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Objective: Current guidelines suggest the immediate initiation of crystalloid for sepsis-induced hypoperfusion but note that supporting evidence is low quality. The aim of this study is to examine the effect of timing of fluid initiation on mortality for adults with sepsis. Data Sources: Two authors independently reviewed relevant articles and extracted study details from PubMed, Scopus, Cochrane, Google Scholar, and previous relevant systematic reviews from 1-1-2000 to 1-6-2022. Registered with PROSPERO (CRD42021245431) and bias assessed using CLARITY. Study Selection: A minimum of severe sepsis (Sepsis-2) or sepsis (Sepsis-3) for patients =18 years old. Fluid initiation timing ranging from prehospital to 120 min within sepsis onset defined as "early" initiation. Data Extraction: Included studies providing mortality-based odds ratios (or comparable) adjusting for confounders or prospective trials. Data Synthesis: From 1643 citations, five retrospective cohort studies were included (n =20,209) with in-hospital mortality of 21.8%. A pooled analysis (odds ratio =OR [95% CI]) did not observe an impact on mortality for the early initiation of fluids among all patients, OR=0.79 [0.62-1.02]; heterogeneity: I2=86% [70-94%], but when studies analyzed cases of hypotension where available, a survival benefit was observed, OR=0.74 [0.61-0.90]. Initiation of fluids in two prehospital studies did not impact mortality, OR=0.82 [0.27-2.43]. However, both prehospital cohorts observed benefit among hypotensive patients individually, although heterogenous results precluded significance when pooled, OR=0.50 [0.21-1.18]. Three hospital-based studies with initiation stratified at 30, 100, and 120 min, observed survival benefit both individually and when pooled, OR=0.78 [0.63-0.97]. No differences were observed between prehospital versus hospital subgroups. Conclusion: This meta-analysis supports the guideline recommendations for early fluid initiation once sepsis is recognized, especially in cases of hypotension. Findings are limited by the small number, heterogeneity, and retrospective nature of available studies. Further retrospective investigations may be worthwhile as randomized studies on fluid initiation are unlikely. [ABSTRACT FROM AUTHOR]

Objectives: Describe the variation in practice and identify predictors of invasive mechanical ventilation (IMV) use in shock. Explore the association between the timing of IMV initiation ("Early" vs. "Delayed") on shock duration. Design: Multicenter, prospective, observational cohort study between September 2017 and February 2018 Setting: 34 hospitals in the United States and Jordan. Patients: Consecutive, adult, critically ill patients with shock, defined as a systolic blood pressure less than or equal to 90mm Hg, mean arterial pressure less than or equal to 65mm Hg, or need for a vasopressor medication. Interventions: None. Measurements and Main Results: "Early" IMV was defined as starting IMV 0-6 hours of shock onset and "Delayed" IMV was defined as starting IMV between 6 and 48 hours of shock onset. The primary outcome was shock-free days, defined as the number of days without shock after the first 48 hours of shock onset. Variation and predictors of IMV use were examined within the whole cohort as well as the subgroup of those intubated within 0-48 hours of shock onset. Mixed effects modeling with hospital site as a random effect showed that there was 7% variation by site in the use and timing of IMV in this shock cohort. In a propensity-matched model for the timing of IMV, "Early" IMV after shock onset was associated with more shock-free days when compared to "Delayed" IMV in those intubated within 0-48 hours of shock onset (Beta coefficient 0.65 days, 95% CI 0.14-1.16 days). Conclusions: Timing of IMV initiation for patients in shock has potentially important implications for patient outcomes and merits further study. [ABSTRACT FROM AUTHOR]

