Mechanisms of Shock in Healthcare
Word count: 1616
Table of Contents
SOFA- Sequential Organ Failure Assessment
WHO – World Health Organization
Mechanisms of Shock in Healthcare
Shock is a condition where tissues become inactive and perfuse due to inadequate blood flow and subsequently result in cellular dysfunction and possible death. Shock operates under different mechanisms which may include; vasodilation decreased cardiac performance, decreased circulatory volume, and possible shutting down of blood vessels. Once shock occurs, it deprives cells of required nutrients and oxygen, this condition could lead to the death of the affected cells and cause serious bodily harm rapidly.
Pathophysiology of shock
The most distinguishing feature of shock is the reduced perfusion to vital tissues and organs. In a case where perfusion increases and organs receive inadequate nutrients and oxygen for aerobic metabolism; the cell’s metabolism changes to anaerobic and subsequently produces Carbon (iv) Oxide which increases the lactate levels of the blood (Rice, 1981, p. 48). When Carbon (iv) oxide levels increase, cells cease to function, and shock results; if the shock persists, irreversible damage could occur to the cells and possibly result in death.
In instances of hypoperfusion, both inflammatory and coagulation reactions may be activated during shock. The hypoxic vascular endothelial cells are responsible for activating white blood cells (Leucocytes). The leukocytes attach to the endothelium, releasing harmful chemicals and inflammatory mediators. Some of the mediators attach themselves to surface cell receivers and activate the kappa B (NF-κb) nuclear factor, which results in the creation of extra cytokines and NO2 overproduction, which is a powerful vasodilator (Li et al., 2016, p. 728). The impact of bacterial toxins, especially endotoxins, causes Septic shock which may be more pro-inflammatory than any other kind of shock. Myocardial dysfunction occurs following a septic shock and results in a rapid cytokine storm complication. The condition may worsen the hemodynamic status which is fatal and irreversible.
Compensatory Mechanisms of shock
According to Convertino & Schiller, (2017), once the tissue perforations are threatened, the compensatory stage kicks in an attempt to restore balance in levels of CO2, tissue perfusions, and blood pressure.
The compensatory mechanism of shock occurs when the volume of blood decreases in what is referred to as acute blood loss. This decline causes a fall in the pressure of the central venous system and subsequently a cardiac filling resulting in a fall in pressure of the arterial and cardiac.
If oxygen supply (DO2) is reduced, the tissue compensates for the supply by extracting a larger portion of delivered Oxygen (Convertino & Schiller, 2017). Usually, low arterial pressure induces an adrenergic reaction with sympathy vasoconstriction that increases the heart rate. At first, the vasoconstriction process is selective and shift away blood circulation from the splanchnic circulation to the heart and the brain. Their circulation also improves heart contractility prompting the discharge of corticosteroids from kidney renin, adrenal glands, and hepatic glucose. Increased glucose can accumulate mitochondria and cause additional production of lactate.
Hypovolemic shock results from a fall in blood pressure where the heart is unable to pump enough blood to vital cells and therefore prompting anaerobic metabolism. On the other hand, septic shock is mostly caused by a bacterial infection in the blood which multiplies rapidly and releases toxins that could cause the death of vital cells.
According to Cantle & Cotton, (2017, p. 1002), hypovolemic shock occurs when an individual loses about 20% of the total blood possibly due to accidents or severe anemia. In such cases, the heart is unable to supply enough blood to vital organs thereby leading to reduced access to nutrients and oxygen. Subsequently, the cells tend to metabolize anaerobically leading to the production of CO2 which could, in turn, lead to the death of vital cells and organ failure which eventually results in a shock (Suresh et al., 2018, p. 692).
According to Minasyan, (2019), sepsis is a serious infection that emanates when an infection (bacterial) causes the immune response to react overwhelmingly releasing a large amount of chemicals into the bloodstream and subsequently result in inflammation throughout the body. The chemicals released by the immune response could attack the body cells and even damage vital organs.
Developments in shock assessment
According to empirical research conducted by Cecconi et al., (2018, p. 76), septic shock is usually fatal and most of those who survive from the condition live with long-term morbidity. In 2017, the WHO made sepsis a global health concern in an attempt to improve the prevention, diagnosis, and management of the condition. Sepsis has been for a long time been subjected to intensive research especially due to its fatal status if not detected early. In 2016, a new sepsis definition emerged (Sepsis-3), the new definition refers to Sepsis as an infection with organ dysfunction (Singer et al., 2016). The new definition of sepsis codifies organ disfunction using the SOFA score. Research is however ongoing to improve diagnosis of the condition and also have management strategies that are specific to individuals and have them matched to biochemical and molecular profiles.
