Shock Severity Classification and Mortality in Adults With Cardiac, Medical, Surgical, and Neurological Critical Illness

OBJECTIVE

To evaluate whether the Society for Cardiovascular Angiography and Interventions (SCAI) Shock Classification could perform risk stratification in a mixed cohort of intensive care unit (ICU) patients, similar to its validation in patients with acute cardiac disease.

METHODS

We included 21,461 adult Mayo Clinic ICU patient admissions from December 1, 2014, to February 28, 2018, including cardiac ICU (16.7%), medical ICU (37.4%), neurosciences ICU (27.7%), and surgical ICU (18.2%). The SCAI Shock Classification (a 5-stage classification from no shock [A] to refractory shock [E]) was assigned in each 4-hour period during the first 24 hours of ICU admission.

RESULTS

The median age was 65 years, and 43.2% were female. In-hospital mortality occurred in 1611 (7.5%) patients, with a stepwise increase in in-hospital mortality in each higher maximum SCAI Shock stage overall: A, 4.0%; B, 4.6%; C, 7.0%; D, 13.9%; and E, 40.2%. The SCAI Shock Classification provided incremental mortality risk stratification in each ICU, with the best performance in the cardiac ICU and the worse performance in the neurosciences ICU. The SCAI Shock Classification was associated with higher adjusted in-hospital mortality (adjusted odds ratio, 1.32 per each stage; 95% CI, 1.24 to 1.41; P<.001); this association was not observed in the neurosciences ICU when considered separately.

CONCLUSION

The SCAI Shock Classification provided incremental mortality risk stratification beyond established prognostic markers across the spectrum of medical and surgical critical illness, proving utility outside its original intent.

Emergency medical services shock index is the most accurate predictor of patient outcomes after blunt torso trauma

INTRODUCTION

Shock index (SI) and delta shock index (∆SI) predict mortality and blood transfusion in trauma patients. This study aimed to evaluate the predictive ability of SI and ∆SI in a rural environment with prolonged transport times and transfers from critical access hospitals or level IV trauma centers.

METHODS

We completed a retrospective database review at an American College of Surgeons verified level 1 trauma center for 2 years. Adult subjects analyzed sustained torso trauma. Subjects with missing data or severe head trauma were excluded. For analysis, poisson regression and binomial logistic regression were used to study the effect of time in transport and SI/∆SI on resource utilization and outcomes. p < 0.05 was considered significant.

RESULTS

Complete data were available on 549 scene patients and 127 transfers. Mean Injury Severity Score was 11 (interquartile range, 9.0) for scene and 13 (interquartile range, 6.5) for transfers. Initial emergency medical services SI was the most significant predictor for blood transfusion and intensive care unit care in both scene and transferred patients (p < 0.0001) compared with trauma center arrival SI or transferring center SI. A negative ∆SI was significantly associated with the need for transfusion and the number of units transfused. Longer transport time also had a significant relationship with increasing intensive care unit length of stay. Cohorts were analyzed separately.

CONCLUSION

Providers must maintain a high level of clinical suspicion for patients who had an initially elevated SI. Emergency medical services SI was the greatest predictor of injury and need for resources. Enroute SI and ∆SI were less predictive as time from injury increased. This highlights the improvements in en route care but does not eliminate the need for high-level trauma intervention.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Kawasaki Disease and Kawasaki Disease Shock Syndrome Hospitalization Rates in the United States, 2006-2018

BACKGROUND

Kawasaki disease (KD) is a febrile illness of unknown etiology. Patients with Kawasaki disease shock syndrome (KDSS) may present with clinical signs of poor perfusion and systolic hypotension in addition to typical KD features. The United States Centers for Disease Control and Prevention analyzes and interprets large hospitalization databases as a mechanism for conducting national KD surveillance.

METHODS

The Kids' Inpatient Database (KID), the National (Nationwide) Inpatient Sample (NIS), and the IBM MarketScan Commercial (MSC) and MarketScan Medicaid (MSM) databases were analyzed to determine KD-associated hospitalization rates and trends from 2006 to the most recent year of available data. KD and potential KDSS hospitalizations were defined using International Classification of Disease-Clinical Modification codes.

