Jeffrey J. Presneill

Vasopressin versus Norepinephrine Infusion in Patients with Septic Shock

BACKGROUND Vasopressin is commonly used as an adjunct to catecholamines to support blood pressure in refractory septic shock, but its effect on mortality is unknown. We hypothesized that low-dose vasopressin as compared with norepinephrine would decrease mortality among patients with septic shock who were being treated with conventional (catecholamine) vasopressors. METHODS In this multicenter, randomized, double-blind trial, we assigned patients who had septic shock and were receiving a minimum of 5 microg of norepinephrine per minute to receive either low-dose vasopressin (0.01 to 0.03 U per minute) or norepinephrine (5 to 15 microg per minute) in addition to open-label vasopressors. All vasopressor infusions were titrated and tapered according to protocols to maintain a target blood pressure. The primary end point was the mortality rate 28 days after the start of infusions. RESULTS A total of 778 patients underwent randomization, were infused with the study drug (396 patients received vasopressin, and 382 norepinephrine), and were included in the analysis. There was no significant difference between the vasopressin and norepinephrine groups in the 28-day mortality rate (35.4% and 39.3%, respectively; P=0.26) or in 90-day mortality (43.9% and 49.6%, respectively; P=0.11). There were no significant differences in the overall rates of serious adverse events (10.3% and 10.5%, respectively; P=1.00). In the prospectively defined stratum of less severe septic shock, the mortality rate was lower in the vasopressin group than in the norepinephrine group at 28 days (26.5% vs. 35.7%, P=0.05); in the stratum of more severe septic shock, there was no significant difference in 28-day mortality (44.0% and 42.5%, respectively; P=0.76). A test for heterogeneity between these two study strata was not significant (P=0.10). CONCLUSIONS Low-dose vasopressin did not reduce mortality rates as compared with norepinephrine among patients with septic shock who were treated with catecholamine vasopressors. (Current Controlled Trials number, ISRCTN94845869 [controlled-trials.com].).

Continuous plasmafiltration in sepsis syndrome

Objective:To assess the effect of plasmafiltration (PF) on biochemical markers of inflammation, cytokines, organ dysfunction, and 14-day mortality in human sepsis.Design:Multicenter, prospective, randomized, controlled clinical trial.Setting:Seven university-affiliated intensive care units.Patients:

Interaction of vasopressin infusion, corticosteroid treatment, and mortality of septic shock

Objective:Vasopressin and corticosteroids are often added to support cardiovascular dysfunction in patients who have septic shock that is nonresponsive to fluid resuscitation and norepinephrine infusion. However, it is unknown whether vasopressin treatment interacts with corticosteroid treatment. Design:Post hoc substudy of a multicenter randomized blinded controlled trial of vasopressin vs. norepinephrine in septic shock. Setting:Twenty-seven Intensive Care Units in Canada, Australia, and the United States. Patients:Seven hundred and seventy-nine patients who had septic shock and were ongoing hypotension requiring at least 5 &mgr;g/min of norepinephrine infusion for 6 hours. Interventions:Patients were randomized to blinded vasopressin (0.01–0.03 units/min) or norepinephrine (5–15 &mgr;g/min) infusion added to open-label vasopressors. Corticosteroids were given according to clinical judgment at any time in the 28-day postrandomization period. Measurements:The primary end point was 28-day mortality. We tested for interaction between vasopressin treatment and corticosteroid treatment using logistic regression. Secondary end points were organ dysfunction, use of open-label vasopressors and vasopressin levels. Main Results:There was a statistically significant interaction between vasopressin infusion and corticosteroid treatment (p = 0.008). In patients who had septic shock and were also treated with corticosteroids, vasopressin, compared to norepinephrine, was associated with significantly decreased mortality (35.9% vs. 44.7%, respectively, p = 0.03). In contrast, in patients who did not receive corticosteroids, vasopressin was associated with increased mortality compared with norepinephrine (33.7% vs. 21.3%, respectively, p = 0.06). In patients who received vasopressin infusion, use of corticosteroids significantly increased plasma vasopressin levels by 33% at 6 hours (p = 0.006) to 67% at 24 hours (p = 0.025) compared with patients who did not receive corticosteroids. Conclusions:There is a statistically significant interaction between vasopressin and corticosteroids. The combination of low-dose vasopressin and corticosteroids was associated with decreased mortality and organ dysfunction compared with norepinephrine and corticosteroids.

