Complicated acute myocardial infarction requiring mechanical ventilation in the intensive care unit: Prognostic factors of clinical outcome in a series of 157 patients*

Mechanical ventilation in acute myocardial infarction: Outcomes from a prospective audit at a cardiovascular hospital in Pakistan

BACKGROUND

This clinical audit aims to evaluate the clinical data regarding the management and outcomes of acute myocardial infarction (AMI) patients requiring mechanical ventilator (MV) support, along with identifying factors associated with prolonged MV support and 180-day mortality.

MATERIALS AND METHODS

In this study, we audited clinical data regarding management, in-hospital and short-term outcomes of adult patients with AMI required MV support. Patients with prolonged MV duration (>24h) and/or 180-day mortality were compared with their counterparts, and associated factors were identified. The binary logistic and Cox regression analyses were performed to determine the predictors of prolonged MV duration and 180-day mortality.

RESULTS

In a sample of 312 patients, 72.8% were male, and the mean age was 60.3±11.5 years. The median MV duration was 24 [24-48] hours, with 48.7% prolonged MV duration. The admission albumin level was found to be the independent predictor of prolonged MV duration with an adjusted OR of 0.42 [0.22-0.82]. Overall 7.4% were re-intubated, 6.7% needed renal replacement therapy, 17.6% required intra-aortic balloon pump (IABP) placement, and 16.7% required temporary pacemaker placement. The survival rate was 80.4% at the time of hospital discharge, 74.7% at 30-day, 71.2% at 90-day, and 68.6% at 180-day follow-up. Age, prolonged MV duration, and ejection fraction were found to be the independent predictors of cumulative 180-day mortality with adjusted HR of 1.04 [1.02-1.07], 1.02 [1.01-1.03], and 0.95 [0.92-0.98], respectively.

CONCLUSIONS

Prolonged ventilator duration has significant prognostic implications; hence, tailored early recognition of high-risk patients needing more aggressive care can improve the outcomes.

Mechanical ventilation in patients with cardiogenic pulmonary edema: a sub-analysis of the LUNG SAFE study

BACKGROUND

Patients with acute respiratory failure caused by cardiogenic pulmonary edema (CPE) may require mechanical ventilation that can cause further lung damage. Our aim was to determine the impact of ventilatory settings on CPE mortality.

METHODS

Patients from the LUNG SAFE cohort, a multicenter prospective cohort study of patients undergoing mechanical ventilation, were studied. Relationships between ventilatory parameters and outcomes (ICU discharge/hospital mortality) were assessed using latent mixture analysis and a marginal structural model.

RESULTS

From 4499 patients, 391 meeting CPE criteria (median age 70 [interquartile range 59-78], 40% female) were included. ICU and hospital mortality were 34% and 40%, respectively. ICU survivors were younger (67 [57-77] vs 74 [64-80] years, p < 0.001) and had lower driving (12 [8-16] vs 15 [11-17] cmH2O, p < 0.001), plateau (20 [15-23] vs 22 [19-26] cmH2O, p < 0.001) and peak (21 [17-27] vs 26 [20-32] cmH2O, p < 0.001) pressures. Latent mixture analysis of patients receiving invasive mechanical ventilation on ICU day 1 revealed a subgroup ventilated with high pressures with lower probability of being discharged alive from the ICU (hazard ratio [HR] 0.79 [95% confidence interval 0.60-1.05], p = 0.103) and increased hospital mortality (HR 1.65 [1.16-2.36], p = 0.005). In a marginal structural model, driving pressures in the first week (HR 1.12 [1.06-1.18], p < 0.001) and tidal volume after day 7 (HR 0.69 [0.52-0.93], p = 0.015) were related to survival.

CONCLUSIONS

Higher airway pressures in invasively ventilated patients with CPE are related to mortality. These patients may be exposed to an increased risk of ventilator-induced lung injury. Trial registration Clinicaltrials.gov NCT02010073.

