Survival following mechanical ventilation for acute respiratory failure in adult men

Prognostic nomogram for elderly patients with acute respiratory failure receiving invasive mechanical ventilation: a nationwide population-based cohort study in Taiwan

Patients in critical care medicine are ageing. There is limited literature evaluating long-term outcomes and prognostic factors for the growing number of elderly patients with acute respiratory failure (ARF) receiving invasive mechanical ventilation (IMV). Data on elderly patients (≧ 65 years old) with ARF receiving intubation and IMV during 2003–2012 were retrospectively collected from the national health database in Taiwan. We included 7,095 elderly patients. The 28-day mortality was 33%, the 60-day mortality was 47.5%, and the 1-year mortality was 70.4%. Patients were divided into groups: young-old (65–74 years), middle-old (75–84 years), and oldest-old (≧ 85 years). Patients in the oldest-old and middle-old groups had higher 1-year mortality than the young-old group (p < 0.001). The multivariate logistic regression revealed 9 significant factors associated with 1-year mortality, and these factors were used to develop a prognostic nomogram. The present study showed that the long-term prognosis of elderly patients with ARF and IMV is very poor. This nomogram can help physicians estimate the 1-year mortality of elderly patients in the early stage of ARF and assist in clinical decision making.

Survival of mechanically ventilated patients admitted to intensive care units. Results from a tertiary care center between 2016-2018

Objectives:

To estimate the survival of adult and pediatric patients receiving mechanical ventilation and determine the associated risk factors

Methods:

A retrospective cohort study was carried out in the intensive care unit (ICU) at King Abdulaziz Medical City (KAMC) and King Abdullah Children’s Specialist Hospital (KACSH), Riyadh, Saudi Arabia. The analysis includes data from medical records of all patients admitted to ICUs who received mechanical ventilation between 2016-2018. For each patient, potential risk factors were collected. The main outcome of this study was the mortality during the stay in ICU after receiving mechanical ventilation

Results:

A total of 262 adults and 175 pediatric patients were admitted to ICUs and received mechanical ventilation during the study period. For adult patients, the overall mortality was 37%, with a median survival time of 11 days (interquartile range [IQR] 6-20 days). The main risk factors independently associated with the increased mortality rate were being aged 51-60 (odds ratio [OR] 2.6, 95% confidence interval [CI] 6.7-1.0) and factors related to ICU admission. For the pediatric population, the mortality rate was 17%, with a median survival time of 16 days (IQR 7-37 days). Prematurity with respiratory problems was the main recorded cause of initiation of mechanical ventilation (50% of patients). Neonates who had mechanical ventilation within one month of their birth and were born extremely preterm had a high mortality rate after the initiation of mechanical ventilation.

Conclusion:

Both patient age and the causes of the initiation of mechanical ventilation were influencing the survival of patients who required mechanical ventilation.

Critical Illness in the Elderly: Review of Pathophysiology of Aging and Outcome of Intensive Care

The goal of this article is to review the literature on age and its influence on the pathophysiology of critical illness, outcome after critical illness, and end of life decision making in critically ill elderly patients. Sources for this review included the MEDLINE database and bibliographies of original articles, reviews, and book chapters. The population is aging and the need for medical care and its costs increase with increasing age. A majority of the elderly lead independent lives, although some need help with various functional activities related to daily living. It is difficult to separate the effects of aging from the effects of the comorbidities that develop with increasing age. The physiologic reserve decreases in the elderly and they may not be able to tolerate a critical injury or illness as well as a younger individual. As the elderlyare usually on multiple medications, they are prone to have more drug interactions and side effects, and need close monitoring of the drugs and adjustment of the dosage. Mortality after a critical illness in the elderly is higher compared to younger patients, and it is more related to the acuity of physiologic disturbance than age alone. The effect of age alone on long-term outcome is not well studied, but individuals with poor functional status and/or increased comorbidities have a poor short-term outcome. Functional status usually deteriorates after critical illness, but the long-term survivors usually recover functional abilities, and they are satisfied with their quality of life. Decision making at the end of life is difficult because of the paucity of data on long-term mortality and quality of life, lack of information about patient wishes, and the uncertainty of the prognosis. Because many elderly patients survive critical illness and may return to their previous lifestyle, age alone should not weigh heavily in end of life decisions. As with other age groups, end of life decisions in the elderly should be made after considering long-term outcomes, patient goals, and the benefits and burdens of life-sustaining technology.

Design and Control of a Mechatronic Tracheostomy Tube for Automated Tracheal Suctioning

GOAL

Mechanical ventilation is required to aid patients with breathing difficulty to breathe more comfortably. A tracheostomy tube inserted through an opening in the patient neck into the trachea is connected to a ventilator for suctioning. Currently, nurses spend millions of person-hours yearly to perform this task. To save significant person-hours, an automated mechatronic tracheostomy system is needed. This system allows for relieving nurses and other carers from the millions of person-hours spent yearly on tracheal suctioning. In addition, it will result in huge healthcare cost savings.

METHODS

We introduce a novel mechatronic tracheostomy system including the development of a long suction catheter, automatic suctioning mechanisms, and relevant control approaches to perform tracheal suctioning automatically. To stop the catheter at a desired position, two approaches are introduced: 1) Based on the known travel length of the catheter tip; 2) Based on a new sensing device integrated at the catheter tip. It is known that backlash nonlinearity between the suction catheter and its conduit as well as in the gear system of the actuator are unavoidable. They cause difficulties to control the exact position of the catheter tip. For the former case, we develop an approximate model of backlash and a direct inverse scheme to enhance the system performances. The scheme does not require any complex inversions of the backlash model and allows easy implementations. For the latter case, a new sensing device integrated into the suction catheter tip is developed and backlash compensation controls are avoided.

RESULTS

Automated suctioning validations are successfully carried out on the proposed experimental system. Comparisons and discussions are also introduced.

SIGNIFICANCE

The results demonstrate a significant contribution and potential benefits to the mechanical ventilation areas.

