Metabolic acidosis occurs when there is an accumulation of acid in the body. It occurs when the body can’t excrete acid properly, too much acid is produced, acid is ingested, or too much bicarbonate is lost. The body attempts to compensate for this imbalance through the respiratory system by hyperventilation to blow off excess CO2 and readjust the bicarbonate to CO2 ratio.
To confirm metabolic acidosis, arterial blood gas results will show:
- pH <7.35
- PaCO2 <35 mmHg
- HCO3 (bicarbonate) <22 mEq/L
Causes of metabolic acidosis include the following:
- Diabetic ketoacidosis
- Starvation
- Lactic acidosis
- Diarrhea
- Renal failure
- Renal tubular acidosis
- Gastrointestinal fistulas
- Aspirin overdose
- Shock
The symptoms of metabolic acidosis are associated with the underlying cause. Common symptoms include rapid breathing, acute confusion, fatigue, nausea, vomiting, diarrhea, and weakness. Severe metabolic acidosis can cause coma, shock, or death.
Metabolic acidosis is diagnosed through laboratory tests like arterial blood gas, blood ketones, basic metabolic panel, lactic acid test, urine pH, and urine ketones.
There is also metabolic alkalosis, which occurs when the body contains excessive amounts of base or alkali.
Nursing Process
The ultimate goal in the management of metabolic acidosis is to correct and maintain a healthy balance of the body’s acid-base levels. Treatment of this condition includes correcting the underlying cause and raising the blood pH through oral or intravenous sodium bicarbonate. Monitoring vital signs, laboratory results, and level of consciousness is also a priority to determine the effectiveness of the treatment regimen and to prevent complications.
Nursing Care Plans Related to Metabolic Acidosis
Acute Confusion
Metabolic acidosis leads to acid buildup in the body and often causes changes in mental status.
Nursing Diagnosis: Acute Confusion
Related to:
- Disease process
- Electrolyte imbalance
- Impaired metabolism
As evidenced by:
- Alterations in consciousness
- Difficulty initiating goal-directed behavior
- Difficulty initiating purposeful behavior
- Inappropriate responses
- Disorientation
- Lethargy
- Psychomotor agitation
Expected outcomes:
- Patient will remain oriented to person, place, time, and situation.
- Patient will demonstrate alertness and appropriate decision-making.
Assessment:
1. Assess the causative factors for the patient’s confusion.
Understanding the underlying cause of the patient’s alteration in mental status can help formulate an appropriate plan of care. Assess glucose levels and lab work, and perform a medication review.
2. Perform a neurological assessment.
A thorough neurological assessment can help differentiate systemic conditions from neurologic or psychiatric disorders. It can help guide appropriate interventions, diagnostics tests, and referrals to other providers.
Interventions:
1. Orient the patient as needed.
Since metabolic acidosis causes confusion, frequent reorientation allows the patient to comprehend the situation and remain aware of the current setting.
2. Closely monitor laboratory results.
When initiating treatment for metabolic acidosis, it’s vital that the nurse reviews the results of ongoing lab testing, such as ABGs, electrolyte levels, ammonia levels, and kidney function.
3. Explain procedures and interventions.
Patients with metabolic acidosis are often confused and will require explanations about nursing interventions and procedures. An understanding of procedures and treatment promotes adherence and reduces anxiety or agitation.
4. Plan care that allows adequate sleep and rest.
Sleep deprivation can aggravate confusion in patients with metabolic acidosis.
Risk for Electrolyte Imbalance
Metabolic acidosis is a serious disorder associated with an imbalance in the acid-base balance in the body. The body attempts to increase bicarbonate by exchanging hydrogen for potassium in the cells, moving potassium into the blood, leading to hyperkalemia.
Nursing Diagnosis: Risk for Electrolyte Imbalance
Related to:
- Disease process
- Compromised regulatory mechanism
- Endocrine regulatory dysfunction
- Fluid imbalance
- Effects of metabolic acidosis
- Renal dysfunction
As evidenced by:
A risk diagnosis is not evidenced by signs and symptoms, as the problem has not occurred yet, and nursing interventions will be directed at the prevention of signs and symptoms.
