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Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest, as complications worsen.
Cardiac output (CO), also known as heart output denoted by the symbols , or , is a term used in cardiac physiology that describes the volume of blood being pumped by the heart, by the left and right ventricle, per unit time. Cardiac output (CO) is the product of the heart rate (HR), i.e. the number of heartbeats per minute (bpm), and the stroke volume (SV), which is the volume of blood pumped from the ventricle per beat; thus, CO = HR × SV. Values for cardiac output are usually denoted as L/min. For a healthy person weighing 70 kg, the cardiac output at rest averages about 5 L/min; assuming a heart rate of 70 beats/min, the stroke volume would be approximately 70 ml.
Fluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced with oral rehydration therapy (drinking), intravenous therapy, rectally such as with a Murphy drip, or by hypodermoclysis, the direct injection of fluid into the subcutaneous tissue. Fluids administered by the oral and hypodermic routes are absorbed more slowly than those given intravenously.
Hypovolemic shock is a medical emergency and an advanced form of hypovolemia due to insufficient amounts of blood and/or fluid inside the human body to let the heart pump enough blood to the body. Hypovolemic shock could be due to severe dehydration through a variety of mechanisms or from blood loss.
Hyperchloremia is an electrolyte disturbance in which there is an elevated level of the chloride ions in the blood. The normal serum range for chloride is 96 to 106 mEq/L, therefore chloride levels at or above 110 mEq/L usually indicate kidney dysfunction as it is a regulator of chloride concentration. As of now there are no specific symptoms of hyperchloremia, however, it can be the influenced by multiple abnormalities that cause a loss of electrolyte-free fluid, loss of hypotonic fluid, or increased administration of sodium chloride. These abnormalities are caused by diarrhea, vomiting, increased sodium chloride intake, renal dysfunction, diuretic use, and diabetes. Hyperchloremia should not be mistaken for hyperchloremic metabolic acidosis as hyperchloremic metabolic acidosis is characterized by two major changes: a decrease in blood pH and bicarbonate levels, as well as an increase in blood chloride levels. Instead those with hyperchloremic metabolic acidosis are usually predisposed to hyperchloremia.
Intraosseous infusion (IO) is the process of injecting directly into the marrow of a bone. This provides a non-collapsible entry point into the systemic venous system. This technique is used to provide fluids and medication when intravenous access is not available or not feasible. Intraosseous infusions allow for the administered medications and fluids to go directly into the vascular system. A comparison of intravenous (IV), intramuscular (IM), and intraosseous (IO) routes of administration concluded that the intraosseous route is demonstrably superior to intramuscular and comparable to intravenous administration. This route of fluid and medication administration is an alternative one to the preferred intravascular route when the latter cannot be established in a timely manner. Intraosseous infusions are utilized when trauma patients have compromised intravenous access and need immediate delivery of life saving fluids and medications.
Bupivacaine, marketed under the brand name Marcaine among others, is a medication used to decrease feeling in a specific area. In nerve blocks, it is injected around a nerve that supplies the area, or into the spinal canal's epidural space. It is available mixed with a small amount of epinephrine to increase the duration of its action. It typically begins working within 15 minutes and lasts for 2 to 8 hours.
Hyperchloremic acidosis is a form of metabolic acidosis associated with a normal anion gap, a decrease in plasma bicarbonate concentration, and an increase in plasma chloride concentration. Although plasma anion gap is normal, this condition is often associated with an increased urine anion gap, due to the kidney's inability to secrete ammonia.
Bivalirudin (Bivalitroban), sold under the brand names Angiomax and Angiox and manufactured by The Medicines Company, is a direct thrombin inhibitor (DTI).
Deep hypothermic circulatory arrest (DHCA) is a surgical technique that induces deep medical hypothermia. It involves cooling the body to temperatures between 20 °C (68 °F) to 25 °C (77 °F), and stopping blood circulation and brain function for up to one hour. It is used when blood circulation to the brain must be stopped because of delicate surgery within the brain, or because of surgery on large blood vessels that lead to or from the brain. DHCA is used to provide a better visual field during surgery due to the cessation of blood flow. DHCA is a form of carefully managed clinical death in which heartbeat and all brain activity cease.
Capillary leak syndrome is characterized by the escape of blood plasma through capillary walls, from the blood circulatory system to surrounding tissues, muscle compartments, organs or body cavities. It is a phenomenon most commonly witnessed in sepsis, and less frequently in autoimmune diseases, differentiation syndrome, engraftment syndrome, hemophagocytic lymphohistiocytosis, the ovarian hyperstimulation syndrome, viral hemorrhagic fevers, and snakebite and ricin poisoning. Pharmaceuticals, including the chemotherapy medications gemcitabine and tagraxofusp, as well as certain interleukins and monoclonal antibodies, can also cause capillary leaks. These conditions and factors are sources of secondary capillary leak syndrome.
In medicine, intravascular volume status refers to the volume of blood in a patient's circulatory system, and is essentially the blood plasma component of the overall volume status of the body, which otherwise includes both intracellular fluid and extracellular fluid. Still, the intravascular component is usually of primary interest, and volume status is sometimes used synonymously with intravascular volume status.