A randomized trial of protocol-directed sedation management for mechanical ventilation in an Australian intensive care unit

Objective:To compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients. Design:Randomized, controlled trial. Setting:General intensive care unit (24 beds) in an Australian metropolitan teaching hospital. Patients:Adult, mechanically ventilated patients (n = 312). Interventions:Patients were randomly assigned to receive sedation directed by formal guidelines (protocol group, n = 153) or usual local clinical practice (control, n = 159). Measurements and Main Results:The median (95% confidence interval) duration of ventilation was 79 hrs (56–93 hrs) for patients in the protocol group compared with 58 hrs (44–78 hrs) for patients who received control care (p = .20). Lengths of stay (median [range]) in the intensive care unit (94 [2–1106] hrs vs. 88 (14–962) hrs, p = .58) and hospital (13 [1–113] days vs. 13 (1–365) days, p = .97) were similar, as were the proportions of subjects receiving a tracheostomy (17% vs. 15%, p = .64) or undergoing unplanned self-extubation (1.3% vs. 0.6%, p = .61). Death in the intensive care unit occurred in 32 (21%) patients in the protocol group and 32 (20%) control subjects (p = .89), with a similar overall proportion of deaths in hospital (25% vs. 22%, p = .51). A Cox proportional hazards model, after adjustment for age, gender, Acute Physiology and Chronic Health Evaluation II score, diagnostic category, and doses of commonly used drugs, estimated that protocol sedation management was associated with a 22% decrease (95% confidence interval 40% decrease to 2% increase, p = .07) in the occurrence of successful weaning from mechanical ventilation. Conclusions:This randomized trial provided no evidence of a substantial reduction in the duration of mechanical ventilation or length of stay, in either the intensive care unit or the hospital, with the use of protocol-directed sedation compared with usual local management. Qualified high-intensity nurse staffing and routine Australian intensive care unit nursing responsibility for many aspects of ventilatory practice may explain the contrast between these findings and some recent North American studies.

Epidemiology of sepsis in Victoria, Australia

Objective:To determine the clinical and epidemiologic characteristics of patients with sepsis admitted to hospitals in Victoria, Australia, including the incidence of sepsis and severe sepsis, utilization of intensive care unit (ICU) resources, and hospital mortality. Design:A population-based hospital morbidity database generated from hospital discharge coding. Setting:State of Victoria, Australia (population, 4.5 million), the 4-yr period from July 1, 1999, to June 30, 2003. Patients:A total of 3,122,515 overnight hospitalizations. Interventions:None. Measurements and Main Results:The overall hospital incidence of sepsis was 1.1%, with a mortality of 18.4%. Of septic patients, 23.8% received some care in an ICU. For these patients, hospital mortality was 28.9%. Severe sepsis, defined by sepsis and at least one organ dysfunction, occurred in 39% of sepsis patients and was accompanied by a hospital mortality of 31.1%. Fifty percent of patients with severe sepsis received at least some care in an ICU. Conclusions:Australian state hospital administrative data reveal epidemiologic features of sepsis and severe sepsis that are strikingly similar to those recently reported from comparable populations in North American and Europe. This suggests that lessons learned in this area may be directly applicable internationally.

Early mobilization and recovery in mechanically ventilated patients in the ICU: a bi-national, multi-centre, prospective cohort study.