Hypovolemic shock is quite fatal, however, there have been very few measures taken to raise awareness about the condition. According to Suresh et al., (2018, p. 701), hypovolemic shock is quite fatal; health practitioners are expected to be aware of the condition and take corrective measures especially after accidents.
Causes of shock and individuals at risk
Septic shock mostly attacks immune response of children below 1 year and adults who are more than 65 years old. Implanted medical devices such as breathing tubes have been identified as the major predisposing factor to sepsis (Samaha et al., 2012). Other factors which could place individuals at risk would be open wound burns and injuries leading to blood infections. On the other hand, hypovolemic shock emanates from decreased blood volume (Minasyan, 2019). Hypervolemic shock is equally likely for everyone. However, it is more severe in older individuals as compared to younger ones.
The figure below shows various causes of septic and hypovolemic shock;
|Hypovolemic shock||Septic shock|
|Bleeding from serious cut wounds||Mostly caused by bacterial infections|
|Bleeding from blunt traumatic injuries especially due to accidents||Infection in an organ such as the urinary tract or a lung infection.|
|Internal bleeding||Viral and Fungal infections especially in individuals with low immunity.|
|Excessive vaginal bleeding|
|Bleeding in the digestive tract|
|Loss of excessive body fluids through; diarrhea, vomiting, or excessive sweating.|
According to Suresh et al., (2018, p. 696) hypovolemic shock usually exists in form of a spectrum in its early stages with subtle tissue damage however, as it advances, the late stages are characterized by multiple system dysfunction which could be fatal and possibly lead to death. Suresh et al., (2018, p. 698) refer to hypovolemic shock as being quite fatal and it is crucial for early detection and fast response. If medical intervention is not taken early, it would lead to multiple organ dysfunction and death which is usually irreversible.
According to Sinha et al., (2018, p. 31) the primary diagnosis of sepsis has been through blood cultures. This has however gone to include other body fluids such as urine and saliva. In recent times, there has been a massive technological advancement in the diagnosis of sepsis. Based on research conducted by Sinha et al., (2018) molecular diagnostic techniques have immensely revolutionized the diagnosis of the condition increasing the speed at which corrective measures such as administration of antibiotics are taken.
The following figure shows a comparison in the diagnosis of septic shock and hypovolemic shock.
|Hypovolemic Shock||Septic Shock|
|Physical examination for a fast heart rate and low blood pressure.||Confusion or other similar signs of abnormal brain functioning|
|Less responsiveness during medical examinations||A breathing rate of more than 22 breaths per minute|
|Echocardiogram and electrocardiogram of the heart||Systolic blood pressure at 100 mm/Hg or less.|
|Right heart catheterization to check the effectiveness of the heart in pumping blood.||Blood cultures tests|
|Blood testing catheter||Wond secretion tests|
|Physical excessive bleeding||Respiratory secretion tests|
|Ultrasound or CT scan|
Management of hypovolemic shock
Hypovolemic shock is quite a serious condition. Once a patient suspected to have the condition goes to the hospital, they are offered blood products or fluids through intravenous lines (Pacagnella & Borovac-Pinheiro, 2019, p. 92).
The most effective measure to correct this shock is through blood and blood products transfusion. There are also other measures taken to improve blood pumping and blood circulation. These measures include administration of the following drugs; epinephrine, dopamine, norepinephrine, and dobutamine (Pacagnella & Borovac-Pinheiro, 2019, p. 92). With hypovolemic shock, cuts and open wounds could predispose an individual to sepsis; it is, therefore, crucial to administer antibiotics to prevent bacterial infections in the blood.
Management of septic shock
After diagnosis, it is crucial for immediate medical intervention. According to Berger et al., (2017, p. 2282), sepsis is a serious medical condition that intensifies with time, it is crucial that immediate and intensive medical intervention effectively deals with the condition. The following corrective measures can be taken to effectively deal with the condition.
Administration of antibiotics.
Sepsis is mostly caused by bacteria and it would be effective to administer antibiotics within the first 6 hours from diagnosis (Berger et al., 2017, p. 2284). The antibiotics are injected directly into the blood
Administration of Vasopressors
This medication is usually crucial especially in individuals who suffer from septic shock; they are usually vital in maintaining blood pressure. Vasopressors work by tightening blood vessels to maintain blood pressure (Berger et al., 2017, p. 2285).
