Validation of the Intermountain patient perception of quality (PPQ) survey among survivors of an intensive care unit admission: a retrospective validation study

Background

Patients’ perceptions of the quality of their hospitalization have become important to the American healthcare system. Standard surveys of perceived quality of healthcare do not focus on the Intensive Care Unit (ICU) portion of the stay. Our objective was to evaluate the construct validity and internal consistency of the Intermountain Patient Perception of Quality (PPQ) survey among patients discharged from the ICU.

Methods

We analyzed prospectively collected results from the ICU PPQ survey of all inpatients at Intermountain Medical Center whose hospitalization included an ICU stay. We employed principal components analysis to determine the constructs present in the PPQ survey, and Cronbach’s alpha to evaluate the internal consistency (reliability) of the items representing each construct.

Results

We identified 5,680 patients who had completed the PPQ survey. There were three basic domains measured: nursing care, physician care, and overall perception of quality. Most of the variability was explained with the first two principal components. Constructs did not vary by type of respondent.

Conclusions

The Intermountain ICU PPQ survey demonstrated excellent construct validity across three distinct constructs. This, in addition to its previously established content validity, suggests the utility of the PPQ survey as an assay of the perceived quality of the ICU experience.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-0828-x) contains supplementary material, which is available to authorized users.

Phenotypic clusters within sepsis-associated multiple organ dysfunction syndrome

INTRODUCTION

Sepsis is a devastating condition that is generally treated as a single disease. Identification of meaningfully distinct clusters may improve research, treatment and prognostication among septic patients. We therefore sought to identify clusters among patients with severe sepsis or septic shock.

METHODS

We retrospectively studied all patients with severe sepsis or septic shock admitted directly from the emergency department to the intensive care units (ICUs) of three hospitals, 2006-2013. Using age and Sequential Organ Failure Assessment (SOFA) subscores, we defined clusters utilizing self-organizing maps, a method for representing multidimensional data in intuitive two-dimensional grids to facilitate cluster identification.

RESULTS

We identified 2533 patients with severe sepsis or septic shock. Overall mortality was 17 %, with a mean APACHE II score of 24, mean SOFA score of 8 and a mean ICU stay of 5.4 days. Four distinct clusters were identified; (1) shock with elevated creatinine, (2) minimal multi-organ dysfunction syndrome (MODS), (3) shock with hypoxemia and altered mental status, and (4) hepatic disease. Mortality (95 % confidence intervals) for these clusters was 11 (8-14), 12 (11-14), 28 (25-32), and 21 (16-26) %, respectively (p < 0.0001). Regression modeling demonstrated that the clusters differed in the association between clinical outcomes and predictors, including APACHE II score.

CONCLUSIONS

We identified four distinct clusters of MODS among patients with severe sepsis or septic shock. These clusters may reflect underlying pathophysiological differences and could potentially facilitate tailored treatments or directed research.

Polymorphisms in key pulmonary inflammatory pathways and the development of acute respiratory distress syndrome

PURPOSE/AIM

Acute Respiratory Distress Syndrome (ARDS) is an important clinical and public health problem. Why some at-risk individuals develop ARDS and others do not is unclear but may be related to differences in inflammatory and cell signaling systems. The Receptor for Advanced Glycation Endproducts (RAGE) and Granulocyte-Monocyte Stimulating Factor (GM-CSF) pathways have recently been implicated in pulmonary pathophysiology; whether genetic variation within these pathways contributes to ARDS risk or outcome is unknown.

MATERIALS AND METHODS

We studied 842 patients from three centers in Utah and 14 non-Utah ARDS Network centers. We studied patients at risk for ARDS and patients with ARDS to determine whether Single Nucleotide Polymorphisms (SNPs) in the RAGE and GM-CSF pathways were associated with development of ARDS. We studied 29 SNPs in 5 genes within the two pathways and controlled for age, sepsis as ARDS risk factor, and severity of illness, while targeting a false discovery rate of ≤ 5%. In a secondary analysis we evaluated associations with mortality.

RESULTS

Of 842 patients, 690 had ARDS, and 152 were at-risk. Sepsis was the risk factor for ARDS in 250 (30%) patients. When controlling for age, APACHE III score, sepsis as risk factor, and multiple comparisons, no SNPs were significantly associated with ARDS. In a secondary analysis, only rs743564 in CSF2 approached significance with regard to mortality (OR 2.17, unadjusted p = 0.005, adjusted p = 0.15).

CONCLUSIONS

Candidate SNPs within 5 genes in the RAGE and GM-CSF pathways were not significantly associated with development of ARDS in this multi-centric cohort.

