Nonrespiratory predictor of mechanical ventilation dependency in intensive care unit patients

Serial estimations of serum albumin levels as a prognostic marker in critically ill patients admitted in ICU in tertiary center: An observational study

Critical illness is a severe condition that poses a significant threat to multiple organ systems and can lead to substantial morbidity and mortality. Serum albumin concentration can serve as an independent predictor of mortality risk in critically ill patients. This study aimed to determine the role of serial monitoring of serum albumin (SA) levels as a prognostic marker of mortality and morbidity. This observational prospective study was conducted at a tertiary hospital over a period from January 1, 2020, to December 31, 2020, among critically ill patients admitted to the intensive care unit. Data collection was performed using a prestructured proforma. Statistical analysis was carried out using Statistical Package for the Social Sciences software version 23, employing appropriate tests. The P-value <.05 was considered statistically significant. The study included 78 patients with 59 (75.6%) were survivors, and 19 (24.4%) were non-survivors. Mean SA levels did not significantly differ between non-survivors (3.30 ± 0.40 g/dL) and survivors (3.42 ± 0.35 g/dL) on admission (day 1) (P = .234). However, on day 3, non-survivors had significantly lower levels (3.02 ± 0.46 g/dL) compared to survivors (3.31 ± 0.29 g/dL) (P = .001). This trend continued on day 5, with non-survivors having significantly lower levels (2.92 ± 0.30 g/dL) compared to survivors (3.31 ± 0.33 g/dL) (P = .003). The decline in SA levels from day 1 to day 3 and from day 1 to day 5 was statistically significant in non-survivors (P = .001). In survivors, a significant decline was observed from day 1 to day 3 (P = .019), while the decline from day 1 to day 5 was not statistically significant (P = .074). Serial estimation of SA levels in critically ill patients can serve as a valuable prognostic marker, aiding in the identification of individuals at a higher risk of mortality and morbidity.

Indicative Factors for 48 or More Hours of Mechanical Ventilation to Optimize the Use of Orotracheal Tubes with Supra-cuff Suction Devices: a Retrospective Study

The objective of this study is to verify the risk factors for invasive mechanical ventilation (IMV) for ≥48h, aiming at the best indication of orotracheal tubes (OTTs) with supra-cuff suction devices. This retrospective and observational study was carried out at the Adult Intensive Care Unit of the University Hospital during a 2-year period. Patients undergoing orotracheal intubation were enrolled. Demographic and clinical data were collected from medical records. A total of 1185 medical records were analyzed, of which 820 were included in the study. The markers associated with intubation for ≥48h were as follows: positive history of diseases (RR=1.42; 95%CI=1.17 to 1.74), especially alcohol addiction (RR=1.60; 95%CI=1.22 to 2.09) or former alcohol addiction (RR=1.50; 95%CI=1.06 to 2.13); clinical hospitalization (RR=1.06; 95%CI=0.98 to 1.16); emergency intubation (RR=3.24; 95%CI=3.01 to 3.95); intubation performed in the emergency department (RR=3.44; 95%CI=3.01 to 3.95) and other hospital facilities (RR=2.92; 95%CI=2.49 to 3.42); and intubation due to lowered level of consciousness (RR=3.40; 95%CI=2.95 to 3.93), acute respiratory failure (RR=3.43; 95%CI=2.98 to 3.54), and airway protection (RR=2.87; 95%CI=2.32 to 3.54). Patients on IMV for ≥48h had an RR of 2.07 (95%CI=1.79 to 2.40) for death. Patients with history of diseases, especially past or current history of alcoholism with clinical hospitalization, who underwent emergency intubation in the emergency department or in other hospital facilities due to lowered level of consciousness, acute respiratory failure, or protect airways, are most likely to require IMV for ≥48h. Also, patients on IMV for ≥48h had an high RR for death.

Daily intra-abdominal pressure, Sequential Organ Failure Score and fluid balance predict duration of mechanical ventilation

BACKGROUND

Elevated intra-abdominal pressure (IAP) is a common occurrence in mechanically ventilated patients in the intensive care unit (ICU). This study was undertaken to determine the relationship between IAP, pulmonary compliance and the duration of mechanical ventilation.

METHODS

A prospective study of 220 consecutively enrolled mechanically ventilated patients admitted to a mixed surgical-medical ICU in a tertiary referral hospital. The IAP was measured at least twice daily, benchmarked against consensus guidelines. Dynamic pulmonary compliance was calculated together with admission Acute Physiology and Chronic Health Evaluation (APACHE III) score and daily Sequential Organ Failure Assessment (SOFA) score.

RESULTS

No relationship between highest IAP for the day and pulmonary compliance (P = 0.61) was found. For each 5 mm Hg increase in IAP, the risk of remaining intubated increased 19% (HR = 1.19, 95% CI: 0.98-1.44); for each standard deviation increase in SOFA score (3.7 points), the risk of remaining intubated increased by 14% (HR = 1.14, 95% CI: 0.98-1.33); and for each 1 L increase in fluid balance, the risk of remaining intubated increased by 11% (HR = 1.11, 95% CI: 1.04-1.19). A nomogram was developed to predict the probability of extubation based on daily highest IAP for the day, SOFA score and fluid balance.