The aim of this study was to investigate current mobilization practice, strength at ICU discharge and functional recovery at 6 months among mechanically ventilated ICU patients. This was a prospective, multi-centre, cohort study conducted in twelve ICUs in Australia and New Zealand. Patients were previously functionally independent and expected to be ventilated for >48 hours. We measured mobilization during invasive ventilation, sedation depth using the Richmond Agitation and Sedation Scale (RASS), co-interventions, duration of mechanical ventilation, ICU-acquired weakness (ICUAW) at ICU discharge, mortality at day 90, and 6-month functional recovery including return to work. We studied 192 patients (mean age 58.1 ± 15.8 years; mean Acute Physiology and Chronic Health Evaluation (APACHE) (IQR) II score, 18.0 (14 to 24)). Mortality at day 90 was 26.6% (51/192). Over 1,351 study days, we collected information during 1,288 planned early mobilization episodes in patients on mechanical ventilation for the first 14 days or until extubation (whichever occurred first). We recorded the highest level of early mobilization. Despite the presence of dedicated physical therapy staff, no mobilization occurred in 1,079 (84%) of these episodes. Where mobilization occurred, the maximum levels of mobilization were exercises in bed (N = 94, 7%), standing at the bed side (N = 11, 0.9%) or walking (N = 26, 2%). On day three, all patients who were mobilized were mechanically ventilated via an endotracheal tube (N = 10), whereas by day five 50% of the patients mobilized were mechanically ventilated via a tracheostomy tube (N = 18). In 94 of the 156 ICU survivors, strength was assessed at ICU discharge and 48 (52%) had ICU-acquired weakness (Medical Research Council Manual Muscle Test Sum Score (MRC-SS) score <48/60). The MRC-SS score was higher in those patients who mobilized while mechanically ventilated (50.0 ± 11.2 versus 42.0 ± 10.8, P = 0.003). Patients who survived to ICU discharge but who had died by day 90 had a mean MRC score of 28.9 ± 13.2 compared with 44.9 ± 11.4 for day-90 survivors (P <0.0001). Early mobilization of patients receiving mechanical ventilation was uncommon. More than 50% of patients discharged from the ICU had developed ICU-acquired weakness, which was associated with death between ICU discharge and day-90. ClinicalTrials.gov NCT01674608. Registered 14 August 2012.

Relationship of anti-GM-CSF antibody concentration, surfactant protein A and B levels, and serum LDH to pulmonary parameters and response to GM-CSF therapy in patients with idiopathic alveolar proteinosis

Background: Conventional measures of the severity of alveolar proteinosis (AP) include alveolar-arterial oxygen gradient ([A – a]Do2), vital capacity (VC), and carbon monoxide transfer factor (Tlco), but alternative serological measures have been sought. Granulocyte-macrophage colony stimulating factor (GM-CSF) neutralising autoantibody is found in patients with idiopathic acquired AP. We have investigated the interrelationships between the levels of this antibody and those of surfactant protein (SP)-A and -B, lactate dehydrogenase (LDH), and conventional measures of disease severity, and the capacity of these parameters to predict the response to rhGM-CSF treatment. Methods: Blood levels of anti-GM-CSF antibodies, SP-A, SP-B, LDH, and [A – a]do2, VC, and Tlco were measured before rhGM-CSF treatment and every 2 weeks thereafter in 14 patients with AP. Results: At baseline, high levels of anti-GM-CSF antibodies and increased SP-A and SP-B levels were seen in all patients, and LDH was raised in 83%. SP-A was highly correlated with [A – a]do2, VC, and Tlco (p≤0.02), but other markers were not. Only a normal LDH level was predictive of a response to rhGM-CSF treatment (p=0.03). During treatment a correlation between conventional and serological variables within patients was seen only between SP-A and [A – a]do2 (p=0.054), LDH levels and [A – a]do2 (p=0.010), and LDH levels and VC (p=0.019). Conclusions: Of the serological parameters studied, only SP-A and LDH levels were correlated with conventional measures of disease severity, with LDH most accurately reflecting [A – a]Do2 and vital capacity. Only a normal LDH level predicted a higher likelihood of response to treatment with GM-CSF.

A pilot feasibility trial of allocation of freshest available red blood cells versus standard care in critically ill patients

BACKGROUND: Prolonged storage of red blood cells (RBCs) may increase posttransfusion adverse events in critically ill patients. We aimed to evaluate in intensive care unit (ICU) patients 1) the feasibility of allocating freshest available compatible RBCs versus standard care and 2) the suitability of this approach in the design of a large randomized controlled trial (RCT).