A Review of Prognosis Model Associated With Cardiogenic Shock After Acute Myocardial Infarction

Objective: Cardiogenic shock seriously affects the survival rate of patients. However, few prognostic models are concerned with the score of cardiogenic shock, and few clinical studies have validated it. In order to optimize the diagnosis and treatment of myocardial infarction complicated with cardiogenic shock and facilitate the classification of clinical trials, the prognosis score model is urgently needed. Methods: Cardiogenic shock, severe case, prognosis score, myocardial infarction and external verification were used as the search terms to search PubMed, Embase, Web of Science, Cochrane, EBSCO (Medline), Scopus, BMC, NCBI, Oxford Academy, Science Direct, and other databases for pertinent studies published up until 1 August 2021. There are no restrictions on publication status and start date. Filter headlines and abstracts to find articles that may be relevant. The list of references for major studies was reviewed to obtain more references. Results and Conclusions: The existing related models are in urgent need of more external clinical verifications. In the meanwhile, with the development of molecular omics and the clinical need for optimal treatment of CS, it is urgent to establish a prognosis model with higher differentiation and coincidence rates.

Development and Validation of Nomogram to Predict Long-Term Prognosis of Critically Ill Patients with Acute Myocardial Infarction

Purpose

Acute myocardial infarction (AMI) is a common cardiovascular disease with a poor prognosis. The aim of this study was to construct a nomogram for predicting the long-term survival of critically ill patients with AMI. This nomogram will help in assessing disease severity, guiding treatment, and improving prognosis.

Patients and Methods

The clinical data of patients with AMI were extracted from the MIMIC-III v1.4 database. Cox proportional hazards models were adopted to identify independent prognostic factors. A nomogram for predicting the long-term survival of these patients was developed on the basis of the results of multifactor analysis. The discriminative ability and accuracy of the multifactor analysis were evaluated according to concordance index (C-index) and calibration curves.

Results

A total of 1202 patients were included in the analysis. The patients were randomly divided into a training set (n = 841) and a validation set (n = 361). Multivariate analysis revealed that age, blood urea nitrogen, respiratory rate, hemoglobin, pneumonia, cardiogenic shock, dialysis, and mechanical ventilation, all of which were incorporated into the nomogram, were independent predictive factors of AMI. Moreover, the nomogram exhibited favorable performance in predicting the 4-year survival of patients with AMI. The training set and the validation set had a C-index of 0.789 (95% confidence interval [CI]: 0.765–0.813) and 0.762 (95% CI: 0.725–0.799), respectively.

Conclusion

The nomogram constructed herein can accurately predict the long-term survival of critically ill patients with AMI.

Mechanical ventilation in cardiogenic shock

PURPOSE OF REVIEW

Mechanical ventilation is frequently needed in patients with cardiogenic shock. The aim of this review is to summarize and discuss the current evidence and the pathophysiological mechanism that a clinician should consider while setting the ventilator.

RECENT FINDINGS

Little attention has been placed specifically to ventilatory strategies in patients with cardiogenic shock undertaking mechanical ventilation. Lung failure in patients with cardiogenic shock is associated with worsening outcome as well as a delay in mechanical ventilation institution. The hemodynamic profile and cardiogenic shock cause, considering the preload dependency of the failing heart, must be defined to adjust ventilatory setting.

SUMMARY

Evidence is growing regarding the role of lung failure as adverse prognostic factor and beneficial effect of positive pressure ventilation as part of first-line treatment in patients with cardiogenic failure.

Percutaneous coronary intervention assisted by invasive mechanical ventilation and intra-aortic balloon pump for acute myocardial infarction with cardiogenic shock: Retrospective cohort study and meta-analyses

There is little evidence to recommend the optimal invasive mechanical ventilation (IMV) modes and ideal positive end-expiratory pressure stress levels for acute myocardial infarction-cardiogenic shock (AMI-CS) patients. The aim of this study was to compare the mortality outcome in patients with AMI-CS who were treated with percutaneous coronary intervention (PCI) assisted by intra-aortic balloon pump (IABP) + IMV with historical controls. From January 1, 2016 to June 1, 2017, 60 patients were retrospectively enrolled at Tianjin Chest Hospital. Out of these, 88.3% of patients achieved thrombolysis in myocardial infarction (TIMI) flow 3 after PCI. The all-cause mortality rate in-hospital and at 1 year was 25% (95% CI: 0.14–0.36) and 33.9% (0.22–0.46), respectively. A systematic review followed by meta-analysis was performed with four historical studies of patients treated by PCI + IMV with partial IABP, which found an in-hospital mortality rate of 66.0% (95% CI: 0.62–0.71). Recently, a meta-analysis of patients receiving PCI + IABP with partial IMV showed that the 1 year mortality rate was 52.2% (95% CI: 0.47–0.58). In Cox regression analysis of patient data from the current study, lactic acid level ≥4.5 mmol/L, hyperuricemia, and TIMI flow <3 were independent predictors of death at 1 year. All-cause mortality, in-hospital and at 1 year, in patients with AMI-CS treated with PCI + IABP and IMV was lower than in those treated with PCI + partial IABP or IMV. Larger, longer-term direct comparisons are warranted.