Long-term outcome of chronic obstructive pulmonary disease patients with acute respiratory failure following intensive care unit discharge in Turkey

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) remains a globally significant cause of mortality, although COPD mortality varies from country to country, and across different regions within each country. The primary objective of this study was to determine the mortality rates of COPD patients who present with acute respiratory failure (ARF) to a tertiary care referral center in different stages of their follow-up (ICU, in-hospital and after discharge). The secondary objective was to determine factors associated with mortality in this group of patients.

RESULTS

Medical records of consecutive COPD patients over a 10-year period were reviewed.The study included 147 patients. Of these, 72 were treated initially with noninvasive positive pressure ventilation (NIPPV), and 12 of these required intubation after NIPPV failed. Therefore, 86 patients were intubated for invasive mechanical ventilation (IMV), while NIPPV was succesful in 60 patients. Survival time was independently associated with advanced age, high APACHE II score, co-morbidity and the need for IMV. The cumulative mortality was 27% in the medical ICU and 31% in hospital following ICU discharge. The mortality rate at 1, 2 and 5 years was 54%, 66% and 84%, respectively.

CONCLUSION

COPD patients admitted to the ICU for ARF have an approximately 70% chance of leaving hospital alive, but half of these may die in the first 6 months after discharge. The risk factors related to mortality were advanced age, high APACHE II score, co-morbidity and IMV requirement.

Effect of pressure support vs unassisted breathing through a tracheostomy collar on weaning duration in patients requiring prolonged mechanical ventilation: a randomized trial

IMPORTANCE

Patients requiring prolonged mechanical ventilation (>21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated.

OBJECTIVE

To compare weaning duration with pressure support vs unassisted breathing through a tracheostomy collar in patients transferred to an LTACH for weaning from prolonged ventilation.

DESIGN, SETTING, AND PARTICIPANTS

Between 2000 and 2010, a randomized study was conducted in tracheotomized patients transferred to a single LTACH for weaning from prolonged ventilation. Of 500 patients who underwent a 5-day screening procedure, 316 did not tolerate the procedure and were randomly assigned to receive weaning with pressure support (n = 155) or a tracheostomy collar (n = 161). Survival at 6- and 12-month time points was also determined.

MAIN OUTCOME MEASURE

Primary outcome was weaning duration. Secondary outcome was survival at 6 and 12 months after enrollment.

RESULTS

Of 316 patients, 4 were withdrawn and not included in analysis. Of 152 patients in the pressure-support group, 68 (44.7%) were weaned; 22 (14.5%) died. Of 160 patients in the tracheostomy collar group, 85 (53.1%) were weaned; 16 (10.0%) died. Median weaning time was shorter with tracheostomy collar use (15 days; interquartile range [IQR], 8-25) than with pressure support (19 days; IQR, 12-31), P = .004. The hazard ratio (HR) for successful weaning rate was higher with tracheostomy collar use than with pressure support (HR, 1.43; 95% CI, 1.03-1.98; P = .033) after adjusting for baseline clinical covariates. Use of the tracheostomy collar achieved faster weaning than did pressure support among patients who did not tolerate the screening procedure between 12 and 120 hours (HR, 3.33; 95% CI, 1.44-7.70; P = .005), whereas weaning time was equivalent with the 2 methods in patients who did not tolerate the screening procedure within 0 to 12 hours. Mortality was equivalent in the pressure-support and tracheostomy collar groups at 6 months (55.92% vs 51.25%; 4.67% difference, 95% CI, -6.4% to 15.7%) and at 12 months (66.45% vs 60.00%; 6.45% difference, 95% CI, -4.2% to 17.1%).

CONCLUSION AND RELEVANCE

Among patients requiring prolonged mechanical ventilation and treated at a single long-term care facility, unassisted breathing through a tracheostomy, compared with pressure support, resulted in shorter median weaning time, although weaning mode had no effect on survival at 6 and 12 months.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01541462.

Respiratory dialysis with an active-mixing extracorporeal carbon dioxide removal system in a chronic sheep study

PURPOSE

The objective of this study was to demonstrate the safety and performance of a unique extracorporeal carbon dioxide removal system (Hemolung, ALung Technologies, Pittsburgh, PA) which incorporates active mixing to improve gas exchange efficiency, reduce exposure of blood to the circuit, and provide partial respiratory support at dialysis-like settings.

METHODS

An animal study was conducted using eight domestic crossbred sheep, 6-18 months of age and 49-115 kg in weight. The sheep were sedated and intubated, and a 15.5-Fr dual lumen catheter was inserted into the right jugular vein. The catheter was connected to the extracorporeal circuit primed with heparinized saline, and flow immediately initiated. The animals were then awakened and encouraged to stand. The animals were supported in a stanchion and monitored around the clock. Anticoagulation was maintained with heparin to achieve an aPTT of 46-70 s.

RESULTS

Measurements included blood flow rate through the device, carbon dioxide exchange rate, pump speed and sweep gas flow rate. Safety and biocompatibility measurements included but were not limited to plasma-free hemoglobin, hematocrit, white blood cell count, platelet count and fibrinogen. The Hemolung removed clinically significant amounts of carbon dioxide, more than 50 ml/min, at low blood flows of 350-450 ml/min, with minimal adverse effects.

CONCLUSIONS

The results of 8-day trials in awake and standing sheep supported by the Hemolung demonstrated that this device can consistently achieve clinically relevant levels of carbon dioxide removal without failure and without significant risk of adverse reactions.

Short courses of mechanical ventilation with high-O2 levels in elderly rat lungs

PURPOSE

To evaluate the effects of mechanical ventilation (MV) of high-oxygen concentration in pulmonary dysfunction in adult and elderly rats.

METHODS

Twenty-eight adult (A) and elderly (E), male rats were ventilated for 1 hour (G-AV1 and G-EV1) or for 3 hours (G-AV3 and G-EV3). A and E groups received a tidal volume of 7 mL/kg, a positive end-expiratory pressure of 5 cm H2O, respiratory rate of 70 cycles per minute, and an inspiratory fraction of oxygen of 1. We evaluated total protein content and malondialdehyde in bronchoalveolar lavages (BAL) and performed lung histomorphometrical analyses.