Fluid management with a simplified conservative protocol for the acute respiratory distress syndrome*

OBJECTIVES

In the Fluid and Catheter Treatment Trial (FACTT) of the National Institutes of Health Acute Respiratory Distress Syndrome Network, a conservative fluid protocol (FACTT Conservative) resulted in a lower cumulative fluid balance and better outcomes than a liberal fluid protocol (FACTT Liberal). Subsequent Acute Respiratory Distress Syndrome Network studies used a simplified conservative fluid protocol (FACTT Lite). The objective of this study was to compare the performance of FACTT Lite, FACTT Conservative, and FACTT Liberal protocols.

DESIGN

Retrospective comparison of FACTT Lite, FACTT Conservative, and FACTT Liberal. Primary outcome was cumulative fluid balance over 7 days. Secondary outcomes were 60-day adjusted mortality and ventilator-free days through day 28. Safety outcomes were prevalence of acute kidney injury and new shock.

SETTING

ICUs of Acute Respiratory Distress Syndrome Network participating hospitals.

PATIENTS

Five hundred three subjects managed with FACTT Conservative, 497 subjects managed with FACTT Liberal, and 1,124 subjects managed with FACTT Lite.

INTERVENTIONS

Fluid management by protocol.

MEASUREMENTS AND MAIN RESULTS

Cumulative fluid balance was 1,918 ± 323 mL in FACTT Lite, -136 ± 491 mL in FACTT Conservative, and 6,992 ± 502 mL in FACTT Liberal (p < 0.001). Mortality was not different between groups (24% in FACTT Lite, 25% in FACTT Conservative and Liberal, p = 0.84). Ventilator-free days in FACTT Lite (14.9 ± 0.3) were equivalent to FACTT Conservative (14.6 ± 0.5) (p = 0.61) and greater than in FACTT Liberal (12.1 ± 0.5, p < 0.001 vs Lite). Acute kidney injury prevalence was 58% in FACTT Lite and 57% in FACTT Conservative (p = 0.72). Prevalence of new shock in FACTT Lite (9%) was lower than in FACTT Conservative (13%) (p = 0.007 vs Lite) and similar to FACTT Liberal (11%) (p = 0.18 vs Lite).

CONCLUSIONS

FACTT Lite had a greater cumulative fluid balance than FACTT Conservative but had equivalent clinical and safety outcomes. FACTT Lite is an alternative to FACTT Conservative for fluid management in Acute Respiratory Distress Syndrome.

Prospective Surveillance for Surgical Site Infection in St. Petersburg, Russian Federation

Objective.

To assess the risk-adjusted incidence and predictors of surgical site infections (SSIs).

Design.

Prospective, multicenter, observational cohort study.

Setting.

Seven surgical departments at 3 urban academic hospitals in St. Petersburg, Russian Federation.

Patients.

All patients had surgery performed between January 15 and May 12, 2000. A total of 1,453 surgical procedures were followed up. Medical records were unavailable for less than 3% of all patients; patients were not excluded for any other reason. The mean patient age was 49.3 years, 61% were female, and 34% had an American Society of Anesthesiologists physical status classification (hereafter, “ASA classification”) of at least 3. Surgery for 45% of the patients was emergent.

Results.

In all, 138 patients (9.5%) developed SSI, for a rate that was approximately 3.5 times the risk-stratified rates in the United States. Male sex (odds ratio [OR], 1.54), ASA classifications of 3 (OR, 3.7) or 4 (OR, 5.0), longer duration of surgery (OR, 2.2), and wound classes of 3 (OR, 5.5) or 4 (OR, 14.3) were associated with increased SSI risk in multivariate analysis. Endoscopic surgery was associated with a lower risk of SSI (OR, 0.23). Antibiotic prophylaxis was used in 0%-33% of operations, and 69% of uninfected patients received antibiotics after the operation.

Conclusions.

The SSI rates are significantly higher than previously reported. Although this finding may be attributable to inadequate antibiotic prophylaxis, local infection control and surgical practices may also be contributors. Use of antibiotic prophylaxis should be encouraged and the effect of local practices further investigated. Active SSI surveillance should be expanded to other parts of the Russian Federation.

Platelet-monocyte aggregate formation and mortality risk in older patients with severe sepsis and septic shock

BACKGROUND

Aging-related changes in platelet and monocyte interactions may contribute to adverse outcomes in sepsis but remain relatively unexamined. We hypothesized that differential platelet-monocyte aggregate (PMA) formation in older septic patients alters inflammatory responses and mortality.

