Management Of Patients In Shock Research Articles

State-of-the-Art Review-Endovascular Resuscitation.

The emerging concept of endovascular resuscitation applies catheter-based techniques in the management of patients in shock to manipulate physiology, optimize hemodynamics, and bridge to definitive care. These interventions hope to address an unmet need in the care of severely injured patients, or those with refractory non-traumatic cardiac arrest, who were previously deemed non-survivable. These evolving techniques include Resuscitative Endovascular Balloon Occlusion of Aorta, Selective Aortic Arch Perfusion, and Extracorporeal Membrane Oxygenation and there is a growing literature base behind them. This review presents the up-to-date techniques and interventions, along with their application, evidence base, and controversy within the new era of endovascular resuscitation.

Diastolic pressure should be used to guide management of patients in shock: PRO

Based primarily on the rational that adequate diastolic pressure is needed to maintain sufficient coronary blood for myocardial needs, diastolic pressure has been proposed as a treatment target for patients in shock. To date, clinical evidence supporting this is limited to observational data. Key points are that what is important for tissues is flow not pressure; the coronary circulation has very large flow reserves and can maintain flow with a low pressure; raising arterial pressure by only increasing vascular resistance does not alter tissue perfusion and could even increase myocardial oxygen demand. Targeting diastolic pressure can lead to over use of vasopressors, which studies have associated with worse outcome. Pressor management in shock should include assessment of indicators of tissue perfusion and changes in flow if possible.

Central Venous Oxygenation for Mixed Venous Oxygen Saturation

AbstractVenous oxygen saturation has been traditionally used as a marker for tissue hypoxia. A wide range of factors can affect it. Literature abounds with articles on the use of the same in decision making and clinical management of patients in shock. Likewise, the application of venous saturation in patients undergoing cardiac and noncardiac surgery has been demonstrated. The controversy as to whether superior vena cava oxygen saturation can replace the traditional mixed venous oxygen saturation is never ending. Irrespective of the body of evidence, it is recommended that clinical decision should not be based on a single value, and a range of values needs to be incorporated to differentiate a critically ill from a noncritically ill patient.

Recent advances in bedside microcirculation assessment in critically ill patients.

Parameters related to macrocirculation, such as the mean arterial pressure, central venous pressure, cardiac output, mixed venous saturation and central oxygen saturation, are commonly used in the hemodynamic assessment of critically ill patients. However, several studies have shown that there is a dissociation between these parameters and the state of microcirculation in this group of patients. Techniques that allow direct viewing of the microcirculation are not completely disseminated, nor are they incorporated into the clinical management of patients in shock. The numerous techniques developed for microcirculation assessment include clinical assessment (e.g., peripheral perfusion index and temperature gradient), laser Doppler flowmetry, tissue oxygen assessment electrodes, videomicroscopy (orthogonal polarization spectral imaging, sidestream dark field imaging or incident dark field illumination) and near infrared spectroscopy. In the near future, the monitoring and optimization of tissue perfusion by direct viewing and microcirculation assessment may become a goal to be achieved in the hemodynamic resuscitation of critically ill patients.

Role of echocardiography in the management of shock

Hemodynamic instability and inade-quate cardiac performance is frequently found in critically ill patients. Tran-sthoracic and transesophageal (in the case of inadequate visibility) echocar-diography is increasingly used for non-invasive hemodynamic assessment and monitoring in the ICU setting. Using echocardiography, it is possible to assess preload, fluid responsiveness, systolic and diastolic cardiac function, and cal-culate cardiac output, intravascular and intra-cardiac pressures. It is the golden standard in the initial hemodynamic assessment and should be used as com-plementary tool in invasively monitored patients in the case of new circulatory or respiratory failure. Echocardiography is indispensable in the management of shock patients and is extremely power-ful diagnostic role for the cardiac abnor-malities (pericardial effusion and tam-ponade, acute cor pulmonale and acute or chronic valvular disorders) as a cause for hemodynamic instability. It is the most important and suitable method for assessment of right ventricular function, for diagnosis of septic cardiomyopathy and cardiac causes of weaning failure. Because of these advantages it should be routinely used by intensivists for hemo-dynamic assessment and monitoring and should be continuously available in the intensive care unit. The most important limitations of echocardiography are its inability to estimate adequacy of car-diac output and its intermittent nature. Therefore it should be used in rational combination with other complementary and continuous monitoring methods.