In-hospital Outcomes of Patients with ST-segment Elevation Myocardial Infarction who were Intubated before Primary Percutaneous Intervention: Experience of a tertiary center

OBJECTIVES

ST-segment elevation myocardial infarction (STEMI) complicated by respiratory failure is associated with a greater number of in-hospital and out-of-hospital adverse cardiovascular events (CVEs). The aim of this study was to analyze in-hospital outcomes and the factors affecting the outcomes of intubated patients diagnosed with STEMI who underwent primary percutaneous coronary intervention (pPCI) at a single tertiary care center.

METHODS

The data of 592 patients diagnosed with acute STEMI who were admitted to the emergency department between May 2017 and January 2019 and subsequently underwent pPCI were retrospectively reviewed. Cardiovascular risk factors as well as biochemical and angiographic characteristics of patients who were intubated in the emergency room or ambulance due to cardiac arrest and those who were not intubated were compared. Adverse CVEs were defined as in-hospital death, cerebrovascular stroke, and acute stent thrombosis.

RESULTS

A total of 60 patients (70% male; mean age: 63.6±14.0 years) who were intubated and 532 non-intubated patients (81% male; mean age: 60.2±12.1 years) were included in the study. The angiographic features of the 2 groups were similar. An adverse CVE was experienced by 43.3% of the intubated patients and 3.6% of the non-intubated patients. Multivariate analysis indicated that age (odds ratio [OR]: 1.065; p<0.001), serum lactate level (OR: 1.308; p<0.001), and left ventricle ejection fraction (OR: 0.946; p<0.001) were independent predictors of in-hospital adverse CVE in the intubated patient group.

CONCLUSION

The results of this single-center study showed that 1 in 10 patients hospitalized with STEMI were intubated, and approximately 4 in 10 intubated STEMI patients had an in-hospital CVE.

Clinical outcomes of patients undergoing primary percutaneous coronary intervention for acute myocardial infarction requiring the intensive care unit

Background

Outcomes for patients with ST-segment elevation myocardial infarction continue to improve, largely due to timely provision of reperfusion by primary percutaneous coronary intervention (PPCI). However, despite prompt and successful PPCI, a small proportion of patients require ventilatory and hemodynamic support in an intensive care unit (ICU). The outcome of these patients remains poorly defined.

Methods

A retrospective review of all consecutive admissions post-PPCI pathway to a single ICU between January 2009 and May 2014 was performed. Patients were analysed based on survival and indication for admission. Preadmission characteristics and ICU course were reviewed. Univariate and multivariable regression analysis was performed to determine predictors of outcome.

Results

During the study period 2902 PPCI were performed and 101 patients were admitted to ICU following PPCI (incidence 3.5%). ICU mortality post-PPCI was 33.7%. Pre-ICU admission factors in a multivariable logistic regression analysis associated with increased mortality included requirement for an intra-aortic balloon pump and a high SOFA score.

Conclusions

ICU admission post PPCI is associated with significant mortality. Mortality was related to high presenting SOFA score and need for IABP. These results provide important prognostic information and an acceptable method for risk-stratifying patients with acute myocardial infarction requiring intensive care.