RESULTS

In G-EV1 animals, total protein in BAL was higher (33.0±1.9 µg/mL) compared with G-AV1 (23.0±2.0 µg/mL). Upon 180 minutes of MV, malondialdehyde levels increased in elderly (G-EV3) compared with adult (G-AV3) groups. Malondialdehyde and total proteins in BAL after 3 hours of MV were higher in elderly group than in adults. In G-EV3 group we observed alveolar septa dilatation and significative increase in neutrofiles number in relation to adult group at 60 and 180 minutes on MV.

CONCLUSION

A higher fraction of inspired oxygen in short courses of mechanical ventilation ameliorates the parameters studied in elderly lungs.

Prediction of outcome and prognosis of patients on mechanical ventilation using body mass index, SOFA score, C-Reactive protein, and serum albumin

Context:

Body mass index (BMI), serum albumin, and C-reactive protein (CRP) appear to be major determinants of hospitalization.

Aim:

To determine the predictive ability of BMI, Sequential Organ Failure Assessment (SOFA score), serum albumin, and CRP to assess the duration and outcome of mechanical ventilation (MV).

Materials and Methods:

Thirty patients aged >18 years who required mechanical ventilation (MV) were enrolled for the study. They were divided into two groups; patients who improved (Group 1), patients who expired (Group 2). Group 1 was further divided into two groups: patients on MV for <5 days (Group A), and patients on MV for >5days (Group B). BMI and SOFA score were calculated, and serum albumin and CRP were estimated.

Results and Discussion:

Out of the 30 patients, 18 patients successfully improved after MV (Group 1) and 12 patients expired (Group 2). Among the 18 patients in group 1, ten patients improved within 5 days (Group A) and 8 patients after 5 days (Group B). SOFA score and CRP were significantly increased (P value 0.0003 and 0.0001, respectively) in group 2 when compared to group 1. CRP >24.2 mg/L or SOFA score >7 at the start of MV increases the probability of mortality by factor 13.08 or 3.92, respectively The above parameters did not show any statistical difference when group A was compared to group B.

Conclusion:

Simple, economic and easily accessible markers like CRP and assessment tools of critically ill patients with SOFA score are important determinants of possible outcomes of a patient from MV.

Short-term prognosis of critically ill surgical patients: the impact of duration of invasive organ support therapies

PURPOSE

We wanted to identify the importance of the duration of invasive ventilation and of renal replacement therapy for short-term prognosis of surgical patients treated in an intensive care unit (ICU).

METHODS

We analyzed adult patients (n = 1462) who had an ICU length of stay of more than 4 days and who were followed up until the end of the short-term phase after ICU admission. Duration of different invasive therapies was evaluated by constructing specific vectors that tested effects of time-dependent variables on outcome after a lag time of 7 days.

MEASUREMENTS AND MAIN RESULTS

Eight hundred eight patients (56.6%) were still alive at the end of the short-term phase. During the short-term phase, 85.3% of the 1462 patients required invasive ventilation, and 16.1%, a continuous renal replacement therapy. Besides the underlying disease and disease severity at ICU admission, the need for invasive ventilation or renal replacement therapy was associated with poorer outcome. Duration of invasive ventilation shortened survival if treatment lasted for more than 11 days (nonlinear association). In contrast, duration of renal replacement therapy was unimportant for short-term prognosis.

CONCLUSION

Prolonged duration of invasive ventilation but not of renal replacement therapy is inversely related to short-term survival.

The epidemiology of mechanical ventilation use in the United States

OBJECTIVE

Few contemporary population-based data exist about the incidence, patient characteristics, and outcomes of mechanical ventilation in acute care hospitals. We sought to describe the epidemiology of mechanical ventilation use in the United States.

DESIGN

Retrospective cohort study using year 2005 hospital discharge records from six states. National projections were generated from age-, race-, and sex-specific rates in the cohort.

SETTING

Nonfederal acute care hospitals.

PATIENTS

All discharges that included invasive mechanical ventilation identified using International Classification of Diseases, 9th Revision, Clinical Modification procedure codes (96.7x).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 6,469,674 hospitalizations in the six states, 180,326 (2.8%) received invasive mechanical ventilation. There was a wide age distribution with 52.2% of patients <65 yrs of age. A total of 44.6% had at least one major comorbid condition. The most common comorbidities included diabetes (13.2%) and pulmonary disease (13.2%). Inhospital mortality was 34.5%, and only 30.8% of patients were discharged home from the hospital. Almost all patients received care in urban (73.5%) or suburban (23.6%) hospitals vs. rural hospitals (2.9%). Patients in urban hospitals experienced a higher number of organ dysfunctions, more dialysis and tracheostomies, and higher mortality compared with patients in rural hospitals. Projecting to national estimates, there were 790,257 hospitalizations involving mechanical ventilation in 2005, representing 2.7 episodes of mechanical ventilation per 1000 population. Estimated national costs were $27 billion representing 12% of all hospital costs. Incidence, mortality, and cumulative population costs rose significantly with age.

CONCLUSIONS

Mechanical ventilation use is common and accounts for a disproportionate amount of resource use, particularly in urban hospitals and in elderly patients. Mortality for mechanically ventilated patients is high. Quality improvement and cost-reduction strategies targeted at these patients are warranted.

Elderly patients undergoing mechanical ventilation in and out of intensive care units: a comparative, prospective study of 579 ventilations

INTRODUCTION

Many mechanically ventilated elderly patients in Israel are treated outside of intensive care units (ICUs). The decision as to whether these patients should be treated in ICUs is reached without clear guidelines. We therefore conducted a study with the aim of identifying triage criteria and factors associated with in-hospital mortality in this population.

METHODS

All mechanically invasive ventilated elderly (65+) medical patients in the hospital were included in a prospective, non-interventional, observational study.

RESULTS

Of the 579 ventilations, 283 (48.9%) were done in ICUs compared with 296 (51.1%) in non-ICU wards. The percentage of ICU ventilations in the 65 to 74, 75 to 84, and 85+ age groups was 62%, 45%, and 23%, respectively. The decision to ventilate in ICUs was significantly and independently influenced by age (Odds Ratio (OR) = 0.945, P < 0.001), and pre-hospitalization functional status by functional independence measure (FIM) scale (OR = 1.054, P < 0.001). In-hospital mortality was 53.0% in ICUs compared with 68.2% in non-ICU wards (P < 0.001), but the rate was not independently and significantly affected by hospitalization in ICUs.

