Deciphering Acid-Base Imbalance: Understanding HCO3 Values in Elderly Patient Care

In the realm of elderly patient care, a scenario unfolds as an elderly client is admitted to the hospital in a coma. A critical analysis of the arterial blood sample delivers key values: PCO2 at 16 mm Hg, HCO3- at 5 mmol/L, and pH at 7.1. As a diligent and well-rounded nurse, it is crucial to comprehend the significance of these values and, more specifically, to identify the normal range for HCO3 (bicarbonate) levels in the blood.

Complex Clinical Presentation: Elderly Client in Coma

The admission of an elderly client in a comatose state is undoubtedly a challenging medical scenario. Coma can result from various underlying causes, ranging from neurological disorders to systemic disturbances. In this case, the focus is on understanding the acid-base status of the patient to provide appropriate care.

Arterial Blood Analysis: Key Values

The arterial blood analysis conducted in this case has provided critical values that shed light on the patient’s acid-base balance:

  • PCO2 (Partial Pressure of Carbon Dioxide) = 16 mm Hg: This value indicates the partial pressure of carbon dioxide in the arterial blood, which plays a pivotal role in assessing respiratory function.
  • HCO3- (Bicarbonate) = 5 mmol/L: Bicarbonate is a crucial buffer in the body’s acid-base regulation, and its levels are closely monitored in clinical assessments.
  • pH = 7.1: The pH value is a measure of the acidity or alkalinity of a solution and is indicative of the overall acid-base balance in the body.

Understanding the Acid-Base Imbalance: Metabolic Acidosis

The values obtained from the arterial blood analysis point towards a state of metabolic acidosis. Metabolic acidosis occurs when there is an excess of acid in the body or a significant decrease in bicarbonate levels (HCO3-) in the blood.

In this scenario, the low bicarbonate level of 5 mmol/L is a clear indicator of metabolic acidosis. Additionally, the pH value of 7.1 falls below the normal range, confirming the acidotic state of the patient.

Normal HCO3 Value:

The normal range for bicarbonate (HCO3) levels in the blood typically falls between 22 and 28 milliequivalents per liter (mmol/L). In this case, the HCO3 level of 5 mmol/L is significantly below the normal range, reaffirming the diagnosis of metabolic acidosis.

Conclusion and Urgency of Medical Care:

The elderly client’s presentation of metabolic acidosis in a comatose state demands immediate and comprehensive medical attention. Healthcare professionals, including nurses and physicians, must work collaboratively to diagnose and treat the underlying cause of the acid-base imbalance while addressing the broader clinical context of the patient’s coma. Timely intervention and diligent monitoring are essential to ensure the client’s well-being and optimize the chances of recovery.


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