CONCLUSION

IAPs did not correlate with pulmonary compliance in critically ill patients. Increased IAP was associated with a longer duration of mechanical ventilation. A nomogram integrating daily IAP, SOFA score and fluid balance may be used to predict the duration of mechanical ventilation.

Plasma Concentrations of Soluble Suppression of Tumorigenicity-2 and Interleukin-6 Are Predictive of Successful Liberation From Mechanical Ventilation in Patients With the Acute Respiratory Distress Syndrome

OBJECTIVES

Soluble suppression of tumorigenicity-2 and interleukin-6 concentrations have been associated with the inflammatory cascade of acute respiratory distress syndrome. We determined whether soluble suppression of tumorigenicity-2 and interleukin-6 levels can be used as prognostic biomarkers to guide weaning from mechanical ventilation and predict the need for reintubation.

DESIGN, SETTING, AND PATIENTS

We assayed plasma soluble suppression of tumorigenicity-2 (n = 826) concentrations and interleukin-6 (n = 755) concentrations in the Fluid and Catheter Treatment Trial, a multicenter randomized controlled trial of conservative fluid management in acute respiratory distress syndrome. We tested whether soluble suppression of tumorigenicity-2 and interleukin-6 levels were associated with duration of mechanical ventilation, the probability of passing a weaning assessment, and the need for reintubation.

MEASUREMENTS AND MAIN RESULTS

In models adjusted for Acute Physiology and Chronic Health Evaluation score and other relevant variables, patients with higher day 0 and day 3 median soluble suppression of tumorigenicity-2 and interleukin-6 concentrations had decreased probability of extubation over time (day 0 soluble suppression of tumorigenicity-2: hazard ratio, 0.85; 95% CI, 0.72-1.00; p = 0.05; day 0 interleukin-6: hazard ratio, 0.64; 95% CI, 0.54-0.75; p < 0.0001; day 3 soluble suppression of tumorigenicity-2: hazard ratio, 0.64; 95% CI, 0.54-0.75; p < 0.0001; and day 3 interleukin-6: hazard ratio, 0.73; 95% CI, 0.62-0.85; p = 0.0001). Higher biomarker concentrations were also predictive of decreased odds of passing day 3 weaning assessments (soluble suppression of tumorigenicity-2: odds ratio, 0.62: 95% CI, 0.44-0.87; p = 0.006 and interleukin-6: odds ratio, 0.61; 95% CI, 0.43-0.85; p = 0.004) and decreased odds of passing a spontaneous breathing trial (soluble suppression of tumorigenicity-2: odds ratio, 0.45; 95% CI, 0.28-0.71; p = 0.0007 and interleukin-6 univariate analysis only: odds ratio, 0.55; 95% CI, 0.36-0.83; p = 0.005). Finally, higher biomarker levels were significant predictors of the need for reintubation for soluble suppression of tumorigenicity-2 (odds ratio, 3.23; 95% CI, 1.04-10.07; p = 0.04) and for interleukin-6 (odds ratio, 2.58; 95% CI, 1.14-5.84; p = 0.02).

CONCLUSIONS

Higher soluble suppression of tumorigenicity-2 and interleukin-6 concentrations are each associated with worse outcomes during weaning of mechanical ventilation and increased need for reintubation in patients with acute respiratory distress syndrome. Biomarker-directed ventilator management may lead to improved outcomes in weaning of mechanical ventilation in patients with acute respiratory distress syndrome.

An Integrative Index for Predicting Extubation Outcomes After Successful Completion of a Spontaneous Breathing Trial in an Adult Medical Intensive Care Unit

Background:

Among respiratory predictors, rapid shallow breathing index (RSBI) has been a commonly used respiratory parameter to predict extubation outcomes. However, the outcome of prediction remains inconsistent. Regarding nonrespiratory predictors, serum albumin, hemoglobin, bicarbonate, and patients’ alertness have been reported to be associated with successful weaning or extubation. We aimed to develop an integrative index combining commonly used predictors in the adult medical intensive care units (MICUs) and to compare the predictability of the index with RSBI.

Methods:

This prospective observational study with retrospective data collection of planned extubations was conducted in a 14-bed adult MICU. We enrolled patients who received mechanical ventilation via an endotracheal tube in the adult MICU for >24 hours and passed a 2-hour spontaneous breathing trial and underwent extubation. Extubation failure was defined as reinstitution of invasive mechanical ventilation within 48 hours of extubation. Respiratory parameters and Glasgow Coma Scale (GCS) scores of patients were recorded prospectively. Nonrespiratory parameters were recorded retrospectively. Logistic regression was used to determine significant predictors of extubation outcomes.