Incidence and Prognostic Impact of Respiratory Support in Patients With ST-Segment Elevation Myocardial Infarction

Data addressing the use of respiratory support in acute coronary syndromes are lacking. To address this evidence gap, we characterized prognostic impact and trends in utilization of invasive mechanical ventilation (IMV) and noninvasive ventilation (NIV) in patients hospitalized with ST-segment elevation myocardial infarction (STEMI) from 2002 through 2013 using the National Inpatient Sample. Multivariate logistic regression was performed to identify patient, hospital, and clinical characteristics associated with requiring IMV or NIV within 24 hours of hospitalization. Multivariate Cox proportional hazards regression was used to quantify the magnitude of in-hospital mortality associated with IMV and NIV use. From 2002 to 2013, we identified 1,867,114 patients with STEMI. Age, gender, higher co-morbidity burden, and chronic pulmonary disease were significantly associated with need for respiratory support. The use of IMV and NIV increased at average annual rates of 6.6% and 14.3%, respectively (p_trend <0.001). Age- and gender-adjusted mortality rates are high but declined for patients with STEMI requiring IMV (44.7% in 2002 to 37.6% in 2013, p_trend = 0.002) and NIV (11.6% in 2002 to 6.8% in 2013, p_trend <0.001). Compared to patients with STEMI with no ventilation need, a requirement for IMV or NIV was associated with increased adjusted in-hospital mortality (hazard ratio 2.5, p <0.001 and 1.7, p <0.001, respectively). In conclusion, approximately 1 in 23 patients hospitalized with STEMI will require respiratory support in the form of IMV or NIV. Patients with STEMI who require respiratory support have a high risk of death, although rates of in-hospital mortality have decreased over time.

Outcome After Tracheostomy for Respiratory Failure in the Elderly

The purpose of this study was to determine hospital and postdischarge survival and functional status at follow-up in elderly patients receiving tracheostomy for respiratory failure and to determine if these outcomes differed between the younger elderly (65-74 years) and the older elderly (= 75 years). This was a retrospective chart review with prospective administration of the SF-36 conducted in 228 patients aged 65 years or older who had undergone tracheostomy to facilitate mechanical ventilation for respiratory failure at a tertiary care, university-affiliated, urban medical center. Demographics, comorbidities, hospital survival, liberation from mechanical ventilation, long-term survival, and functional status were determined. Combined hospital and hospice mortality did not differ by age, being 34% and 26% in the 65- to 74-year and = 75-year groups, respectively ( P> .05). However, older patients (= 75 years old) were more likely to be discharged still requiring mechanical ventilation (62% vs 45%, P< .05). Only one half of hospital survivors survived for 1 additional year. Those discharged ventilator-dependent were more likely to die. Of the 20 participants in the SF-36 portion of the study, most had fair to good emotional and social functioning but were extremely limited physically.

Mechanical Ventilation and Clinical Outcomes in Patients with Acute Myocardial Infarction: A Retrospective Observational Study

Purpose

Patients with acute myocardial infarction (AMI) and respiratory impairment may be treated with either invasive or non-invasive mechanical ventilation (MV). However, there has been little testing of non-invasive MV in the setting of AMI. Our objective was to evaluate the incidence and associated clinical outcomes of patients with AMI who were treated with non-invasive or invasive MV.

Methods

This was a retrospective observational study in which consecutive patients with AMI (n = 1610) were enrolled. The association between exclusively non-invasive MV, invasive MV and outcomes was assessed by multivariable models.

Results

Mechanical ventilation was used in 293 patients (54% invasive and 46% exclusively non-invasive). In-hospital mortality rates for patients without MV, with exclusively non-invasive MV, and with invasive MV were 4.0%, 8.8%, and 39.5%, respectively (P<0.001). The median lengths of hospital stay were 6 (5.8–6.2), 13 (11.2–4.7), and 28 (18.0–37.9) days, respectively (P<0.001). Exclusively non-invasive MV was not associated with in-hospital death (adjusted HR = 0.90, 95% CI 0.40–1.99, P = 0.79). Invasive MV was strongly associated with a higher risk of in-hospital death (adjusted HR = 3.07, 95% CI 1.79–5.26, P<0.001).

Conclusions

In AMI setting, 18% of the patients required MV. Almost half of these patients were treated with exclusively non-invasive strategies with a favorable prognosis, while patients who needed to be treated invasively had a three-fold increase in the risk of death. Future prospective randomized trials are needed to compare the effectiveness of invasive and non-invasive MV for the initial approach of respiratory failure in AMI patients.