RESULTS

For the most recent year, the KD-associated hospitalization rates for children <5 years of age were 19.8 (95% CI: 17.2-22.3, KID: 2016), 19.6 (95% CI: 16.8-22.4, NIS: 2017), 19.3 (MSC: 2018), and 18.4 (MSM: 2018) per 100,000. There was no indication of an increase in KD rates over the time period. Rates of potential KDSS among children <18 years of age, ranging from 0.0 to 0.7 per 100,000, increased; coding indicated potential KDSS for approximately 2.8%-5.3% of KD hospitalizations.

CONCLUSIONS

Analyses of these large, national databases produced consistent KD-associated hospitalization rates, with no increase over time detected; however, the percentage of KD hospitalizations with potential KDSS increased. Given reports of increasing incidence elsewhere and the recent identification of a novel virus-associated syndrome with possible Kawasaki-like features, continued national surveillance is important to detect changes in disease epidemiology.

Relative blood loss in forensic medicine-do we need a change in doctrine?

In forensic medicine, blood loss is encountered frequently, either as a cause of death or as a contributing factor. Here, risk to life and lethality assessment is based on the concept of relative blood loss (absolute loss out of total volume). In emergency medicine, the Advanced Trauma Life Support (ATLSⓇ) classification also refers to relative blood loss. We tested the validity of relative blood loss benchmarks with reference to lethality. Depending on the quality of the total blood volume (TBV) estimation formula, relative blood loss rates should be reflected in the case cohort as significantly higher absolute blood loss in heavier individuals since all TBV estimation formulas positively correlate body weight with TBV.

METHOD

80 autopsy cases with sudden, quantifiable, exclusively internal blood loss were retrospectively analyzed and a total of 8 different formulas for TBV estimation were applied.

RESULTS

No statistical correlation between body weight and absolute blood loss was found for any of the tested TBV estimation algorithms. All cases showed a wide spread of both absolute and relative blood loss.

DISCUSSION

The principle of relative blood loss is of very limited use in casework. It opens the forensic expert opinion to unnecessary criticism and possible negative legal implications.

CONCLUSION

We challenge the use of relative blood loss benchmarks in textbooks and practical casework and advocate for its elimination from the ATLSⓇ 's grading system. If necessary, we recommend the use of BMI-adjusted algorithms for TBV estimation.

The Nomenclature, Definition and Distinction of Types of Shock

BACKGROUND

A severe mismatch between the supply and demand of oxygen is the common feature of all types of shock. We present a newly developed, clinically oriented classification of the various types of shock and their therapeutic implications.

METHODS

This review is based on pertinent publications (1990-2018) retrieved by a selective search in PubMed, and on the relevant guidelines and meta-analyses.

RESULTS

There are only four major categories of shock, each of which is mainly related to one of four organ systems. Hypovolemic shock relates to the blood and fluids compartment while distributive shock relates to the vascular system; cardiogenic shock arises from primary cardiac dysfunction; and obstructive shock arises from a blockage of the circulation. Hypovolemic shock is due to intravascular volume loss and is treated by fluid replacement with balanced crystalloids. Distributive shock, on the other hand, is a state of relative hypovolemia resulting from pathological redistribution of the absolute intravascular volume and is treated with a combination of vasoconstrictors and fluid replacement. Cardiogenic shock is due to inadequate function of the heart, which shall be treated, depending on the situation, with drugs, surgery, or other interventional procedures. In obstructive shock, hypoperfusion due to elevated resistance shall be treated with an immediate life-saving intervention.

CONCLUSION

The new classification is intended to facilitate the goal-driven treatment of shock in both the pre-hospital and the inpatient setting. A uniform treatment strategy should be established for each of the four types of shock.