Results:

Fifty-nine patients comprising 70 extubations were enrolled. Extubation failure was significantly and positively associated with lower serum albumin (albumin < 2.6 g/dL, odds ratio [OR] = 5.1; 95% confidence interval [CI], 1.04-24.66), lower hemoglobin (hemoglobin < 10.0 g/dL, OR = 10.8; 95% CI, 2.00-58.04), and lower GCS scores (GCS score ≤ 8, OR = 6.1; 95% CI = 1.15-32.34). By using an integrative index combining the 3 parameters together, the sensitivity and specificity to predict extubation outcomes were 78.6% and 75.9%, respectively. The area under the receiver operating characteristic curve of the index was significantly higher than RSBI (0.84 vs 0.61, P = .026).

Conclusion:

The integrative index combining serum albumin, hemoglobin, and GCS scores could predict extubation outcomes better than RSBI in an adult MICU.

Predicting Which Patients will Likely Benefit from Subglottic Secretion Drainage Endotracheal Tubes: A Retrospective Study

BACKGROUND

Subglottic secretion drainage endotracheal tubes (SSD ETTs) have been shown to decrease ventilator-associated pneumonia and are recommended for patients intubated > 48 h or 72 h. However, it is difficult to determine which patients will be intubated > 48 h or 72 h at the time of intubation.

OBJECTIVE

We attempted to determine which patient characteristics were associated with intubations ≥ 48 h or 72 h in order to guide proper placement of SSD ETTs.

METHODS

The medical records of 2,159 ventilated patients at a single institution were retrospectively reviewed for intubation duration, age, sex, race, body mass index, weight, intubation reason, whether the intubation was emergent, operative status, intensive care unit (ICU) diagnosis, intubation location, ICU location, comorbidities (e.g., congestive heart failure, chronic obstructive pulmonary disorder, coronary artery disease, dementia, and liver disease), acute kidney injury (AKI), and chronic renal injury. A multivariate regression analysis was then performed with all reliable data.

RESULTS

The following were associated with intubation ≥ 48 h: neuroscience critical care unit (NCCU) admission (risk ratio [RR] = 1.85; 95% confidence interval [CI] 1.34-2.56), emergent intubation (RR = 1.97; 95% 1.28-3.03), comorbid dementia (RR = 2.31; 95% 1.28-4.18), nonoperative intubation (RR = 1.77; 95% 1.28-4.18), and AKI (RR = 3.32; 95% 2.56-4.3). The following were independently associated with intubation ≥ 72 h: NCCU admission (RR = 2.2; 95 CI 1.57-3.08), nonoperative intubation (RR = 3.38; 95% CI 2.63-4.35), comorbid dementia (RR = 3.03; 95% CI 1.67-5.48), and AKI (RR = 3.11; 95% CI 2.38-4.07).

CONCLUSION

Nonoperative intubation, emergent intubation, history of dementia, admission to NCCU and AKI all appear to be independently associated with increased RRs for either ≥ 48 h or 72 h of ventilation.

Predictive models of prolonged mechanical ventilation yield moderate accuracy

PURPOSE

To develop a model to predict prolonged mechanical ventilation within 48 hours of its initiation.

MATERIALS AND METHODS

In 282 general intensive care unit patients, multiple variables from the first 2 days on mechanical ventilation and their total ventilation duration were prospectively collected. Three models accounting for early deaths were developed using different analyses: (a) multinomial logistic regression to predict duration > 7 days vs duration ≤ 7 days alive vs duration ≤ 7 days death; (b) binary logistic regression to predict duration > 7 days for the entire cohort and for survivors only, separately; and (c) Cox regression to predict time to being free of mechanical ventilation alive.

RESULTS

Positive end-expiratory pressure, postoperative state (negatively), and Sequential Organ Failure Assessment score were independently associated with prolonged mechanical ventilation. The multinomial regression model yielded an accuracy (95% confidence interval) of 60% (53%-64%). The binary regression models yielded accuracies of 67% (61%-72%) and 69% (63%-75%) for the entire cohort and for survivors, respectively. The Cox regression model showed an equivalent to area under the curve of 0.67 (0.62-0.71).

CONCLUSIONS

Different predictive models of prolonged mechanical ventilation in general intensive care unit patients achieve a moderate level of overall accuracy, likely insufficient to assist in clinical decisions.

Characterization of pediatric patients receiving prolonged mechanical ventilation

OBJECTIVE

To describe the characteristics and risk factors of pediatric patients who receive prolonged mechanical ventilation, defined as ventilatory support for >21 days.

DESIGN

Prospective cohort.

SETTING

Four medical-surgical pediatric intensive care units in four university-affiliated hospitals in Argentina.