CONCLUSIONS

In Israel, most elderly patients are ventilated outside ICUs and the percentage of ICU ventilations decreases as age increases. In our study groups, the lower mortality among elderly patients ventilated in ICUs is related to patient characteristics and not to their treatment in ICUs per se. Although the milieu in which this study was conducted is uncommon today in the western world, its findings point to possible means of managing future situations in which the demand for mechanical ventilation of elderly patients exceeds the supply of intensive care beds. Moreover, the findings of this study can contribute to the search for ways to reduce costs without having a negative effect on outcome in ventilated elderly patients.

Age, invasive ventilatory support and outcomes in elderly patients admitted to intensive care units

BACKGROUND

although advancing age is associated with worse outcomes on mechanically ventilated elderly patients admitted to intensive care units (ICU), this relation has not been extensively investigated on patients not requiring invasive ventilatory support.

OBJECTIVE

to determine the relationship between age and in-hospital mortality of elderly patients, admitted to ICU, requiring and not requiring invasive ventilatory support.

DESIGN

prospective observational cohort study conducted over a period of 11 months.

SETTING

medical-surgical ICU at a Brazilian university hospital.

SUBJECTS

a total of 840 patients aged 55 years and older were admitted to ICU.

METHODS

in-hospital death rates for patients requiring and not requiring invasive ventilatory support were compared across three successive age intervals (55-64; 65-74 and 75 or more years), adjusting for severity of illness using the Acute Physiologic Score.

RESULTS

age was strongly correlated with mortality among the invasively ventilated subgroup of patients and the multivariate adjusted odds ratios increased progressively with every age increment (OR = 1.60, 95% CI = 1.01-2.54 for 65-74 years old and OR = 2.68, 95% CI = 1.58-4.56 for > or =75 years). For the patients not submitted to invasive ventilatory support, age was not independently associated with in-hospital mortality (OR = 2.28, 95% CI = 0.99-5.25 for 65-74 years old and OR = 1.95, 95% CI = 0.82-4.62 for > or =75 years old).

CONCLUSIONS

the combination of age and invasive mechanical ventilation is strongly associated with in-hospital mortality. Age should not be considered as a factor related to in-hospital mortality of elderly patients not requiring invasive ventilatory support in ICU.

Epidemiology of Acute Respiratory Failure and Mechanical Ventilation

Acute respiratory failure, and the need for mechanical ventilation, remains one of the most common reasons for admission to the intensive care unit (ICU). The burden of acute respiratory failure is high in terms of mortality and morbidity as well as the cost of its principal treatment, mechanical ventilation. Very few epidemiologic studies have evaluated the prevalence and outcome of acute respiratory failure and mechanical ventilation in general. Most of the published literature has focused on specific forms of acute respiratory failure, particularly acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In this chapter, we provide a brief review of the pathophysiology of acute respiratory failure, its definition and classification, and then present the incidence and outcomes of specific forms of acute respiratory failure from epidemiologic studies.

Epidemiology of Acute Respiratory Failure and Mechanical Ventilation

Acute respiratory failure, and the need for mechanical ventilation, remains one of the most common reasons for admission to the intensive care unit (ICU). The burden of acute respiratory failure is high in terms of mortality and morbidity as well as the cost of its principal treatment, mechanical ventilation. Very few epidemiologic studies have evaluated the prevalence and outcome of acute respiratory failure and mechanical ventilation in general. Most of the published literature has focused on specific forms of acute respiratory failure, particularly acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In this chapter, we provide a brief review of the pathophysiology of acute respiratory failure, its definition and classification, and then present the incidence and outcomes of specific forms of acute respiratory failure from epidemiologic studies.

"Oldest old" patients in intensive care: prognosis and therapeutic activity

OBJECTIVE

In view of ethical considerations and the limited resources in intensive care medicine, the present investigation aims to give a descriptive overview of the prognosis and therapeutic activity for the oldest age group of elderly patients admitted to an intensive care unit (ICU) in comparison with younger ICU patients.

PATIENTS AND METHODS

3069 patients admitted to the ICU during a seven-year period were categorized into four age groups: under 65 years (48%), 65 to 74 years (26%), 75 to 85 years (22%) and 85 years or older (5%). Type and reason for ICU admission, length of ICU stay, severity of illness as measured by the simplified acute physiology score (SAPS)-II, level of provided care as measured by the simplified therapeutic intervention scoring system (TISS)-28, and vital status at the date of ICU discharge were recorded.

RESULTS

The ICU mortality rate of patients aged 85 years or older was significantly higher than in patients under 65 (OR of mortality: 1.8, p < 0.001). Non-survivors had higher SAPS II levels (even when excluding age points) in all age groups, but higher daily average TISS points only in patients under 85. The daily average TISS score was negatively correlated to age (r = -0.03; p < 0.001) and was significantly lower in the oldest group when compared with all the younger groups (p < 0.001). The oldest patients had a significantly shorter length of stay (median: 2; interquartile range [IQR] 1-3, p < 0.001) than the younger patient groups.

CONCLUSIONS

Within the very elderly population, age is an important and independent predictor of mortality, but acute severity of illness is even more strongly associated with mortality. Consequently, age alone may be an inappropriate criterion for allocation of ICU resources.

Experience with a step-down respiratory care center at a tertiary referral medical center in Taiwan

OBJECTIVE

The aim of the study was to describe the outcome of patients after 1 year's implementation of an integrated delivery system for respiratory care mandated by the National Health Insurance Bureau in Taiwan.

DESIGN

A retrospective observational study was conducted in a step-down respiratory care center (RCC).

PATIENTS

Patients included adults receiving prolonged mechanical ventilation (> or =21 days).

MEASUREMENTS AND MAIN RESULTS

A total of 224 cases were available for review; 108 (48.2%) patients were successfully weaned. Those who failed weaning had a longer stay in the intensive care unit and RCC (25.1 vs 20.9 and 31.4 vs 18.6 days, P < .05), but there were no differences in the patients' ages (74.3 vs 70.4 years, P = .17) or the Simplified Acute Physiology Score II (52 vs 46.9, P = .18) before admission to the RCC. After discharge from the RCC, only 4.9% of the patients still on a ventilator were weaned within 1 year. Patients who failed weaning in the RCC had a shorter overall survival (5.2 vs 10.4 months, P < .05) and a lower 1-year survival (23.6% vs 44.6%, P < .05).

