Topic: Retrospective or Prospective Cohort Study
Differences in outcomes in chronic critically ill medical and surgical patients admitted to the intensive care unit
Han Yao, D. Jayaraman, J. Shahin
Internal Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada | Internal Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada | Respiratory Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada
Introduction:
The chronic critically ill are patients who survive the initial acute stage of a critical illness but continue to require high intensity support in an intensive care unit, specifically prolonged mechanical ventilation [1]. Improvements in critical care have led to an increase in the chronically critical ill population [2]. It is unclear what effect intensive care unit case mix has on the outcome of the chronic critically ill.
Objectives: The primary objective of this study was to explore differences in outcomes between medical and surgical chronic critically ill admissions to the intensive care unit.
Methods:
We conducted a retrospective study between July 2012 and June 2013 at two university hospital intensive care units, screening for patients who had a tracheostomy placed during their admission. As chronic critical illness is often defined by prolonged mechanical ventilation we used the placement of a tracheostomy tube as a marker for chronic critical illness. We excluded patients with prior chronic mechanical ventilation or tracheostomy placement due to airway obstruction or compromise.
Patient level data was collected and included demographic information, comorbidities, APACHE II scores and outcome data. Patients were defined by admission type and considered surgical if they were admitted post-operatively or for a surgical condition (ex. trauma) or as a complication of a surgical procedure. Patients were defined as a medical admission if the primary reason for admission was due to a medical disease and had not undergone an operation or been admitted for a surgical condition. The primary outcome was acute hospital mortality. Secondary outcome consisted of discharge home or to a rehabilitation center, and hospital length of stay. A multivariable analysis was performed to assess the association of admission type with the primary outcome after adjusting for apache II score, age and sex.
Results:
During the study period, 152 patients received a tracheostomy. 34 patients were excluded because they did not have recorded APACHE II scores on admission. 8 were excluded because a tracheostomy was placed for airway obstruction. The remaining 110 patients were divided by admission type with 40 (36%) being medical and 70 (64%) surgical. The mean age was 62.2 for medical and 55.4 (p=0.02) for the surgical patients. Medical admissions had significantly higher APACHE II scores (28.2) compared to surgical admissions (23.3) (p=0.001). Mortality in medical admissions was more than double that of surgical admissions (40.0% vs. 15.7%, p=0.004) even though they had similar average hospital length of stays (80.7 vs. 84.9 days, p=0.42). Medical admissions were less also less likely to be discharged home or to a rehabilitation centre (30.0% vs. 62.9%, p=0.001). After adjusting for the a priori selected confounders in a multivariable analysis medical admission was highly associated with acute hospital mortality (odds ratio 5.10 95% CI 1.69-15.44, p=0.004).
Conclusion:
This study demonstrated significant outcome differences between medical and surgical chronic critically ill admissions. Even after adjusting for severity of illness medical admissions were more likely to die in hospital. Residual confounding cannot be ruled out as an explanation for the outcome differences. Further investigations are necessary to identify risk factors on admission and at the time of tracheostomy that would accurately predict outcome for the chronic critically ill.
References:
1. Martin, C.M., et al., Characteristics and outcomes for critically ill patients with prolonged intensive care unit stays. Crit Care Med, 2005. 33(9): p. 1922-7; quiz 1936.
2. Nelson, J.E., et al., Chronic critical illness. Am J Respir Crit Care Med, 2010. 182(4): p. 446-54.
Topic: Retrospective or Prospective Cohort Study
Differences in outcomes in chronic critically ill medical and surgical patients admitted to the intensive care unit
Han Yao, D. Jayaraman, J. Shahin
Internal Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada | Internal Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada | Respiratory Medicine, Critical Care Medicine, McGill University Health Center, Montreal, Canada
Introduction:
The chronic critically ill are patients who survive the initial acute stage of a critical illness but continue to require high intensity support in an intensive care unit, specifically prolonged mechanical ventilation [1]. Improvements in critical care have led to an increase in the chronically critical ill population [2]. It is unclear what effect intensive care unit case mix has on the outcome of the chronic critically ill.
Objectives: The primary objective of this study was to explore differences in outcomes between medical and surgical chronic critically ill admissions to the intensive care unit.
Methods:
We conducted a retrospective study between July 2012 and June 2013 at two university hospital intensive care units, screening for patients who had a tracheostomy placed during their admission. As chronic critical illness is often defined by prolonged mechanical ventilation we used the placement of a tracheostomy tube as a marker for chronic critical illness. We excluded patients with prior chronic mechanical ventilation or tracheostomy placement due to airway obstruction or compromise.
Patient level data was collected and included demographic information, comorbidities, APACHE II scores and outcome data. Patients were defined by admission type and considered surgical if they were admitted post-operatively or for a surgical condition (ex. trauma) or as a complication of a surgical procedure. Patients were defined as a medical admission if the primary reason for admission was due to a medical disease and had not undergone an operation or been admitted for a surgical condition. The primary outcome was acute hospital mortality. Secondary outcome consisted of discharge home or to a rehabilitation center, and hospital length of stay. A multivariable analysis was performed to assess the association of admission type with the primary outcome after adjusting for apache II score, age and sex.
Results:
During the study period, 152 patients received a tracheostomy. 34 patients were excluded because they did not have recorded APACHE II scores on admission. 8 were excluded because a tracheostomy was placed for airway obstruction. The remaining 110 patients were divided by admission type with 40 (36%) being medical and 70 (64%) surgical. The mean age was 62.2 for medical and 55.4 (p=0.02) for the surgical patients. Medical admissions had significantly higher APACHE II scores (28.2) compared to surgical admissions (23.3) (p=0.001). Mortality in medical admissions was more than double that of surgical admissions (40.0% vs. 15.7%, p=0.004) even though they had similar average hospital length of stays (80.7 vs. 84.9 days, p=0.42). Medical admissions were less also less likely to be discharged home or to a rehabilitation centre (30.0% vs. 62.9%, p=0.001). After adjusting for the a priori selected confounders in a multivariable analysis medical admission was highly associated with acute hospital mortality (odds ratio 5.10 95% CI 1.69-15.44, p=0.004).
Conclusion:
This study demonstrated significant outcome differences between medical and surgical chronic critically ill admissions. Even after adjusting for severity of illness medical admissions were more likely to die in hospital. Residual confounding cannot be ruled out as an explanation for the outcome differences. Further investigations are necessary to identify risk factors on admission and at the time of tracheostomy that would accurately predict outcome for the chronic critically ill.
References:
1. Martin, C.M., et al., Characteristics and outcomes for critically ill patients with prolonged intensive care unit stays. Crit Care Med, 2005. 33(9): p. 1922-7; quiz 1936.
2. Nelson, J.E., et al., Chronic critical illness. Am J Respir Crit Care Med, 2010. 182(4): p. 446-54.