PATIENTS

All consecutive patients from 1 month to 15 yrs old admitted to participating pediatric intensive care units from June 1, 2007, to August 31, 2007, who received mechanical ventilation (invasive or noninvasive) for >12 hrs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic and physiologic data on admission to the pediatric intensive care units, drugs and events during the study period, and outcomes were prospectively recorded. A total of 256 patients were included. Of these, 23 (9%) required mechanical ventilation for >21 days and were assigned to the prolonged mechanical ventilation group. Patients requiring prolonged mechanical ventilation had higher mortality (43% vs. 21%, p < .05) and longer pediatric intensive care unit stay: 35 days [28-64 days] vs. 10 days [6-14]). There was no difference between the groups in age and gender distribution, reasons for admission, incidence of immunodeficiencies, or Paediatric Index of Mortality 2 score. The only difference at admission was a higher rate of genetic diseases in prolonged mechanical ventilation patients (26% vs. 9%, p < .05). There was a higher incidence of septic shock (87% vs. 34%, p < .01), acute respiratory distress syndrome (43% vs. 20%, p < .01), and ventilator-associated pneumonia (35% vs. 8%, p < .01) and higher utilization of dopamine (78% vs. 42%, p < .01), norepinephrine (61% vs. 15%, p < .01), multiple antibiotics (83% vs. 20%, p < .01), and blood transfusions (52% vs. 14%, p < .01). The proportion of extubation failure was higher in the prolonged mechanical ventilation group with similar rates of unplanned extubations in both groups. Variables remaining significantly associated with prolonged mechanical ventilation after multivariate analysis were treatment with multiple antibiotics, septic shock, ventilator-associated pneumonia, and use of norepinephrine.

CONCLUSIONS

Patients with prolonged mechanical ventilation have more complications and require more pediatric intensive care unit resources. Mortality in these patients duplicates that from those requiring shorter support.

Predictors of successful weaning from prolonged mechanical ventilation in Taiwan

BACKGROUND

For adult patients on prolonged mechanical ventilation (PMV, >/=21 days), successful weaning has been attributed to various factors. The purpose of this study was to describe patient outcomes, weaning rates and factors in successful weaning at a hospital-based respiratory care center (RCC) in Taiwan.

METHODS AND RESULTS

This was a retrospective observational study performed in a 24-bed RCC over six years. A total of 1307 patients on PMV were included in the study. The overall survival rate was 62%. Fifty-six percent of patients were successfully weaned. Unsuccessfully weaned patients had higher MICU transfer rates, higher Acute Physiology and Chronic Health Evaluation II scores, longer duration of RCC stay, higher rates of being bed-ridden prior to admission, increased hemodialysis rates, higher modified Glasgow Coma Scale scores, higher rapid shallow breathing index, lower inspiratory pressure at residual volume (PImax) and lower blood urea nitrogen (BUN) and creatinine levels. Factors found to be associated with unsuccessful weaning were length of RCC stay (OR=1.04, P<0.001), modified GCS score (OR=0.93, P<0.046), PImax (OR=0.97, P<0.001), serum albumin concentration (OR=0.62, P<0.023) and BUN level (OR=1.01, P<0.002).

CONCLUSION

High rates of ventilator independence can be achieved in an RCC setting as an alternative to ICU care. Factors associated with unsuccessful weaning included longer duration of RCC stay, elevated BUN levels and lower modified GCS scores, serum albumin and PImax levels.

The distinct clinical profile of chronically critically ill patients: a cohort study

Introduction

Our goal was to describe the epidemiology, clinical profiles, outcomes, and factors that might predict progression of critically ill patients to chronically critically ill (CCI) patients, a still poorly characterized subgroup.

Methods

We prospectively studied all patients admitted to a university-affiliated hospital intensive care unit (ICU) between 1 July 2002 and 30 June 2005. On admission, we recorded epidemiological data, the presence of organ failure (multiorgan dysfunction syndrome (MODS)), underlying diseases (McCabe score), acute respiratory distress syndrome (ARDS) and shock. Daily, we recorded MODS, ARDS, shock, mechanical ventilation use, lengths of ICU and hospital stay (LOS), and outcome. CCI patients were defined as those having a tracheotomy placed for continued ventilation. Clinical complications and time to tracheal decannulation were registered. Predictors of progression to CCI were identified by logistic regression.

Results

Ninety-five patients (12%) fulfilled the CCI definition and, compared with the remaining 690 patients, these CCI patients were sicker (APACHE II, 21 ± 7 versus 18 ± 9 for non-CCI patients, p = 0.005); had more organ dysfunctions (SOFA 7 ± 3 versus 6 ± 4, p < 0.003); received more interventions (TISS 32 ± 10 versus 26 ± 8, p < 0.0001); and had less underlying diseases and had undergone emergency surgery more frequently (43 versus 24%, p = 0.001). ARDS and shock were present in 84% and 83% of CCI patients, respectively, versus 44% and 48% in the other patients (p < 0.0001 for both). CCI patients had higher expected mortality (38% versus 32%, p = 0.003), but observed mortality was similar (32% versus 35%, p = 0.59). Independent predictors of progression to CCI were ARDS on admission, APACHE II and McCabe scores (odds ratio (OR) 2.26, p < 0.001; OR 1.03, p < 0.01; and OR 0.34, p < 0.0001, respectively). Lengths of mechanical ventilation, ICU and hospital stay were 33 (24 to 50), 39 (29 to 55) and 55 (37 to 84) days, respectively. Tracheal decannulation was achieved at 40 ± 19 days.