Hypovolemic shock resuscitation

Several changes in the way patients with hemorrhagic shock are resuscitated have occurred over the past decades, including permissive hypotension, minimal crystalloid resuscitation, earlier blood transfusion, and higher plasma and platelet-to-red cell ratios. Hemostatic adjuncts, such as tranexamic acid and prothrombin complex, and the use of new methods of assessing coagulopathy are also being incorporated into resuscitation of the bleeding patient. These ideas have been incorporated by many trauma centers into institutional massive transfusion protocols, and adoption of these protocols has resulted in improvements in mortality and morbidity. This article discusses each of these new resuscitation strategies and the evidence supporting their use.

[Epidemiological data on shock in forensic medicine]

The shock is a relative frequent diagnostic in forensic medicine.

MATERIAL AND METHOD

We realized a statistical study, using 323 deaths through diverse shock typology, registered within the Forensic Medicine Institute of Iaşi in 2000-2009. The concerned variables were: the spread of cases on years, the clinical forms, age, sex, provenience environment, volemic feature, the survival time from the shock to the death, the spread of complications on the form of the shock and survival, the juridical way of death. Our data were introduced in the EXCEL database and statisticaly analyzed by SPSS program.

RESULTS

We obtained statistic data on shock typology, based on the survival time and based on the complications of shock types.

CONCLUSION

Relevant statistic data were obtained on the relations between the factors that generated the shock, the complications induced and the shock types, related also to the juridical way of death.

[Physiological monitoring and clinical assessment of patients in shock]

Shock is a life-threatening situation for which circulatory failure represents a major potential complication. While there are numerous disposing factors, the detrimental impacts on the human body are similar. Drop in blood pressure is a common clinical presentation. Severity of impact and chance of survival from shock depend heavily on the speed with which blood pressure recovers and tissue oxygenation is preserved. This article describes the types, pathophysiological process, and major complications of shock, along with relevant disposing factors, risk groups, assessment techniques, monitoring skills and nursing care.

Accuracy of Sequential Organ Failure Assessment (SOFA) scoring in clinical practice

BACKGROUND

The Sequential Organ Failure Assessment (SOFA) score is used to quantify the severity of illness daily during intensive care. Our aim was to evaluate how accurately SOFA is recorded in clinical practice, and whether this can be improved by a refresher course in scoring rules.

METHODS

The scores recorded by physicians in a university hospital intensive care unit (ICU) were compared with the gold standard determined by two expert assessors. Data concerning all consecutive patients during two 6-week-long observation periods (baseline and after the refresher course) were compared.

RESULTS

SOFA was accurate on 75/158 (48%) patient days at baseline. The cardiovascular, coagulation, liver, and renal component scores showed excellent accuracy (>or=82%, weighted kappa >or=0.92), while the neurological score showed only moderate (70%, weighted kappa 0.51) and the respiration score showed good accuracy (75%, weighted kappa 0.79). After the refresher course, the number of >or=2 point errors decreased (P<0.01). Sedation precluded neurological evaluation on 135/311 (43%) days. The accuracy of the assumed neurological scores was lower than those based on timely data: 89/135 (66%, weighted kappa 0.55) vs. 125/176 (71%, weighted kappa 0.81) (P<0.01).

CONCLUSION

Only half of the SOFA scores were accurate. In most cases, they were accurate enough to allow the recognition of organ failure and detection of change. The component scores showed good to excellent accuracy, except the neurological score. After the refresher course, the results improved slightly. The moderate accuracy of the neurological score was not amended. A simpler neurological classification tool than the Glasgow Coma Scale is needed in the ICU.

