This lecture was conducted during the Nephrology Unit Grand Ground by a Sub-intern under Nephrology Division, Department of Medicine in King Saud University. Nephrology Division is NOT responsible for the content of the presentation for it is intended for learning and /or education purpose only.

HOW TO APPROACH PATIENTS WITH ACIDOSIS Hadeel Salah Al Jamei

OUTLINE Definitions Brief Physiology Etiology Presentation Of The Patient How To Approach The Patient Investigations Treatment OUTLINE

Acid, Acidosis, Acidemia? pH? Base, Alkalosis, Alkalemia? DEFINITIONS

MEANS OF REGULATING H+ Buffer Systems (Buffer + H+  HBuffer) Bicarbonate exatracellular CO2 + H2O  H2CO3 H2CO3  H+ + HCO3- Phospahte exatracellular Protiens intracellualr Respiratory Systems Hypoventilation vs. hyperventilation Renal System MEANS OF REGULATING H+

CAUSES OF ACIDOSIS What is the anion gap? Respiratory Acute Chronic Metabolic Normal Anion Gap Increased Anion Gap What is the anion gap? How to calculate it? [Na+] – [HCO3-] – [Cl-] CAUSES OF ACIDOSIS

Hx is V.IMP SIGNS AND SYMPTOMS

Respiratory compensation Renal compensation Respiratory compensation Arterial blood sample pH pH < 7.35 pH > 7.45 Acidosis Alkalosis HCO3- < 22 PCO2 > 45 HCO3- > 26 PCO2 < 35 Metabolic respiratory Metabolic respiratory Respiratory compensation Renal compensation Respiratory compensation Renal compensation PCO2 < 35 HCO3- > 26 PCO2 > 45 HCO3- < 22

OTHER MODALITIES OF INVESTIGATIONS Metabolic Anion gap serum chemistry Urinalysis Ketone levels Lactate levels Salicylate levels ECG Respiratory Chest X-ray Ct scan Drug toxicology CT scan MRI PFTs EMG NCV OTHER MODALITIES OF INVESTIGATIONS

Treat the underlying cause ABC and Vitals Metabolic Acidosis Treat the underlying cause NaHCO3 Respiratory Acidosis Pharmacological Oxygen Ventilatory support TREATMENT

SUMMARY History Is Important Acidemia Or Alkalemia Respiratory Or Metabolic If respiratory: acute or chronic If metabolic: normal or increased anion gap? Is There A Compensation? SUMMARY

Acidosis App

Qx Calculate App

Textbook of medical physiology by Guyton and Hall 11th edition Pocket medicine by marc sabatine 4th edition. Step up to medicine 2nd edition. http://emedicine.medscape.com/article/768268-overview#a0104 http://emedicine.medscape.com/article/301574-overview http://cmbi.bjmu.edu.cn/uptodate/critical%20care/Intoxications/Approach%20to%20the%20patient%20with%20metabolic%20acidosis.htm http://fitsweb.uchc.edu/student/selectives/TimurGraham/Welcome.html REFERENCES