METHODS

We prospectively studied 113 septic adults admitted to the intensive care unit with severe sepsis or septic shock. Patients were dichotomized a priori into one of two groups: older (age ≥ 65 years, n = 28) and younger (age < 65 years, n = 85). PMA levels were measured in whole blood via flow cytometry within 24 hours of admission. Plasma levels of IL-6 and IL-8, proinflammatory cytokines produced by monocytes upon PMA formation, were determined by commercial assays. Patients were followed for the primary outcome of 28-day, all-cause mortality.

RESULTS

Elevated PMA levels were associated with an increased risk of mortality in older septic patients (hazard ratio for mortality 5.64, 95% confidence interval 0.64-49.61). This association remained after adjusting for potential confounding variables in multivariate regression. Receiver operating curve analyses demonstrated that PMA levels greater than or equal to 8.43% best predicted 28-day mortality in older septic patients (area under the receiver operating curve 0.82). Plasma IL-6 and IL-8 levels were also significantly higher in older nonsurvivors. In younger patients, neither PMA levels nor plasma monokines were significantly associated with mortality.

CONCLUSIONS

Increased PMA formation, and associated proinflammatory monokine synthesis, predicts mortality in older septic patients. Although larger studies are needed, our findings suggest that heightened PMA formation in older septic patients may contribute to injurious inflammatory responses and an increased risk of mortality.

Do heart and respiratory rate variability improve prediction of extubation outcomes in critically ill patients?

Introduction

Prolonged ventilation and failed extubation are associated with increased harm and cost. The added value of heart and respiratory rate variability (HRV and RRV) during spontaneous breathing trials (SBTs) to predict extubation failure remains unknown.

Methods

We enrolled 721 patients in a multicenter (12 sites), prospective, observational study, evaluating clinical estimates of risk of extubation failure, physiologic measures recorded during SBTs, HRV and RRV recorded before and during the last SBT prior to extubation, and extubation outcomes. We excluded 287 patients because of protocol or technical violations, or poor data quality. Measures of variability (97 HRV, 82 RRV) were calculated from electrocardiogram and capnography waveforms followed by automated cleaning and variability analysis using Continuous Individualized Multiorgan Variability Analysis (CIMVA™) software. Repeated randomized subsampling with training, validation, and testing were used to derive and compare predictive models.

Results

Of 434 patients with high-quality data, 51 (12%) failed extubation. Two HRV and eight RRV measures showed statistically significant association with extubation failure (P <0.0041, 5% false discovery rate). An ensemble average of five univariate logistic regression models using RRV during SBT, yielding a probability of extubation failure (called WAVE score), demonstrated optimal predictive capacity. With repeated random subsampling and testing, the model showed mean receiver operating characteristic area under the curve (ROC AUC) of 0.69, higher than heart rate (0.51), rapid shallow breathing index (RBSI; 0.61) and respiratory rate (0.63). After deriving a WAVE model based on all data, training-set performance demonstrated that the model increased its predictive power when applied to patients conventionally considered high risk: a WAVE score >0.5 in patients with RSBI >105 and perceived high risk of failure yielded a fold increase in risk of extubation failure of 3.0 (95% confidence interval (CI) 1.2 to 5.2) and 3.5 (95% CI 1.9 to 5.4), respectively.

Conclusions

Altered HRV and RRV (during the SBT prior to extubation) are significantly associated with extubation failure. A predictive model using RRV during the last SBT provided optimal accuracy of prediction in all patients, with improved accuracy when combined with clinical impression or RSBI. This model requires a validation cohort to evaluate accuracy and generalizability.

Trial registration

ClinicalTrials.gov NCT01237886. Registered 13 October 2010.

Profiling gene expression to distinguish the likely active diazotrophs from a sea of genetic potential in marine sediments

Nitrogen (N) cycling microbial communities in marine sediments are extremely diverse, and it is unknown whether this diversity reflects extensive functional redundancy. Sedimentary denitrifiers remove significant amounts of N from the coastal ocean and diazotrophs are typically regarded as inconsequential. Recently, N fixation has been shown to be a potentially important source of N in estuarine and continental shelf sediments. Analysis of expressed genes for nitrite reductase (nirS) and a nitrogenase subunit (nifH) was used to identify the likely active denitrifiers and nitrogen fixers in surface sediments from different seasons in Narragansett Bay (Rhode Island, USA). The overall diversity of diazotrophs expressing nifH decreased along the estuarine gradient from the estuarine head to an offshore continental shelf site. Two groups of sequences related to anaerobic sulphur/iron reducers and sulphate reducers dominated libraries of expressed nifH genes. Quantitative polymerase chain reaction (qPCR) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) data shows the highest abundance of both groups at a mid bay site, and the highest nifH expression at the head of the estuary, regardless of season. Several potential environmental factors, including water temperature, oxygen concentration and metal contamination, may influence the abundance and nifH expression of these two bacterial groups.

