: 1.91–10.06) were independently associated with weaning failure. Also, Cox-hazard proportional model showed that NOX4 D7 level >18.2 ng/mL (hazard ratio [HR], 2.29; 95% CI, 1.26–4.16), APACHE II (HR: 1.07; 95% CI: 1.02–1.14), Sequential Organ Failure Assessment (SOFA) (HR: 1.10; 95% CI: 1.01–1.20) and coexisting cancer (HR: 1.99; 95% CI, 1.01–3.94), were independently associated with 28-day mortality. The longitudinal trend of NOX4 level varied according to the clinical outcomes.

Conclusions

An increased plasma NOX4 D7 level was associated with weaning failure and 28-day mortality in patients with mechanical ventilation. Our results suggest that NOX4-directed management may lead to improved outcomes in patients with mechanical ventilation.

Rapid Shallow Breathing Index as a Predictor of Extubation Outcomes in Pediatric Patients Underwent Cardiac Surgeries at King Faisal Cardiac Center

Introduction

Weaning patients of ventilation is an important step in the intensive care unit; therefore, assessing the perfect timing to do such critical action is of equal significance to prevent complications. Rapid shallow breathing index (RSBI) has been used as a prediction tool for weaning adult patients, but for pediatric patients it is still an area of unclarity. Accordingly, the aim of this study is to evaluate the RSBI as a predictor of extubation outcome in pediatric patients underwent cardiac surgery at King Faisal Cardiac Center from 2016 until 2019.

Methods

A retrospective cohort study was conducted at King Faisal Cardiac Center on all extubated children having cardiac surgeries from 2016 to 2019 with excluding the patients who were admitted for causes other than cardiac surgery. Their age was ranged from birth until 14 years. Moreover, the patients were grouped based on the extubation outcomes into: success, success with non-invasive ventilation, or failure which was defined as reintubation within 48 hours after extubation. Regarding the collected data, three readings of RSBI on hourly basis prior to extubation were calculated by dividing respiratory rate (RR) over tidal volume (VT) with a correction based on the body weight.

Results

A total of 86 patients met the inclusion and exclusion criteria. Thirty (34.9%) patients were successfully extubated, 51 (59.3%) patients had successful extubation with the use of non-invasive ventilation, and only five (5.8%) patients suffered from extubation failure. Two-hour RSBI as a predictor of outcome had a P-value of 0.003, one-hour RSBI had a P-value of 0.01, RSBI at time of extubation had a P-value of 0.02. Mean corpuscular volume (MCV) is higher in extubation failure group with a p-value of 0.01.

Conclusion

This study suggests that pediatric patients who suffer from extubation failure usually have a higher RSBI measurement compared to the patients who have a successful extubation. The most significant RSBI measurements to predict the extubation outcome were recorded two hours prior to extubation. Our study also found that extubation failure patients could have higher MCV than the success group.

The prognostic value of rapid shallow breathing index and physiologic dead space for weaning success in intensive care unit patients under mechanical ventilation

Background

Mechanical ventilation (MV) is a life-saving intervention that should be considered for patients with respiratory failure. This study was conducted to evaluate the predictive value of physiologic dead space for weaning success and compare it with rapid shallow breathing index (RSBI).

Materials and Methods

This cross-sectional study was conducted on 80 intensive care unit (ICU) patients who were under MV and candidate for weaning; among them, 68 patients experienced weaning success. RSBI was measured by dividing the respiratory rate by tidal volume. End-tidal CO₂ (PETCO₂) was obtained using caponometry, then dead-space was calculated as (VD/VT = (PaCO₂ - PETCO₂)/PaCO₂). PaCO₂ was also obtained from arterial blood gas recorded chart.

Results

Age, PaCO₂, PETCO₂, and RSBI were significantly different between those patients with and without weaning success (P < 0.05). RSBI ≤ 98 could predict the success of weaning with sensitivity 91.7%; specificity 76.5% and (AUC) area under the ROC curve (AUC = 0.87; 95% confidence interval [CI]: 0.78-0.94; P < 0.001). Dead space was not statistically significant prognostic index (AUC = 0.50; 95% CI: 0.31-0.69; P = 0.09).