Introduction: Remotely tele-mentored ultrasound (RTMUS) involves the real-time guidance of US-naïve providers as they perform point-of-care ultrasound (POCUS) by remotely located, US-proficient providers via telemedicine. The concordance between RTMUS and POCUS in the evaluation of critically ill patients has not been reported. This study sought to evaluate the concordance between RTMUS and POCUS for the cardiopulmonary evaluation of patients in acute respiratory insufficiency and/or shock. Methods: Ultrasound-naÏve nurses performed RTMUS on critically ill patients. Concordance between RTMUS and POCUS (performed by critical care fellows) in the evaluation of the heart and lungs was reported. The test characteristics of RTMUS were calculated using POCUS as a gold standard. Concordance between RTMUS and available transthoracic echocardiography (TTE) and computed tomography (CT) scans was also reported. Results: Twenty patients were enrolled. Concordance between RTMUS and POCUS was good (90%-100%) for left ventricle function, right ventricle (RV) dilatation/dysfunction, pericardial effusion, lung sliding, pulmonary interstitial syndrome, pleural effusion, and fair (80%) for lung consolidation. Concordance between RTMUS and TTE or CT was similar. RTMUS was highly specific (88%-100%) for all abnormalities evaluated and highly sensitive (89%-100%) for most abnormalities although sensitivity for the detection of RV dilatation/dysfunction (33%) and pulmonary interstitial syndrome (71%) was negatively impacted by false negatives. Conclusions: RTMUS may be a reasonable substitute for POCUS in the cardiopulmonary evaluation of patients with acute respiratory insufficiency and/or shock. These findings should be validated on a larger scale. [ABSTRACT FROM AUTHOR]

Background and Objectives: In severe circulatory failure agreement between arterial and mixed venous or central venous values is poor; venous values are more reflective of tissue acid–base imbalance. No prior study has examined the relationship between peripheral venous blood gas (VBG) values and arterial blood gas (ABG) values in hemodynamic compromise. The objective of this study was to examine the correlation between hemodynamic parameters, specifically systolic blood pressure (SBP) and the arterial–peripheral venous (A-PV) difference for all commonly used acid–base parameters (pH, P co 2, and bicarbonate). Design, Setting, Participants, and Measurements: Data were obtained prospectively from adult patients with trauma. When an ABG was obtained for clinical purposes, a VBG was drawn as soon as possible. Patients were excluded if the ABG and VBG were drawn >10 minutes apart. Results: The correlations between A-PV pH, A-PV P co 2, and A-PV bicarbonate and SBP were not statistically significant (P =.55,.17, and.09, respectively). Although patients with hypotension had a lower mean arterial and peripheral venous pH and bicarbonate compared to hemodynamically stable patients, mean A-PV differences for pH and P co 2 were not statistically different (P =.24 and.16, respectively) between hypotensive and normotensive groups. Conclusions: In hypovolemic shock, the peripheral VBG does not demonstrate a higher CO2 concentration and lower pH compared to arterial blood. Therefore, the peripheral VBG is not a surrogate for the tissue acid–base status in hypovolemic shock, likely due to peripheral vasoconstriction and central shunting of blood to essential organs. This contrasts with the selective venous respiratory acidosis previously demonstrated in central venous and mixed venous measurements in circulatory failure, which is more reflective of acid–base imbalance at the tissue level than arterial blood. Further work needs to be done to better define the relationship between ABG and both central and peripheral VBG values in various types of shock. [ABSTRACT FROM AUTHOR]

Study Objective: Vasodilatory shock is the most common type of shock. Catecholamine vasopressors are the cornerstone of hemodynamic therapy but carry risks. Angiotensin II (AT2) was recently approved, and other novel agents (selepressin and terlipressin) are under investigation and used outside the United States (terlipressin). We performed a systematic review to summarize the efficacy and safety of these novel vasopressors and to offer guidance on their appropriate use. Design: Systematic review of controlled trials. Methods: Numerous databases were searched using terms related to angiotensin II, selepressin, terlipressin, vasopressor, and shock. Twenty-one citations, including 16 prospective comparative trials and 5 post hoc analyses reporting effects of AT2, selepressin, and terlipressin, were reviewed for data on outcomes related to hemodynamic measures, mortality, severity and duration of illness, concomitant vasopressor utilization, and adverse effects. Findings from eligible literature are described qualitatively using Cochrane methods. Results: Fourteen controlled trials were assessed after exclusion of 2 dated trials of a distinct AT2 formulation. Trials are limited for AT2 (n = 2) and selepressin (n = 1), while terlipressin was investigated in 11 small trials. Overall, the trials have an unclear risk of bias. Most report mean arterial pressure (MAP) as primary end point, and all indicate novel vasopressors increase MAP compared to placebo and to a similar degree as with catecholamine vasopressors. Mortality findings are preliminary, as they have been limited to specific subgroups in trials of terlipressin and post hoc analyses of one trial of AT2. Trials reported safety concerns for each agent including thromboembolism with AT2 and ischemia with terlipressin/selepressin. Conclusion: In this systematic review, controlled trials of novel vasopressors in treatment of vasodilatory shock were limited and of low quality. Angiotensin II, selepressin, and terlipressin appear to significantly increase MAP, but further study is required, particularly for selepressin, to determine their safety, efficacy, and role in treatment of vasodilatory shock. [ABSTRACT FROM AUTHOR]