[Easy echo diagnosis for hypotension and shock]

Hypotension and shock can be classified as hypotension caused by reduced or maintained left ventricular (LV) ejection. Reduced left ventricular ejection can result from intrinsic left ventricular, aortic valve or mitral valve failure, which includes dilated or ischemic cardiomyopathy, left main trunk disease, acute myocarditis, etc. Acute and subacute severe aortic regurgitation can also cause shock. Echocardiography allows noninvasive diagnosis of infective endocarditis and Takayasu's arteritis to cause severe arotic regurgitation and can also be used to diagnose obstruction of the left ventricular outflow tract. Reduced left ventricular preload can be caused by pericardial effusion and right ventricular ejection failure, and can result from pulmonary embolism, tricuspid regurgitation, right ventricular infarction, tension pneumothorax, hypovolemia and others characterized by a small left ventricle with good ejection fraction. Normal left ventricular ejection may be associated with hypotension. Sepsis, anaphylactic shock and neural disorder are associated with hypotension and normal cardiac output. Pseudohypotension may result from aortic dissection, Takayasu's arteritis, arteriosclerosis obliterans and aortic coarctation. A right parasternal approach enables better visualization of the ascending aorta. Fundamental echochocardiographic scanning allows approximate yet useful diagnosis of hypotension and shock.

Understanding hypovolaemic, cardiogenic and septic shock

Shock is a complex physiological syndrome. If it is not detected and treated promptly, it can lead to death. This article reviews and summarises the latest findings, treatment and nursing and medical interventions for three of the most common forms of shock, namely, hypovolaemic, cardiogenic and septic shock.

Hemodynamic monitoring in shock and implications for management. International Consensus Conference, Paris, France, 27-28 April 2006

OBJECTIVE

Shock is a severe syndrome resulting in multiple organ dysfunction and a high mortality rate. The goal of this consensus statement is to provide recommendations regarding the monitoring and management of the critically ill patient with shock.

METHODS

An international consensus conference was held in April 2006 to develop recommendations for hemodynamic monitoring and implications for management of patients with shock. Evidence-based recommendations were developed, after conferring with experts and reviewing the pertinent literature, by a jury of 11 persons representing five critical care societies.

DATA SYNTHESIS

A total of 17 recommendations were developed to provide guidance to intensive care physicians monitoring and caring for the patient with shock. Topics addressed were as follows: (1) What are the epidemiologic and pathophysiologic features of shock in the ICU? (2) Should we monitor preload and fluid responsiveness in shock? (3) How and when should we monitor stroke volume or cardiac output in shock? (4) What markers of the regional and micro-circulation can be monitored, and how can cellular function be assessed in shock? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock? One of the most important recommendations was that hypotension is not required to define shock, and as a result, importance is assigned to the presence of inadequate tissue perfusion on physical examination. Given the current evidence, the only bio-marker recommended for diagnosis or staging of shock is blood lactate. The jury also recommended against the routine use of (1) the pulmonary artery catheter in shock and (2) static preload measurements used alone to predict fluid responsiveness.

CONCLUSIONS

This consensus statement provides 17 different recommendations pertaining to the monitoring and caring of patients with shock. There were some important questions that could not be fully addressed using an evidence-based approach, and areas needing further research were identified.

Mechanisms of critical illness--classifying microcirculatory flow abnormalities in distributive shock

Over 30 years ago Weil and Shubin proposed a re-classification of shock states and identified hypovolemic, cardiogenic, obstructive and distributive shock. The first three categories have in common that they are associated with a fall in cardiac output. Distributive shock, such as occurs during sepsis and septic shock, however, is associated with an abnormal distribution of microvascular blood flow and metabolic distress in the presence of normal or even supranormal levels of cardiac output. This Bench-to-bedside review looks at the recent insights that have been gained into the nature of distributive shock. Its pathophysiology can best be described as a microcirculatory and mitochondrial distress syndrome, where time and therapy form an integral part of the definition. The clinical introduction of new microcirculatory imaging techniques, such as orthogonal polarization spectral and side-stream dark-field imaging, have allowed direct observation of the microcirculation at the bedside. Images of the sublingual microcirculation during septic shock and resuscitation have revealed that the distributive defect of blood flow occurs at the capillary level. In this paper, we classify the different types of heterogeneous flow patterns of microcirculatory abnormalities found during different types of distributive shock. Analysis of these patterns gave a five class classification system to define the types of microcirculatory abnormalities found in different types of distributive shock and indicated that distributive shock occurs in many other clinical conditions than just sepsis and septic shock. It is likely that different mechanisms defined by pathology and treatment underlie these abnormalities observed in the different classes. Functionally, however, they all cause a distributive defect resulting in microcirculatory shunting and regional dysoxia. It is hoped that this classification system will help in the identification of mechanisms underlying these abnormalities and indicate optimal therapies for resuscitating septic and other types of distributive shock.