Conclusion

In our study, RSBI was an effective predictive index for weaning success in ICU patients under MV, but dead space did not show significant predictive value. Further studies with larger sample sizes for providing more evidence are recommended.

Prospective observational cohort study of patients with weaning failure admitted to a specialist weaning, rehabilitation and home mechanical ventilation centre

OBJECTIVES

According to National Health Service England (NHSE) specialist respiratory commissioning specification for complex home ventilation, patients with weaning failure should be referred to a specialist centre. However, there are limited data reporting the clinical outcomes from such centres.

SETTING

Prospective observational cohort study of patients admitted to a UK specialist weaning, rehabilitation and home mechanical ventilation centre between February 2005 and July 2013.

PARTICIPANTS

262 patients admitted with a median age of 64.2 years (IQR 52.6-73.2 years). 59.9% were male.

RESULTS

39.7% of patients had neuromuscular and/or chest wall disease, 21% were postsurgical, 19.5% had chronic obstructive pulmonary disease (COPD), 5.3% had obesity-related respiratory failure and 14.5% had other diagnoses. 64.1% of patients were successfully weaned, with 38.2% weaned fully from ventilation, 24% weaned to nocturnal non-invasive ventilation (NIV), 1.9% weaned to nocturnal NIV with intermittent NIV during the daytime. 21.4% of patients were discharged on long-term tracheostomy ventilation. The obesity-related respiratory failure group were most likely to wean (relative risk (RR) for weaning success=1.48, 95% CI 1.35 to 1.77; p<0.001), but otherwise weaning success rates did not significantly vary by diagnostic group. The median time-to-wean was 19 days (IQR 9-33) and the median duration of stay was 31 days (IQR 16-50), with no difference observed between the groups. Weaning centre mortality was 14.5%, highest in the COPD group (RR=2.15, 95% CI 1.19 to 3.91, p=0.012) and lowest in the neuromuscular and/or chest wall disease group (RR=0.34, 95% CI 0.16 to 0.75, p=0.007). Of all patients discharged alive, survival was 71.7% at 6 months and 61.8% at 12 months postdischarge.

CONCLUSIONS

Following NHSE guidance, patients with weaning delay and failure should be considered for transfer to a specialist centre where available, which can demonstrate favourable short-term and long-term clinical outcomes.

Can integrative weaning index be a routine predictor for weaning success?

Objective:

To assess the effectiveness of integrative weaning index (IWI) as a predictor of weaning success.

Materials and Methods:

This is a prospective randomized controlled observer-blinded study and carried out on 120 patients of both sexes; patients who received mechanical ventilation for more than 24 h and met defined criteria for a weaning trial, underwent a 2-h spontaneous breathing trial with either IWI plus routine criteria of weaning (Group I n = 60) or routine criteria of weaning alone (control group) (Group C n = 60), in Group C the IWI was measured retrospective as it is not used in weaning decision. Those tolerated the trial would be immediately extubated. The primary outcome measure was the ability to maintain spontaneous, unassisted breathing for more than 48 h after extubation. Secondary outcome measures were the duration of mechanical ventilation, length of Intensive Care Unit (ICU) stay, and length of hospital stay.

Results:

The mean duration (hours) of mechanical ventilation and length of ICU stay (days) were significantly shorter in the Group I where the IWI was used (83.6 ± 34.3 vs. 97.49 ± 47.2 h, P = 0.002 and 5.5 ± 1.6 vs. 7.12 ± 2.3 days, P = 0.03, respectively). Weaning success rate was significantly higher in the Group I (53 vs. 34, P = 0.0001) while weaning failure rate was significantly lower in the Group I C (7 vs. 26, P = 0.0001).

Conclusion:

IWI is a strong predictor of both successful and failed weaning.

Institutional care for long-term mechanical ventilation in Canada: A national survey

INTRODUCTION

No national Canadian data define resource requirements and care delivery for ventilator-assisted individuals (VAIs) requiring long-term institutional care. Such data will assist in planning health care services to this population.

OBJECTIVE

To describe institutional and patient characteristics, prevalence, equipment used, care elements and admission barriers for VAIs requiring long-term institutional care.

