Treatment Principles In The Management Of Hypovolemia And Its Consequences

Mechanisms of the Human Body in Response to Hypovolemia

Discuss about the Treatment Principles in the Management.

Hypovolemia is a condition of loss blood volume, particularly plasma component of the blood following a open fracture in case of Jensen. Human body reacts to this large volume of blood loss by stimulation the vital physiological functions of the body like hematologic, cardiovascular, renal, and neuroendocrine systems.

Due to the large volume of blood loos, there is the increased activity of the sympathetic system by releasing more amount norepinephrine and decreased activity of parasympathetic system by decreasing baseline vagal tone. Norepinephrine increases the heart rate through action on β1- receptors. In Jensen also there is increase heart rate due to post-surgery hypovolemia. In case of hypovolemia there is the less blood supply to the tissues and organs also there is less intravascular fluid due to the loss of blood during surgery.  Amount of blood in the blood vessels is also very less. These are the reasons responsible for the occurrence of hypotension in hypovolemia. Measurement of blood pressure in case of Jensen also exhibited low blood pressure or hypotension (Kong et al., 2016; Moranville et al., 2011). In such cases of hypovolemia, cardiovascular system redistributes blood to the vital organs like heart, brain and kidney from skin and muscles. In post-operative patient temperature is generally low because anesthetics or antibiotics and in hypovolemia condition low temperature required to slower down metabolic process of the body and to preserve ischemic tissue. In Jensen also right leg is cool.

In response to hypovolemia, kidney of the renal system reacts by activating the release of renin from the juxtaglomerular apparatus of the kidney. This juxtaglomerular apparatus plays important role in the blood pressure regulation and glomerulus filtration rate. Due to more release of renin, angiotensin released from the liver gets converted to angiotensin I. Angiotensin I gets converted to angiotensin II by the action of angiotensin converting enzyme which plays vital role in maintaining blood pressure. Angiotensin II has two main functions like       vasoconstriction of arteriolar smooth muscle and stimulation of aldosterone secretion by the adrenal cortex. These two functions of angiotensin II comes into action as a consequence of hypovolemia. Vasoconstriction of arteriolar smooth muscle leads to raised myocardial contractility and constricting peripheral blood vessels. Increased secretion of aldosterone leads to sodium absorption and consequently water conservation in proximal tubule. In case of hypovolemia, there is decreased flow of blood to the kidneys. In such scenario kidney retain sodium salt because kidney noticed that body require extra fluid at the cost of loss of blood. Due to this accumulation of sodium, there is more retention of sodium and water resulting in the edema and swelling as it is evident in case of Jensen. Due to the fluid loss in hypovolemia in post-operative patients, there is electrolyte imbalance in the patient.

Identified Problems in Hypovolemia Management

In response to hypovolemia, neuroendocrine system gets activated and there is increase in the secretion of antidiuretic hormone (ADH). Posterior pituitary gland releases ADH hormone in response to the decreased BP which is detected by baroreceptors present in the carotid sinus and in the aortic arch and in response to the depleted sodium concentration which is detected by osmoreceptors present in the hypothalamus of the brain. ADH manly performs two functions such as retaining water and sodium salt by the distal tubule, collecting ducts, and the loop of Henle and constricting blood vessels. As a result there is rise in the blood pressure which acts as compensatory mechanism for hypovolemia. In hypovolemia, there is the deficiency of insulin in the blood due to blood loss during surgery. As there is deficiency of insulin, cells cannot use enough glucose and follow anaerobic metabolism to produce energy. In such scenario, cells can’t use glucose for their functioning and there is the accumulation of glucose in the blood stream. Hence there is increase in the blood glucose level in Jensen. As there is increased sympathetic activity in hypovolemia , it leads to the hyperventilation and bronchodilation which leads to the more delivery of oxygen to the tissues (Kennedy, 2006; Hobson &  Chima, 2013). As a result there is the gases imbalance in the blood. In case of Jensen, SaO₂ is in towards the lower range. As oxygen saturation level is towards lower side, respiratory system compensate for this by increasing respiratory rate, which is evident in the Jensen.                 

These complicated mechanisms mentioned are useful in controlling vital organ perfusion in case of blood loss due to surgery. In the absence of effective management for blood loss and as a result fluid loss, there is the possibility of hemorrhage, normal circulation impaired, effective perfusion to the organs and tissues impaired and high chances of multiple organ failure.

First identified problem is breathing. Due to the increased airway resistance respiratory rate may increase. In case of Jensen also, there is the increase breathing rate. In case of Jensen respiratory rate is 24 BPM. This respiratory rate in Jensen is towards higher side of the normal respiratory rate. Respiratory rate generally increases when there in gas exchange imbalance in the respiratory tract. In case of Jensen SaO₂ is 95%. SaO₂ is the oxygen saturation in the blood. 95 % oxygen saturation is towards lower side of its normal value. Jensen also has smoking habit, hence it can exaggerate airway resistance and leads to the increased respiratory rate and decrease oxygen saturation. Due to the problem in breathing, Jensen is on oxygen therapy using Hudson mask with FiO₂ 6 liters. This FiO₂ is fraction of inspired oxygen. Keeping patient on FiO₂ 6 liters using Hudson mask is not advisable.