Coefficient of Variation of Coarsely Sampled Heart Rate is Associated With Early Vasopressor Independence in Severe Sepsis and Septic Shock

PURPOSE

To determine whether variability of coarsely sampled heart rate and blood pressure early in the course of severe sepsis and septic shock predicts successful resuscitation, defined as vasopressor independence at 24 hours after admission.

METHODS

In an observational study of patients admitted with severe sepsis or septic shock from 2009 to 2011 to either of 2 intensive care units (ICUs) at a tertiary-care hospital, in whom blood pressure was measured via an arterial catheter, we sampled heart rate and blood pressure every 30 seconds over the first 6 hours of ICU admission and calculated the coefficient of variability of those measurements. Primary outcome was vasopressor independence at 24 hours; and secondary outcome was 28-day mortality.

RESULTS

We studied 165 patients, of which 97 (59%) achieved vasopressor independence at 24 hours. Overall, 28-day mortality was 15%. Significant predictors of vasopressor independence at 24 hours included the coefficient of variation of heart rate, age, Acute Physiology and Chronic Health Evaluation II, the number of increases in vasopressor dose, mean vasopressin dose, mean blood pressure, and time-pressure integral of mean blood pressure less than 60 mm Hg. Lower sampling frequencies (up to once every 5 minutes) did not affect the findings.

CONCLUSIONS

Increased variability of coarsely sampled heart rate was associated with vasopressor independence at 24 hours after controlling for possible confounders. Sampling frequencies of once in 5 minutes may be similar to once in 30 seconds.

Admission decisions and outcomes of community-acquired pneumonia in the homeless population: a review of 172 patients in an urban setting

OBJECTIVES

We compared admission rates, outcomes, and performance of the CURB-65 mortality prediction score of homeless patients and nonhomeless patients with community-acquired pneumonia (CAP).

METHODS

We compared homeless (n = 172) and nonhomeless (n = 1897) patients presenting to a Salt Lake City, Utah, emergency department with CAP from 1996 to 2006. In the homeless cohort, we measured referral from and follow-up with the local homeless health care clinic and arrangement of medical housing.

RESULTS

Homeless patients were younger (44 vs 59 years; P < .001) and had lower CURB-65 scores and higher hospitalization risk (severity-adjusted odds ratio = 1.89; 95% confidence interval = 1.33, 2.69) than did nonhomeless patients, with a similar length of stay, median inpatient cost, and median outpatient cost, even after severity adjustment. Of homeless patients, 22% were referred from the homeless health care clinic to the emergency department; 54% of outpatients and 51% of hospital patients were referred back to the clinic, and medical housing was arranged for 23%.

CONCLUSIONS

A large cohort of homeless patients with CAP demonstrated higher hospitalization risk than but similar length of stay and costs as nonhomeless patients. The strong relationship between the hospital and homeless health care clinic may have contributed to this finding.

Multicenter implementation of a severe sepsis and septic shock treatment bundle

RATIONALE

Severe sepsis and septic shock are leading causes of intensive care unit (ICU) admission, morbidity, and mortality. The effect of compliance with sepsis management guidelines on outcomes is unclear.

OBJECTIVES

To assess the effect on mortality of compliance with a severe sepsis and septic shock management bundle.

METHODS

Observational study of a severe sepsis and septic shock bundle as part of a quality improvement project in 18 ICUs in 11 hospitals in Utah and Idaho.

MEASUREMENTS AND MAIN RESULTS

Among 4,329 adult subjects with severe sepsis or septic shock admitted to study ICUs from the emergency department between January 2004 and December 2010, hospital mortality was 12.1%, declining from 21.2% in 2004 to 8.7% in 2010. All-or-none total bundle compliance increased from 4.9-73.4% simultaneously. Mortality declined from 21.7% in 2004 to 9.7% in 2010 among subjects noncompliant with one or more bundle element. Regression models adjusting for age, severity of illness, and comorbidities identified an association between mortality and compliance with each of inotropes and red cell transfusions, glucocorticoids, and lung-protective ventilation. Compliance with early resuscitation elements during the first 3 hours after emergency department admission caused ineligibility, through lower subsequent severity of illness, for these later bundle elements.