METHODS

Centres were identified from a national inventory and snowball referrals. The survey weblink was provided from December 2012 to April 2013. Weekly reminders were sent for six weeks.

RESULTS

The response rate was 84% (54 of 64), with 44 adult and 10 pediatric centres providing data for 428 VAIs (301 invasive ventilation; 127 noninvasive ventilation [NIV]), equivalent to 1.3 VAIs per 100,000 population. An additional 106 VAIs were on wait lists in 18 centres. More VAIs with progressive neuromuscular disease received invasive ventilation than NIV (P<0.001); more VAIs with chronic obstructive pulmonary disease (P<0.001), obesity hypoventilation syndrome (P<0.001) and central hypoventilation syndrome (P=0.02) required NIV. All centres used positive pressure ventilators, 21% diaphragmatic pacing, 15% negative pressure and 13% phrenic nerve stimulation. Most centres used lung volume recruitment (55%), manually (71%) and mechanically assisted cough (55%). Lack of beds and provincial funding were common admission barriers.CONCLUSIONS: Variable models and care practices exist for institutionalized care of Canadian VAIs. Patient prevalence was 1.3 per 100,000 Canadians.

Evaluation of a new index of mechanical ventilation weaning: the timed inspiratory effort

PURPOSE

The performance of most indices used to predict ventilator weaning outcomes remains below expectation. The purpose of this study was to evaluate a new weaning index, the timed inspiratory effort (TIE) index, which is based on the maximal inspiratory pressure and the occlusion time required to reach it.

METHODS

This observational prospective study included patients undergoing mechanical ventilation. Patients ready to be weaned had their TIE index and 6 previously reported indices recorded. The primary end point was the overall predictive performance of the studied weaning indices (area under the receiver operating characteristic curves [AUCs]). The secondary end points were sensitivity, specificity, positive predictive value, and negative predictive value. P values <.05 were considered significant.

RESULTS

From the 128 initially screened patients, the 103 patients selected for the study included 45 women and 58 men (mean age 60.8 ± 19.8 years). In all, 60 patients were weaned, 43 were not weaned, and 32 died during the study period. Tracheotomy was necessary in 61 patients. The mean duration of mechanical ventilation was 17.5 ± 17.3 days. The AUC of 3 weaning predictors (the TIE index, the integrative weaning index, and the frequency-to-tidal volume [f/Vt] ratio index) was higher than the other indices. The TIE index had the largest AUC.

CONCLUSION

The TIE index performed better than the best weaning indices used in clinical practice.

Patient characteristics and outcomes of a provincial prolonged-ventilation weaning centre: a retrospective cohort study

BACKGROUND

Growing numbers of critically ill patients require prolonged mechanical ventilation and experience difficulty with weaning. Specialized centres may facilitate weaning through focused interprofessional expertise with an emphasis on rehabilitation.

OBJECTIVE

To characterize the population of a specialized prolonged-ventilation weaning centre (PWC) in Ontario, and to report weaning, mobility, discharge and survival outcomes.

METHODS

Data from consecutively admitted patients were retrospectively extracted from electronic and paper medical records by research staff and verified by the primary investigator.

RESULTS

From January 2004 to March 2011, 144 patients were admitted: 115 (80%) required ventilator weaning, and 29 (20%) required tracheostomy weaning or noninvasive ventilation. Intensive care unit length of stay before admission was a median 51 days (interquartile range [IQR] 35 to 86 days). Of the patients admitted for ventilator weaning, 76 of 115 (66% [95% CI 55% to 75%]) achieved a 24 h tracheostomy mask trial in a median of 15 days (IQR eight to 25 days). Weaning success, defined as no further ventilation for seven consecutive days, was achieved by 61 patients (53% [95% CI 44% to 62%]) in a median duration of 62 days (IQR 46 to 95 days) of ventilation, and 14 days (IQR nine to 29 days) after PWC admission. Seventeen patients died during admission. Of the 91 patients discharged from the PWC for one year, 43 (47.3% [95% CI 37.3% to 57.4%]) survived; of the 78 discharged for two years, 27 (34.6% [95% CI 25.0% to 45.7%]) were alive; of the 53 discharged for three years, 19 (35.9% [95% CI 24.3% to 49.3%]) were alive; and seven of 22 (31.8% [95% CI 16.4% to 52.7%]) survived to five years.

