Homeostasis means highly complex interactions, which are regulated to maintain the balance within the body of humans. Homeostasis establishes optimum conditions within an organism thereby this balance is required for the normal and proper functioning of the body. To perform the division of labor Homeostasis is divided into sub categories like temperature and acid-base homeostasis. Acid base homeostasis deals with the pH of the body. Any organism’s body is highly sensitive to maintain a level of its pH such metabolic pathways exist which maintain its normal level.
PH is very important to maintain as more than 70% of the body is proteins and enzymes. Outside the normal pH range of each segment of body, denaturation of proteins and enzymes occur. Sometimes the situation becomes worse enough that it causes death of the individual. The body’s acid base level is highly regulated because a minor deviation in the acidity or alkalinity badly affects different organs of the body .
Role of kidneys
Kidneys are known as the excretory organs of the body. They put effort in keeping the normal pH of the body by removing acids and bases via urine. Unlike kidneys, lungs are employed in maximum removal of the excess acids and bases from the body and blood. Kidneys normally take several days for the completion of excretion process .
Role of lungs
The primary source of acid production in the body is carbon dioxide, which is an acidic gas. Carbon dioxide is produced as the result of different metabolic activities ongoing at cellular level. Like all waste materials produced in the body, carbon dioxide also needs to be excreted from the blood to maintain the normal pH of the blood. In the normal body, carbon dioxide is carried to lungs via blood to be exhaled out of the body . On the other hand, if carbon dioxide accumulates in the body it lowers the pH and increases the acidity. Human brain regulates the amount of carbon dioxide exhaled by monitoring the breathing rate and depth.
Buffering system
The acid base buffering system is regulated via bicarbonate buffering system. When free carbon dioxide reacts reversibly with the water available to form carbonic acid, which further dissociates reversibly into hydrogen ions and bicarbonate.
In the case of imbalance, there are two abnormalities
Acidosis – when the blood pH becomes too low
Alkalosis – when the blood pH becomes too high
Acidosis and Alkalosis are not diseases but are indicators of the diseases, which determine whether some metabolic or respiratory disorder has occurred, or not. Normally, the blood pH range is 7.35 – 7.45 slightly basic, which help doctor, monitor the diseases in the patient .
We can determine the ABGs i.e. Arterial Blood Gases by three different ways:
pH
PaCO2
HCO-3
Step 1. Use pH to determine acidity and alkalinity of the blood.
<7.35 = acidosis
7.35 – 7.45 = normal
>7.45 = alkalosis
Step 2. Use PaCO2 to determine respiratory effect
<35 = tends towards alkalosis, causes high pH
35 – 45 = normal
>45 = tends towards acidosis, causes low pH
Step 3. Use HCO3 to monitor metabolic effects
Normal range is 22 – 26
Thereby, we can say high PaCO2 and low HCO3 show acidosis and vice versa.
Nurses’ intervention
A sample of 2mL is obtained from the artery in the wrist, arm, or groin. Nurses or paramedical staff apply antiseptic alcohol swab on the skin of the patient and then use sterile needle to draw blood. The blood sample further goes for the laboratory analysis. For best results, the blood should be tested within 10 minutes of drawing. The treatment associated with the ABGs is not direct, rather one should look for the real cause i.e. disease in the body. ABGs are just biomarkers which tell that some disease has occurred. The respective doctors can diagnose the real cause.
References
Hennessey, L. M., & Japp, A. G. (2007). Arterial blood gases made easy. UK: Churchill Livingstone Elsevier.
Primerose, P. (2015). Complete Phlebotomy Exam review. Missouri: Elsevier.
Rosdahl, C. B., & Kowalski, M. T. (2008). Text book of basic nursing. US: Lippincott Williams and Wilkins.
Thillai, M., & Hattotuwa, K. (2012). Understanding ABGs and Lung function tests. London: JP Medical Ltd.