The highs and lows of blood pressure: toward meaningful clinical targets in patients with shock.

Measurement of blood pressure is fundamental for the management of patients in shock, yet the physiological basis and meaning of blood pressure measurements are complex and often not well understood. This article is in two parts: part 1 deals with the mechanical and physiological aspects of blood pressure and its measurement and part 2 deals with the role of changes in regional resistances in the determination of tissue perfusion and bedside approaches to management of shock. This review is based on physiological principles from texts and experimental studies which elucidate some of the key principles. The views expressed are the author's synthesis of the views of others and his own opinions. Arterial blood pressure is a major determinant of regional flow and is often used as a surrogate indicator of tissue perfusion, but in reality, it is a poor indicator of blood flow. Blood pressure is determined by cardiac output (total flow) and total vascular resistance. Distribution of flow for a given blood pressure is dependent on the relative values of resistances in different vascular beds. If this distribution of resistances were known, this would be the ideal guide to therapy. Unfortunately, regional resistances cannot be assessed in the clinical setting, and so we are left with blood pressure as a guide to therapy. This article discusses the implications of these points and explores factors that need to be taken into account when designing empiric trials to determine appropriate blood pressure targets for patients in shock. Even if well-studied empirically developed guidelines become available, it likely still will be important to individualize patient management and approaches for this are discussed too.

Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol.

Assessment of hemodynamic status in a shock state remains a challenging issue in Emergency Medicine and Critical Care. As the use of invasive hemodynamic monitoring declines, bedside-focused ultrasound has become a valuable tool in the evaluation and management of patients in shock. No longer a means to simply evaluate organ anatomy, ultrasound has expanded to become a rapid and noninvasive method for the assessment of patient physiology. Clinicians caring for critical patients should strongly consider integrating ultrasound into their resuscitation pathways.

Causes of inpatient death for patients with warfare-related limb trauma and logistic regression analysis of the risk factors.

To explore the causes and risk factors of inpatient death for patients with warfare-related limb trauma. A retrospective study involving 339 patients with warfare-related limb trauma who were admitted to our hospital from 1998 to 2002 was conducted. Autopsy was performed for 15 cases who died in order to investigate the cause of death. Furthermore, based on the clinical features of warfare-related trauma patients, 11 factors were selected for further analysis: X1: causes of trauma, X2: shock after injury, X3: time from injury to hospital admission, X4: injured sites, X5: combined trauma (including head, thorax, abdomen, and vascular injury), X6: number of surgical procedures, X7: foreign body remaining, X8: fracture, X9: amputation, X10: duration of tourniquet homeostasis, X11: infection. All variables were available in all cases, and all parameters were quantified and fed into a computer. Multivariate statistical analysis was performed with a logistic regression model to elucidate the risk factors influencing death. Fifteen of the 339 inpatient cases died (4.4%). The causes were primarily acute renal failure (ARF) (seven cases, 46.7%), pulmonary embolism (PE) (three cases, 20.0%), multiple organ system failure (MOSF) (two cases, 13.3%), and gas gangrene (three cases, 20.0%). There was one case of gas gangrene with concomitant ARF, and one of gas gangrene with MOSF. The primary risk factors influencing death included shock, amputation, and complicating infection (P<0.05). The primary cause of death from warfare-related limb trauma is ARF. The appropriate and prompt management of shock patients, the correct timing of amputation, and the prevention and correct handling of infection are important in reducing mortality.

Comparison between values of central venous and arterial lactate and standard base excess in shocked patients

Hemodynamic optimization based on tissue perfusion markers is a strategy considered adequate for the management of patients in shock in ICUs.

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.