Administration of Corticosteroids:
In cases when the blood pressure continues to drop even after the administration of vasopressors, the patients are given Corticosteroids.
Offer insulin to stabilize blood sugar, and
Administer drugs to correct the immune response.
Changes in management of Septic shock
Increased adoption of molecular pathophysiology tests to detect sepsis
Equip health practitioners with the necessary skills to detect and combat sepsis in the early stages.
Changes in management of hypovolemic shock
Global recognition by the WHO.
Global sensitization of the population on first aid measures to prevent hypovolemic shock
This research is crucial in determining the pathopsychological aspect of shock and especially in septic and hypovolemic shock. I believe the recent improvements done in recognizing and managing sepsis will go a long way in mitigating the number of patients suffering from septic shock. However, I believe that health practitioners should be equipped with adequate skills to detect and combat sepsis in the early stages. Moreover, there have been little efforts taken in recognizing hypervolemic shock. I believe that WHO should recognize it as a fatal condition and take measures to educate the public on first aid precautionary measures, especially to accident victims.
Berger, R. E., Rivers, E., & Levy, M. M. (2017). Management of septic shock. New England Journal of Medicine, 376(23), 2282-2285. https://doi.org/10.1056/nejmclde1705277
Cantle, P. M., & Cotton, B. A. (2017). Balanced resuscitation in trauma management. Surgical Clinics of North America, 97(5), 999-1014. https://doi.org/10.1016/j.suc.2017.06.002
Cecconi, M., Evans, L., Levy, M., & Rhodes, A. (2018). Sepsis and septic shock. The Lancet, 392(10141), 75-87. https://doi.org/10.1016/s0140-6736(18)30696-2
Convertino, V. A., & Schiller, A. M. (2017). Measuring the compensatory reserve to identify shock. Journal of Trauma and Acute Care Surgery, 82(6S), S57-S65. https://doi.org/10.1097/ta.0000000000001430
Li, W., Wang, Y., Wang, X., He, Z., Liu, F., Zhi, W., Zhang, H., & Niu, X. (2016). Esculin attenuates endotoxin shock induced by lipopolysaccharide in mice and NO production in vitro through inhibition of NF-κb activation. European Journal of Pharmacology, 791, 726-734. https://doi.org/10.1016/j.ejphar.2016.10.013
Minasyan, H. (2019). Sepsis: Mechanisms of bacterial injury to the patient. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 27(1). https://doi.org/10.1186/s13049-019-0596-4
Pacagnella, R. C., & Borovac-Pinheiro, A. (2019). Assessing and managing hypovolemic shock in puerperal women. Best Practice & Research Clinical Obstetrics & Gynaecology, 61, 89-105. https://doi.org/10.1016/j.bpobgyn.2019.05.012
Rice, V. (1981). Shock, a clinical syndrome. Part I: Definition, etiology, and pathophysiology. Critical Care Nurse, 1(2), 44-50. https://doi.org/10.4037/ccn19184.108.40.206
Samaha, G., Casserly, B., & Stevens, J. (2012). Management of severe sepsis and septic shock. Severe Sepsis and Septic Shock – Understanding a Serious Killer. https://doi.org/10.5772/29876
Singer, M., Deutschman, C. S., Seymour, C. W., Shankar-Hari, M., Annane, D., Bauer, M., Bellomo, R., Bernard, G. R., Chiche, J., Coopersmith, C. M., Hotchkiss, R. S., Levy, M. M., Marshall, J. C., Martin, G. S., Opal, S. M., Rubenfeld, G. D., Van der Poll, T., Vincent, J., & Angus, D. C. (2016). The third international consensus definition for sepsis and septic shock (sepsis-3). JAMA, 315(8), 801. https://doi.org/10.1001/jama.2016.0287
Sinha, M., Jupe, J., Mack, H., Coleman, T. P., Lawrence, S. M., & Fraley, S. I. (2018). Emerging technologies for molecular diagnosis of sepsis. Clinical Microbiology Reviews, 31(2). https://doi.org/10.1128/cmr.00089-17
Suresh, M. R., Chung, K. K., Schiller, A. M., Holley, A. B., Howard, J. T., & Convertino, V. A. (2018). Unmasking the Hypovolemic shock continuum: The compensatory reserve. Journal of Intensive Care Medicine, 34(9), 696-706. https://doi.org/10.1177/0885066618790537