Pathophysiology of Hemodynamics - Essay Sample

Introduction

The underlying pathophysiology of Hemodynamics in an 80-year-old patient whose weight is 60Kg, the patient has been admitted to an intensive care unit following a fall at home three days earlier.

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Hemodynamics is described as the dynamic flow of the blood. The hemostatic mechanisms tend to manage and regulate the circulatory system mechanisms within the body of an individual, for example, the hydraulic circuits (Moor and Murtaugh 2001, pp.1115). Hemodynamic feedback regularly monitors and adjusts to the ever-changing situation within the in the body and its surrounding. Therefore, hemodynamics seems to describe the physical techniques which control the flow of the blood in the blood vessels (Glago, Zarins, Giddens, & Ku, 1988, pp.354)). The flow of blood has the significant responsibility of ensuring that the hormones, nutrients, and air are efficiently and effectively transported within the body in an aim to regulate the cell-level metabolism, maintain; and also to prevent the harm of the various body tissues from both the mechanical and microbial factors (Glagov, et al.1988).

Blood as a non-Newtonian fluid can be effectively examined by the application of using rheology instead of the hydrodynamics since the vessels are relatively flexible tubes; and therefore, ideal hydrodynamics and d the mechanism of fluid with the implementation of standard viscometer is not necessarily appropriate in assessing and describing the mode of Hemodynamics (Bersano et al.2015, pp.19). The variation in pressure in the blood vessels tends to build the cardiac output, and the regulations of these blood vessels ultimately result in the flow of blood. This specific mechanism seems to demonstrate conclusively the vital principle of Poiseuille's law that describes that blood flow "Q" is equal to pressure "P," that is, alteration in the blood pressure and Central venous pressure and then divided by resistance (Q=P/R).

Several factors tend to contribute to most of the experienced abnormalities in hemodynamics such as age, stress, and anxiety. At certain circumstances, the heart seems to pump relatively more blood into the vessel thus causing enhanced pressure. Due to such pressure, vascular damage may occur from high pressure (hemorrhagic stroke) or high cardiac contractility constricting blood vessels leading to high vascular resistance.

More than 25% of the world's population suffers from hypovolemic shock. Even though hypovolemic shock can be effectively managed, the raptures of the bold vessels be may cause almost permanent damage, therefore posing a life-threatening condition and necessitating the need for effective control and management in a critical care setting and consideration of mechanical ventilation of the patient. This case study demonstrates the essential requirements of care of an 80-year-old patient whose weight is 60Kg, and the patient has been admitted to intensive care unit following a fall at home three days earlier with a Cardiovascular Hemodynamics. Assessment findings are linked to the underlying pathophysiology and treatment strategies such as mechanical ventilation, which are critically evaluated and rationalized.

Pathophysiology

Many pathological processes tend to affect the functionality and structure of the blood vessels exceptionally severely. An understanding of such methods is needed to interpret assessment results and rationalize treatment effectively. Virtually every hypovolemic shock augments normal hemodynamics in either one form or another such as the age-related vascular disease. The condition is still under debate on the various mechanisms for this particular condition; the outcome is a loss of standard endothelial adjustment in the various blood vessels (Kolobow et al.1987). Therefore, causing the blood vessels to seem to resist and relatively appear to be less distensible with the systole pressures. The significant outcome of this minor alteration is increased blood pressure. Due to the maximization of the blood pressure, more burdens tend to be instilled on the heart; and therefore, exposing to even more risk as the heart becomes thicker while trying to push against the vascular resistance (hypertrophy).

Age seems to be a significant cause of hypovolemic shock besides other factors. Many endogenous substances seem to play the role of vasoconstrictors and inflict their impacts to manage blood pressure. Such as Angiotensin (I and II) and aldosterone and renin which creates a significant component of the renin-angiotensin-aldosterone system (RAAS) (Dzau et al.1981, pp.654). Aberrations found in this route results to the escalated levels of the substances in the blood, and thus increases the pressure of the blood via enhanced vascular resistance. Stenosis leads to a reduced flow of blood to the kidney and strengthening the release of renin; thus leading to a cascade, resulting in heightened aldosterone. Therefore, vasoconstriction and salt retention occur in hypertension resistant to classic modes of treatment.

Nonetheless, Stress and anxiety are also contributing factors to increased pressure. This happens too in case of the presence of extreme catecholamine's that maximizes cardiac contractility thus expand in blood flow, and constrict blood vessels resulting in vascular resistance. Some patients may have a family history of the ailment which may also be considered to be a contributing factor. However, hypertension is sometimes found essential in cardiac modeling and enhances reflex changes to the blood vessels; and the reflexively constrict to protect the relatively delicate capillary beds from these harms (Jevon, 2010, pp.404).

Analysis of Assessment Findings

The patient's assessment findings were consistent with the manifestations of hypovolemic shock. The critical observations are diagnosed and related to the underlying pathophysiology.

