Year in review 2009: Critical Care - shock

Research, Society and Development

Refractory shock is characterized by hemodynamic instability unresponsive to norepinephrine with a high mortality rate. As there are still doubts regarding the pharmacological benefit of the vasopressin addition, this retrospective study aimed to assess the profile of vasopressin use in the intensive care unit of a university hospital in Paraná, Brazil. The information collected was obtained through the analysis of electronic medical records. 73 patients with refractory shock, mainly of septic etiology (61.6%), were included. The dose (μg/Kg/minute) and duration of norepinephrine, upon finding refractoriness, was 35.6% infusion < 1, 34, 3% of 1-1.9, 30.1% > 2 and mean time of 1.5 days. High mortality (80.8%) was observed, with a mean hospital stay of 8.2 days. Median survival after vasopressin infusion was 4.5 days until the unfavorable outcome. Still, 80.5% of patients used other adjuvant therapy, 71.2% being corticotherapy and 9.6% dobutamine. Due to the great variability, i...

Critical Care Research and Practice, 2013

There is no consensual definition of refractory shock. The use of more than 0.5 mcg/kg/min of norepinephrine or epinephrine to maintain target blood pressure is often used in clinical trials as a threshold. Nearly 6% of critically ill patients will develop refractory shock, which accounts for 18% of deaths in intensive care unit. Mortality rates are usually greater than 50%. The assessment of fluid responsiveness and cardiac function can help to guide therapy, and inotropes may be used if hypoperfusion signs persist after initial resuscitation. Arginine vasopressin is frequently used in refractory shock, although definite evidence to support this practice is still missing. Its associations with corticosteroids improved outcome in observational studies and are therefore promising alternatives. Other rescue therapies such as terlipressin, methylene blue, and high-volume isovolemic hemofiltration await more evidence before use in routine practice.

Canadian Journal of Anesthesia/Journal canadien d'anesthésie

Purpose Hemodynamic management of adults with distributive shock often includes the use of catecholamine-based vasoconstricting medications. It is unclear whether adding vasopressin or vasopressin analogues to catecholamine therapy is beneficial in the management of patients with distributive shock. The purpose of this guideline was to develop an evidencebased recommendation regarding the addition of vasopressin to catecholamine vasopressors in the management of adults with distributive shock.

2007

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 str...

Frontiers in Physiology, 2023

Shock is a common but fatal complication and represents a major preventable cause of death in trauma patients. Controversy still exists concerning using appropriate types and timing of resuscitation fluids, allowing permissive hypotension, and preventing coagulopathy and multiple organ failure in severely injured patients. The current Research Topic of Shock and Resuscitation welcomed submissions from clinical and basic science research. This Research Topic includes summaries on different types of shock-associated injuries including their etiology, mechanisms, pathophysiology. Also included are novel potential therapeutics and techniques targeting patient survival, multiple organ failure, abnormal coagulation, tissue tolerance to ischemia, and optimal strategies for hemorrhage resuscitation. In theory, the most effective antishock treatment is one that targets the root mechanism of shock-lack of tissue perfusion. Such treatments should improve tissue perfusion at microcirculatory levels rather than primarily focusing on systemic blood pressure Dubin et al., 2020). Notably, microcirculatory responses to shock or resuscitation are not always connected to systemic hemodynamics, and, likewise, macrohemodynamic variables cannot always be relied upon to monitor the outcome of shock conditions. With this understanding, blood flow in vital organs needs to be considered as a routinely measured index to evaluate severity of shock and efficacy of treatment (Elansary et al.; Yoshimoto et al.). For example, Patel et al. demonstrated that cerebral blood flow during cardiac massage in pigs undergoing cardiac arrest remained severely compromised, and the effect of cardiac massage on cardiac flow was absent until volume resuscitation was provided. These measurements suggest that open cardiac massage is a poor technique to achieve adequate vital organ perfusion, and volume expansion is still the priority when considering critical restoration of vital organ perfusion and energy supplies. Indeed, recovery of organ function from hemorrhagic shock tightly correlates with restoration of ATP levels in tissues Clowes and Hershey, 1971). Notably, adding metabolic substrates alone to prevent cellular fatigue during prolonged shock without improving oxygen supply is likely an effort in vain. For example, without oxygen, lipid oxidation is suppressed, and glucose would rapidly be consumed via anaerobic glycolysis to meet ATP demands. If ischemia is prolonged, accumulation of intermediates of the tricarboxylic acid cycle (TCA) further shifts

Critical Care, 2009

Recent clinical data suggest that early administration of vasopressin analogues may be advantageous compared to a last resort therapy. However, it is still unknown whether vasopressin and terlipressin are equally effective for hemodynamic support in septic shock. The aim of the present prospective, randomized, controlled pilot trial study was, therefore, to compare the impact of continuous infusions of either vasopressin or terlipressin, when given as first-line therapy in septic shock patients, on open-label norepinephrine requirements.