Conclusion

CCI patients were a severely ill population, in which ARDS, shock, and MODS were frequent on admission, and who suffered recurrent complications during their stay. However, their prognosis was equivalent to that of the other ICU patients. ARDS, APACHE II and McCabe scores were independent predictors of evolution to chronicity.

Assessing Nutritional Status in Chronically Critically Ill Adult Patients

• Background Numerous methods are used to measure and assess nutritional status of chronically critically ill patients.

• Objectives To discuss the multiple methods used to assess nutritional status in chronically critically ill patients, describe the nutritional status of chronically critically ill patients, and assess the relationship between nutritional indicators and outcomes of mechanical ventilation.

• Methods A descriptive, longitudinal design was used to collect weekly data on 360 adult patients who required more than 72 hours of mechanical ventilation and had a hospital stay of 7 days or more. Data on body mass index and biochemical markers of nutritional status were collected. Patients’ nutritional intake compared with physicians’ orders, dieticians’ recommendations, and indirect calorimetry and physicians’ orders compared with dieticians’ recommendations were used to assess nutritional status. Relationships between nutritional indicators and variables of mechanical ventilation were determined.

• ResultsInconsistencies among nurses’ implementation, physicians’ orders, and dieticians’ recommendations resulted in wide variations in patients’ calculated nutritional adequacy. Patients received a mean of 83% of the energy intake ordered by their physicians (SD 33%, range 0%–200%). Patients who required partial or total ventilator support upon discharge had a lower body mass index at admission than did patients with spontaneous respirations (Mann-Whitney U = 8441, P = .001).

• Conclusions In this sample, the variability in weaning progression and outcomes most likely reflects illness severity and complexity rather than nutritional status or nutritional therapies. Further studies are needed to determine the best methods to define nutritional adequacy and to evaluate nutritional status.

Weaning from long-term mechanical ventilation: a nonpulmonary weaning index

OBJECTIVE

Despite the extensive investigations in the area of weaning, clinicians are still struggling with the question of when to begin the process of weaning. Clinical weaning indices designed to predict the weaning potential are most frequently based on pulmonary factors. However, many physiological, respiratory, and mechanical factors also have impact on weaning, but are often overlooked. We suggest a new "nonpulmonary weaning index" (NPWI), which assesses the influence of factors such as blood albumin and total blood protein on the weaning success.

METHODS

We assess the information value of 17 clinical and paraclinical indices in a retrospective study covering 151 patients on a long-term (at least 7 days) mechanical ventilation. The most informative of those 17 indices are used in the formulation of NPWI. Its threshold differentiates the successful from the unsuccessful weaning trials.

RESULTS

From all 17 indices the most significant are: total blood protein, blood albumin, PaO2, hematocrit, lactate, the ratio PaO2/FiO2, hemoglobine, and RUE. The proposed index uses only two of them: blood albumin and total blood protein. It is easily calculated and can easily be tracked in time. It has high sensitivity and specificity.

CONCLUSIONS

The results of this study suggest that in the decision whether to attempt weaning from long-term mechanical ventilation, more attention should be paid to the nonpulmonary factors.

Shock on Admission Day Is the Best Predictor of Prolonged Mechanical Ventilation in the ICU

STUDY OBJECTIVES

To determine the incidence of prolonged mechanical ventilation (PMV), which is associated with increased health-care costs and risks of adverse events, and to identify its early predictors.

DESIGN

Retrospective cohort.

SETTING

A medical-surgical ICU in a university-affiliated hospital.

PATIENTS OR PARTICIPANTS

All patients admitted to the ICU over 3 years who received mechanical ventilation (MV) for > 12 h.

INTERVENTIONS

None.

MEASUREMENTS

PMV was defined as MV lasting > 21 days. We recorded epidemiologic data, severity scores, worst Pao(2)/fraction of inspired oxygen (Fio(2)), presence of shock on ICU admission day, cause for MV, length of MV, ICU length of stay (LOS), and hospital LOS. PMV patients were compared to patients weaned before 21 days (non-PMV group) to determine predictors of PMV.

RESULTS

Of 551 hospital admissions, 319 patients (58%) required MV > 12 h. One hundred thirty patients died early and were excluded. Seventy-nine patients (14%) required PMV. The non-PMV group consisted of 110 patients. Simplified acute physiology score (SAPS) II, APACHE (acute physiology and chronic health evaluation) II, therapeutic intervention scoring system, Pao(2)/Fio(2), shock, ICU LOS, and hospital LOS differed significantly between groups. However, logistic regression identified shock on ICU admission day as the only independent predictor of PMV (odds ratio, 3.10; p = 0.001). SAPS II and Pao(2)/Fio(2) had the nearest coefficients and were used to build the predictive model. Sensitivity analysis was performed including the 130 patients who died early, and shock remained the most powerful predictor.

CONCLUSIONS

PMV was a frequent event in this cohort. The presence of shock on ICU admission day was the only prognostic factor, even adjusting for severity of illness and hypoxemia.