The patient was assessed based on the ABCDE (airway, breathing, circulation, disability, and environment) model (Thim et al.2012, p.117). The ABCDE framework allows for the assessment of any life-threatening changes that may be detrimental to the patient's health. It primarily focuses on patients who are injured or critically ill patients (Smith and Bowden 2017, pp.56). The model can be applied without the use of any equipment in all clinical emergencies rooms, in intensive care units or general wards. Therefore, the aim of adopting the ABCDE approach during the assessment of the 80-year-old patient was to buy time to allow for diagnosis and treatment, to function as an assessment and treatment tool, and to provide more life-saving treatment (Smith and Bowden 2017, pp.78).

The Abcde Model Is a Broadly Accepted Method as Observed Below:

Airway

The patient's airway appears to be affected because he is reusable to speech and looks exhausted. This means that the airway obstruction is partly because of the reduced consciousness level of the patient. Left untreated the airway obstruction, although to a degree it can still result in cardiac arrest. Thus, the airway assessment was critical to reduce the level of unconsciousness of the patient(Kolobow 1987,pp.312-315). The patient seemed to have suffered from the airflow from the Naso-oral pharynx to the lungs that possibly induced upper airway obstruction. The obstruction may be due to the patient having the trauma of his airway structures; and thus causing cardiac arrest (Hogg 2004, pp.2645-2653).

Breathing

The patient's rate of respiration was determined the observation of symmetrical chest expansion, assessment of the inspiration depth, and counting the rate of respiration. According to the evaluation, it was determined that:

• The rate of respiration was 26 BPM
• The patient experienced shallow breaths and expanded his lungs using accessory muscles.
• The patient was found to be dyspnoeic.
• The patient did not have signs of central cyanosis

The shallow breaths accompanied by the use of accessory muscles imply that the patient was struggling to breathe. As a result, he was self-ventilated on 60% oxygen with the saturation of oxygen being 95% (SpO2). Thus the SpO2 of 95% was within the recommended target (Koishi, Miyazaki, & Ooe, 1999).

The patient's breathing assessment demonstrated an unprecedented high respiration rate (RR). Hyperventilation and high blood pressure are indicated as symptoms of hypovolemic shock but with unclear contributing factors. It is suggested that the several blood gases such as the pH, pCO2, HCO3, BE, and pO2 seem to indicate abnormal level which may be below 9kPa; therefore, enhances the respiratory metabolism via chemoreceptors stimulation and sometimes due to the stretch receptors as a result of lung hyperinflation(Kunik et al.2005, pp.1205-1211). The shallow breath is due to the progressive airway narrowing and expansion of the patient's lungs. The rousable to his speech and signs of exhaustion and use of his accessory muscles that were assessed showed that the patient had for a relatively long period increased work of breathing (WB).

The resistance of the Airway is enhanced due to extreme airway narrowing and thus causing the shallow breathing. As a result, he appears not to have central cyanosis because of the depletion of oxygen in the blood, and then the same blood flows throughout the body into the veins showing bluish pigments. The patient's SpO2 is indicated negative and not present and demonstrate very poor ventilation and hypoxia regardless of the current treatment of 60% oxygen as the patient had to self-ventilate. Two arterial blood gases had to be extracted an hour apart to examine the respiratory and metabolic function and guide future treatment. The constant changes in the blood gases indicated that the patient is becoming hypoxic. And the changed physiology and function of the lungs seem to be a significant contributing factor to the patient's deterioration.

The patient showed the symptoms of acute respiratory distress syndrome and thus progressive respiratory failure which is due to the mismatch of ventilation. However, the pulmonary vasculature reacts by trying to increases the blood oxygenation of blood through hypoxic vasoconstriction (HPV). The blood gases also show an increase from an original low pCO2 to a high pCO2 (hypercapnia). However, an increased alveolar ventilation results into excessive exhalation of CO2 and low levels in the blood, and a significant fall in pH (Koishi, Miyazaki, and Ooe 1999, pp.54-56).

The fall in pH tends to illustrate an enhanced hydrogen ions' concentration in the body and can have various negative impacts on cellular activity. Hypoxaemia leads an alteration in the cellular respiration from aerobic to anaerobic resulting in the production of lactate that in turn changes the pH of the blood if hydrolyzed. Interferences in pH are facilitated by the buffering action of bases/alkalis (BE) such as bicarbonate (HCO3); and thus, the minimized HCO3, BE and maximized levels of lactate show cellular hypoxia (Roux, Ambrosio and Mohsenin 2000.pp.396-405).

Circulation

The 80 years old patients cardiovascular assessment depicted some abnormalities and negative results. Showing that he is actually tachycardic, even though his BP and CVP did not indicate any alarm; tachycardia may have been due to the enhanced WB that needed maximized supply of blood thus relatively high heart rate to cover up. The situation might have been brought about by either shock or exercise; this was evident due to the patient's heart palpitations. The patient's results showed that he had cold limbs. The cause of the cold limb is likely to be due to reduced circulation (atherosclerosis) since the arteries are relatively narrowed thus deterring sufficient flow of blood into the limbs (Klibanov et al 1990, pp.235-237). His feet a...