Vasopressin during cardiopulmonary resuscitation and different shock states: a review of the literature

Vasopressin administration may be a promising therapy in the management of various shock states. In laboratory models of cardiac arrest, vasopressin improved vital organ blood flow, cerebral oxygen delivery, the rate of return of spontaneous circulation, and neurological recovery compared with epinephrine (adrenaline). In a study of 1219 adult patients with cardiac arrest, the effects of vasopressin were similar to those of epinephrine in the management of ventricular fibrillation and pulseless electrical activity; however, vasopressin was superior to epinephrine in patients with asystole. Furthermore, vasopressin followed by epinephrine resulted in significantly higher rates of survival to hospital admission and hospital discharge. The current cardiopulmonary resuscitation guidelines recommend intravenous vasopressin 40 IU or epinephrine 1mg in adult patients refractory to electrical countershock. Several investigations have demonstrated that vasopressin can successfully stabilize hemodynamic variables in advanced vasodilatory shock. Use of vasopressin in vasodilatory shock should be guided by strict hemodynamic indications, such as hypotension despite norepinephrine (noradrenaline) dosages >0.5 mug/kg/min. Vasopressin must never be used as the sole vasopressor agent. In our institutional routine, a fixed vasopressin dosage of 0.067 IU/min (i.e. 100 IU/50 mL at 2 mL/h) is administered and mean arterial pressure is regulated by adjusting norepinephrine infusion. When norepinephrine dosages decrease to 0.2 microg/kg/min, vasopressin is withdrawn in small steps according to the response in mean arterial pressure. Vasopressin also improved short- and long-term survival in various porcine models of uncontrolled hemorrhagic shock. In the clinical setting, we observed positive effects of vasopressin in some patients with life-threatening hemorrhagic shock, which had no longer responded to adrenergic catecholamines and fluid resuscitation. Clinical employment of vasopressin during hemorrhagic shock is experimental at this point in time.

A clinical profile of shock in children in Punjab, India

This prospective study was conducted to determine the frequency, etiology, type and outcome of shock in hospitalized children in the age group of 1 month to 15 years. There were 98 cases of shock, constituting 4.3% out of total admissions. Mean age was 2.8 +/-3.4 years. Maximum number of patients (39) was seen in infancy. Hypovolemic shock due to acute diarrheal disease was the commonest type (45.9%) followed by septic, cardiogenic and distributive shock. Compensated stage was common in hypovolemic shock (88.9%) whereas majority of patients with septic shock (73.5%) presented in decompensated stage. Overall survival was 73.6%. The survival rate was best in hypovolemic shock (97.7%;) followed by septic(53.3%) and cardiogenic shock(43.7%). Inotropes and ventilatory support were required in 46% and 23% patients, respectively. Diagnosis and management of shock in compensated stage carried better prognosis than in uncompensated shock irrespective of the age of the patient.

Early recognition and treatment of shock in the pediatric patient

Pediatric cardiopulmonary arrest is frequently a terminal event of an unrecognized progressive shock state. This article describes predisposing factors and classifications of shock as they relate to pediatric patients. It assists the experienced pediatric nurse as well as the nurse who is less experienced in caring for children in identifying early shock in this population and provides practical advice on the assessment of children. In addition, management and intervention techniques are addressed.

[Recognition of cardiorespiratory distress and failure in children]

Every pediatrician and general practitioner can face children with life-threatening conditions in their private practice. Recognition of symptoms of respiratory failure and shock is essential to initiate therapy promptly in order to prevent the development of cardiopulmonary failure. This article provides clinical information on detecting critical respiratory and cardiac conditions, anticipating cardiac arrest in children, establishing priorities in care, and transferring to an emergency center.