Shock, 2007

We investigated the possible differences in epidemiology, clinical course, management, and outcome between early and late occurrence of shock using data from the Sepsis Occurrence in Acutely Ill Patients Study, a large European multicenter study, which prospectively collected data from all adult intensive care unit (ICU) patients admitted to a participating center within a 2-week period in 2002. Shock was defined as hemodynamic compromise necessitating the administration of vasopressor agents. Early and late shock were defined as onset of shock within the first 2 days in the ICU or later, respectively. Of 3,147 patients, 1,058 (33.6%) had shock at any time, of whom 462 (43.7%) had septic shock. Patients with late shock had a higher incidence of respiratory (87.4 vs. 69.7%, P G 0.001) and hepatic (15.5 vs. 8.7%, P G 0.05) failure, and more often received dopamine (44.7% vs. 34.5%, P G 0.05) and albumin (31.1% vs. 20.3%, P G 0.001) than patients who developed shock early. Intensive care unit and hospital mortality rates were greater in patients who developed shock late, rather than early (52.4% vs. 36.8% and 55.3% vs. 43%, respectively, P G 0.02). In a multivariable analysis, late shock was associated with an independent risk of higher ICU mortality in shock patients (odds ratio, 2.6; 95% confidence interval, 1.6Y4.3, P G 0.001). These observations have important implications in establishing individual prognosis as well as in the design and interpretation of clinical trials.

World Journal of Surgery, 1987

Descriptions of the sequence of hemodynamic and oxygen transport patterns in the various types of shock syndromes have shown reduced oxygen consumption (VO2) as the earliest pathop.hysiologic event that precedes the initial hypotensive crisis. Inadequate VO2 may be produced by low flow, as in hemorrhagic and cardiogenic shock, by increased metabolic need, as in traumatic and septic shock, and/or by maldistribution of flow in all types of shock. These physiologic patterns are also related to the degree of the shock State and its outcome; the patterns of the survivors and nonsurvivors can be predicted from these patterns with a high degree of sensitivity and specificity by multivariate analysis. Therapy directed toward optimizing the "~O2 and its compensations to the range of survivors of life-threatening shock was shown to improve outcome in prospective clinical trials. A branched chain decision tree was developed for fluid resuscitation of critically ill postoperative patients. The algorithm was developed from decision rules based on objective physiologic heuristic data from survivors as the criteria. The improved mortality in prospective studies supports the hypothesis that compensatory responses of the survivors are major determinants of outcome. Therefore, therapy that supports these compensations and produces the survivor pattern will improve survival rates. These prospective studies confirm the validity of an organized, coherent physiologic approach in contrast to the traditional approach, the objectives of which are to restore hemodynamic and biochemical abnormalities to normal if and when they are discovered. The use of a branched chain decision tree helps to achieve these therapeutic goals expeditiously by providing a coherent, organized patient management plan. It is not necessary to wait for patients to develop cardiorespiratory deficits before initiating therapy. Therapy should be started to optimize the important variables as soon as possible after the onset of accidental trauma or before, during, and immediately after surgery in the high-risk patient. Traditional Approach to Shock Evaluation and therapy of shock have traditionally been approached by separating shock syndromes according to their etiologies. These etiologic categories usually include the hemorrhagic, cardiogenic, traumatic, and septic shock syndromes. Each of these etiologic types of shock are then described by their clinical signs and symptoms, laboratory findings, and primary pathophysiologic derangements. On the basis of this analysis, therapeutic principles are developed for each etiologic type. Table 1 exemplifies this approach. The tacit assumptions

Journal of Veterinary Emergency and Critical Care, 2009

Objective-To discuss 3 potential mechanisms for loss of peripheral vasomotor tone during vasodilatory shock; review vasopressin physiology; review the available animal experimental and human clinical studies of vasopressin in vasodilatory shock and cardiopulmonary arrest; and make recommendations based on review of the data for the use of vasopressin in vasodilatory shock and cardiopulmonary arrest. Data Sources-Human clinical studies, veterinary experimental studies, forum proceedings, book chapters, and American Heart Association guidelines. Human and Veterinary Data Synthesis-Septic shock is the most common form of vasodilatory shock. The exogenous administration of vasopressin in animal models of fluid-resuscitated septic and hemorrhagic shock significantly increases mean arterial pressure and improves survival. The effect of vasopressin on return to spontaneous circulation, initial cardiac rhythm, and survival compared with epinephrine is mixed. Improved survival in human patients with ventricular fibrillation, pulseless ventricular tachycardia, and nonspecific cardiopulmonary arrest has been observed in 4 small studies of vasopressin versus epinephrine. Three large studies, though, did not find a significant difference between vasopressin and epinephrine in patients with cardiopulmonary arrest regardless of initial cardiac rhythm. No veterinary clinical trials have been performed using vasopressin in cardiopulmonary arrest. Conclusion-Vasopressin (0.01-0.04 U/min, IV) should be considered in small animal veterinary patients with vasodilatory shock that is unresponsive to fluid resuscitation and catecholamine (dobutamine, dopamine, and norepinephrine) administration. Vasopressin (0.2-0.8 U/kg, IV once) administration during cardiopulmonary resuscitation in small animal veterinary patients with pulseless electrical activity or ventricular asystole may be beneficial for myocardial and cerebral blood flow.