Background: Intensive care patients with nonocclusive mesenteric ischemia (NOMI) show mortality rates of 70% to 90%. Besides emergency surgery, different interventional local vasodilatory treatment (LVT) attempts have been described. We performed a systematic review and a meta-analysis to evaluate feasibility, efficacy, and tolerability of LVT in patients with life-threatening NOMI. Methods: Searches of PubMed, EMBASE, Web of Science, and Cochrane Library databases were performed until February 2019. Measured outcomes included immediate technical success rates (as indicated by mesenteric vasodilation on angiography or clinical improvement) and adverse events (AEs). Therapeutic efficacy was measured by the assessment of overall mortality. Results: Twelve studies (335 patients, 245 received LVT) from 1977 to 2018 were included. All studies were retrospective (4 comparative and 8 noncomparative). Different intra-arterial vasodilators (4× papaverine, 6× prostaglandin E1, 1× tolazoline/heparin, 1× tolazoline + iloprost) were reported. Initial technical success rate was 75.9% (95% confidence interval [CI], 55.1%-89%, P =.017) with an AE rate of 2.9% (95% CI: 1.3%-6.6%; P =.983). Overall mortality in LVT patients was 40.3% (95% CI: 28.7%-53%, P =.134). In 4 studies, outcomes were compared between patients receiving LVT to those who received standard of care (odds ratio for death in LVT patients was 0.261 [95% CI: 0.095-0.712, P =.009]). Conclusions: Local vasodilatory treatment appears to be safe in patients with NOMI and might have the potential to at least partially reverse mesenteric vasoconstriction features in control angiographies. However, with no randomized and prospective studies available yet, the overall quality of published studies has to be considered as low; therefore, it is not possible to draw generalizable conclusions from the present data concerning clinical end points. Its application might hold promise as a rescue treatment strategy and deserves further evaluation in randomized controlled trials. [ABSTRACT FROM AUTHOR]

Hypovolemic shock exists as a spectrum, with its early stages characterized by subtle pathophysiologic tissue insults and its late stages defined by multi-system organ dysfunction. The importance of timely detection of shock is well known, as early interventions improve mortality, while delays render these same interventions ineffective. However, detection is limited by the monitors, parameters, and vital signs that are traditionally used in the intensive care unit (ICU). Many parameters change minimally during the early stages, and when they finally become abnormal, hypovolemic shock has already occurred. The compensatory reserve (CR) is a parameter that represents a new paradigm for assessing physiologic status, as it comprises the sum total of compensatory mechanisms that maintain adequate perfusion to vital organs during hypovolemia. When these mechanisms are overwhelmed, hemodynamic instability and circulatory collapse will follow. Previous studies involving CR measurements demonstrated their utility in detecting central blood volume loss before hemodynamic parameters and vital signs changed. Measurements of the CR have also been used in clinical studies involving patients with traumatic injuries or bleeding, and the results from these studies have been promising. Moreover, these measurements can be made at the bedside, and they provide a real-time assessment of hemodynamic stability. Given the need for rapid diagnostics when treating critically ill patients, CR measurements would complement parameters that are currently being used. Consequently, the purpose of this article is to introduce a conceptual framework where the CR represents a new approach to monitoring critically ill patients. Within this framework, we present evidence to support the notion that the use of the CR could potentially improve the outcomes of ICU patients by alerting intensivists to impending hypovolemic shock before its onset. [ABSTRACT FROM AUTHOR]

