Pathophysiology And Nursing Priorities For A Patient With Post-operative Hypovolemia

Physiological compensatory mechanisms for hypovolemia

She reported a change in bowel habits recently which led her GP order a range of blood tests and colonoscopy having in mind that she had never had a colonoscopy done before or undergo the National Bowel screening program. Objective data was taken which from her BMI of 28.4 it indicated that she was pre-obese. The carcino-embryonic antigen was highly increased, hematocrit was decreased and her hemoglobin also was decreased when compared with the normal range of her gender. Past medical history showed that she has a history of suffering from 3 different diseases including; Hypercholesterolemia, Myocardial Infarction, and Asthma. She also had a history of one major surgery, Laparoscopic cholecystectomy. Social history outlines that she smokes 10 cigarettes and drinks two units of alcohol per day. Her family history shows that both her parents had a history of cancer. Eleanor Wilson presented with a three-month history of constipation, blood in her stool and general malaise. Colonoscopy results showed a mass on the ascending colon which was biopsied and revealed an adenocarcinoma. She was therefore scheduled for urgent surgery for resection of the tumor and ended up hypovolemic. 

Pathophysiology of Eleanor’s post-operative hypovolemia;

Hypovolemia is a clinical syndrome which results from a decrease in blood volume as a result of blood loss which may lead to dehydration (Pachtinger, 2014). However, a trauma which is a deeply disturbing or distressing experience can also cause hypovolemia. The acute surgery which Eleanor Wilson underwent for resection of the tumor leads to a reduced amount of circulating blood volume. This lowers venous return and cardiac refill leading to arterial hypotension. Estimates of intraoperative blood loss can be inaccurate and this can lead to inappropriate fluid management. Decreased circulating blood volume leads to decreased tissue perfusion which can lead to increased myocardial oxygen demand that can lead to myocardial infarction. The reduced tissue perfusion can also lead to anaerobic metabolism (Tyler, 2011). Metabolism in the absence of oxygen results in acidosis thus precipitating multi-organ failure. Trauma, Eleanor reports being stressed by her daughter having divorced with her husband. Some of the assessment data indicating hypovolemia are the reduced blood pressure, lower than the normal range for the same gender. Systolic pressure is 90 which is lower compared to the normal systolic range of 100-120 and diastolic pressure which is 54 and is lower than the normal diastolic range of 60-80. This indicates hypotension which is a sign of the hypovolemia. The client also has tachycardia with a heart rate of 106 beats per minute as compared to the normal range of heart rate that ranges between 60-100 beats per minute as per age and gender. Hematocrit (HCT) of 0.36 which is lower compared to the normal range of the same age and gender which is 0.37-0.47.
 

Assessment data for outlining nursing priorities

Physiological compensatory mechanisms for hypovolemia;

The client’s body may compensate for the reduced circulating blood volume physiologically through the baroreceptor reflexes, circulatory vasoconstrictions, chemoreceptor reflexes, renal reabsorption of water and sodium, activation of thirst mechanisms and finally through reabsorption of tissue fluids (Schiller, Howard & Convertino, 2017). If bleeding is managed, the arterial pressure gradually recovers and heart rate decreases. The long-term compensatory mechanisms get activated thus leading to restoration of the normal arterial pressure and blood volume back to normal. The physiological mechanisms work in order to increase cardiac output and increasing the arterial pressure. The body through its arterial and cardiopulmonary baroreceptors can detect a fall in central venous blood pressure. In response to this, it activates the sympathetic adrenergic system which produces catecholamines such as norepinephrine, epinephrine, and dopamine.