CONCLUSION

Patients admitted to the RCC were still critically ill. Patients who failed weaning in the RCC had had a longer intensive care unit and RCC stay and a worse outcome after leaving the RCC.

Outcome of older critically ill patients: a matched cohort study

BACKGROUND

Admission of older patients to intensive care units is a controversial issue.

OBJECTIVE

To estimate age-associated mortality of critically ill patients.

METHODS

A prospective matched cohort study in the Medical-Surgical Intensive Care Unit of a tertiary hospital was conducted. We included 100 consecutive patients older than 70 years admitted to the intensive care unit (cases) and 100 patients younger than 70 years (controls). The matching criterion was the severity of illness at admission to the intensive care unit as estimated by the simplified acute physiological score (SAPS II) without including age in its calculation.

RESULTS

Mortality in the intensive care unit was higher, but not statistically significant, in the older group: 26% vs. 19% (p = 0.23). Patients older than 70 years had a longer duration of mechanical ventilation (median 7 vs. 3 days) and longer stay in the intensive care unit (median 8 vs. 5 days). There were no differences in organ dysfunctions, except for a higher incidence of respiratory failure in the older group (p < 0.001). The use of invasive procedures was similar in both groups. There were more orders for the withholding/withdrawal of treatment in patients older than 70 years (9 vs. 3%, p = 0.07).

CONCLUSION

In our study, age was not related with a significant higher mortality. In the older patients included in our study the survival was greater than 70% with a similar resource utilization except for a longer stay in the intensive care unit.

Is hypercapnea a predictor of better survival in the patients who underwent mechanical ventilation for chronic obstructive pulmonary disease (COPD)?

BACKGROUND

There are contradictory reports concerning hypercapnia as a predictor of a better outcome in COPD. This study examined the clinical implications of hypercapnea in COPD patients (M:F = 59:19) who required mechanical ventilation.

METHODS

The clinical parameters at the time of MICU admission, the total ventilation time, the APACHE II score and the pulmonary function testing were retrospectively analyzed between the survivors and nonsurvivors.

RESULTS

Univariate analysis showed that compared with the nonsurvivors, the survivors had lower AaDO2 values (59.8 +/- 53.5 vs. 105.0 +/- 73.3 mmHg, p=0.000), higher PaCO2 values (64.9 +/- 16.0 vs. 48.9 +/- 17.8 mmHg, p=0.000), lower APACHE II scores (19.0 +/- 3.8 vs. 24.1 +/- 5.1, p=0.002), the more frequent application of initial noninvasive positive pressure ventilation (44.0 vs. 14.3%, p=0.008), and a lower combined rate of septic shock (4.0 vs. 39.3%, p=0.000). Multivariate analysis revealed that a lower PaCO2 (OR: 0.94, p=0.008), the presence of septic shock (OR: 10.16, p=0.011), a higher APACHE II score (OR: 1.22, p=0.040) and a longer ventilation time (OR: 1.002, p=0.041) were the risk factors for mortality. A lower PaCO2 was also verified as the predictor. for mortality by multivariate analysis when excluding septic shock.

CONCLUSIONS

Hypercapnia at admission is thought to be an independent predictor of better survival for the COPD patients who require mechanical ventilation.

Prolonged invasive ventilation following acute ventilatory failure in COPD: weaning results, survival, and the role of noninvasive ventilation

BACKGROUND

Invasive ventilation for COPD has significant mortality, and weaning can be difficult. At Papworth Hospital, we provide a specialist weaning service using noninvasive ventilation (NIV) for patients requiring prolonged invasive ventilation after recovery from acute illness. We analyzed our results for patients with COPD to identify factors associated with weaning outcome and survival.

METHODS

A retrospective analysis was conducted of COPD patients admitted for weaning from invasive ventilation, from 1992 to 2003. Weaning success and survival were assessed. Associations were sought between these outcomes and age, sex, spirometry, arterial blood gas levels, APACHE (acute physiology and chronic health evaluation) II score, length of stay (LOS), and the use of NIV and long-term oxygen therapy.

RESULTS

Sixty-seven patients were identified, all of whom were receiving tracheostomy ventilation on transfer to the Respiratory Support and Sleep Centre (RSSC). Sixty-four patients (95.5%) were weaned, and 62 patients survived to hospital discharge. NIV was used in weaning 40 patients and in the long term in 25 patients. Median survival was 2.5 years (interquartile range, 0.7 to 4.6 years). One-year, 2-year, and 5-year survival rates were 68%, 54%, and 25%, respectively. Long-term survival was inversely associated with age and LOS in the ICU and the RSSC. The provision of maintenance NIV after weaning was associated with better long-term survival, independent of age and LOS (hazard rate, 0.48; p = 0.03).

CONCLUSIONS

These results demonstrate that a specialist multidisciplinary approach, including the use of NIV, can be successful in weaning most COPD patients from prolonged invasive ventilation. The data also suggest that long-term NIV may improve survival in selected patients.

Clinical characteristics and prognostic factors in patients with complicated acute coronary syndromes requiring prolonged mechanical ventilation

Patients with acute coronary syndromes (ACSs) may develop serious multiorgan complications and require prolonged intensive care. Our aim was to characterize and identify factors that are associated with outcomes in these patients. We retrospectively identified 267 consecutive patients admitted to the coronary care unit for an ACS who required >3 days of mechanical ventilation. Multiple clinical and laboratory variables were correlated with mortality. Patients' ages were 68.3 +/- 10.9 years (mean +/- SD) and 165 (62%) were men. Seventy-six patients (29%) died within 30 days of admission, and the 1 year mortality was 46%. Moderate or severe left ventricular systolic dysfunction was found in 72% of the patients. Eighty-nine patients (33.3%) required vasopressors, of whom 64 (72%) did not survive 30 days. Among 127 patients who required antibiotics (48.3%), 30-day mortality was 53% compared with 4% among patients who did not require antibiotics (p <0.001). The 30-day mortality among patients who received both antibiotics and vasopressors was 64 of 87 patients (74%), and the 1-year mortality in this subgroup was 86.2%. Parameters found to be independent predictors of 30-day mortality were (in descending order): vasopressor requirement, use of antibiotics, peripheral vascular disease, ST-elevation myocardial infarction, renal failure, obesity and Killip class on admission. In conclusion, mortality among patients who require prolonged mechanical ventilation after an ACS is substantial. The main independent predictors of with mortality are the severity of heart failure and the presence of co-morbidities.