Choosing a volume expander in critical care medicine

The debate concerning the choice of crystalloids or colloids for resuscitation of the critically ill child is still unsettled. Moreover, the use of albumin in critically ill patients has been increasingly questioned because of the lack of clear-cut advantages over crystalloids as well as the concern for cost and the very minor risk of infection. Despite several meta-analyses addressing these issues, there is no data that supports the use of albumin unequivocally in any specific disease states. The suggestion that the use of albumin increases mortality in critically ill patients is not supported by data. There may be niche areas such as hypoalbuminic states, cirrhosis and burns where albumin may have distinct benefits. Alternatively synthetic colloids may be useful, however, concerns about coagulation problems and organ dysfunction persists.

Subjective Perceptions and Physiological Variables During Weaning From Mechanical Ventilation

• Background As costs related to mechanical ventilation increase, clear indicators of patients’ readiness to be weaned are needed. Research has not yet yielded a consensus on physiological variables that are consistent correlates of weaning outcomes. Subjective perceptions rarely have been examined for their contribution to successful weaning.

• Objective To explore the subjective perceptions of dyspnea, fatigue, and self-efficacy and selected physiological variables in patients being weaned from mechanical ventilation.

• Methods Data were collected prospectively on 68 patients being weaned from mechanical ventilation. Subjective perceptions were measured by using 3 visual analog scales; physiological variables were measured by using the Burns Weaning Assessment Program and a patient profile. Weaning outcomes were recorded 24 hours after data collection.

• Results Participants were primarily white women and required mechanical ventilation for a mean of less than 4 days. Participants reported mild dyspnea, moderate fatigue, and high weaning self-efficacy. High Pao2, low Paco2, stable hemodynamic status, adequate cough and swallow reflexes, no metabolic changes, and no abdominal problems were associated with complete weaning (P = .05). Subjective perceptions were associated with physiological variables but not with weaning outcomes.

• Conclusions Multidimensional assessment of both primary and secondary indicators of readiness to be weaned is necessary for timely, efficient weaning from mechanical ventilation. Primary assessments include physiological variables related to gas exchange, hemodynamic status, diaphragmatic expansion, and airway clearance. Secondary assessments include perceptions related to key physiological variables. Additional research is needed to determine the predictive value of physiological variables and perceptions of dyspnea, fatigue, and self-efficacy.

Burns

During the past 20 yrs, as burn care has evolved as a specialty of surgery, survival and outcome quality have soared. Public expectations for survival and long-term outcomes are at previously unprecedented levels. These changes are the result of a number of advances in aspects of burn care that have occurred in parallel and have fostered increasing regionalization of this resource-intensive activity into fewer specialized centers. These are complex hospitalizations and can be divided into four phases: initial evaluation and resuscitation, initial wound excision and biological closure, definitive wound closure, and rehabilitation and reconstruction.

Factors influencing the patient during weaning from mechanical ventilation: a national survey

Successful weaning depends on the application of skilled judgement and decision making to nursing and medical interventions. The intensive care nurse is in an unique position for adopting a holistic approach to weaning. Such an approach needs teamwork and consideration of all the factors that could influence the outcome of the weaning phase. The aim of this study was to conduct a survey, to establish the factors taken into consideration and documented during weaning at the intensive care units (ICUs) in Sweden. A questionnaire was developed and sent to all 92 ICUs. The results identified that nutrition, communication, analgesics and sedatives, psychological and metabolic factors, as well as weaning methods and measurable parameters were taken into consideration. Written instructions for weaning were used by only three ICUs and weaning protocols were not common. A holistic approach to the discontinuation of mechanical ventilation is a valuable means of improving the quality of care and merits further research.

Weaning success among ventilator-dependent patients in a rehabilitation facility

OBJECTIVES

To determine outcomes of difficult-to-wean, ventilator-dependent patients transferred from intensive care units to rehabilitation hospitals and to determine predictors of weaning success in such patients.

DESIGN

A retrospective cohort study.

SETTING

A rehabilitation facility.

PARTICIPANTS

One hundred forty-five difficult-to-wean patients (55.2% men; 83.4% white; mean age +/- standard deviation, 65.8 +/- 16.4y) transferred to a rehabilitation facility between July 1994 and June 1996.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Demographic and clinical data, including variables identified previously as predictive of weaning success among highly selected populations.

RESULTS

Patients' Gillespie categories (reason for ventilator dependency) included "other medical conditions" (eg, pneumonia, neurologic) in 42.1% of the cases, postoperative in 24.8%, previous lung disease (eg, chronic obstructive pulmonary disease, interstitial lung disease) in 15.2%, trauma in 11.7%, respiratory failure with multisystem failure in 3.4%, and uncomplicated acute lung injury (acute respiratory distress syndrome) in 2.8%. Of 145 patients, 50.3% were completely weaned, 4.8% were partially weaned, and 44.8% remained ventilator dependent. In a stepwise multivariable logistic regression analysis, significant predictors of weaning success included white race (odds ratio [OR] = 3.4), serum albumin level (OR = 2.1g/dL), and blood urea nitrogen (BUN) level (OR = .97mg/dL); in addition, compared with postoperative patients, patients with "other medical conditions" (OR = .15) or previous lung disease (OR = .08) were less likely to be weaned (area under receiver operating characteristic curve = .76). Among 31 long-term survivors who were interviewed at least 6 months after discharge from the rehabilitation facility, 58.1% rated their health-related quality of life as good or better.