Objective: To determine resource utilization and outcomes of out-of-hospital transfer patients admitted to the intensive care unit (ICU) of a cancer referral center. Design: Single-center cohort. Setting: A tertiary oncological center. Patients: Patients older than 18 years transferred to our ICU from an outside hospital between January 2013 and December 2015. Measurements and Main Results: A total of 2127 (90.3%) were emergency department (ED) ICU admissions and 228 (9.7%) out-of-hospital transfers. The ICU length of stay (LOS) was longer in the out-of-hospital transfers when compared to all other ED ICU admissions (P = .001); however, ICU and hospital mortality were similar between both groups. The majority of patients were transferred for a higher level of care (77.2%); there was no difference in the amount of interventions performed, ICU LOS, and ICU mortality between nonhigher level-of-care and higher level-of-care patients. Factors associated with an ICU LOS ≥10days were a higher Sequential Organ Failure Assessment (SOFA) score, weekend admissions, presence of shock, need for mechanical ventilation, and acute kidney injury on admission or during ICU stay (P < .008). The ICU mortality of transferred patients was 17.5% and associated risk factors were older age, higher SOFA score on admission, use of mechanical ventilation and vasopressors during ICU stay, and renal failure on admission (P < .0001). Data related to the transfer such as LOS at the outside facility, time of transfer, delay in transfer, and longer distance traveled were not associated with increased LOS or mortality in our study. Conclusion: Organ failure severity on admission, and not transfer-related factors, continues to be the best predictor of outcomes of critically ill patients with cancer when transferred from other facilities to the ICU. Our data suggest that transferring critically ill patients with cancer to a specialized center does not lead to worse outcomes or increased resource utilization when compared to patients admitted from the ED. [ABSTRACT FROM AUTHOR]

Purpose: Bloodstream infections (BSIs) caused by Acinetobacter species have been extensively reported, however, which majorly focused on respiratory tract infections. The risk of mortality and the effect of early catheter removal on survival in catheter-related BSIs (CRBSIs) caused by Acinetobacter spp. remain unclear. This study aims to investigate that. Methods: This is a retrospective multicentric study conducted in Taiwan from 2012 to 2014. Patients with at least 1 positive blood culture and catheter culture for the same Acinetobacter spp., showing symptoms and signs of CRBSIs, were included (n = 119). Risk factors for 30-day mortality were analyzed using a logistic regression model. The characteristics of patients with early catheter removal (within 48 hours after CRBSIs) were compared to those without removal matching for age, sex, and disease severity. Results: There were no differences in 30-day mortality with regard to causative Acinetobacter spp., catheter type, site, and appropriateness of antimicrobial therapy. Patients with higher Acute Physiologic and Chronic Health Evaluation (APACHE) II scores (odds ratio [OR]: 1.12; 95% confidence interval [CI]: 1.02-1.23; P = .014), shock (OR: 6.43; 95% CI: 1.28-32.33; P = .024), and longer hospitalization before CRBSIs (OR: 1.04; 95% CI: 1.00-1.08; P = .027) had a significantly higher 30-day mortality rate. Early removal of catheters after CRBSIs was not associated with better survival benefits. Conclusion: Higher disease severity (APACHE II score), shock, and longer hospitalization before bacteremia were independently associated with a higher 30-day mortality in CRBSIs caused by Acinetobacter spp. In previous published guidelines, infected catheters were suggested to be removed in CRBSIs caused by gram-negative bacilli. Even though early removal of catheters did not associate with a better survival outcome in current results, it should be judiciously evaluated according to the clinical conditions and risks individually. For better elucidation of these issues, further well-controlled prospective study may be warranted. [ABSTRACT FROM AUTHOR]

Bedside goal-directed ultrasound is a powerful tool for rapid differential diagnosis and monitoring of cardiopulmonary disease in the critically ill patient population. The bedside intensivist is in a unique position to integrate ultrasound findings with the overall clinical situation. Medically critically ill patients who require urgent bedside diagnostic assessment fall into 2 categories: (1) acute respiratory failure and (2) hemodynamic derangements. The first portion of this review outlines the diagnostic role of bedside ultrasound in the medically critically ill patient population for the diagnosis and treatment of acute respiratory failure, acute respiratory distress, and severe hypoxemia. The second portion will focus on the diagnostic role of ultrasound for the evaluation and treatment of shock states, as well as describe protocolized approaches for evaluation of shock during cardiopulmonary resuscitation. Different respiratory system pathologies that result in acute respiratory failure (such as increased interstitial fluid, alveolar consolidation, pleural effusion) cause characteristic ultrasonographic findings; diaphragmatic assessment may also add information. Intracardiac shunting can cause severe hypoxemia. Protocolized approaches for the evaluation of patients with acute respiratory failure or distress are discussed. [ABSTRACT FROM AUTHOR]

