Michael R. Pinsky

Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care.

ObjectiveTo determine the incidence, cost, and outcome of severe sepsis in the United States. DesignObservational cohort study. SettingAll nonfederal hospitals (n = 847) in seven U.S. states. PatientsAll patients (n = 192,980) meeting criteria for severe sepsis based on the International Classification of Diseases, Ninth Revision, Clinical Modification. InterventionsNone. Measurements and Main Results We linked all 1995 state hospital discharge records (n = 6,621,559) from seven large states with population and hospital data from the U.S. Census, the Centers for Disease Control, the Health Care Financing Administration, and the American Hospital Association. We defined severe sepsis as documented infection and acute organ dysfunction using criteria based on the International Classification of Diseases, Ninth Revision, Clinical Modification. We validated these criteria against prospective clinical and physiologic criteria in a subset of five hospitals. We generated national age- and gender-adjusted estimates of incidence, cost, and outcome. We identified 192,980 cases, yielding national estimates of 751,000 cases (3.0 cases per 1,000 population and 2.26 cases per 100 hospital discharges), of whom 383,000 (51.1%) received intensive care and an additional 130,000 (17.3%) were ventilated in an intermediate care unit or cared for in a coronary care unit. Incidence increased >100-fold with age (0.2/1,000 in children to 26.2/1,000 in those >85 yrs old). Mortality was 28.6%, or 215,000 deaths nationally, and also increased with age, from 10% in children to 38.4% in those >85 yrs old. Women had lower age-specific incidence and mortality, but the difference in mortality was explained by differences in underlying disease and the site of infection. The average costs per case were

Effect of Intrathoracic Pressure on Left Ventricular Performance

22,100, with annual total costs of

Passive leg raising predicts fluid responsiveness in the critically ill.

16.7 billion nationally. Costs were higher in infants, nonsurvivors, intensive care unit patients, surgical patients, and patients with more organ failure. The incidence was projected to increase by 1.5% per annum. ConclusionsSevere sepsis is a common, expensive, and frequently fatal condition, with as many deaths annually as those from acute myocardial infarction. It is especially common in the elderly and is likely to increase substantially as the U.S. population ages.

Patients' recollections of stressful experiences while receiving prolonged mechanical ventilation in an intensive care unit*

Left ventricular dysfunction is common in respiratory-distress syndrome, asthma and obstructive lung disease. To understand the contribution of intrathoracic pressure to this problem, we studied the effects of Valsalva and Müller maneuvers on left ventricular function in eight patients. Implantation of intramyocardial markers permitted beat-by-beat measurement of the velocity of fiber shortening (VCF) and left ventricular volume. During the Müller maneuver, VCF and ejection fraction decreased despite an increase in left ventricular volume and a decline in arterial pressure. In addition, when arterial pressure was corrected for changes in intrapleural pressure during either maneuver it correlated better with left ventricular end-systolic volumes than did uncorrected arterial pressures. These findings suggest that negative intrathoracic pressure affects left ventricular function by increasing left ventricular transmural pressures and thus afterload. We conclude that large intrathoracic-pressure changes, such as those that occur in acute pulmonary disease, can influence cardiac performance.

Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine.

Objective:Passive leg raising (PLR) represents a “self-volume challenge” that could predict fluid response and might be useful when the respiratory variation of stroke volume cannot be used for that purpose. We hypothesized that the hemodynamic response to PLR predicts fluid responsiveness in mechanically ventilated patients. Design:Prospective study. Setting:Medical intensive care unit of a university hospital. Patients:We investigated 71 mechanically ventilated patients considered for volume expansion. Thirty-one patients had spontaneous breathing activity and/or arrhythmias. Interventions:We assessed hemodynamic status at baseline, after PLR, and after volume expansion (500 mL NaCl 0.9% infusion over 10 mins). Measurements and Main Results:We recorded aortic blood flow using esophageal Doppler and arterial pulse pressure. We calculated the respiratory variation of pulse pressure in patients without arrhythmias. In 37 patients (responders), aortic blood flow increased by ≥15% after fluid infusion. A PLR increase of aortic blood flow ≥10% predicted fluid responsiveness with a sensitivity of 97% and a specificity of 94%. A PLR increase of pulse pressure ≥12% predicted volume responsiveness with significantly lower sensitivity (60%) and specificity (85%). In 30 patients without arrhythmias or spontaneous breathing, a respiratory variation in pulse pressure ≥12% was of similar predictive value as was PLR increases in aortic blood flow (sensitivity of 88% and specificity of 93%). In patients with spontaneous breathing activity, the specificity of respiratory variations in pulse pressure was poor (46%). Conclusions:The changes in aortic blood flow induced by PLR predict preload responsiveness in ventilated patients, whereas with arrhythmias and spontaneous breathing activity, respiratory variations of arterial pulse pressure poorly predict preload responsiveness.