CONCLUSIONS

Half of the patients admitted to a rehabilitation facility were weaned from their ventilators. Predictors of weaning success included race, BUN level, albumin level, and reason for ventilator dependency.

The impact of long-term acute-care facilities on the outcome and cost of care for patients undergoing prolonged mechanical ventilation

OBJECTIVES

To compare the 6-month mortality rate of chronically ventilated patients treated either exclusively in a traditional acute-care hospital or transferred during hospitalization to a long-term acute-care facility. To analyze the hospital cost of care and estimate the amount of uncompensated care incurred by acute-care hospitals under the Medicare prospective payment diagnostic related groups system.

DESIGN

Retrospective chart review and questionnaire.

SETTING

Fifty-four acute-care referral hospitals and 26 longterm acute-care institutions.

PATIENTS

A total of 432 ventilated patients selected from 3,266 patients referred but not transferred to a study long-term acute-care facility and 1,702 ventilated patients from 4,174 patients referred and then subsequently transferred to the long-term acute-care facility. Six-month outcomes were determined for the subgroup of patients > or =65 yrs old (279 and 1,340 patients, respectively). Hospital charges were available for 192 of the 279 nontransferred patients who were > or =65 yrs old and 1,332 of the 1,340 transferred patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The 6-month mortality rate was 67.4% for the 279 nontransferred patients and 67.2% for the 1,340 transferred patients. On multiple regression analysis, variables associated with the 6-month mortality rate included initial admitting diagnosis, age, the acute physiology score, and presence of decubitus ulcer. After controlling for these variables, there was no significant difference in 6-month mortality rate, but admission to the long-term acute-care facility was associated with a longer mean survival time. Average total hospital costs for the 192 nontransferred patients was $78,474, and estimated Medicare reimbursement was $62,472, resulting in an average of $16,002 of uncompensated care per patient. Estimated costs for the long-term acute-care facility admissions were $56,825.

CONCLUSIONS

Patients undergoing prolonged ventilation have high hospital and 6-month mortality rates, and 6-month outcomes are not significantly different for those transferred to long-term acute-care facilities. These patients generate high costs, and acute-care hospitals are significantly underreimbursed by Medicare for these costs. Acute-care hospitals can reduce the amount of uncompensated care by earlier transfer of appropriate patients to a long-term acute-care facility.

Correlation between lung injury score and serum albumin levels in patients at risk for developing acute lung injury

This is a prospective observational study of 100 consecutive patients who were at risk for developing acute lung injury and were admitted into the surgical intensive care unit. We found a highly significant correlation between an increase in serum albumin levels and a fall in lung injury score and vice versa (r = -0.51, P = 0.000). A highly significant association was also found between mortality, fall in serum albumin levels, rise in lung injury score, and a higher simplified acute physiology score at admission (P = 0.000).

Weaning from mechanical ventilation

For the ventilator-dependent patient, weaning should be accomplished by withdrawing support safely, efficaciously, and efficiently. Success depends largely on physiologic determinants of respiratory system function, avoidance of ventilator-associated complications, and attention to patient readiness. Recent clinical trials, predictors of weaning, current techniques of weaning, the concept of reloading the respiratory pump, and determinants of ventilator dependency are all discussed.

Serum albumin and colloid osmotic pressure in survivors and nonsurvivors of prolonged critical illness

We retrospectively compared the changes in serum albumin concentration and colloid osmotic pressure between survivors and nonsurvivors of prolonged (> or = 7 days) critical illness over a 2-year period from 1 July 1995. All patients had serum albumin measured daily, and colloid osmotic pressure measured 5 days a week, throughout their ICU admission. They received crystalloid and colloid infusions as well as parenteral or enteral feeding. Infusions of albumin were not used to treat hypoalbuminaemia. One hundred and forty-five patients were included, 66 nonsurvivors and 79 survivors. Nonsurvivors were significantly older than survivors [mean (95% CI): 58 (3.8) and 49 (4.1) years, respectively] and had a greater risk of death [mean (95% CI): 0.44 (0.06) and 0.28 (0.05); p < 0.05]. There was no significant difference in gender, APACHE II score [mean (95% CI): 22 (2.7) (nonsurvivors); 18 (2.3) (survivors)] or length of stay [median (interquartile range): 14 (9-27) days (nonsurvivors); 15 (9-26) days (survivors)]. There was no difference between the two groups in the absolute minimum serum albumin concentrations reached, the time to reach that minimum or the minimum in the first 7 days. However, nonsurvivors had a significantly lower mean serum albumin concentration: [mean (95% CI): 15.7 (5.1) g.l-1 compared with 18.3 (4.6) g.l-1 in survivors; p < 0.05]. They also had a lower recovery mean (the weighted mean after the minimum value): [mean (95% CI): 13.3 (5.1) g.l-1 (nonsurvivors) and 18.6 (5.3) g.l-1 (survivors); p < 0.01]. Analysis of colloid osmotic pressure results showed no difference between the groups in mean, minimum or recovery mean. Regression analysis of mean colloid osmotic pressure and albumin revealed that albumin only contributed 17% of the colloid osmotic pressure in these patients. The similar decrease in albumin in nonsurvivors and survivors may reflect the acute inflammatory response and/or haemodilution. However, survivors showed an ability to increase serum albumin concentrations, possibly owing to resumption of synthesis. The colloid osmotic pressure varied little between or within either group of patients, possibly because of the use of artificial colloids. There was no relationship between death and colloid osmotic pressure.