Long-term Effect of Optimized Sedation and Pain Management after Sudden Cardiac Arrest

BACKGROUND AND AIMS

Appropriate use of sedatives and analgesics is essential to keep critically ill patients comfortable and to prevent prolonged mechanical ventilation time and length of stay in ICU. Aim of this study was to analyse the long-term effect of an algorithm-based individual analgesic-sedative protocol on mechanical ventilation time and ICU length of stay in critically ill patients after sudden cardiac arrest due to ST-elevated myocardial infarction.

SUBJECT AND METHODS

We examined a total of 109 patients before and after implementation of an algorithm-based sedation management. Our sedation protocol included individual defined sedation goals achieved by standardized sedation strategies. Mechanical ventilation time and ICU length of stay were analysed for three groups of patients: before and after the intervention and in the long-term follow-up.

RESULTS

We observed shorter median mechanical ventilation time and ICU length of stay in the interventional and longterm follow-up group compared to the standard-care group without statistical significance.

CONCLUSION

Our results demonstrate a long-term reduction of mechanical ventilation time and ICU length of stay achieved by implementation of an individual sedation management. This suggests sedation guidelines as effective tools to reduce the mechanical ventilation time and ICU length of stay in patients after sudden cardiac arrest in ST-elevated myocardial infarction. Investigations with a larger patient number and higher statistical power are required to confirm these findings.

Invasive mechanical ventilation in acute coronary syndromes in the era of percutaneous coronary intervention

BACKGROUND

Percutaneous coronary intervention (PCI) improves prognosis in patients with acute coronary syndromes (ACS) reducing ischaemic complications and the development of heart failure, thus potentially changing invasive mechanical ventilation (IMV) requirements. Little information exists about patients with ACS requiring IMV in the current era. We aimed to analyze IMV requirements and characteristics of ACS patients treated under current recommendations (including a high rate of PCI).

METHODS

Baseline characteristics, indications for IMV, management and in-hospital and mid-term clinical course were analyzed prospectively in a consecutive series of patients with ACS admitted to a tertiary care hospital.

RESULTS

We included 1821 patients, of which 106 (5.8%) required IMV. Mean follow-up was 347 days. PCI was performed in 84% of cases. Patients with IMV had more comorbidities, worse left ventricular function and more unstable hemodynamic parameters on admission. In-hospital mortality in patients requiring IMV was 29%. These patients also had higher mid-term mortality (hazard ratio (HR) 6.58; 95% confidence interval (CI) 4.49-9.64; p 0.001). The most common indication for IMV was cardiopulmonary arrest (CA) (65; 61%), followed by pulmonary oedema (27; 26%) and shock (14; 13.2%). Patients with CA were younger, with better hemodynamic parameters at admission, more favourable coronary anatomy and higher rates of PCI. There were no significant differences in overall mortality between the three groups. The main cause of death in CA patients was persistent vegetative state.

CONCLUSIONS

Mortality in patients with ACS requiring IMV remained high despite a high rate of PCI. Baseline characteristics, management and clinical course were different according to the reason for IMV. The most common cause for IMV requirement was CA.

State of the evidence: mechanical ventilation with PEEP in patients with cardiogenic shock

The need to provide invasive mechanical ventilatory support to patients with myocardial infarction and acute left heart failure is common. Despite the large number of patients requiring mechanical ventilation in this setting, there are remarkably few data addressing the ideal mode of respiratory support in such patients. Although there is near universal acceptance regarding the use of non-invasive positive pressure ventilation in patients with acute pulmonary oedema, there is more concern with invasive positive pressure ventilation owing to its more significant haemodynamic impact. Positive end-expiratory pressure (PEEP) is almost universally applied in mechanically ventilated patients due to benefits in gas exchange, recruitment of alveolar units, counterbalance of hydrostatic forces leading to pulmonary oedema and maintenance of airway patency. The limited available clinical data suggest that a moderate level of PEEP is safe to use in severe left ventricular (LV) dysfunction and cardiogenic shock, and may provide haemodynamic benefits as well in LV failure which exhibits afterload-sensitive physiology.