Stroke output variations calculated by esophageal Doppler is a reliable predictor of fluid response

OBJECTIVE

Esophageal Doppler allows continuous monitoring of stroke volume index (SVI) and corrected flow time (FTc). We hypothesized that variations in stroke output index SOI (SVI/FTc) during volume expansion can predict the hemodynamic response to subsequent fluid loading better than the static values.

DESIGN AND SETTING

Prospective study in the intensive care unit of a university hospital.

PATIENTS

Fifty-one patients with circulatory failure were monitored by esophageal Doppler.

INTERVENTIONS

Patients who responded to a first fluid challenge received a second one. Patients who responded to both were classified as responders-responders, and those who did not respond to the second as responders-nonresponders. In these two groups we compared DeltaSVI, DeltaFTc, and DeltaSOI during each fluid challenge and also static values at the end of each fluid challenge.

MEASUREMENTS AND RESULTS

After the first fluid challenge DeltaSOI and DeltaSVI were significantly higher in patients who responded to subsequent volume expansion than in patients who no longer responded. ROC curves showed that DeltaSOI was a better predictor of fluid responsiveness than DeltaSVI. During volume expansion a DeltaSOI value of 11% discriminated between responders and nonresponders to subsequent volume expansion with a sensitivity of 91% and a specificity of 97%. There was no significant difference between the two groups for FTc value at the end of first fluid challenge.

CONCLUSIONS

Analysis of DeltaSOI during fluid challenge predicts response to subsequent fluid challenge and FTc is not a reliable indicator of cardiac preload.

How the brain recognizes and responds to shock

The rat that wishes to reach the goal of his learning and attain the reward, his very own mountain of cheese, must be able to navigate through the maze (Figure One). So the nurse, to reach the goal of understanding why the outward manifestations of shock occur must learn to navigate through the physiological maze of the body. After considering some general information on shock, we will embark on a tour through the maze created by the shock syndrome.

[Pre-clinical management of shock patients]

The preclinical diagnosis of shock is still based on the patient's history, the physical examination, the injury pattern and a few hemodynamic parameters available in the emergency set-up. The clinical picture is characterised by hypotension and tachycardia, tachypnoe and dyspnoea as well as cerebral impairment. Results from recent clinical trials indicate, that a adapted and specific therapeutic approach for the various shock forms is necessary. In case of traumatic hypovolemic-hemorrhagic shock it is of particular relevance if penetrating trauma and/or uncontrolled bleeding exists. Under these conditions an immediate definite surgical treatment is required ("scoop and run") and a moderate hypotension should be tolerated. ("treat and run"). Fluid substitution and therapy with catecholamines should be used conservatively. In all other forms of shock the treatment approach can and should be more aggressive in order to improve microvascular perfusion as early as possible. Besides adequate fluid resuscitation in a combination of crystalloid and colloid solutions catecholamines and-under specific circumstances-also vasopressin should be used. Of utmost importance in the pre-clinical management of patients in shock is the optimal selection of the centre that the patient is referred to in order to establish the fastest and best possible definite treatment for the patient.

[Emergency room patients]

The aim of the study was to examine the predictive value of CT for severe intracranial lesions of mild (GCS 15-13) and moderate (12-9) head injuries. Further,we examined the possibility of predicting these lesions by various variables/factors. Data were collected prospectively from the trauma registry of the DGU (Deutsche Gesellschaft für Unfallchirurgie). Patients with a GCS score from 15-13 and from 12-9 were included in this study and examined for intracranial lesions (AIS(head) 3-6). Over a time period from 1993 to 1999, 1778 patients with mild head injury and 235 patients with moderate head injury were analyzed. Severe intracranial lesions were suffered by 18.6% of the patients with mild head injury and 50.4% of the patients with moderate head injuries. Of the predictive variables, heart rate,patients' age,and primary assessment by the emergency physician showed a strong correlation with the later observed intracranial lesions.

IN CONCLUSION

(1) independently of the initially good GCS, a high percentage of patients suffered from severe intracranial lesions and (2) besides the GCS only the patients'age and primary assessment by the emergency physician were useful for identifying patients at risk for an intracranial lesion.