Early onset of acute pulmonary dysfunction after cardiovascular surgery: risk factors and clinical outcome

OBJECTIVE

To define the incidence, risk factors, and clinical outcome of early pulmonary dysfunction after cardiovascular surgery for adults.

STUDY

Inception cohort.

SETTING

Adult cardiovascular intensive care unit (ICU).

PATIENTS

All adult admissions after cardiovascular surgery without preoperative pulmonary parenchyma or vascular disease over a period of 12 consecutive months.

INTERVENTION

Collection of data on demographics, preoperative organ insufficiency, emergency surgery, type of surgical procedure, cardiopulmonary bypass time, transfusion of blood products, postoperative arterial blood gases, and systemic hemodynamics on admission to the cardiovascular ICU.

MEASUREMENTS AND MAIN RESULTS

Early postoperative pulmonary dysfunction was defined by mechanical ventilation with a PaO2/FIO2 ratio of < or = 150 torr (< or = 20 kPa) and chest radiography on admission to the cardiovascular ICU. Secondary outcome included postoperative renal and neurologic dysfunction, nosocomial infections, length of mechanical ventilation, hospitalization, and death. A total of 3,122 patients were evaluated and 1,461 patients satisfied the entry criteria of the study. Early postoperative pulmonary dysfunction was present in 180 (12%) patients on admission to the cardiovascular ICU. Preoperative variables: age of > or = 75 yrs (odds ratio 1.69, 95% confidence interval [CI] 1.06 to 2.65), body mass index of > or = 30 kg/m2 (odds ratio 1.60, 95% CI 1.09 to 2.32), mean pulmonary arterial pressure of > or = 20 mm Hg (odds ratio 1.60, 95% CI 1.13 to 2.28), stroke volume index of < or = 30 mL/m2 (odds ratio 1.57, 95% CI 1.08 to 2.26), serum albumin (odds ratio 0.71, 95% CI 0.49 to 0.97), history of cerebral vascular disease (odds ratio 1.81; 95% CI 1.08 to 2.96); operative variables: emergency surgery (odds ratio 2.12, 95% CI 1.01 to 4.51), total cardiopulmonary bypass time of > or = 140 mins (odds ratio 1.54, 95% CI 1.0 to 2.34); and postoperative variables (on admission to cardiovascular ICU): hematocrit of > or = 30% (odds ratio 2.46, 95% CI 1.71 to 3.56), systemic mean arterial pressure of > or = 90 mm Hg (odds ratio 1.67, 95% CI 1.13 to 2.42), and cardiac index of > or = 3.0 L/min/m2 (odds ratio 2.09, 95% CI 1.44 to 3.01) were predictors of early postoperative pulmonary dysfunction. Pulmonary dysfunction was associated with a postoperative increase of serum creatinine (1.36 +/- 0.4 vs. 1.24 +/- 0.4 mg/dL, p < .02), neurologic complications (3% vs. 1.6%, p < .001), nosocomial infections (3% vs. 1.6%, p < .001), prolonged mechanical ventilation (2.2 +/- 5.9 vs. 1.7 +/- 5.6 days, p < .001), length of stay in the cardiovascular ICU (4.4 +/- 12.2 vs. 2.6 +/- 6.2 days, p < .001) and hospital (14.8 +/- 13.1 vs. 10.5 +/- 8.0 days, p < .001), and death (4.4% vs. 1.6%, p < .001).

CONCLUSIONS

The incidence of early postoperative pulmonary dysfunction is uncommon; however, once developed, it is associated with increased morbidity and mortality after cardiovascular surgery. Advanced age, large body mass index, preoperative increased pulmonary arterial pressure, low stroke volume index, hypoalbuminemia, history of cerebral vascular disease, emergency surgery, and prolonged cardiopulmonary bypass time are risk factors for early onset of severe pulmonary dysfunction after surgery. Postoperative hematocrit and systemic hemodynamics suggest that early postoperative pulmonary dysfunction can be a component of a generalized inflammatory reaction to cardiovascular surgery.