CONCLUSIONS

Total severe sepsis and septic shock bundle compliances increased substantially and were associated with a marked reduction in hospital mortality after adjustment for age, severity of illness, and comorbidities in a multicenter ICU cohort. Early resuscitation bundle element compliance predicted ineligibility for subsequent bundle elements.

Initial fractal exponent of heart rate variability is associated with success of early resuscitation in patients with severe sepsis or septic shock: a prospective cohort study

INTRODUCTION

Heart rate variability (HRV) reflects autonomic nervous system tone as well as the overall health of the baroreflex system. We hypothesized that loss of complexity in HRV upon intensive care unit (ICU) admission would be associated with unsuccessful early resuscitation of sepsis.

METHODS

We prospectively enrolled patients admitted to ICUs with severe sepsis or septic shock from 2009 to 2011. We studied 30 minutes of electrocardiogram, sampled at 500 Hz, at ICU admission and calculated heart rate complexity via detrended fluctuation analysis. Primary outcome was vasopressor independence at 24 hours after ICU admission. Secondary outcome was 28-day mortality.

RESULTS

We studied 48 patients, of whom 60% were vasopressor independent at 24 hours. Five (10%) died within 28 days. The ratio of fractal alpha parameters was associated with both vasopressor independence and 28-day mortality (P = .04) after controlling for mean heart rate. In the optimal model, Sequential Organ Failure Assessment score and the long-term fractal α parameter were associated with vasopressor independence.

CONCLUSIONS

Loss of complexity in HRV is associated with worse outcome early in severe sepsis and septic shock. Further work should evaluate whether complexity of HRV could guide treatment in sepsis.

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.

METHODS

In a retrospective study of consecutive patients with CAP admitted from 1996-2006 to the ICUs of a tertiary care hospital, we measured serial severity scores, intensive therapies received, ICU-free days, and 30-day mortality. Primary outcome was mortality. We developed a regression model of mortality with ward triage (and subsequent ICU transfer within 72 h) as the predictor, controlled by propensity for ward triage and radiographic progression.

RESULTS

Of 1059 hospital-admitted patients, 269 (25%) were admitted to the ICU during hospitalization. Of those, 167 were directly admitted to the ICU without current requirement for life support, while 61 (23%) were initially admitted to the hospital ward, 50 of those undergoing ICU transfer within 72 h. Ward triage was associated with increased mortality (OR 2.6, P = 0.056) after propensity adjustment. The effect was less (OR 2.2, P = 0.12) after controlling for radiographic progression. The effect probably increased (OR 4.1, P = 0.07) among patients with ≥ 3 severity predictors at admission.

CONCLUSIONS

Initial ward triage among patients transferred to the ICU is associated with twofold higher 30-day mortality. This effect is most apparent among patients with ≥ 3 severity predictors at admission and is attenuated by controlling for radiographic progression. Intensive monitoring of ward-admitted patients with CAP seems warranted. Further research is needed to optimize triage in CAP.

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.

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.

Withdrawal of nonfutile life support after attempted suicide

End-of-life decision making is fraught with ethical challenges. Withholding or withdrawing life support therapy is widely considered ethical in patients with high treatment burden, poor premorbid status, or significant projected disability even when such treatment is not "futile." Whether such withdrawal of therapy in the aftermath of attempted suicide is ethical is not well established in the literature. We provide a clinical vignette and propose criteria under which such withdrawal would be ethical. We suggest that it is appropriate to withdraw life support, regardless of the cause of the critical illness or disability, when the following criteria are met: (1) Surrogates request withdrawal of care and the adequacy of surrogates is confirmed, (2) an external reasonability standard is met, (3) passage of time, perhaps 72 hours, to allow certainty regarding the patient's wishes, and (4) psychiatric morbidity should be considered as grounds for withdrawal only in truly treatment-refractory cases. Fundamentally, we believe the question to ask is, "If this were not an attempted suicide, would a request to withdraw care be reasonable?" We believe that under these circumstances, such withdrawal of life support, even in an individual who has attempted suicide, does not constitute physician assistance with suicide and is distinct from physician aid-in-dying in several important respects.

Asking the right questions: the relationship between incident ventilator-associated pneumonia and mortality

Whether ventilator-associated pneumonia is a manifestation of severity of illness or an independent cause of mortality in ventilator-dependent patients is not known. In this complex area, which cannot be readily subjected to randomized controlled trials, studies should focus on the underlying questions of relevance, how to improve care of ventilated patients.

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 physician's 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.