In-Hospital and 5-Year Mortality of Patients Treated in the ICU for Acute Exacerbation of COPD

STUDY OBJECTIVES

The prognosis of patients with COPD requiring admission to the ICU is generally believed to be poor. There is a paucity of long-term survival data. We undertook a study to examine both the in-hospital and 5-year mortality rates and to identify the clinical predictors of these outcomes.

DESIGN

We conducted a retrospective cohort study of 57 patients admitted to the ICU between January 1999 and December 2000 for acute respiratory failure attributable to COPD.

RESULTS

The mean (+/-SD) age of the study population was 70 +/- 8 years. More than 90% of patients required intubation, and the mean duration of mechanical ventilation (MV) was 2.3 +/- 2.2 days. The in-hospital mortality rate for the entire cohort was 24.5%. The mortality rates at 6 months and 1, 3, and 5 years were 39.0%, 42.7%, 61.2%, and 75.9%, respectively, following admission to the ICU. The median survival time for all patients was 26 months. The mortality rate at 5 years was 69.6% for patients who were discharged alive from the hospital. Using multivariate analysis, hospital mortality correlated positively with age, previous history of MV, long-term use of oral corticosteroids, ICU admission albumin level, APACHE (acute physiology and chronic health evaluation) II score, and duration of hospitalization. No factors predictive of mortality at 5 years were identified.

CONCLUSIONS

We support previous findings of good early survival and significant but acceptable long-term mortality rates in patients who have been admitted to the ICU for acute exacerbation of COPD. Increased age, previous history of MV, poor nutritional status, and higher APACHE II score on ICU admission could be identified as risk factors associated with increased mortality rates. Long-term survival of patients with COPD who required MV for an acute exacerbation of their disease cannot be predicted simply from data available at the time of intubation. Physicians should incorporate these factors in their decision-making process.

Survivors of acute respiratory distress syndrome: Relationship between pulmonary dysfunction and long-term health-related quality of life*

BACKGROUND

Patients who survive acute respiratory distress syndrome (ARDS) often report decreased general health-related quality of life (HRQOL) following hospital discharge. The extent to which this impairment is due to pulmonary or nonpulmonary causes is unclear. We describe the pattern of recovery of patients surviving ARDS to illuminate any relationships between lung spirometry values, pulmonary symptoms, and overall HRQOL.

METHODS

Seventy-three survivors of ARDS were enrolled in a 12-month follow-up study as part of a phase III randomized, multicenter trial. Patients were contacted at 3, 6, and 12 months after enrollment to complete generic and disease-specific HRQOL questionnaires and have lung spirometry tests performed.

RESULTS

For all domains of the Medical Outcomes Study Short Form-36 (SF-36) and the St. George's Respiratory Questionnaire (SGRQ) at all time intervals, survivors of ARDS had significantly lower scores than age- and sex-matched population values. Over the 12-month follow-up period, we observed significant improvements to the overall Physical Component Score, but the Mental Component Score of the SF-36 and the SGRQ scores were not statistically different. Physical performance measures suggested that by 12 months, 57% had not returned to "normal activity." At 12 months, lung spirometry tests demonstrated mild abnormalities that were stable over time (64% and 49% had <80% predicted forced expiratory volume in 1 sec [Fev1] and forced vital capacity [Fvc], respectively). At 12 months, the forced expiratory volume in 1 sec correlated strongly with the physical function domain of the SF-36 (correlation coefficient = 0.601; p < .01) and moderately with all domains of the SGRQ (correlation coefficient = -0.36, -50; p < .01 in all cases). In addition, there were several strong to moderate correlations between the various domains of the SF-36 and SGRQ.

CONCLUSIONS

Survivors of ARDS have considerable respiratory symptoms and reduced HRQOL that is still prevalent at 12 mos following onset of injury. There are significant correlations between lung spirometry, pulmonary symptoms, and overall HRQOL, thus suggesting the acute lung injury/ARDS is causally contributing to the observed long-term outcome.

Evaluation of a decision aid for making choices about intubation and mechanical ventilation in chronic obstructive pulmonary disease

To assist patients with chronic obstructive pulmonary disease (COPD) in advance planning for life-threatening exacerbations, we developed a structured decision aid that describes the process, risks, and outcomes of intubation and mechanical ventilation (MV). Thirty-three patients with severe COPD took part in a before-after evaluation study. At baseline, only two participants (6%) reported that they had already made an advance decision about MV. After reviewing the decision aid, 31 participants (94%) reported that they had made a choice, which in 23 cases (74% of those deciding) was to forego MV. These choices were associated with more accurate expectations of MV outcome, and reduced decisional conflict. Qualitatively, participants who would accept MV emphasized their wish to prolong life, whereas those who would forego MV were more influenced by the burdens of treatment and the perception of a poor long-term outcome. However, there was evidence that 24% of participants did not completely comprehend the decision aid and 27% found the experience to be stressful. These findings indicate that a decision aid for MV helps patients plan for life-threatening exacerbations, and may be a useful adjunct to counseling for some patients with severe COPD.

Readmission rates and life threatening events in COPD survivors treated with non-invasive ventilation for acute hypercapnic respiratory failure

BACKGROUND

Non-invasive ventilation (NIV) has been shown to reduce intubation and in-hospital mortality in patients with chronic obstructive pulmonary disease (COPD) and acute hypercapnic respiratory failure (AHRF). However, little information exists on the outcomes following discharge. A study was undertaken to examine the rates of readmission, recurrent AHRF, and death following discharge and the risk factors associated with them.

METHODS

A cohort of COPD patients with AHRF who survived after treatment with NIV in a respiratory high dependency unit was prospectively followed from July 2001 to October 2002. The times to readmission, first recurrent AHRF, and death were recorded and analysed against potential risk factors collected during the index admission.

