Management of Patients with Acid-Base Imbalances

Vocabulary and key clinical indicators for acid-base imbalances, including respiratory and metabolic acidosis and alkalosis based on Med/Surg and Saunders review materials.

pH

The measurement of hydrogen concentration within the arterial blood, where a greater concentration results in a more acidic state ($lower\,pH$) and a lower concentration results in a more alkaline state ($higher\,pH$).

Normal pH Level

The steady balance range for blood pH, which is $7.35 - 7.45$.

Respiratory System Defense

The first line of defense that works immediately by retaining or blowing off carbon dioxide ($CO_2$), which is an acid.

Kidney Defense

The second line of defense that works slowly by increasing or decreasing the production of sodium bicarbonate ($HCO_3$), which is a base.

Compensation

The process by which the body attempts to correct changes and imbalances in pH levels.

Full Compensation

Occurs when the pH level of the blood returns to the normal range of $7.35 - 7.45$.

Respiratory Acidosis

A condition caused by hypoventilation (less than $12$ breaths per minute) resulting in the retention of carbon dioxide ($CO_2$).

Respiratory Acidosis Assessment Findings

Weakness, paralysis, hyporeflexia, hypotension, thready peripheral pulses, lethargy, confusion, stupor, coma, dysrhythmias, and pale/cyanotic skin.

Respiratory Alkalosis

A condition caused by hyperventilation (tachypnea greater than $20$ breaths per minute) where the body blows off carbon dioxide ($CO_2$).

Kussmaul Respirations (Respiratory Alkalosis)

Deep and rapid breathing characterized by a rate greater than $20$ breaths per minute.

Tetany

Abnormal muscle spasms that can be seen in both Respiratory and Metabolic Alkalosis assessment.

Metabolic Acidosis

An imbalance characterized by high acid levels or low bicarbonate levels, specifically $pH < 7.35$ and $HCO_3 < 22$.

Metabolic Acidosis Causes

Diabetes/Ketoacidosis, starvation, heavy exercise, seizure, fever, hypoxia, salicylate intoxication, renal failure, pancreatitis, liver failure, dehydration, and diarrhea.

Metabolic Acidosis Assessment Findings

Bradycardia, weak peripheral pulses, hypotension, hyporeflexia, flaccid paralysis, fatigue, hyperkalemia, Kussmaul Respiration, and warm, dry, flushed skin.

Metabolic Alkalosis

An imbalance characterized by low acid levels or high bicarbonate levels, specifically $pH > 7.45$ and $HCO_3 > 26$.

Metabolic Alkalosis Causes

Excessive antacid ingestion, blood transfusions, TPN, loss of gastric secretions (prolonged vomiting or NG suction), potassium depletion, and thiazide diuretics.

Normal Tic-Tac-Toe Balances

Normal ranges used for interpretation: pH is $7.35 - 7.45$, $paCO_2$ is $45 - 35$, and $HCO_3$ is $22 - 26$.