Comparison of thrombolysis in myocardial infarction, Global Registry of Acute Coronary Events, and Acute Physiology and Chronic Health Evaluation II risk scores in patients with acute myocardial infarction who require mechanical ventilation for more than 24 hours

The ability to provide an accurate prognosis in an intensive care unit is of major importance. Numerous risk scores have been developed to predict hospital mortality based on demographic, physiologic, and clinical data. These scores were universally developed in general medical or surgical intensive care units. Patients admitted to a cardiac care unit differ in many aspects from those admitted to general medical intensive care units. Few patients require mechanical ventilation and prolonged intensive care. Performance of risk scores developed for patients with acute myocardial infarction (AMI) in this subgroup is unknown. We prospectively studied 51 consecutive patients who were admitted to a cardiac care unit from September 2006 to March 2008 for AMI and received mechanical ventilation for >24 hours. Acute Physiology and Chronic Health Evaluation II (APACHE II), Thrombolysis In Myocardial Infarction, and Global Registry of Acute Coronary Events risk scores were calculated for each patient. Mortality rates were extrapolated based on these 3 risk scores. Twenty-two of 51 patients (43%) died in hospital. Age, mean arterial pressure, urea, albumin, hemoglobin, need for vasopressors, and estimated glomerular filtration rate were predictive of mortality. APACHE II and Global Registry of Acute Coronary Events scores were higher in nonsurvivors but Thrombolysis In Myocardial Infarction risk score was not predictive of mortality. APACHE II score had the highest value for area under receiver operator characteristics curve for mortality prediction. In conclusion, patients with AMI requiring mechanical ventilation have a high mortality rate. This risk is predicted by co-morbidities better than by direct cardiac parameters. Consequently, conventional AMI risk scores do not perform well in this very sick population and the APACHE II score better predicts their short-term outcome.

Characteristics and clinical outcome of 458 patients with acute myocardial infarction requiring mechanical ventilation. Results of the BEAT registry of the ALKK-study group

BACKGROUND

Information about the clinical course of patients with acute myocardial infarction requiring mechanical ventilation is scarce. We sought to evaluate the clinical outcome of a large cohort of such patients in clinical practice.

METHODS

The German BEAT registry prospectively enrolled consecutive patients requiring mechanical ventilation who were admitted to an internal intensive care unit (ICU) of 45 participating German hospitals between September 2001 and June 2002. For this analysis, we created a subgroup of patients with acute ST-segment-elevation or non-ST-segment-elevation myocardial infarction.

RESULTS

During the 9-month study period, 458 consecutive patients fulfilled our inclusion criteria. The mean age was 68 ± 8 years and 71% were men. 40% of the patients were already intubated in the prehospital phase. The initial reason for intubation was in 48% of the cases ventricular fibrillation/tachycardia or sudden cardiac death, in 39% congestive heart failure and in 13% of the cases non-cardiac. The median time of ventilation was 2 days (1-5) among survivors and 1 day (0-5) among non-survivors. Of the 458 patients, 256 (56%) had already or developed cardiogenic shock, 86 (19%) acute renal failure, 76 (17%) coma or brain damage, 64 (14%) severe infection, 46 (10%) sepsis and 28 (6%) multiorgan distress syndrome; 11% were treated with fibrinolysis, 39% with PCI and 6% with coronary artery bypass grafting. The overall hospital mortality rate was 48%. In patients with cardiogenic shock, mortality was even higher with 69%.

CONCLUSIONS

Patients requiring mechanical ventilation during an acute myocardial infarction constitute a high risk group with a mortality of about 50%. Further research is necessary to improve the outcome of these patients.