Blood transfusion, independent of shock severity, is associated with worse outcome in trauma

BACKGROUND

We have previously shown that blood transfusion in the first 24 hours is an independent predictor of mortality, intensive care unit (ICU) admission, and increased ICU length of stay in the acute trauma setting when controlling for Injury Severity Score, Glasgow Coma Scale score, and age. Indices of shock such as base deficit, serum lactate level, and admission hemodynamic status (systolic blood pressure, heart rate) and admission hematocrit were considered potential confounding variables in that study. The objectives of this study were to evaluate admission anemia and blood transfusion within the first 24 hours as independent predictors of mortality, ICU admission, ICU length of stay (LOS), and hospital LOS, with serum lactate level, base deficit, and shock index (heart rate/systolic blood pressure) as covariates.

METHODS

Prospective data were collected on 15,534 patients admitted to a Level I trauma center over a 3-year period (1998-2000) and stratified by age, gender, race, Glasgow Coma Scale score, and Injury Severity Score. Admission anemia and blood transfusion were assessed as independent predictors of mortality, ICU admission, ICU LOS, and hospital LOS by logistic regression analysis, with base deficit, serum lactate, and shock index as covariates.

RESULTS

Blood transfusion was a strong independent predictor of mortality (odds ratio [OR], 2.83; 95% confidence interval [CI], 1.82-4.40; p < 0.001), ICU admission (OR, 3.27; 95% CI, 2.69-3.99; p < 0.001), ICU LOS (p < 0.001), and hospital LOS (Coef, 4.37; 95% CI, 2.79-5.94; p < 0.001) when stratified by indices of shock (base deficit, serum lactate, shock index, and anemia). Patients who underwent blood transfusion were almost three times more likely to die and greater than three times more likely to be admitted to the ICU. Admission anemia (hematocrit < 36%) was an independent predictor of ICU admission (p = 0.008), ICU LOS (p = 0.012), and hospital LOS (p < 0.001).

CONCLUSION

Blood transfusion is confirmed as an independent predictor of mortality, ICU admission, ICU LOS, and hospital LOS in trauma after controlling for severity of shock by admission base deficit, lactate, shock index, and anemia. The use of other hemoglobin-based oxygen-carrying resuscitation fluids (such as human or bovine hemoglobin substitutes) in the acute postinjury period warrants further investigation.

Nursing considerations for fluid management in hypovolaemia

Nurses need to be aware of the physiological aspects of fluid homeostasis and the nursing care and management required to manage patients with fluid balance problems effectively. This paper examines fluid management for patients with hypovolaemia, and provides reflective study points to encourage nurses to investigate the issues further.

Shock

Shock is a life-threatening condition and to provide the best treatment, nursing care needs to focus on the cause of shock. Different types of shock and their causes are discussed to provide a better understanding of the nursing priorities involved.

Determining optimal cardiac preload during resuscitation using measurements of ventricular compliance

BACKGROUND

While the right ventricular end-diastolic volume index (RVEDVI) has been shown to be a better indicator of preload than cardiac filling pressures, optimal values during resuscitation from trauma are unknown. This study examines right ventricular stiffness as a guide to optimal values of RVEDVI.

METHODS

Prospective study of 19 critically injured patients monitored with a volumetric pulmonary artery catheter during resuscitation. Per resuscitation protocol, the target RVEDVI was > or = 120 mL/m2. Sequential fluid boluses of 500 to 1000 mL were administered to obtain at least four values of RVEDVI and right ventricular end-diastolic pressure (estimated by central venous pressure [CVP]). For each patient, nonlinear regression was used to construct the ventricular compliance curve based on the equation, CVP = aek(RVEDVI), where k is the coefficient of chamber stiffness.

RESULTS

Overall, the derived compliance curves had excellent fit with the theoretical equation (mean R2, 0.95 +/- 0.04). Mean k was 0.043 +/- 0.012 (range, 0.029-0.067). For each patient, mean RVEDVI during resuscitation was significantly correlated with k (R2 = 0.75, p < 10-5) indicating that chamber stiffness, measured during initial fluid administration, may be used to determine RVEDVI during the ensuing resuscitation.