Hydroxyethyl starch (HES/HAES), sold under the brand name Voluven among others, is a nonionic starch derivative, used as a volume expander in intravenous therapy. The use of HES on critically ill patients is associated with an increased risk of death and kidney problems.
Early goal-directed therapy was introduced by Emanuel P. Rivers in The New England Journal of Medicine in 2001 and is a technique used in critical care medicine involving intensive monitoring and aggressive management of perioperative hemodynamics in patients with a high risk of morbidity and mortality. In cardiac surgery, goal directed therapy (GDT) has proved effective when commenced after surgery. The combination of GDT and Point-of-Care Testing has demonstrated a marked decrease in mortality for patients undergoing congenital heart surgery. Furthermore, a reduction in morbidity and mortality has been associated with GDT techniques when used in conjunction with an electronic medical record.
Autotransfusion is a process wherein a person receives their own blood for a transfusion, instead of banked allogenic (separate-donor) blood. There are two main kinds of autotransfusion: Blood can be autologously "pre-donated" before a surgery, or alternatively, it can be collected during and after the surgery using an intraoperative blood salvage device. The latter form of autotransfusion is utilized in surgeries where there is expected a large volume blood loss – e.g. aneurysm, total joint replacement, and spinal surgeries. The effectiveness, safety, and cost-savings of intraoperative cell salvage in people who are undergoing thoracic or abdominal surgery following trauma is not known.
A volume expander is a type of intravenous therapy that has the function of providing volume for the circulatory system. It may be used for fluid replacement or during surgery to prevent nausea and vomiting after surgery.
Clevidipine is a dihydropyridine calcium channel blocker indicated for the reduction of blood pressure when oral therapy is not feasible or not desirable.
Permissive hypotension or hypotensive resuscitation is the use of restrictive fluid therapy, specifically in the trauma patient, that increases systemic blood pressure without reaching normotension. The goal blood pressure for these patients is a mean arterial pressure of 40-50mmHg or a systolic blood pressure less than or equal to 80. This goes along with certain clinical criteria. Following traumatic injury some patients experience hypotension that is usually due to blood loss (hemorrhage) but can be due to other causes as well. In the past, physicians were very aggressive with fluid resuscitation to try to bring the blood pressure to normal values. Recent studies have found that there is some benefit to allowing specific patients to experience some degree of hypotension in certain settings. This concept does not exclude therapy by means of i.v. fluid, inotropes or vasopressors, the only restriction is to avoid completely normalizing blood pressure in a context where blood loss may be enhanced. When a person starts to bleed the body starts a natural coagulation process that eventually stops the bleed. Issues with fluid resuscitation without control of bleeding is thought to be secondary to dislodgement of the thrombus that is helping to control further bleeding. Thrombus dislodgement was found to occur at a systolic pressure greater than 80mm Hg. In addition, fluid resuscitation will dilute coagulation factors that help form and stabilize a clot, hence making it harder for the body to use its natural mechanisms to stop the bleeding. These factors are aggravated by hypothermia.
Emergency Preservation and Resuscitation (EPR) is an experimental medical procedure where an emergency department patient is cooled into suspended animation for an hour to prevent incipient death from ischemia, such as the blood loss following a shooting or stabbing. EPR uses hypothermia, drugs, and fluids to "buy time" for resuscitative surgery. If successful, EPR may someday be deployed in the field so that paramedics can suspend and preserve patients for transport.
Vasopressin infusions are in use for septic shock patients not responding to fluid resuscitation or infusions of catecholamines to increase the blood pressure while sparing the use of catecholamines. These argipressins have much shorter elimination half-life comparing to synthetic non-arginine vasopresines with much longer elimination half-life of many hours. Further, argipressins act on V1a, V1b, and V2 receptors which consequently lead to higher eGFR and lower vascular resistance in the lungs. A number of injectable arginine vasopressins are in clinical use in the United States and the European Union. Pitressin among others, is a medication most commonly used in the treatment of frequent urination, increased thirst, and dehydration such as that resulting from diabetes insipidus, which causes increased and diluted urine. It is used to treat abdominal distension following some surgeries, and in stomach roentgenography. Vasopressin is a hormone that affects the kidneys and reduces urine flow.
References
- 1 2 3 Falk JL, Rackow EC, Weil MH (1983). "Colloid and crystalloid fluid resuscitation". Acute Care. 10 (2): 59–94. PMID 6085668.
- ↑ Younes RN, Yin KC, Amino CJ, Itinoshe M, Rocha e Silva M, Birolini D (1998). "Use of pentastarch solution in the treatment of patients with hemorrhagic hypovolemia: randomized phase II study in the emergency room". World Journal of Surgery. 22 (1): 2–5. doi:10.1007/s002689900340. PMID 9465753. S2CID 37628065.
- ↑ Double Blind Randomized Trial of Saline vs Pentaspan for Resuscitation After Cardiac Surgery. ClinicalTrials.gov. URL: http://clinicaltrials.gov/show/NCT00337805. Accessed on: July 21, 2007.