RESULTS

One hundred and ten patients (87 men) of mean (SD) age 73.2 (7.6) years survived AHRF after NIV during the study period. One year after discharge 79.9% had been readmitted, 63.3% had another life threatening event, and 49.1% had died. Survivors spent a median of 12% of the subsequent year in hospital. The number of days in hospital in the previous year (p = 0.016) and a low Katz score (p = 0.018) predicted early readmission; home oxygen use (p = 0.002), APACHE II score (p = 0.006), and a lower body mass index (p = 0.041) predicted early recurrent AHRF or death; the MRC dyspnoea score (p<0.001) predicted early death.

CONCLUSIONS

COPD patients with AHRF who survive following treatment with NIV have a high risk of readmission and life threatening events. Further studies are urgently needed to devise strategies to reduce readmission and life threatening events in this group of patients.

Respiratory Failure

Respiratory failure is defined as a failure in gas exchange due to an impaired respiratory system--either pump or lung failure, or both. The hallmark of respiratory failure is impairment in arterial blood gases. This review describes the mechanisms leading to respiratory failure, the indices that can be used to better describe gas exchange abnormalities and the physiologic and clinical consequences of these abnormalities. The possible causes of respiratory failure are then briefly mentioned and a quick reference to the clinical evaluation of such patients is made. Finally treatment options are briefly outlined for both acute and chronic respiratory failure.

In-hospital and 2-year survival of patients treated with mechanical ventilation for acute exacerbation of COPD

OBJECTIVE

To analyze in-hospital and 2-year survival of patients who require mechanical ventilation with intubation after acute respiratory failure due to exacerbation of chronic obstructive pulmonary disease (COPD). The secondary objective was to identify the prognostic factors for in-hospital mortality and mortality at 2 years.

PATIENTS AND METHODS

We retrospectively studied 101 patients with suspected COPD admitted to the intensive care unit between July 1993 and December 1998. Variables potentially related to mortality were analyzed with a univariate model and by logistic regression.

RESULTS

In-hospital survival was 74.3% and 2-year survival was 55.4%. Survival at 2 years was 81% for patients discharged from hospital. The variables associated with in-hospital mortality were age greater than 65 years, electrocardiographic diagnosis of chronic cor pulmonale, and development of multiorgan dysfunction syndrome. No factors predictive of mortality at 2 years were identified.

CONCLUSIONS

The in-hospital survival rate for patients with an acute exacerbation of COPD who require mechanical ventilation is good and the 2-year survival rate is acceptable. Age, electrocardiographic signs of cor pulmonale, and development of multiorgan dysfunction syndrome were associated with greater risk of in-hospital mortality.

Outcome of coal worker's pneumoconiosis with acute respiratory failure

STUDY OBJECTIVE

To investigate the clinical features and prognosis of patients with coal worker's pneumoconiosis (CWP) requiring invasive mechanical ventilation (MV) in the ICU for their first episode of acute respiratory failure (ARF), with special attention to the prognostic implication of radiographic progressive massive fibrosis (PMF).

DESIGN

Retrospective study.

SETTING

A 16-bed medical ICU at a community hospital.

PATIENTS AND METHODS

We reviewed 53 patients with CWP and ARF requiring invasive MV in the ICU for the first time between August 1998 and March 2002.

RESULTS

Of the 53 patients with CWP, 28 patients (53%) with PMF had their first ARF at a younger age than those without PMF (69.1 +/- 7.9 years vs 74.8 +/- 7.2 years, p = 0.008 [mean +/- SD]). Pneumonia (49%) was the most common cause of ARF. The mean APACHE (acute physiology and chronic health evaluation) II score was 26.0 +/- 9.9, and the mean ICU stay was 14.7 +/- 16.1 days. Twenty-one patients (40%) were weaned successfully in the ICU, with mean ventilator time of 17.0 +/- 25.1 days. The ICU and in-hospital mortality rates were 40% and 43%, respectively. The median survivals for all patients and the ICU survivors were 2.6 months and 14.3 months, respectively. Multivariate analysis showed the following risk (or protective) factors for the ICU mortality: PaCO(2) > 45 mm Hg at the time of intubation (adjusted odds ratio [OR], 0.04; 95% confidence interval [CI], 0.003 to 0.44), PaO(2)/fraction of inspired oxygen ratio < 200 mm Hg at the time of intubation (OR, 8.78; 95% CI, 1.36 to 56.48), and APACHE II score >or= 25 (OR, 11.99; 95% CI, 1.49 to 96.78). PMF was not associated with the ICU mortality (OR, 1.18; 95% CI, 0.20 to 7.10).

CONCLUSIONS

Radiographic PMF was not associated with the ICU mortality in patients with CWP and ARF receiving invasive MV in the ICU. Although a substantial proportion of them could be weaned from the ventilator and discharged from the hospital, their long-term prognosis was poor.

Outcome of older patients receiving mechanical ventilation

OBJECTIVE

To determine the threshold of age that best discriminates the survival of mechanically ventilated patients and to estimate the outcome of mechanically ventilated older patients.

DESIGN

International prospective cohort study.

SETTING

Three hundred sixty-one intensive care units from 20 countries. PATIENTS AND PARTICIPANTS. Five thousand one hundred eighty-three patients mechanically ventilated for more than 12 h.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Recursive partitioning and logistic regression were used and an outcome model was derived and validated using independent subgroups of the cohort. Two age thresholds (43 and 70 years) were found, by partitioning recursive analysis, to be associated with outcome. This study focuses on the analysis of patients older than 43 years of age, divided in two subgroups: between 43 and 70 years (middle age group) and older than 70 years (elderly group). Survival in hospital was 45% (95% C.I.: 43-48) for the elderly group and 55% (53-57) for the middle age group ( p<0.001). Advanced age was not associated with prolongation of mechanical ventilation, weaning or length of stay in the ICU and in hospital ( p>0.05). Variables associated with mortality in the elderly were: acute renal failure, shock, Simplified Acute Physiology Score II and a ratio of PaO(2) to FIO(2) more than 150.