Primary and acquired abdominal pathology accounts for a significant proportion of sepsis and SIRS in the ICU population. Abdominal processes often present a difficult diagnostic dilemma in the truly critically ill patient who, due to hemodynamic instability or severe acute respiratory distress syndrome (ARDS) requiring high-level ventilatory support, is at significant risk during transport to radiology department. Furthermore, the accuracy of radiologic studies in the ICU setting is often limited. Laparoscopy provides a “minimally invasive” definitive modality to diagnose intra-abdominal problems. It may quickly provide the necessary information to define further management. In selective circumstances, it may actually allow appropriate intervention. However, the overall mortality of patients who undergo diagnostic laparoscopy in the ICU is high regardless of diagnostic findingsduring this procedure. Although not a technically difficult procedure, diagnostic laparoscopy does require a certain skill level, especially when limited time and unfavorable patient physiology are taken into account. The use of diagnostic laparoscopy should be limited to patients in whom a therapeutic intervention is feasible. [ABSTRACT FROM AUTHOR]

Auto–positive end-expiratory pressure (PEEP) is a common but frequently unrecognized problem in critically ill patients. It has important physiologic consequences and can cause shock and cardiac arrest. Treatment consists of relieving expiratory airflow obstruction and reducing minute ventilation delivered by positive pressure ventilation. Sedation and fluid management are important adjunctive therapies. This analytic review discusses the prevalence, pathophysiology, and hemodynamic consequences of auto-PEEP and an approach to its treatment. [ABSTRACT FROM AUTHOR]

Gastric reactance has been proposed as a measure of mucosal ischemic injury in the critically ill. The purpose of this study was to evaluate the incidence of gastric mucosal injury as measured by gastric reactance in different subgroups of critical patients. We studied 100 adult patients admitted to 7 different hospital intensive care units, requiring a nasogastric tube. Gastric impedance measurements were continuously obtained from each patient for 24 hours. Patients were managed based on conventional protocols by hospital staff, blinded to the changes in gastric impedance parameters. The low-frequency central reactance (XL) reflects tissue edema caused by prolonged ischemia. The previously reported threshold of XL ≥ 13 − jΩ was used to classify injured mucosa; 80% of all patients had mean XL above this threshold. No significant differences were found in the incidence of mucosal ischemia between medical versus surgical, hemodynamic versus respiratory or neurological patients. Significant lower urine output was found in patients with XL above threshold (P < .01); also, there was a significant effect of fluid balance in those patients (P < .05). More complicated patients had higher average reactance. This study shows that gastric ischemia as estimated by gastric reactance has a very high incidence in the critically ill, independently of the reason for admission. High reactance is related with higher morbidity in agreement with other reports using different methods of assessing splanchnic hypoperfusion in this patient population. [ABSTRACT FROM AUTHOR]

Introduction: Vasoactive drugs are routinely used in critically ill patients with shock to optimize the hemodynamic state while evaluating and treating potentially reversible causes. Limited data exist on the use of multiple vasoactive drugs in the intensive care unit. We hypothesize that the use of 3 or more vasoactive drugs is associated with worse outcomes. Methods: We retrospectively examined the outcome in patients, at least 18 years of age, in whom 3 or more vasoactive drugs were administered simultaneously. We included patients admitted between November 2007 and August 2009. Vasoactive drugs included dopamine, dobutamine, epinephrine, norepinephrine, phenylephrine, and vasopressin. The primary end point was survival to hospital discharge. Results: Sixty-six patients received 3 or more vasoactive drugs simultaneously. Nine patients (14%) survived to ICU discharge and 6 patients (9%) survived to hospital discharge. There was a significant difference in mean Simplified Acute Physiology Score II between survivors (32.3 + 28.6) and nonsurvivors (72.1 + 30.4), P ¼ .003. Five of the 6 survivors had an acute cardiac procedure, either percutaneous cardiac intervention or heart transplantation. The 1 patient with septic shock who survived had surgery for a bowel perforation. All patients who survived received inotropic therapy (dobutamine). None of the patients who received 4 or more vasoactive drugs survived. Conclusion: Patients requiring 3 or more vasoactive drugs rarely survive in the absence of an intervention aimed at correcting the underlying cause such as revascularization or source control surgery. [ABSTRACT FROM AUTHOR]