Catecholamines regulate physiological functions resulting in heart stimulation thus increasing its rate and force of contractility (Gordan,  Gwathmey,  & Xie, 2015). There is also vasoconstriction; the blood vessels constrict increasing systemic vascular resistance. Vasoconstriction particularly occurs in the gastrointestinal, skeletal muscles and renal muscles. Cardiac output is redistributed from the less vital organs at the moment to the organs that are critical for survival which is; brain and myocardium. A Reduce in organ blood flow and arterial blood pressure lead to anaerobic metabolism. Anaerobic metabolism causes metabolic acidosis that is detected by chemoreceptors. The chemoreceptor reflex triggers the adrenergic sympathetic system whereby its neurons produces the catecholamines hence reinforcing the baroreceptor reflex. When the effects of arterial hypotension are combined with the effects of sympathetic activation it leads into activation of humoral compensatory mechanisms. During hemorrhage, the kidneys may compensate physiologically by increasing release of renin (Hultström, 2013). Renin leads to elevated levels of circulating angiotensin 11 together with aldosterone. These leads to vasoconstriction, enhanced sympathetic activity, stimulation of higher thirst centers. It also leads to stimulation of vasopressin release and lastly increases renal reabsorption of sodium and water in the kidney tubules resulting in increased circulating blood volume. Capillary hydrostatic pressure causes fluid filtration from the cardiovascular compartments across the capillary endothelium into the interstitial space. Reduced capillary hydrostatic pressure results into little fluid leaving the capillaries and when it reduces severely due to excessive hemorrhage, fluid reabsorption may happen from the tissue interstitium back into the capillary plasma increasing blood plasma volume. The above is the pathophysiology of Eleanor’s post-operative hypovolemia and physiological body compensation. 

2.The assessment data obtained from Eleanor Williams that could be used in outlining nursing priorities for her care included; blood pressure of 90/54, heart rate of 106 beats per minute, sedation score of +1 and lastly urine output 15-20ml/hr. From the above-collected data, we can outline different nursing care plans considering the clinical features of hypovolemia, which comes as a result of the severity of the fluid loss.

Nursing care priorities for hypovolemic patients

The prognosis purely depends on the extent of volume loss. Nursing care priorities for Eleanor Williams who is a hypovolemic patient should focus mainly on treatment aimed at the factors leading to shock and restoring intravascular volume. Therefore, from the above assessment data we can drive four nursing priorities as follows; care focusing on the reduced cardiac output, care for insufficient fluid volume, care for infective perfusion of tissues and lastly care for anxiety.

Reduced cardiac output; this simply means less blood pumped by the heart to meet the metabolic demands of the body (Kemp & Conte, 2012).  In this case study it is related to ventricular filling (preload), abnormal arterial blood gasses in this case acidosis due to the anaerobic metabolism due to reduced perfusion. It is also related to the decreased urinary output of 15-20 ml/hour, which is lower than 30 ml/hour. Reduced pulse pressure and decreased blood pressure and lastly, it is evidenced by tachycardia, 106 beats per minute which is more than the normal heart rate range for the same gender.

Inadequate fluid volume; this is reduced intravascular, intracellular and interstitial fluid due to active fluid volume loss during the surgery for resection of the tumor, and severe blood loss during the surgery. Infective tissue perfusion; this is reduction in the oxygen leading to the failure to supply nutrients to the tissues by the blood capillaries, may be due to the severe blood loss, reduced preload and evidenced by shallow respirations of 12 per minute. Lastly Is the Anxiety which means a vague feeling of discomfort which is followed by an autonomic response (Gibson, 2014, October). It is related to change in health status, fear of death or unfamiliar environment for the first one hour after surgery in the post-operative room. It is evidenced by sympathetic stimulation rising the heart rate to 106 beats per minute. It is also evidenced by agitation measured by the Richmond Agitation-Sedation Scale giving a score of +1 which means restlessness, described as the patient being anxious or apprehensive but movements not aggressive or vigorous. 

3.The goal for each priority problem will guide the nursing staff choosing their interventions well for quality and appropriate health care service delivery satisfying the client’s needs fully. The desired outcome for anxiety is that Eleanor Wilson will describe a reduction in the level of anxiety experienced and that she will use effective coping mechanisms (Newton, Asimakopoulou, Daly, Scambler, & Scott, 2012). The goal should give us a 0-score defined as alert and calm whereby she spontaneously pays attention to the caregiver. The desired outcome for the decreased cardiac output is that Eleanor Wilson will maintain adequate cardiac output. This should be evidenced by reduced heart rate to the normal range of 60 to 100 beats per minute with regular rhythm and urinary output of 30 ml/hour or greater. The desired outcome for ineffective tissue perfusion is that Eleanor Wilson will ensure maximum perfusion of tissues to the vital organs as evidenced by vitals within the patient’s normal range, balanced input and output, and normal arterial blood gasses (Jauch et.al 2013). Lastly, Eleanor Wilson will be normovolemic with a heart rate of 60-100 beats/min, systolic blood pressure of more than or equal to 90 mm Hg and urinary output of more than 30 ml/hour.