Quantitative Assessment of Alterations in Regional Left Ventricular Contractility With Color-Coded Tissue Doppler Echocardiography Comparison With Sonomicrometry and Pressure-Volume Relations

Objective To describe stressful experiences of adult patients who received mechanical ventilation for ≥48 hrs in an intensive care unit. Design Prospective cohort study. Setting Four intensive care units within an East Coast tertiary-care university medical center. Patients Patients were 150 adult intensive care unit patients receiving mechanical ventilation for ≥48 hrs. Intervention None. Measurements and Main Results As part of a study of the long-term outcomes of adult patients requiring prolonged mechanical ventilation, we used a 32-item questionnaire to collect data on patients’ stressful experiences, both psychological (e.g., fearfulness, anxiety) and physical (e.g., pain, difficulty breathing), associated with the mechanical ventilation endotracheal tube and with being in an intensive care unit.Of 554 patients who met study criteria and survived prolonged mechanical ventilation, 150 consented and were oriented to person, place, and situation. Two thirds of these patients remembered the endotracheal tube and/or being in an intensive care unit. The median numbers of endotracheal tube and intensive care unit experiences remembered were 3 (of 7) and 9 (of 22), respectively. If a patient remembered an experience in the questionnaire, it was likely to be moderately to extremely bothersome.Some of the items that many patients found to be moderately to extremely bothersome were pain, fear, anxiety, lack of sleep, feeling tense, inability to speak/communicate, lack of control, nightmares, and loneliness. Stressful experiences associated with the endotracheal tube were strongly associated with subjects’ experiencing spells of terror, feeling nervous when left alone, and poor sleeping patterns. Conclusions Subjects were more likely to remember experiences that were moderately to extremely bothersome. This might be because the more bothersome experiences were easier to recall or because most of these experiences are common and significant stressors to many of these patients. In either case, these data indicate that these patients are subject to numerous stressful experiences, which many find quite bothersome. This suggests the potential for improved symptom management, which could contribute to a less stressful intensive care unit stay and improved patient outcomes.

Functional Hemodynamic Monitoring

ObjectiveCirculatory shock is a life-threatening syndrome resulting in multiorgan failure and a high mortality rate. The aim of this consensus is to provide support to the bedside clinician regarding the diagnosis, management and monitoring of shock.MethodsThe European Society of Intensive Care Medicine invited 12 experts to form a Task Force to update a previous consensus (Antonelli et al.: Intensive Care Med 33:575–590, 2007). The same five questions addressed in the earlier consensus were used as the outline for the literature search and review, with the aim of the Task Force to produce statements based on the available literature and evidence. These questions were: (1) What are the epidemiologic and pathophysiologic features of shock in the intensive care unit? (2) Should we monitor preload and fluid responsiveness in shock? (3) How and when should we monitor stroke volume or cardiac output in shock? (4) What markers of the regional and microcirculation can be monitored, and how can cellular function be assessed in shock? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock? Four types of statements were used: definition, recommendation, best practice and statement of fact.ResultsForty-four statements were made. The main new statements include: (1) statements on individualizing blood pressure targets; (2) statements on the assessment and prediction of fluid responsiveness; (3) statements on the use of echocardiography and hemodynamic monitoring.ConclusionsThis consensus provides 44 statements that can be used at the bedside to diagnose, treat and monitor patients with shock.

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

BACKGROUND Tissue Doppler imaging (TDI) is a novel method of color-coding myocardial velocity on-line. The objective of the present study was to evaluate endocardial velocity with TDI as a method of objectively quantifying alterations in regional contractility over a wide range induced by inotropic modulation. METHODS AND RESULTS Myocardial length crystals were used to simultaneously assess regional left ventricular (LV) function, and high-fidelity pressure and conductance catheters were used to assess global LV contractility by pressure-volume relations in nine open-chest dogs. Mid-LV M-mode and two-dimensional color TDI images were recorded during control and inotropic modulation stages with dobutamine and esmolol. Predicted significant increases in TDI indices occurred with dobutamine: peak systolic velocity of 4.41 +/- 1.07 to 6.67 +/- 1.07 cm/s*, systolic time-velocity integral (TVI) of 0.43 +/- 0.12 to 0.62 +/- 0.10 cm*, and diastolic TVI of 0.49 +/- 0.11 to 0.71 +/- 0.17 cm*. Opposing significant decreases occurred with esmolol: peak systolic velocity of 4.46 +/- 0.94 to 2.31 +/- 0.81 cm/s*, systolic TVI of 0.47 +/- 0.12 to 0.19 +/- 0.11 cm*, and diastolic TVI of 0.55 +/- 0.11 to 0.33 +/- 0.11 cm* (*all P < .001 versus control). Changes in TDI peak systolic velocity were correlated with changes in fractional shortening (r = .88) and shortening velocity (r = .87) by sonomicrometry. Changes in TDI peak velocity from multiple mid-LV sites also correlated significantly with maximal elastance (r = .85 +/- .04) from pressure-volume relations. CONCLUSIONS TDI measures reflect directional and incremental alterations in regional and global LV contractility and have the potential to quantify regional LV function.

The American-European Consensus Conference on ARDS, part 2. Ventilatory, pharmacologic, supportive therapy, study design strategies and issues related to recovery and remodeling.

Functional hemodynamic monitoring is the assessment of the dynamic interactions of hemodynamic variables in response to a defined perturbation. Recent interest in functional hemodynamic monitoring for the bedside assessment of cardiovascular insufficiency has heightened with the documentation of its accuracy in predicting volume responsiveness using a wide variety of monitoring devices, both invasive and noninvasive, and across multiple patient groups and clinical conditions. However, volume responsiveness, though important, reflects only part of the overall spectrum of functional physiologic variables that can be measured to define the physiologic state and monitor response to therapy.

Clinical review: Update on hemodynamic monitoring - a consensus of 16

ObjectiveTo describe and identify factors associated with mortality rate and quality of life 1 yr after prolonged mechanical ventilation. DesignProspective, observational cohort study with patient recruitment over 26 months and follow-up for 1 yr. SettingIntensive care units at a tertiary care university hospital. PatientsAdult patients receiving prolonged mechanical ventilation. InterventionsNone. Measurements and Main ResultsWe 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). ConclusionsMortality 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.