Michael J. Lanspa

Applying dynamic parameters to predict hemodynamic response to volume expansion in spontaneously breathing patients with septic shock.

ABSTRACT Volume expansion is a mainstay of therapy in septic shock, although its effect is difficult to predict using conventional measurements. Dynamic parameters, which vary with respiratory changes, appear to predict hemodynamic response to fluid challenge in mechanically ventilated, paralyzed patients. Whether they predict response in patients who are free from mechanical ventilation is unknown. We hypothesized that dynamic parameters would be predictive in patients not receiving mechanical ventilation. This is a prospective, observational, pilot study. Patients with early septic shock and who were not receiving mechanical ventilation received 10-mL/kg volume expansion (VE) at their treating physician’s discretion after initial resuscitation in the emergency department. We used transthoracic echocardiography to measure vena cava collapsibility index and aortic velocity variation before VE. We used a pulse contour analysis device to measure stroke volume variation (SVV). Cardiac index was measured immediately before and after VE using transthoracic echocardiography. Hemodynamic response was defined as an increase in cardiac index 15% or greater. Fourteen patients received VE, five of whom demonstrated a hemodynamic response. Vena cava collapsibility index and SVV were predictive (area under the curve = 0.83, 0.92, respectively). Optimal thresholds were calculated: vena cava collapsibility index, 15% or greater (positive predictive value, 62%; negative predictive value, 100%; P = 0.03); SVV, 17% or greater (positive predictive value 100%, negative predictive value 82%, P = 0.03). Aortic velocity variation was not predictive. Vena cava collapsibility index and SVV predict hemodynamic response to fluid challenge patients with septic shock who are not mechanically ventilated. Optimal thresholds differ from those described in mechanically ventilated patients.

Survival After Shock Requiring High-Dose Vasopressor Therapy

BACKGROUND Some patients with hypotensive shock do not respond to usual doses of vasopressor therapy. Very little is known about outcomes after high-dose vasopressor therapy (HDV). We sought to characterize survival among patients with shock requiring HDV. We also evaluated the possible utility of stress-dose corticosteroid therapy in these patients. METHODS We conducted a retrospective study of patients with shock requiring HDV in the ICUs of five hospitals from 2005 through 2010. We defined HDV as receipt at any point of ≥ 1 μg/kg/min of norepinephrine equivalent (calculated by summing norepinephrine-equivalent infusion rates of all vasopressors). We report survival 90 days after hospital admission. We evaluated receipt of stress-dose corticosteroids, cause of shock, receipt of CPR, and withdrawal or withholding of life support therapy. RESULTS We identified 443 patients meeting inclusion criteria. Seventy-six (17%) survived. Survival was similar (20%) among the 241 patients with septic shock. Among the 367 nonsurvivors, 254 (69%) experienced withholding/withdrawal of care, and 115 (31%) underwent CPR. Stress-dose corticosteroid therapy was associated with increased survival (P = .01). CONCLUSIONS One in six patients with shock survived to 90 days after HDV. The majority of nonsurvivors died after withdrawal or withholding of life support therapy. A minority of patients underwent CPR. Additionally, stress-dose corticosteroid therapy appears reasonable in patients with shock requiring HDV.

Diastolic dysfunction and mortality in early severe sepsis and septic shock: a prospective, observational echocardiography study

BackgroundPatients with severe sepsis or septic shock often exhibit significant cardiovascular dysfunction. We sought to determine whether severity of diastolic dysfunction assessed by transthoracic echocardiography (TTE) predicts 28-day mortality.MethodsIn this prospective, observational study conducted in two intensive care units at a tertiary care hospital, 78 patients (age 53.2 ± 17.1 years; 51% females; mean APACHE II score 23.3 ± 7.4) with severe sepsis or septic shock underwent TTE within 6 h of ICU admission, after 18 to 32 h, and after resolution of shock. Left ventricular (LV) diastolic dysfunction was defined according to modified American Society of Echocardiography 2009 guidelines using E, A, and e’ velocities; E/A and E/e’; and E deceleration time. Systolic dysfunction was defined as an ejection fraction < 45%.ResultsTwenty-seven patients (36.5%) had diastolic dysfunction on initial echocardiogram, while 47 patients (61.8%) had diastolic dysfunction on at least one echocardiogram. Total mortality was 16.5%. The highest mortality (37.5%) was observed among patients with grade I diastolic dysfunction, an effect that persisted after controlling for age and APACHE II score. At time of initial TTE, central venous pressure (CVP) (11+/- 5 mmHg) did not differ among grades I-III, although patients with grade I received less intravenous fluid.ConclusionsLV diastolic dysfunction is common in septic patients. Grade I diastolic dysfunction, but not grades II and III, was associated with increased mortality. This finding may reflect inadequate fluid resuscitation in early sepsis despite an elevated CVP, suggesting a possible role for TTE in sepsis resuscitation.

Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest

BACKGROUND Point-of-care ultrasound has been suggested to improve outcomes from advanced cardiac life support (ACLS), but no large studies have explored how it should be incorporated into ACLS. Our aim was to determine whether cardiac activity on ultrasound during ACLS is associated with improved survival. METHODS We conducted a non-randomized, prospective, protocol-driven observational study at 20 hospitals across United States and Canada. Patients presenting with out-of-hospital arrest or in-ED arrest with pulseless electrical activity or asystole were included. An ultrasound was performed at the beginning and end of ACLS. The primary outcome was survival to hospital admission. Secondary outcomes included survival to hospital discharge and return of spontaneous circulation. FINDINGS 793 patients were enrolled, 208 (26.2%) survived the initial resuscitation, 114 (14.4%) survived to hospital admission, and 13 (1.6%) survived to hospital discharge. Cardiac activity on US was the variable most associated with survival at all time points. On multivariate regression modeling, cardiac activity was associated with increased survival to hospital admission (OR 3.6, 2.2-5.9) and hospital discharge (OR 5.7, 1.5-21.9). No cardiac activity on US was associated with non-survival, but 0.6% (95% CI 0.3-2.3) survived to discharge. Ultrasound identified findings that responded to non-ACLS interventions. Patients with pericardial effusion and pericardiocentesis demonstrated higher survival rates (15.4%) compared to all others (1.3%). CONCLUSION Cardiac activity on ultrasound was the variable most associated with survival following cardiac arrest. Ultrasound during cardiac arrest identifies interventions outside of the standard ACLS algorithm.

Mortality, morbidity, and disease severity of patients with aspiration pneumonia

BACKGROUND Aspiration pneumonia is a common syndrome, although less well characterized than other pneumonia syndromes. We describe a large population of patients with aspiration pneumonia. METHODS In this retrospective population study, we queried the electronic medical records at a tertiary-care, university-affiliated hospital from 1996 to 2006. Patients were initially identified by International Classification of Diseases, 9th Revision code 507.x; subsequent physician chart review excluded patients with aspiration pneumonitis and those without a confirmatory radiograph. Patients with community-acquired aspiration pneumonia were compared to a contemporaneous population of community-acquired pneumonia (CAP) patients. We compared CURB-65 (a clinical prediction rule based on Confusion, Uremia, Respiratory rate, Blood Pressure, and age)-predicted mortality with actual 30-day mortality. RESULTS We identified 628 patients with aspiration pneumonia, of which 510 were community-acquired. Median age was 77 years, with 30-day mortality of 21%. Compared to CAP patients, patients with community-acquired aspiration pneumonia had more frequent inpatient admission (99% vs 58%) and intensive care unit admission (38% vs 14%), higher Charlson comorbidity index (3 vs 1), and higher prevalence of do not resuscitate/intubate orders (24% vs 11%). CURB-65 predicted mortality poorly in aspiration pneumonia patients (area under the curve, 0.66). CONCLUSIONS Patients with community-acquired aspiration pneumonia are older, have more comorbidities, and demonstrate higher mortality than CAP patients, even after adjustment for age and comorbidities. CURB-65 poorly predicts mortality in this population.

Moderate Glucose Control Is Associated With Increased Mortality Compared With Tight Glucose Control in Critically Ill Patients Without Diabetes

BACKGROUND Optimal glucose management in the ICU remains unclear. In 2009, many clinicians at Intermountain Healthcare selected a moderate glucose control (90-140 mg/dL) instead of tight glucose control (80-110 mg/dL). We hypothesized that moderate glucose control would affect patients with and without preexisting diabetes differently. METHODS We performed a retrospective cohort analysis of all patients treated with eProtocol-insulin from November 2006 to March 2011, stratifying for diabetes. We performed multivariate logistic regression for 30-day mortality with covariates of age, modified APACHE (Acute Physiology and Chronic Health Evaluation) II score, Charlson Comorbidity score, and target glucose. RESULTS We studied 3,529 patients in 12 different ICUs in eight different hospitals. Patients with diabetes had higher mean glucose (132 mg/dL vs 124 mg/dL) and greater glycemic variability (SD = 41 mg/dL vs 29 mg/dL) than did patients without diabetes (P < .01 for both comparisons). Tight glucose control was associated with increased frequency of moderate and severe hypoglycemia (30.3% and 3.6%) compared with moderate glucose control (14.3% and 2.0%, P < .01 for both). Multivariate analysis demonstrated that the moderate glucose target was independently associated with increased risk of mortality in patients without diabetes (OR, 1.36; 95% CI, 1.01-1.84; P = .05) but decreased risk of mortality in patients with diabetes (OR, 0.65; 95% CI, 0.45-0.93; P = .01). CONCLUSIONS Moderate glucose control (90-140 mg/dL) may confer greater mortality in critically ill patients without diabetes compared with tight glucose control (80-110 mg/dL). A single glucose target does not appear optimal for all critically ill patients. These data have important implications for the design of future interventional trials as well as for the glycemic management of critically ill patients.

Characteristics associated with clinician diagnosis of aspiration pneumonia: a descriptive study of afflicted patients and their outcomes.