CONCLUSION

In critically injured patients, bedside assessment of right ventricular compliance is possible and may help determine optimal values of RVEDVI during resuscitation.

Understanding shock

Shock is a serious condition that involves many organs of the body and must be treated immediately to ensure that the patient recovers. Timothy Collins provides a guide to shock, including the different types, the signs and symptoms and appropriate nursing care.

Shock at the millennium. I. Walter B. Cannon and Alfred Blalock

Present management of shock derives, in part, from the classic investigations of Walter B. Cannon and Alfred Blalock. The intersections of their professional lives as recorded in the professional literature and in personal correspondence suggest that Blalock's pivotal studies of experimental shock were fueled, at least in part, by Cannon's inability to resolve the inconsistencies of the then-popular toxic theory of shock. Cannon appears to have substantially shaped Blalock's thought and work, initially as authority and competitor and later as colleague and friend. Blalock's experimental proof that injury precipitated obligatory locoregional fluid losses, the effects of which could be ameliorated by vigorous restoration of plasma volume, became a cornerstone of shock theory and therapy.

[A classification of shock based on hemodynamic profiles]

Shock is a syndrome of numerous etiologies. The treatment of shock syndrome depends on the etiology and circulatory pathophysiology. From the viewpoint of circulatory physiology, the mechanism of circulatory failure can be attributed to three factors: blood volume; cardiac contractility; and vascular resistance. Balloon-tipped pulmonary artery (Swan-Ganz) catheters can distinguish between these factors in the clinical setting and allows physicians to treat shock patients most appropriately and logically. The author proposes a treatment-oriented classification of shock based on Swan-Ganz catheter findings and divides shock into three types: hypovolemic; cardiogenic; and low-resistant shock. All clinicians who treat shock must have qualified knowledge of and experience in handling this beneficial but invasive monitoring device.

[Shock]

Shock is a consequence of disturbed circulation and decreased blood perfusion of tissues which, on the whole, cause functional and morphological impairments of organic systems. Occurrence of shock is not high, but it is significant due to bad prognosis and high mortality rate.

CLASSIFICATION

This is one of the classifications of shock: cardiogenic, extracardiogenic-obstructive, oligentic and distributive shock. PATHOPHYSIOLOGIC MECHANISMS OF SHOCK: Regardless of the cause of shock, the clinical picture is dominated by hypotension mostly caused by decrease of minute volume (septic shock may be an exception--minute volume might be high). Due to hypotension a lot of compensatory mechanisms are activated and in the beginning showing the compensatory phase of disease and if nothing is done decompensatory and in the end irreversible phase of shock occurs with fatal outcome. The clinical picture depends on the etiology of shock, type of shock, but it also has certain specificities.

PROGNOSIS

The prognosis depends on the clinical picture dominated by the following symptoms: hypotension, decreased diuresis, acidosis, consciousness disorders, tachypnea, peripheral cyanosis, cold and damp skin.

MANAGEMENT

These patients are managed in intensive care units, where the following parameters are followed-up: arterial pressure, central venous pressure, minute heart volume, systemic vascular resistance, diuresis, continual follow-up of heart rate, breathing and consciousness. In treatment of shock it is necessary to: normalize the circulatory volume, establish electrolyte balance, regulate glycemia and acid-base status, compensate the volume, calm the patient and alleviate pain.

Recognition and management of shock in the pediatric patient

Shock continues to be a challenge for health care professionals because shock is not a single pathologic process but a complex series of interrelated events. After respiratory failure, shock is the second most common cause of death in children. The etiology of shock can be classified into three major categories: hypovolemic, cardiogenic, and distributive shock (septic shock). Despite the etiology of the shock state, if left untreated, the overwhelming response of the body to the inadequate perfusion is death. The key to successful management and treatment of shock is early recognition and rapid intervention.