Acid-Base Disorders Lecture Part 2 PDF

Acid-Base Balance Acid-Base Balance Learning Outcomes Describe Normal acid-base balance. Determine Signs, symptoms, and management of imbalances. Apply Concepts to patient scenarios. Acid-Base Basics 1 Balance 2 Measurement 3 Diagnosis Depends on regulati...

Acid-Base Balance Acid-Base Balance Learning Outcomes Describe Normal acid-base balance. Determine Signs, symptoms, and management of imbalances. Apply Concepts to patient scenarios. Acid-Base Basics 1 Balance 2 Measurement 3 Diagnosis Depends on regulating free Hydrogen ion concentration Arterial blood gases (ABGs) are hydrogen ions (pH). measured as pH. key. Normal pH Values Normal Range Acidemia Alkalemia 7.35-7.45. pH 7.8 pH < 7.35. & pH > 7.45. is life-threatening. Acidosis: disorder that decreases pH Alkalosis: disorder that increases pH Other Normal ABG Values pO2 pCO2 D 1 2 80-100 mmHg, measures oxygenation. 35-45 mmHg, reflects lung function. 3 HCO3- ·i neyuncion 4 Anion Gap 22-26 mEq/L, bicarbonate concentration. 8-12, helps categorize metabolic acidosis. Anion Gap Calculation Anion Gap = Na+ - (Cl- + HCO3-). Latino - Anion ABG Overview C pH 7.35-7.45 PaCO2 35-45 mmHg HCO3 22-26 mEq/L. Acidosis pH < 7.35. Caused by acid accumulation or base loss. Alkalosis pH > 7.45. Occurs with base accumulation or acid loss.  In Class Activity Time=1min What are the main organ/organs that control the Acid Base Balance? 9 Acid-Base Control Kidneys and lungs are the main organs controlling acid-base balance. Regulatory Systems stupid o ↳ id 1 Chemical Buffers underlyinuse Act immediately to neutralize changes. 2 Respiratory System Regulates CO2 levels. 3 change 02 35 in 3 Kidneys Reabsorb or excrete acids/bases. Change in bicarb = Chronic Chemical Buffers Bicarbonate Phosphate Protein Buffers blood and interstitial fluid. Effective in renal tubules. Most plentiful, includes hemoglobin. Respiratory System aii = cor Regulates CO2 High CO2 = (hold on to carbonic acid, slower breathing and lower pH) Low CO2 = (blow off carbonic acid, faster breathing and raise pH) > es - Twice as effective as chemical buffers, but effects are temporary not e  PA poorly Kidneys Reabsorb/excrete acids/bases. Produce bicarbonate. Adjustments take hours to days. Bicarbonate levels and pH levels increase or decrease together Metabolic vs. Respiratory Primary abnormality is most often accompanied by a compensatory change that reflects the body’s desire to return the bicarbonate/ CO2 ratio and pH closer to normal Metabolic Respiratory Alters pH by changing bicarbonate. Alters pH by changing pCO2. Compensation Body never overcompensates, except chronic respiratory alkalosis. pH rarely returns to normal. Normal ABG Values Normal values can still be harmful depending on the patient's condition. PCO2 Assesment Bicar Interpreting ABGs 18 Interpreting ABGs Step 1 sacidosis Check pH. -A 1k &losis Step 2 not PCO2 Go Analyze CO2. ex. PH 7 5. Rispiratory 2002 60 Rispiratory Step 3 PHJ acidosi : Evaluate bicarbonate. > - 9) 169 p 10316 d metabolic > - infosis Step 4 PH7 & Assess compensation. Step 5 Review PaO2 and SaO2.  Step 1: Check pH Acidosis Alkalosis pH < 7.35. pH > 7.45.  Step 2: Analyze CO2 PaCO2 gives info about the respiratory component of acid-base balance 1j If abnormal, does the change correspond with change in pH? > - &! 235 PH T 31981 % primary 345.. condition PCORM7 519 (signu 21 CO2 and pH Relationship High pH Low pH Expects low PaCO2 (hypocapnia). Expects high PaCO2 (hypercapnia). Step 3: Evaluate Bicarbonate Bicarbonate reflects metabolic component. High pH, high bicarb; low pH, low bicarb.  Step 4 – Look for Compensation If a change is seen in BOTH PaCO2 and bicarbonate, the body is trying to compensate ⑳ PHT. 2 Compensation occurs as opposites, (Example: for metabolic acidosis, 91 compensation shows respiratory alkalosis) ·Cor33 24  Step 5 – What is the PaO2 and SaO2 PaO2 reflects ability to pickup O2 from lungs SaO2 less than 95% is inadequate oxygenation Low PaO2 indicates hypoxemia 25  normal In Class Sample Problems e-745 Time=5min High norma Acidosis Rispiratory Acids is low. high normal high Alkolosis Metapoli , < low high high 10 W Acidosis - Comp Rispiratory insatory Acitosis ↑ Iow Iow Meta Polic high 10 W norma Ris Piratory Alkalosis 26 28  Acid-Base Imbalances Respiratory Acidosis Respiratory Alkalosis Metabolic Acidosis Metabolic Alkalosis 29  Respiratory Acidosis 1 Cause Compromised breathing leads to hypoventilation and CO2 buildup. 2 Origins Neuromuscular issues, respiratory center depression, lung disease, or airway obstruction.  