Over the past 30 years, surgical specialties have introduced and expanded the role of open abdominal management in complicated operative cases, necessitating an intensivist’s understanding of the indications and unique intensive care unit (ICU) issues related to the open abdomen. When presented with the open abdomen, resuscitation to correct shock is of primary concern. This is accomplished by correction of hypothermia, acidosis, and coagulopathy in trauma and adequate resolution of intra-abdominal hypertension or source control in general surgery. These patients typically require deep sedation and often paralysis and benefit from low-volume ventilatory strategies to prevent and treat acute lung injury. Antibiotics must be tailored to the clinical situation, but in most cases, 24 hours of perioperative treatment is all that is required. In cases of gross contamination and peritonitis, a 5- to 7-day course of broad-spectrum antibiotics may be of benefit.Adequate source control has been demonstrated to have the greatest impact on outcome and when the patient’s clinical milieu dictates, bedside washouts. Enteral nutrition should be instituted as early as possible after intestinal continuity has been reestablished. Additional protein is required to account for losses from the open abdomen. Reconstruction may require staging, but in general, should proceed following resolution of shock and control of sepsis. Elevated multiorgan dysfunction score, Acute Physiology And Chronic Health Evaluation II (APACHE II), and a rise in peak inspiratory pressure portend poor source control and could result in failure of fascial closure. If unable to proceed to fascial closure, then considerations should be made for planned ventral hernia and subsequent abdominal wall reconstruction. [ABSTRACT FROM PUBLISHER]

Early recognition and differentiation of shock, as well as goal-directed resuscitation, are fundamental principles in the care of the critically ill or injured patient. Substantial progress has been made over the last decade in the understanding of both shock and resuscitation. Specific areas of advancement, particularly pertaining to hemorrhagic shock, include a heightened appreciation of dynamic measurements of preload responsiveness (eg, respiratory-induced pulse pressure and venous diameter variability), an improved awareness of the detrimental effects of blood product transfusion, and better recognition of the complications of overzealous volume expansion. However, several areas of controversy remain regarding the optimal resuscitation strategy. These include the optimal targets for perfusion pressure and oxygen delivery, endpoints of resuscitation, resuscitative fluid, and transfusion strategies for packed red blood cells and blood products. This article reviews the diagnosis and differentiation of shock, measurements of tissue perfusion, current evidence regarding various resuscitative techniques, and complications of resuscitation. [ABSTRACT FROM PUBLISHER]

Introduction: The influenza A 2009 (H1N1) virus is a pandemic respiratory infection commanding international attention. More information is needed on patient demographics, illness severity, and risk indicators. Methods: A total of 43 patients with H1N1 influenza A 2009 presenting to 2 urban academic medical centers during the first wave were assessed for demographics, triage vital signs, hemograms, and serum chemistries including lactate. Chest X-rays were assessed for infiltrate or effusion. Illness severity markers were recorded including anion gap (AG), strong ion gap (SIG), systemic inflammatory response syndrome score, shock index, confusion, uremia, respiratory rate, blood pressure, and age >= 65 years (CURB-65) score, and pneumonia severity index. Subgroup analysis was performed on asthmatic, pregnant, and intensive care unit (ICU) versus non-ICU patients. Results: Eighty-one percent of patients were women. Pregnancy (34.8%), asthma (39.5%), diabetes mellitus (18.6%), and sickle cell (6.98%) were the most frequent comorbidities. In all, 91% had positive influenza nasopharyngeal direct antigen test, while 9% tested positive only by viral culture or real-time reverse transcriptase polymerase chain reaction (rRT-PCR); 14% required ICU admission; and 20.8% had infiltrate on chest X-ray. A trend toward greater incidence of ICU admission existed among patients with elevated SIG (P = .08), however contrary to our prior studies in noninfluenza patients, an elevated SIG in the presence of normal AG and lactate measurements did not correlate with ICU admission. Conclusion: A high percentage of patients with H1N1 presented with underlying comorbid conditions including asthma and pregnancy. Traditional markers of pneumonia severity including CURB-65 score, Pneumonia Severity Index (PSI), serum lactate, and AG did not correlate with ICU admission in patients with H1N1. Strong ion gap effectively identified significant acid−base disturbances not identified by lactate or AG, however the trend of greater ICU admission rates among patients with elevated SIG did not reach statistical significance. Further study is needed to identify clinical tools to aid in risk-stratifying H1N1 patients. [ABSTRACT FROM PUBLISHER]

A variety of cytokines play a role in the inflammatory response. Interleukin-6 (IL-6)-type cytokines are released in response to tissue injury or an inflammatory stimulus, and act locally and systemically to generate a variety of physiologic responses. Interleukin-6 concentrations are elevated after surgery, trauma, and critical illness. The magnitude of IL-6 elevation correlates with the extent of tissue trauma/injury severity. Furthermore, there is an association between IL-6 elevation and adverse outcome. Interleukin-6 levels can also be used to stratify patients for therapeutic intervention. [ABSTRACT FROM PUBLISHER]