Goals for hypovolemic patients

4.From the four nursing priorities, I will give out nursing interventions and rationales for decreased cardiac output and deficient fluid volume. Due to decreased cardiac output, the nursing staff should assess the peripheral together with the central pulses every 4 hours, pulses will likely to be weak with decreased stroke volume together with cardiac output (Lakhal, Ehrmann, Perrotin, Wolff & Boulain, 2013). Respiratory rate should be assessed to ensure that the range, breathing rhythms are normal. Auscultation of the breath sounds should also be done. Hypovolemic shock is characterized by the respirations that were shallow and adventitious breath sounds including crackles and wheezes. Saturation of oxygen measured using the pulse oximetry and arterial blood gasses. Maintenance of normal oxygen saturation at 90 percent or higher. The progression of hypovolemic shock stops aerobic metabolism and lactic acidosis occurs thus increasing carbon dioxide levels and decreasing the blood pH levels (Gutierrez & Theodorou, 2012). Assess the urine output hourly, this is because the renal system normally compensates for low blood pressure by reabsorbing water thus leading oliguria. Oliguria should be used as a sign of inadequate renal perfusion from the lowered cardiac output. Provide electrolyte replacement as ordered by the physician, this is in order to prevent electrolyte imbalances which could lead to dysrhythmias. Fluids and blood administration in severe cases as prescribed in order to maintain an adequate circulating blood volume.

Assessment of central and peripheral blood pulses should take place including peripheral pulses. This is in order to prevent the pulses from becoming weak due to reduced stroke volume and cardiac output. Assess the client’s heart rate and blood pressure, to monitor early stages of sinus tachycardia and increased arterial blood pressure (Gappmaier, 2012) as they maintain adequate cardiac output. Peripheral vasoconstriction may lead to unreliable blood pressure. Assess the client’s electrocardiography for dysrhythmias, this is to prevent dysrhythmias from occurring as a result of the low perfusion state or acidosis. You can also monitor the capillary refill coz it can be slow sometimes more than three seconds and sometimes it can be absent as well.
 

Interventions and rationales for the deficient fluid volume;

The Main goal of the interventions being to increase the circulating blood volume, therefore, the health care provider is required to do the following with their advantages. Monitoring the blood pressure for orthostatic changes because postural hypotension is the common manifestation of fluid loss in the body (Ricci, De Caterina, Fedorowski, 2015). Therefore, strict monitoring of the changes in blood pressure from a supine position to a standing position helps in fluid loss detection early enough. Monitoring for possible fluid loss sources such as wound drainage, polyuria, and severe blood loss. Decreased amount of fluid lost decreases the chances of being hypovolemic. Strict monitoring of the client’s intake and output is of the essence this is because the correct measurement is crucial while deteremining negative fluid balance and guide therapy. Urine that is highly concentrated indicates a fluid deficit. Monitor blood loss by marking the skin area and weighing the dressing to determine fluid loss When the health care provider is keen enough in observing an increasing hematoma or a bulging or increased drainage, she can easily identify bleeding or hemorrhage early enough. Encourage oral fluid intake as it supports in maintaining fluid balance. Monitor hematocrit reevaluating it every 30 minutes for the first 4 hours, hematocrit decreases as fluids are administered this is due to dilution, mostly decreases at a rate of 1 percent per liter of sodium chloride or Ringer’s lactate fluid. And therefore, any other reduction should be evaluated as an indication of persistent bleeding. Initiate intravenous infusion therapy by putting two IV lines. This is in order to maintain an adequate circulating blood volume. Blood products to be administered as prescribed and client transfused with whole blood-packed red blood cells. This increases the amount of circulating blood volume. Monitor the client’s central venous blood pressure and cardiac output. Central venous pressures provide information on filling pressures of the heart whereas cardiac output provides a guide to therapy (Ponikowski et.al 2016).  The health care provider should also monitor the coagulation studies including prothrombin time and platelet count this is because specific deficiencies give guidance to treatment therapy. Lastly, if the hemorrhage exceeds prepare for a return of the client to the theatre to fix the problem. The above nursing interventions and rationale will guide the health care provider in giving out quality healthcare services to Eleanor Wilson as the post-operative client 

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