At-Risk Clients Post-Op Abdominal surgery patients are at increased risk. Ventilation Mechanical ventilation can contribute. Medications Analgesics or sedation increase risk. Respiratory Acidosis: Symptoms Mental State Physical Signs Other Apprehension, restlessness, Decreased DTRs, diaphoresis, Nausea, vomiting, warm flushed confusion, tremors. dyspnea, tachycardia. skin. Respiratory Acidosis: ABGs Uncompensated Compensated pH < 7.35 Close to normal PaCO2 > 45 > 45 metabolic HCO3 Normal > 26 Alkalosis Respiratory Acidosis: Treatment 1 Underlying Cause Address the root cause of the acidosis. 2 Respiratory Support Bronchodilators and supplemental oxygen. 9 · 3 Other Treatments Treat hyperkalemia, infections, and remove obstructions.  Respiratory Alkalosis Hyperventilation, often caused by pain, salicylate poisoning, nicotine, aminophylline, hypermetabolic states, or acute hypoxia. Respiratory Alkalosis: Symptoms Neurological Cardiovascular Other Anxiety, restlessness, paresthesias. - Tachycardia, EKG changes. Diaphoresis, dyspnea (increased rate -- and depth), tetany. Respiratory Alkalosis: ABGs Uncompensated Compensated pH > 7.45 Close to Normal 5 & PaCO2 < 35 < 35 HCO3 Normal < 22  Respiratory Alkalosis: Treatment 1 Underlying Disorder Treat the underlying cause. * 2 Oxygen and Medications ji 3 agents. & Oxygen therapy for hypoxemia, sedatives, or antianxiety Hyperventilation Paper bag breathing can help.  Metabolic Acidosis Characterized by acid gain or bicarbonate loss. Associated with ketone bodies in conditions like diabetes, alcoholism, and starvation Metabolic Acidosis: Other Causes 1 Lactic Acidosis Can be secondary to shock, heart failure, pulmonary disease, hepatic disease, seizures, or strenuous exercise. 2 MUD PILES Methanol, Uremia, Diabetic ketoacidosis, Propylene glycol, Isoniazid, Lactic acidosis, Ethanol/Ethylene glycol, Salicylates. 3 Additional Causes Gastrointestinal bicarbonate loss (diarrhea, fistulas) and renal bicarbonate loss (renal tubular acidosis). Metabolic Acidosis: Symptoms Neurological Gastrointestinal/Muscular Other Confusion, dull headache, decreased Abdominal cramps, diarrhea, muscle Hypotension, Kussmaul's DTRs, lethargy. weakness. respirations, warm and dry skin, EKG changes (hyperkalemia). The Mour > - RAC Anxity - RAL full headache > - MAC Metabolic Acidosis: ABGs 5. g l Uncompensated Compensated sign 11 + -19 pH < 7.35 Close to Normal Symptoms PaCO2 Normal < 35 7 Alkmosis HCO3 < 22 < 22 =>  Metabolic Acidosis: - Treatment 1 DKA & Regular insulin to reverse diabetic ketoacidosis. 2 Acidosis > IV bicarbonate to correct acidosis. 3 Other = & Fluid replacement, dialysis for drug toxicity, and antidiarrheals. = · S &  Metabolic Alkalosis & Often associated with hypokalemia (from diuretic use), - hypochloremia, and hypocalcemia. Caused by vomiting, NG suction, Cushing's disease , or baking soda. ---- Metabolic Alkalosis: Symptoms General Neuro/Muscular Other Anorexia, apathy, confusion, Muscle twitching, paresthesia, loss Nausea, polyuria, vomiting. cyanosis, hypotension. of reflexes, weakness. spesific NOT  Metabolic Alkalosis: ABGs - Uncompensated Compensated pH > 7.45 Close to Normal O zispiratory Gaitosis PaCO2 Normal > 45 HCO3 > 26 > 26 Metabolic Alkalosis: Treatment / 1 Medication dis IV ammonium chloride can be administered. 2 Diuretics/Suction Discontinue thiazide diuretics and NG suctioning. 3 Antiemetics Use antiemetics to control vomiting. Case Study: Patient Presentation chronic - A 35-year-old female with AIDS presents with fever and three - months of copious diarrhea. Vitals: BP 100/60, pulse 100, RR 18, => afebrile. Case Study: Lab Values Test Result Normal Range Sodium 136 mmol/L 136-146 mmol/L Potassium 3.4 mmol/L 3.5-5.3 mmol/L Chloride 112 mmol/L 98-108 mmol/L BUN 30 mg/dl 7-22 mg/dl Creatinine 1.5 mg/dl 0.7-1.5 mg/dl Glucose 105 mg/dl 70-110 mg/dl Case Study: Arterial Blood Gas Diarrhea Test Result pH 7.30 coW acidosi PCO2 27 mmHg 10 W Rispiratory alkalosis · PO2 90 mmHg lowes Bicarbonate 14 mmol/L Total CO2 14 mmol/L  Na Bicarb chorise N. 136 - (14+112) Normal · In Class Case, Time=5min 2 What is/are the critical course of events that is going to alter her acid-base status? diarned What Acid base abnormalities would you expect based on this information?metal Bieary poin Review her blood gases. What is the primary acid-base abnormality? How did Kosis & you decide that? metabolic acidosis/Bicard. 24 Calculate the anion gap in this patient. What is the normal anion gap? Is there a compensatory mechanism for metabolic acidosis? Rispiratory Alkalos' is52  Take Home Messages Describe the normal acid base balance Determine the main signs/symptoms and management for each acid- base disturbance Apply the concept of acid base imbalance on patient scenarios 54