CONCLUSIONS

Older mechanically ventilated patients (age >70 years) had a lower ICU and hospital survival, but the duration of mechanical ventilation, ICU and hospital stay were similar to younger patients. Factors associated with the highest risk of mortality in patients older than 70 were the development of complications during the course of mechanical ventilation, such as acute renal failure and shock.

Long-term mortality and quality of life after prolonged mechanical ventilation

OBJECTIVE

To describe and identify factors associated with mortality rate and quality of life 1 yr after prolonged mechanical ventilation.

DESIGN

Prospective, observational cohort study with patient recruitment over 26 months and follow-up for 1 yr.

SETTING

Intensive care units at a tertiary care university hospital.

PATIENTS

Adult patients receiving prolonged mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured mortality rate and functional status, defined as the inability to perform instrumental activities of daily living (IADLs) 1 yr following prolonged mechanical ventilation. The study enrolled 817 patients. Their median age was 65 yrs, 46% were women, and 44% were alive at 1 yr. Median ages at baseline of 1-yr survivors and nonsurvivors were 53 and 71 yrs, respectively. At the time of admission to the hospital, survivors had fewer comorbidities, lower severity of illness score, and less dependence compared with nonsurvivors. Severity of illness on admission to the intensive care unit and prehospitalization functional status had a significant association with short-term mortality rate, whereas age and comorbidities were related to long-term mortality. Fifty-seven percent of the surviving patients needed caregiver assistance at 1 yr of follow-up. The odds of having IADL dependence at 1-yr among survivors was greater in older patients (odds ratio 1.04 for 1-yr increase in age) and those with IADL dependence before hospitalization (odds ratio 2.27).

CONCLUSIONS

Mortality rate after prolonged mechanical ventilation is high. Long-term mortality rate is associated with older age and poor prehospitalization functional status. Many survivors needed assistance after discharge from the hospital, and more than half still required caregiver assistance at 1 yr. Interventions providing support for caregivers and patients may improve the functional status and quality of life of both groups and thus need to be evaluated.

Cost-effectiveness of ultrasound in preventing femoral venous catheter-associated pulmonary embolism

Femoral central venous catheter use is complicated by a high risk of deep venous thrombosis despite antithrombotic prophylaxis. Although some have recommended screening for femoral catheter-associated thrombosis to prevent pulmonary embolism (PE), this strategy's economic implications are unclear. Therefore, we used a decision model to evaluate the potential cost-effectiveness of a Doppler ultrasound-based screening strategy versus no ultrasound in averting thromboembolic complications associated with femoral catheters. The base-case analysis included a hypothetical cohort of 60-year-old medical patients treated for acute respiratory failure. The perspective was that of the health care payor, and the primary outcomes were quality-adjusted life expectancy, PE, and PE-associated deaths. The ultrasound strategy cost $8,688/quality-adjusted life-year (QALY) gained, $5,305/PE averted, and $99,286/PE death averted. The best- and worst-case scenarios, calculated in multiway sensitivity analyses by varying in-hospital mortality, deep venous thrombosis prevalence, and ultrasound accuracy, ranged from $1,170/QALY to $35,342/QALY, respectively. Probablistic analyses, in which variables with uncertain values were varied randomly within their ranges, demonstrated median costs of $12,793/QALY (interquartile range $8,176/QALY, $20,648/QALY). In summary, ultrasound screening may improve outcomes among the critically ill with femoral venous catheters at acceptable costs and could complement venous thrombosis primary prevention programs.

The epidemiology of critical illness in the elderly

A substantial proportion of patients admitted to intensive care units (ICUs) are elderly patients. Based upon population growth, patient preference, and current physician practice, the number of elderly patients who receive critical care services is likely to increase substantially over the next 10 to 20 years. Numerous studies have shown that survival from critical illness is lower in elderly patients; however, after adjusting for factors such as illness severity, comorbid diseases, and functional status, chronologic age accounts for very little explanatory power for survival from critical illness. Elderly survivors of critical illness often have significant functional limitations, but their perceived quality of life is usually better than that of younger survivors of critical illness. Elderly patients frequently receive less aggressive care in the ICU and probably consume a lower relative proportion of ICU resources than younger patients. However, this does not necessarily result in worse outcomes.

[Intrahospital mortality after discharge from the ICU (hidden mortality) in patients who required mechanical ventilation]

BACKGROUND AND OBJECTIVE

Our goal was to determine the hidden mortality (HM) in patients who underwent an episode of mechanical ventilation (MV). We also analyzed the factors associated with an increase in the risk of hidden mortality.

PATIENTS AND METHOD

Prospective cohort study. Patients admitted to an ICU who required MV and who were monitored until their discharge from hospital. We performed a multivariate study with a logistic regression model including all the variables that were present in a univariate analysis p < 0.20.

RESULTS

Forty-one of the 215 patients who were discharged from the ICU died when they were admitted to hospital, which represents a hidden mortality rate of 19% (CI 95% 11%-27%). A mean period of 9 days elapsed between discharge from the ICU and patient's death, with 25% of patients dying within the first two days. Commonest cause of death was respiratory failure (37%). Factors independently associated with an increase in the risk of hidden mortality were (values expressed as adjusted odds ratio (CI 95%): age > 74 years 1.15 (1.01 to 1.26) (p = 0.02); APACHE II > 29 1.14 (1.01 to 1.27) (p = 0.04); reason for MV being coma 1.21 (1.07 to 1.37) (p = 0.002); reason for MV being cardiopulmonary arrest 1.28 (1.18 to 1.68) (p < 0.001); tracheotomy in ICU 1.31 (1.19 to 1.68) (p < 0.001) and stay in the ICU longer than 16 days 1.35 (1.01 to1.70) (p = 0.04).

CONCLUSIONS

An important number of patients discharged from the ICU after an episode of MV die in hospital. Risk factors associated with an increased risk of death in hospital identify a group of patients who, after excluding those with non-cardiopulmonary resuscitation orders, would possibly benefit from high surveillance or intermediate care units.

Chronic obstructive pulmonary disease * 9: management of ventilatory failure in COPD

The management of respiratory failure during acute exacerbations of COPD and during chronic stable COPD is reviewed and the role of non-invasive and invasive mechanical ventilation is discussed.