The objective of this study is to develop a physicochemical model of the projected change in standard base excess (SBE) consequent to the infused volume of crystalloid solutions in common use. A clinical simulation of modeled acid-base and fluid compartment parameters was conducted in a 70-kg test participant at standard physiologic state: pH = 7.40, partial pressure of carbon dioxide (PCO2) = 40 mm Hg, Henderson--Hasselbalch actual bicarbonate ([HCO3]HH) = 24.5 mEq/L, strong ion difference (SID) = 38.9 mEq/L, albumin = 4.40 g/dL, inorganic phosphate = 1.16 mmol/L, citrate total = 0.135 mmol/L, and SBE = 0.1 mEq/L. Simulations of multiple, sequential crystalloid infusions up to 10 L were conducted of normal saline (SID = 0), lactated Ringer's (SID = 28), plasmalyte 148 (SID = 50), one-half normal saline + 75 mEq/L sodium bicarbonate (NaHCO3; SID = 75), 0.15 mol/L NaHCO3 (SID = 150), and a hypothetical crystalloid solution whose SID = 24.5 mEq/L, respectively. Simulations were based on theoretical completion of steady-state equilibrium and PCO2 was fixed at 40 mm Hg to assess nonrespiratory acid-base effects. A crystalloid SID equivalent to standard state actual bicarbonate (24.5 mEq/L) results in a neutral metabolic acid-base status for infusions up to 10 L. The 5 study solutions exhibited curvilinear relationships between SBE and crystalloid infusion volume in liters. Solutions whose SID was greater than 24.5 mEq/L demonstrated a progressive metabolic alkalosis and less, a progressive metabolic acidosis. In a human model system, the effects of crystalloid infusion on SBE are a function of the crystalloid and plasma SID, volume infused, and nonvolatile plasma weak acid changes. A projection of the impact of a unit volume of various isotonic crystalloid solutions on SBE is presented. The model's validation, applications, and limitations are examined. [ABSTRACT FROM AUTHOR]

Background: Pulmonary artery wedge pressure (PAWP) is an important indicator of volume status in septic patients. Although it requires invasive pulmonary artery catheterization (PAC), a noninvasive method to assess PAWP would be clinically useful in this select patient population. Diastolic indices using transthoracic echocardiography (TTE) may provide an accurate estimate of PAWP. Objective: To determine whether echocardiographic Doppler assessment is accurate in estimating PAWP in patients with septic shock. Methods: A retrospective chart review was performed of 320 patients admitted with a diagnosis of septic shock from 2007-2008. Of the total patient population, 40 patients fulfilled the inclusion criteria, having undergone both TTE and PAC within 4 hours. Spectral Doppler indices including peak early (E) and late (A) transmitral velocities, E/A ratio, and E-wave deceleration time were measured. Tissue Doppler indices including S', E' and A' velocities were determined. Pulmonary artery wedge pressure values measured invasively were compared to the dimensionless index of E/E' in each patient. Results: The mean age was 68 + 12 years with 28 males (70%). On echo assessment, 28% of patients had evidence of mild left ventricular diastolic dysfunction while 17% of patients had moderate diastolic dysfunction. Pulmonary artery wedge pressures ranged from 7 to 31 mm Hg with a mean of 18 + 5 mm Hg. The mean E/E' was 11 + 8. Linear regression analysis between PAWP and E/E7apos; demonstrated a strong correlation (r = .84, P < .05). Conclusion: Tissue Doppler indices using TTE is a feasible and strong predictor of PAWP in patients with septic shock. [ABSTRACT FROM AUTHOR]

Tobias JD. Arginine vasopressin for refractory distributive shock in two adolescents. J Intensive Care Med 2002;17:48–52. Arginine vasopressin is a nine amino acid peptide, most commonly known as antidiuretic hormone. Recent investigations in the areas of cardiopulmonary resuscitation and the treatment of distributive shock have suggested its possible therapeutic potential. Despite increasing experience in the adult population, there is limited experience with vasopressin administration in pediatric patients. The author reports the use of vasopressin in the treatment of refractory distributive shock in two adolescents. Previous reports of its use and potential therapeutic applications are reviewed. [ABSTRACT FROM AUTHOR]