Arterial blood gases
(ABG)
How to Draw an ABG
ABGs are drawn for a variety of reasons
These may include concern for:
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Lung Failure
Kidney Failure
Shock
Trauma
Uncontrolled diabetes
Asthma
Chronic Obstructive Pulmonary Disease (COPD)
Hemorrhage
Drug Overdose
Metabolic Disease
Chemical Poisoning
To check if lung condition treatments are working
Key Components to an ABG
• PCO2 (ventilation) – Partial Carbon Dioxide
• PaO2 - (oxygenation) –Partial Oxygen
• HCO3 – (metabolism) -Bicarbonate
• O2Sat – Oxygen Saturation
• pH – Acid/Base balance
• BE – Base excess
Respiratory Acidosis
Causes of Respiratory Acidosis
• Hypoventilation
• Neuromuscular Weakness
(Gullian Barre Syndrome)
• Obesity
• Asthma
Clinical Manifestation
• Muscular Weakness
• Tachypnea
• Blurred Vision
• Confusion
• Memory loss
• Restlessness
Management
Pharmacological:• Opoid Antagonist:Nalaxone
• β2 Antagonist:Formoterol, Albuterol
• Anticholinergic:Ipratropium bromide
• Corticosteroids:
Prednisone,Prednisolone
Non pharmacological:Ventilator Support:- To
subside the respiratory
problem
Respiratory Alkalosis
Causes
• Hyperventilation
• Fluid loss
• Liver disease
• Alteration in gas exchange
• Pneumonia
• Stress
Clinical Manifestation
• Palpitation
• Tetany (muscle spasm)
• Convulsion
• Paralysis
• Chest pain
Management
Treat the underlying causes:
Pharmacological:• Antibiotic: Levofloxin
•Antipyretic: Acetaminophen
•Anxiolytic: Benzodiazapam
Non-pharmacological:• Breath into a paper bag.
•To reassure the patient who
is anxious.
•If intubated, reduce minute
ventilation by adjusting rate
,tidal volume.
Metabolic Acidosis
Causes
• Alcohol
• Cancer
• Diarrhea
• Liver failure
• Poisoning by aspirin or
methanol
• Sever dehydration
• Seizure
Clinical Manifestation
• Diarrhea
• Chest pain
• Rapid breathing
• Hypotension
• Arrhythmia
• Joint pain
Management
Pharmacological:• Ringer lactate
• Diuretics
• Administer bicarbonates
Non-pharmacological:• To provide IV fluid.
• Stop drinking alcohol.
• To provide plenty of fluid.
Metabolic Alkalosis
Causes
• Diarrhea and vomiting
• High fever
• Diuretic therapy
Clinical Manifestation
• Bradypnea( initial
symptom)
• Apnea go on 15 sec and
longer
• Decrease blood pressure
• Rapid heart rate
• Irritability
• Cyanosis
• Coma
Management
Pharmacological:• Potassium sparing
diuretics: Amiloride
• Antipyretic:- Acetazolamide
• Infuse HCL
Non-pharmacological:• To check vital sign of the
patient.
• To provide antacid and
laxative.
Acid-Base Abnormalities
Primary ABG Abnormalities
Acid-Base
Abnormality
Alkalemia
Metabolic
Respiratory
Acidemia
Metabolic
Respiratory
pH
PaCO2
ABG Changes with Compensation
(if present)
HCO3
Respiratory
(PaCO2)
Metabolic
(HCO3)
Reference
1- B-Essential Books (Text Urden, L.D., Stacy, K.M. and
Lough, M.E. (2015): Priorities in books):
2- Critical Care Nursing; 8th ed. - Elsevier
3- Farcy, D.A., Chiu, W.C., Marshall, J.P. and Osborn, T.M.
4- (2017): Critical Care Emergency Medicine; 2th ed.
5- McGraw-Hill Education, Inc. Emergency & Critical Care
Pocket Guide: 8th ed. Priorities in Critical Care Nursing
Critical Care and Emergency Journals