Nursing Goals to Address Identified Problems

Second identified problem in Jensen is circulatory system. Main problem identified in circulatory system is hypovolemia due to blood loss during surgery and its consequences are increased heart rate and hypotension. In Jensen heart rate is 107 BPM, which is higher than the normal range. This heart rate is increased in Jensen due to increased sympathetic activity. Hypovolemia in Jensen is responsible for the increased sympathetic activity. Blood pressure in Jensen is 104/55mmHg. This blood pressure is lower than the normal range blood pressure. Hypovolemia in Jensen causes less amount of fluid in the blood vessel and it results in the low blood pressure.

Third identified problem in Jensen is disability. In disability first problem is pain. Due to open fracture Jensen has pain. Pain score of Jensen is 7 on a scale of 1-10, which is towards the higher side. Second problem in the disability is the movement of the limb. Due to the open fracture, Jensen has problem in the movement of right leg and moreover there is swelling on the right leg.                

Last identified problem for Jensen is exposure. Due to the open fracture, his skin is opened and exposed to the environment. Moreover there are exudates at the fracture site and this can lead to the infection in the Jensen. Second problem is temperature in exposure. There is decrease in the temperature on the right leg of Jensen. In hypovolemic conditions generally temperature become low (Thim et al., 2012; Thim et al., 2010).

For breathing problem, nursing goal is to improve breathing pattern and normalizing the respiratory rate. Generally high respiratory rate occurred due low oxygen saturation. Breathing pattern and respiratory rate can be improved by increasing the oxygen saturation in the blood. Oxygen therapy is the most effective intervention for this breathing problem. For cardiovascular problem, nursing goal is to reduce heart rate and normalize the low blood pressure. Nurse should look to bring heart rate below 100 bpm and blood pressure in around 12/80 mmHg. For disability problem, nurse should set goal to reduce pain score and to reduce other complications of pain like anxiety and depression. Also nurse should try to improve the movement of the right leg of Jensen without or minimal pain to him. In case of exposure, nurse should set goal for exposed skin. In this goal nurse should make sure that his opened skin is covered and protected from the possibility of infection. Nurse should try to normalize the body temperature (Thim et al., 2012).

First identified goal is to reduce infection due to open fracture. Open wounds in open fracture should be covered with pads covered soaked in saline and not the povidone iodine because povidone iodine can cause irritation to the tissues.  Infection is the major problem in the patients with open fracture. Literature revealed that, upto 20 % of the patients with open fracture suffered through clinical infection. Use of antibiotics is the most effective strategy for the management of infection in such patients. It is evident from the literature that antibiotic treatment within the first 3 hours of injury can reduce the chances of infection by six fold (Halawi & Morwood, 2015). Although cephalosporins are mostly used for infection due to gram positive bacteria some articles stated that these cephalosporins were recommended in infections due to gram negative bacteria also. Infection due to gram negative bacteria and contamination of soil was recommended to be treated with penicillin type of antibiotics. Most of the literature indicated that in hospital settings infection in the open factures should be treated for 1-3 days based on the type of infection and severity of the infection (Zalavras et al., 2007). In few of the articles it has been mentioned that infection in case of open fracture are also due to the Staphylococcus aureus and Pseudomonas. In such case these articles mentioned specific antibiotics for these infections (Zalavras et al., 2004). For effective action of antibiotic in case open fracture infections, there is also literature available for the local or targeted delivery of the antibiotics. In one study, scientists prepared antibiotic based pouch comprising of the antibiotic powder and polymethylmethacrylate. These pouches are available commercially also and these can prepared in a simple manner in the respective hospitals also. Such antibiotic pouch containing tobramycin antibiotic with polymethylmethacrylate proved to be effective in reducing occurrence of infection upto 35 % (Cross et al., 2008; Seligson & Berling, 2015).

Second identified goal is to reduce pain due to open fracture. Paracetamol is the most widely drug used for the pain management. Although, exact mechanism of paracetamol is not evident few studies had established its mechanism of action as inhibitor of prostaglonadin H2 synthese and other studies mentioned that paracetamol acts by interacting with beta-endorphins (Moller et al., 2005; Van der Westhuizen et al., 2011). In few studies it has been established that oral administration of paracetamol gave variable result mainly due to the less therapeutic concentration as compared to the intravenous administration (Tsang et al., 2013; Remy et al., 2006). Patients with open fracture require strong analgesia, hence opioids are recommended in patients with open fracture. Opioids mainly work by acting on the mu-opioid receptors. Commonly used opioids for pain management in the open fracture patients are morphine, codeine and oxycodone. In a study it had been proved that use of oxycodone reduces the frequency of delirium as compared to morphine. Oxycodone can be given in two forms such as controlled release and immediate release. Main advantage with the controlled release oxycodone is that due to continuous release of drug, nurse and other staff gets freed from frequent administration of the drug (Blumenthal et al., 2007; Rothwell et al., 2011). If paracetamol and opioids are not working, then nurse should administer regional anesthetic nerve block. It had been mentioned in few articles that modified methods can be used to perform nerve block to improve the efficiency and effectiveness of the method.

These modifications include use of nerve stimulator and use ultrasound to locate the exact position of nerve. In open fracture there is the possibility of many nerve blocks. In studies it has been established that application of nerve block in pain management has advantages like reduction in the opioid dose, more reduction in the possibility of delirium and more effective in treating pain due open fracture as compared to opioid medication (Newman, et al., 2013; Foss et al., 2007). Along with these medications for the pain relief, physical pain management strategies were also reported in the literature for pain relief in patients with open fracture. These physical strategies include immobilization of the fractured leg or hand and keeping the fractured leg or hand in the comfort position (Marx et al., 2013). In providing these physical strategies for pain management nurse should convince pain with effective communication. Because all the patients may not cooperate to for this physical strategies of pain management.

References:

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