POSITIVE END-EXPIRATORY PRESSURE DOES NOT COMPROMISE MYOCARDIAL CONTRACTILITY IN MYOCARDIAL ISCHEMIA/REPERFUSION

Therapy for severe myocardial ischemia/reperfusion sometimes necessitates intermittent positive pressure ventilation, which may impair left ventricular function by reduction of ventricular loading. It is unknown today whether positive airway pressure also affects contractile force after myocardial ischemia/reperfusion. The authors tested whether positive end-expiratory pressure (PEEP) impairs myocardial contractility in acute ischemic heart failure. In 11 anesthetized mechanically ventilated pigs (28 +/- 3 kg), cardiac output (CO, aortic flow probe), load-independent parameters of left ventricular contractility (conductance method: preload recruitable stroke work [PRSW] and end-systolic elastance [E(es)]) and preload (end-diastolic volume [EDV] conductance) were assessed before and after myocardial ischemia and reperfusion (left anterior descending artery occlusion, 60 min). Data were taken during PEEP 0, 5, and 10 cm H2O. Before myocardial ischemia, both PEEP 5 and 10 cm H2O reduced CO (P < 0.05) because of a reduction of EDV (P < 0.05, PEEP 10 cm H2O). The PRSW remained unchanged (not significant [NS]) and E(es) increased (P < 0.05, PEEP 10 cm H2O). After myocardial ischemia/reperfusion, CO and PRSW, but not E(es) (NS), deteriorated markedly. At the same time, PEEP 10 cm H2O reduced CO (P < 0.05) and, slightly, EDV (NS). Now, both PRSW (P < 0.05, PEEP 5 cm H2O) and E(es) (P < 0.05, PEEP 10 cm H2O) improved upon ventilation with PEEP. In our model, the administration of PEEP impaired global left ventricular function before and after myocardial ischemia/reperfusion. The observed impairment is not attributable to compromised contractility.

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.

Inhospital and 1-year mortality of patients who develop worsening renal function following acute ST-elevation myocardial infarction

BACKGROUND

Recent studies have emphasized the prognostic value of baseline creatinine or estimated creatinine clearance in the setting of acute coronary syndromes. However, the prevalence and prognostic significance of worsening renal function (WRF) in patients with acute ST-elevation myocardial infarction are unknown.

METHODS

We studied 1038 patients presenting with acute ST-elevation infarction. WRF was defined as an increase of > or =0.5 mg/dL in creatinine level at any point during hospital stay. The relation between WRF and subsequent inhospital and 1-year mortality was analyzed by use of multivariate logistic regression and Cox proportional hazards models, respectively, controlling for covariates.

RESULTS

WRF occurred in 98 (9.6%) patients during hospital stay. Baseline renal dysfunction (calculated glomerular filtration rate <60 mL/min) and WRF were strong independent predictors of inhospital mortality (adjusted odds ratios 2.8, 95% CI 1.3-5.9; and 11.4, 95% CI 6.6-19.5, respectively). In a Cox multivariate analysis, both baseline renal dysfunction (adjusted hazard ratio 2.8, 95% CI 1.6-4.9) and WRF (adjusted hazard ratio 7.2, 95% CI 4.9-10.4) remained independent predictors of 1-year mortality. WRF provided incremental prognostic value toward the prediction of 1-year mortality when added to clinical risk predictors and baseline renal function. The increased mortality associated with impaired baseline renal function was largely caused by events occurring in patients with WRF.

CONCLUSION

WRF occurring during admission for ST-elevation myocardial infarction is a powerful and independent predictor of inhospital and 1-year mortality. Small elevations of serum creatinine may serve as a simple marker to identify patients at a very high risk.

Bench-to-bedside review: outcome predictions for critically ill patients in the emergency department

The escalating number of emergency department (ED) visits, length of stay, and hospital overcrowding have been associated with an increasing number of critically ill patients cared for in the ED. Existing physiologic scoring systems have traditionally been used for outcome prediction, clinical research, quality of care analysis, and benchmarking in the intensive care unit (ICU) environment. However, there is limited experience with scoring systems in the ED, while early and aggressive intervention in critically ill patients in the ED is becoming increasingly important. Development and implementation of physiologic scoring systems specific to this setting is potentially useful in the early recognition and prognostication of illness severity. A few existing ICU physiologic scoring systems have been applied in the ED, with some success. Other ED specific scoring systems have been developed for various applications: recognition of patients at risk for infection; prediction of mortality after critical care transport; prediction of in-hospital mortality after admission; assessment of prehospital therapeutic efficacy; screening for severe acute respiratory syndrome; and prediction of pediatric hospital admission. Further efforts at developing unique physiologic assessment methodologies for use in the ED will improve quality of patient care, aid in resource allocation, improve prognostic accuracy, and objectively measure the impact of early intervention in the ED.