A Molecular Host Response Assay to Discriminate Between Sepsis and Infection-Negative Systemic Inflammation in Critically Ill Patients: Discovery and Validation in Independent Cohorts

Background Systemic inflammation is a whole body reaction having an infection-positive (i.e., sepsis) or infection-negative origin. It is important to distinguish between these two etiologies early and accurately because this has significant therapeutic implications for critically ill patients. We hypothesized that a molecular classifier based on peripheral blood RNAs could be discovered that would (1) determine which patients with systemic inflammation had sepsis, (2) be robust across independent patient cohorts, (3) be insensitive to disease severity, and (4) provide diagnostic utility. The goal of this study was to identify and validate such a molecular classifier. Methods and Findings We conducted an observational, non-interventional study of adult patients recruited from tertiary intensive care units (ICUs). Biomarker discovery utilized an Australian cohort (n = 105) consisting of 74 cases (sepsis patients) and 31 controls (post-surgical patients with infection-negative systemic inflammation) recruited at five tertiary care settings in Brisbane, Australia, from June 3, 2008, to December 22, 2011. A four-gene classifier combining CEACAM4, LAMP1, PLA2G7, and PLAC8 RNA biomarkers was identified. This classifier, designated SeptiCyte Lab, was validated using reverse transcription quantitative PCR and receiver operating characteristic (ROC) curve analysis in five cohorts (n = 345) from the Netherlands. Patients for validation were selected from the Molecular Diagnosis and Risk Stratification of Sepsis study (ClinicalTrials.gov, NCT01905033), which recruited ICU patients from the Academic Medical Center in Amsterdam and the University Medical Center Utrecht. Patients recruited from November 30, 2012, to August 5, 2013, were eligible for inclusion in the present study. Validation cohort 1 (n = 59) consisted entirely of unambiguous cases and controls; SeptiCyte Lab gave an area under curve (AUC) of 0.95 (95% CI 0.91–1.00) in this cohort. ROC curve analysis of an independent, more heterogeneous group of patients (validation cohorts 2–5; 249 patients after excluding 37 patients with an infection likelihood of “possible”) gave an AUC of 0.89 (95% CI 0.85–0.93). Disease severity, as measured by Sequential Organ Failure Assessment (SOFA) score or Acute Physiology and Chronic Health Evaluation (APACHE) IV score, was not a significant confounding variable. The diagnostic utility of SeptiCyte Lab was evaluated by comparison to various clinical and laboratory parameters available to a clinician within 24 h of ICU admission. SeptiCyte Lab was significantly better at differentiating cases from controls than all tested parameters, both singly and in various logistic combinations, and more than halved the diagnostic error rate compared to procalcitonin in all tested cohorts and cohort combinations. Limitations of this study relate to (1) cohort compositions that do not perfectly reflect the composition of the intended use population, (2) potential biases that could be introduced as a result of the current lack of a gold standard for diagnosing sepsis, and (3) lack of a complete, unbiased comparison to C-reactive protein. Conclusions SeptiCyte Lab is a rapid molecular assay that may be clinically useful in managing ICU patients with systemic inflammation. Further study in population-based cohorts is needed to validate this assay for clinical use.

Recognition and management of catheter-induced pulmonary artery rupture

BACKGROUND Catheter-induced pulmonary artery rupture is a well-recognized complication of invasive monitoring, but the risk has not diminished. Although commonly associated with cardiopulmonary bypass, injuries also occur in intensive care. Definitive proof requires pulmonary angiography or autopsy. Many cases are never reported, and lesser injuries are probably under-diagnosed. METHODS Seven cases fulfilling accepted diagnostic criteria discovered over 2 years are described in four groups illustrating the common modes of presentation: hemoptysis with hypoxemia, exsanguination, delayed recurrent hemorrhage, and bleeding with cardiopulmonary bypass. RESULTS One patient had a planned elective operation deferred. Four patients were being monitored in intensive care. Two of them died of pulmonary artery rupture. Two other patients had bleeding on weaning from cardiopulmonary bypass. One settled with conservative treatment, the other survived after extracorporeal life support. Recognition and management are discussed, emphasizing means of avoiding pulmonary resection. CONCLUSIONS Catheter-induced pulmonary artery rupture is unavoidable. Constant awareness is essential. A plan of management is presented. Extracorporeal life support may help to avoid pulmonary resection. Early pulmonary angiography is advocated for accurate diagnosis and to enable treatment by embolization.