CONCLUSIONS

Weaning success was moderate despite a prolonged intensive care unit stay before admission, but was comparable with studies reporting weaning outcomes from centres in other countries. Few patients survived to five years.

Testing the prognostic value of the rapid shallow breathing index in predicting successful weaning in patients requiring prolonged mechanical ventilation

OBJECTIVE

The study objective was to assess the prognostic value of the rapid shallow breathing index (RSBI) in predicting successful weaning of patients from prolonged mechanical ventilation (PMV) in long-term acute care (LTAC) facilities. The RSBI predicts successful ventilator weaning in acutely ill patients. However, its value in PMV is unclear.

METHODS

A retrospective cohort study of patients receiving PMV in LTAC facilities was performed. RSBI was measured daily, with weaning per protocol. Initial, mean, and final RSBI; RSBI ≤ 105; rate of change; and variability were assessed.

RESULTS

Twenty-five of 52 patients were weaned from PMV. Only the mean RSBI and the RSBI on the last day of weaning predicted success (78.7 ± 14.2 vs 99.3 ± 30.2, P = .007; 71.7 ± 31.2 vs 123.3 ± 92.5, P = .005, respectively). RSBI variability and rate of change were different between groups (coefficient of variation, .37 ± .12 vs .51 ± .30, P = .02, rate of change: -3.40 ± 9.40 vs 4.40 ± 11.1 RSBI points/day, P = .005, weaned vs failed).

CONCLUSION

Although isolated RSBI measurements do not predict successful weaning from PMV, RSBI trends may have prognostic value.

Predictive parameters for weaning from mechanical ventilation

The use of predictive parameters for weaning from mechanical ventilation is a rather polemic topic, and the results of studies on this topic are divergent. Regardless of the use of these predictive parameters, the spontaneous breathing trial (SBT) is recommended. The objective of the present study was to review the utility of predictive parameters for weaning in adults. To that end, we searched the Medline, LILACS, and PubMed databases in order to review articles published between 1991 and 2009, in English or in Portuguese, using the following search terms: weaning/desmame, extubation/extubação, and weaning indexes/indices de desmame. The use of clinical impression is an inexact means of predicting weaning outcomes. The most widely used weaning parameter is the RR/tidal volume (V T) ratio, although this parameter presents heterogeneous results in terms of accuracy. Other relevant parameters are MIP, airway occlusion pressure (P0.1), the P0.1/MIP ratio, RR, V T, minute volume, and the index based on compliance, RR, oxygenation, and MIP. An index created in Brazil, the integrative weaning index, has shown high accuracy. Although recommended, the SBT is inaccurate, approximately 15% of extubation failures going unidentified in SBTs. The main limitations of the weaning indexes are related to their use in specific populations, the cut-off points selected, and variations in the types of measurement. Since the SBT and the clinical impression are not 100% accurate, the weaning parameters can be useful, especially in situations in which the decision as to weaning is difficult.

Predictors of successful decannulation using a tracheostomy retainer in patients with prolonged weaning and persisting respiratory failure

BACKGROUND

For percutaneously tracheostomized patients with prolonged weaning and persisting respiratory failure, the adequate time point for safe decannulation and switch to noninvasive ventilation is an important clinical issue.

OBJECTIVES

We aimed to evaluate the usefulness of a tracheostomy retainer (TR) and the predictors of successful decannulation.

METHODS

We studied 166 of 384 patients with prolonged weaning in whom a TR was inserted into a tracheostoma. Patients were analyzed with regard to successful decannulation and characterized by blood gas values, the duration of previous spontaneous breathing, Simplified Acute Physiology Score (SAPS) and laboratory parameters.