Expected outcomes:
- Patient will maintain normal levels of electrolytes.
- Patient will exhibit normal vital signs with normal sinus rhythm on EKG.
Assessment:
1. Assess cardiac rate and rhythm.
Hyperkalemia caused by metabolic acidosis may manifest as cardiac irregularities. Monitor the EKG for tall, peaked T waves, which signify severe hyperkalemia.
2. Assess and monitor electrolyte levels.
Tests to assess electrolyte levels can help identify alterations, allowing prompt treatment.
Interventions:
1. Evaluate changes in breathing.
Patients with metabolic acidosis often exhibit hyperventilation as a compensatory response to remove excess acid.
2. Administer parenteral fluids as indicated.
The administration of fluids impacts plasma electrolytes and promotes hemodynamic improvement.
3. Evaluate urinary status.
The kidneys compensate for metabolic acidosis by excreting excess hydrogen ions. When there is reduced renal perfusion, there is decreased renal output, as the kidneys will retain fluids and sodium. Closely monitor intake and output.
4. Administer medications as indicated.
Oral or intravenous sodium bicarbonate is often prescribed to raise blood pH levels.
Risk for Injury
Patients with metabolic acidosis often feel weak, tired, and confused, causing an increased risk for injuries. Acidosis can also result in seizures.
Nursing Diagnosis: Risk for Injury
Related to:
- Electrolyte imbalances
- Hypoxia
- Disorientation
- Muscle weakness
- Fatigue
- Toxin accumulation
As evidenced by:
A risk diagnosis is not evidenced by signs and symptoms, as the problem has not occurred yet, and nursing interventions will be directed at the prevention of signs and symptoms.
Expected outcomes:
- Patient will remain free of injuries.
- Patient will not experience seizure activity.
Assessment:
1. Assess the patient’s risk factors for injuries.
Metabolic acidosis causes symptoms like weakness, confusion, fatigue, and bone loss which can increase the patient’s risk for injuries.
2. Assess the patient’s age, developmental stage, cognitive awareness, and decision-making ability.
These factors can determine the patient’s ability to keep themselves free from injuries. Proper identification can help formulate an appropriate plan of care and patient education.
Interventions:
1. Provide a safe environment.
Patients with metabolic acidosis can become confused and weak and experience injuries from common hazards. Prevent injuries by keeping the bed low with the alarm on and the call bell within reach.
2. Assist the patient in ambulation and encourage the use of assistive aids.
Assistive aids like wheelchairs and walkers can help the patient ambulate. Assist the patient in ambulation and self-care to prevent falls and injuries.
3. Involve the patient and family members in patient care.
A better understanding of the patient’s condition can ensure adherence and encourage the involvement of family members in patient care. Round-the-clock patient monitoring decreases the patient’s risk for injuries.
4. Implement seizure precautions.
Seizures may occur as a result of electrolyte imbalances or toxin accumulation. Implement seizure precautions by padding bed rails, placing mats on the floor, and having emergency equipment at the bedside.
References
- ACCN Essentials of Critical Care Nursing. 3rd Edition. Suzanne M. Burns, MSN, RRT, ACNP, CCRN, FAAN, FCCM, FAANP. 2014. McGraw Hill Education.
- Metabolic Acidosis. Burger MK, Schaller DJ. [Updated 2022 Jul 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482146/
- Metabolic acidosis. Medline Plus. Reviewed: November 6, 2021. From: https://medlineplus.gov/ency/article/000335.htm
- Metabolic Acidosis. National Kidney Foundation. 2022. From: https://www.kidney.org/atoz/content/metabolic-acidosis
- Metabolic Acidosis. Penn Medicine. Reviewed: November 6, 2021. From: https://www.pennmedicine.org/for-patients-and-visitors/patient-information/conditions-treated-a-to-z/metabolic-acidosis
