This document discusses acid-base imbalances, including their interpretation based on pH, PCO2 and HCO3 levels. It describes the causes and types of metabolic and respiratory acidosis and alkalosis. Anion gap is explained as a way to determine the cause of acid-base imbalances. Causes of large, normal and small anion gap metabolic acidosis are provided. Compensated versus uncompensated acid-base imbalances are also summarized. Oxygen delivery methods and the management of type 2 diabetes mellitus are briefly covered.

1. 1. Acid Base Imbalance
By: Dr. Ismah Haron
References: Oxford Handbook of Clinical Medicine & Wiki
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2. Interpretation
pH
<7.35:
Acidosis
<PCO2:
Metabolic
>PCO2:
Respiratory
>7.45:
Alkalosis
>HCO3
-:
Metabolic
<HCO3
-:
Respiratory
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3. Anion gap
• To know the cause of acid base imbalance
• Anion gap = (Na+ + K+) – (Cl- + HCO3
-)
• Normal level: 10 – 18 mmol/L
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4. Metabolic acidosis
• Large anion gap (MUDPILES)
- M-Methanol
- U-Uremia; chronic renal failure
- D-Diabetic ketoacidosis
- P-Propylene glycol
- I-Infection, Isoniazid, Inborn errors of metabolism
- L-Lactic acidosis
- E-Ethanol
- S-Salicylates
• Normal anion gap
- RTA, diarrhea/vomiting, Addison’s disease, pancreatic fistula,
acetazolamide
• Small anion gap
- Hypoalbuminemia e.g. in CLD, nephrotic syndrome
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5. Metabolic alkalosis
• Vomiting
• Hypokalemia
• Burns
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6. Respiratory acidosis
• Type II respi failure
- lung/neuromuscular cause
- E.g. in COPD, GBS, flail chest, pul fibrosis
- Exhaustion in asthma, pneumonia, pul edema  respi arrest
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7. Respiratory alkalosis
• HYPERVENTILATION
- Stroke, anxiety, pregnancy, subarachnoid bleed
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8. Compensated acid base imbalance
1. Evaluate pH—is it normal? Yes
2. Next evaluate pCO2 & HCO3
• pH normal + increased pCO2 + increased HCO3 =
compensated respiratory acidosis
• pH normal + decreased HCO3 + decreased pCO2 =
compensated metabolic acidosis

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11. 2. Oxygen delivery method
Device Oxygen flow rate Oxygen percentage
Nasal prong 1 – 4 L/min 24 – 35%
Simple face mask 5 – 10 L/min 40 – 60%
High flow mask 10 – 15 L/min Almost 100%
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13. 3. Diabetes Mellitus Type 2
Source: QRManagementofType2DiabetesMellitus.MinistryofHealth,Malaysia.2009.
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HOW TO DIAGNOSE?

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17. THANK YOU 
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