BACKGROUND Aspiration pneumonia is a common disease, although less well characterized than other pneumonia syndromes. OBJECTIVE We analyzed patient-level covariates associated with clinician-defined aspiration pneumonia. METHODS We used the Community-Acquired Pneumonia Organization database, a multicenter, international population of patients with community-acquired pneumonia, using data from 2001 to 2012. Aspiration pneumonia was determined by the treating clinician. We analyzed covariates associated with clinician-defined diagnosis of aspiration pneumonia using logistic regression. We compared aspiration pneumonia patients to propensity-matched cases with nonaspiration pneumonia. RESULTS We studied 5185 patients. Four hundred fifty-one of these patients had aspiration pneumonia. Patients with aspiration pneumonia were older, had greater disease severity, and more comorbidities than patients with nonaspiration pneumonia. They were more likely cared for in the intensive care unit (19% vs 13%, P = 0.002), had longer unadjusted hospital length of stay (9 vs 7 days, P < 0.001), and took longer to achieve clinical stability (unadjusted 8 vs 4 days, P < 0.001). Confusion, nursing home residence, and cerebrovascular disease were most associated with clinician diagnosis of aspiration pneumonia (odds ratio: 4.4, 2.9, 2.3, respectively). Unadjusted inpatient mortality was higher (23% vs 9%, P < 0.001). Aspiration pneumonia conferred a 2.3 odds ratio for inpatient mortality after adjusting for age, disease severity, and comorbidities. CONCLUSIONS Among pneumonia patients, confusion, nursing home residence, and cerebrovascular disease are associated with a clinician diagnosis of aspiration. Aspiration pneumonia is associated with greater mortality among patients with community-acquired pneumonia, which is not explained by older age, measured indices of severity, or comorbidities.

Relationships among initial hospital triage, disease progression and mortality in community-acquired pneumonia

Background and objective:  Appropriate triage of patients with community‐acquired pneumonia (CAP) may improve morbidity, mortality and use of hospital resources. Worse outcomes from delayed intensive care unit (ICU) admission have long been suspected but have not been verified.

Central venous pressure and shock index predict lack of hemodynamic response to volume expansion in septic shock: A prospective, observational study ☆,☆☆

PURPOSE Volume expansion is a common therapeutic intervention in septic shock, although patient response to the intervention is difficult to predict. Central venous pressure (CVP) and shock index have been used independently to guide volume expansion, although their use is questionable. We hypothesize that a combination of these measurements will be useful. METHODS In a prospective, observational study, patients with early septic shock received 10-mL/kg volume expansion at their treating physicians discretion after brief initial resuscitation in the emergency department. Central venous pressure and shock index were measured before volume expansion interventions. Cardiac index was measured immediately before and after the volume expansion using transthoracic echocardiography. Hemodynamic response was defined as an increase in a cardiac index of 15% or greater. RESULTS Thirty-four volume expansions were observed in 25 patients. A CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less individually had a good negative predictive value (83% and 88%, respectively). Of 34 volume expansions, the combination of both a high CVP and a low shock index was extremely unlikely to elicit hemodynamic response (negative predictive value, 93%; P = .02). CONCLUSIONS Volume expansion in patients with early septic shock with a CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less is unlikely to lead to an increase in cardiac index.

Association of left ventricular longitudinal strain with central venous oxygen saturation and serum lactate in patients with early severe sepsis and septic shock.

IntroductionIn septic shock, assessment of cardiac function often relies on invasive central venous oxygen saturation (ScvO2). Ventricular strain is a non-invasive method of assessing ventricular wall deformation and may be a sensitive marker of heart function. We hypothesized that it may have a relationship with ScvO2 and lactate.MethodsWe prospectively performed transthoracic echocardiography in patients with severe sepsis or septic shock and measured (1) left ventricular longitudinal strain from a four-chamber view and (2) ScvO2. We excluded patients for whom image quality was inadequate or for whom ScvO2 values were unobtainable. We determined the association between strain and ScvO2 with logistic and linear regression, using covariates of mean arterial pressure, central venous pressure, and vasopressor dose. We determined the association between strain and lactate. We considered strain greater than −17 % as abnormal and strain greater than −10 % as severely abnormal.ResultsWe studied 89 patients, 68 of whom had interpretable images. Of these patients, 42 had measurable ScvO2. Sixty percent of patients had abnormal strain, and 16 % had severely abnormal strain. Strain is associated with low ScvO2 (linear coefficient −1.05, p =0.006; odds ratio 1.23 for ScvO2 <60 %, p =0.016). Patients with severely abnormal strain had significantly lower ScvO2 (56.1 % vs. 67.5 %, p <0.01) and higher lactate (2.7 vs. 1.9 mmol/dl, p =0.04) than those who did not. Strain was significantly different between patients, based on a threshold ScvO2 of 60 % (−13.7 % vs. -17.2 %, p =0.01) but not at 70 % (−15.0 % vs. −18.2 %, p =0.08).ConclusionsLeft ventricular strain is associated with low ScvO2 and hyperlactatemia. It may be a non-invasive surrogate for adequacy of oxygen delivery during early severe sepsis or septic shock.