RESULTS

In 47 patients (28.3%) recannulation was necessary, mostly due to respiratory decompensation and aspiration. Overall, 80.6% of the patients could be liberated from a tracheostomy with the help of a TR. The need for recannulation was associated with a shorter duration of spontaneous breathing within the last 24/48 h (p < 0.01 each), lower arterial oxygen tension (p = 0.025), greater age (p = 0.025), and a higher creatinine level (p = 0.003) and SAPS (p < 0.001). The risk for recannulation was 9.5% when patients breathed spontaneously for 19-24 h within the 24 h prior to decannulation, but 75.0% when patients breathed for only 0-6 h without ventilatory support (p < 0.001). According to ROC analysis, the SAPS best predicted successful decannulation [AUC 0.725 (95% CI: 0.634-0.815), p < 0.001]. Recannulated patients had longer durations of intubation (p = 0.046), tracheostomy (p = 0.003) and hospital stay (p < 0.001).

CONCLUSION

In percutaneously tracheostomized patients with prolonged weaning, the use of a TR seems to facilitate and improve the weaning process considerably. The duration of spontaneous breathing prior to decannulation, age and oxygenation describe the risk for recannulation in these patients.

Determinants of long-term mortality after prolonged mechanical ventilation

STUDY OBJECTIVES

The poor long-term survival of patients requiring prolonged mechanical ventilation may be due to potentially modifiable factors. We therefore sought to assess the early determinants of long-term survival after discharge from a specialized respiratory unit.

METHODS

Eighty of 113 patients (71%) admitted to a respiratory care unit from June 2001 to August 2003 survived to discharge. Mortality outcomes and dates of death were determined by review of the records and survey in April 2005 of a national Death Master File. Potential determinants of survival after discharge were collected during the admission to the unit.

RESULTS

Fifty-five percent of patients died within the first year after discharge. Age of 65 years or older, sacral ulcers, a serum creatinine >124 micromol/L, and failure to wean were each individually associated with shorter survival. Age, skin integrity, and wean status on discharge remained independent determinants of survival in a multivariable analysis. In a post-hoc analysis, chronic irreversible neurologic diseases were also independently associated with poor long-term survival.

CONCLUSIONS

Mortality after discharge from a respiratory care unit is high. Interventions that may favorably impact long-term survival in these patients could target the modifiable factors identified, including measures that facilitate weaning and prevent or treat renal dysfunction and skin breakdown.

Prediction of death and prolonged mechanical ventilation in acute lung injury

Introduction

Prediction of death and prolonged mechanical ventilation is important in terms of projecting resource utilization and in establishing protocols for clinical studies of acute lung injury (ALI). We aimed to identify risk factors for a combined end-point of death and/or prolonged ventilator dependence and developed an ALI-specific prediction model.

Methods

In this retrospective analysis of three multicenter clinical studies, we identified predictors of death or ventilator dependence from variables prospectively recorded during the first three days of mechanical ventilation. After the prediction model was derived in an international cohort of patients with ALI, it was validated in two independent samples of patients enrolled in a clinical trial involving 17 academic centers and a North American population-based cohort.

Results

A combined end-point of death and/or ventilator dependence at 14 days or later occurred in 68% of patients in the international cohort, 60% of patients in the clinical trial, and 59% of patients in the population-based cohort. In the derivation cohort, a model based on age, oxygenation index on day 3, and cardiovascular failure on day 3 predicted death and/or ventilator dependence. The prediction model performed better in the clinical trial validation cohort (area under the receiver operating curve 0.81, 95% confidence interval 0.77 to 0.84) than in the population-based validation cohort (0.71, 95% confidence interval 0.65 to 0.76).

Conclusion

A model based on age and cardiopulmonary function three days after the intubation is able to predict, moderately well, a combined end-point of death and/or prolonged mechanical ventilation in patients with ALI.

Characteristics associated with discharge to home following prolonged mechanical ventilation: a signal detection analysis

The objective of study was to identify characteristics associated with being home at 6 months in 80 patients on prolonged mechanical ventilation (PMV) (> or =7 days). At 6 months, 47.5% were home, 13.8% institutionalized, and 38.8% deceased and classified "not home." Using signal detection methodology (SDM), four mutually exclusive groups at high and low probability of being home were identified. The best outcome (94.4% home) was achieved by patients with an admission Charlson Comorbidity Score < or =3 and an Acute Physiology Score (APS) < or =21 and the worst outcome (23.4% home) by patients with an admission Charlson Comorbidity Score >3 and Health Assessment Questionnaire score >2.7. SDM provided an effective means of identifying subgroups likely to be discharged home using available information.