Acid-Base Balance PDF

 Acid-Base Balance  The “power of hydrogen” pH is changing every minute  Acid-Base is CRUCIAL to sustaining life and maintaining health  The body regulates pH by a buffer system  Acid-Base derangements may be influenced by:  Diseases  Dehydration  Decrease in uri...

 Acid-Base Balance  The “power of hydrogen” pH is changing every minute  Acid-Base is CRUCIAL to sustaining life and maintaining health  The body regulates pH by a buffer system  Acid-Base derangements may be influenced by:  Diseases  Dehydration  Decrease in urine elimination  Shock  Trauma  Cardiovascular assaults  Acid-Base Balance  The HIGHER the hydrogen concentration, the lower the pH number  Water has pH of 7  pH scale Acid Neutral human body Base 0 7 7.35 – 7.45 14  Hydrogen  Hydrogen is necessary for maintaining cellular membranes and for enzyme activities  Acids are substances that provide ions (H+) and lowers pH.  Acids are produced as a by-product of cellular metabolism of proteins, carbohydrates and fats  Acidic by-products are found in body fluids:  Carbonic Acid found in body fluids. Is broken down into hydrogen and bicarbonate  Carbon Dioxide (CO2) found in blood, expelled by breathing and the remaining acid is converted to hydrochloric acid, phosphoric acid and sulfates that are excreted in the urine by the Kidneys  Hydrogen and Potassium “The Lethal Shuffle”  These positively charged ions move in opposite directions in and out of the cell  “Famously located in the gut or stomach” 1. Potassium imbalances can lead to acid-base imbalances 2. Acid-base imbalance can lead to potassium imbalances  Concept #1 Injured and ill patients will have some form of measurable acidosis. Why: Most common cause of metabolic acidosis in ill and injured patients is Lactic acidosis released during cellular metabolism (Krebs Cycle) production of ATP. This can be localized or systemic.  Fun Fact Normal Saline vs Ringer’s Lactate pH 4.5-7.0 pH 6.0-7.6  How They Differ! Lactated Ringers LR does not last long in the body, beneficial to avoid fluid overload. LR has sodium lactate that is metabolized by bicarbonate. This mechanism assist with less acidosis to the body. Sodium Chloride 0.9% NS exacerbates acidosis by hyperchloremic acidosis. NS higher chloride content causes renal vasoconstriction affecting blood flow to the kidneys. NS may increase hyperkalemia.  Acid-Base Derangements Related To Normal Body Functions Bicarbonate Deficit or “losses”: 1. Puking 2. Pooping 3. Peeing 4. Perspiration 5. Poor Perfusion  Acid-Base Derangements Related To Diseases ACID EXCESS: 1. Renal Failure **** 2. Shocks 3. Overdose (aspirin) **** 4. DKA 5. Hypoxia 6. Cardiac Arrest  How We Balance Acids Action of Actions of the Lungs the Kidney Actions of flowing blood  H+ is Hydrogen HCO3- is Bicarbonate H2CO3 is Carbonic Acid also called Carbon Dioxide in Water CO2 is Carbon Dioxide  Acid-Base Balance  This Balance is controlled by three major buffer systems 1. Carbonic Acid-Bicarbonate buffering (Co2)  Exchanged at the Lungs / Pulmonary  Acts in seconds to minutes  Only temporary 2. Protein buffering or circulating blood: (Plasma, Proteins, Hgb)  Exchanged during circulation at the capillaries  Most common of acid illumination  Acts immediately 3. Renal buffering or Phosphate buffing (Hco3)  Exchanged at the Kidneys  Takes hours to days but very effective ACID 7.35 - 7.45 BASE  Carbonic Acid-Bicarbonate Buffering (CO2) Carbonic Acid-Bicarbonate buffering  Exchanged at the lungs  Is a compensatory mechanism  Works closely with renal and protein buffering  Monitored by CO2 reading (PaCo2 or ETCo2) H+ + HCO3- H2CO3 H2O + CO2  CO2 elimination  H+ and CO2 travels to the alveolar of the lung capillaries  H2CO3 turns quickly into CO2 and H2O  CO2 is eliminated through exhalation As Paramedics what is the name of the devise to monitor CO2 elimination? What are the normal ranges?  Ancient Greeks “Kapnos – smoke”  Waveform Capnography  End-tidal Capnography refers to the graphical measurement of carbon dioxide (CO2) partial pressure (mmHg) during expiration Cellular Energy and Gas Exchange VENTILATIONS PERFUSION DIFFUSION METABOLIC  Video Reminder!  Please review the YouTube video “Waveform Capnography” in Canvas before proceeding.  Leave comments in Canvas.  Protein Buffering (Hgb) Protein Buffering  Needs Hemoglobin and Circulating blood  H+ and CO2 binds to Hgb for elimination  Most common of acid elimination Common Cause of derangements:  Hemorrhaging  Renal Buffering (Hco3) Renal Buffering  HCo3 is Bicarbonate  Exchanged at the kidneys  Maintaining balance in the renal system  Bicarbonate is the primary mechanism for Co2 transport in the blood (65%)  Regulates H+ and HCO3- at the Tubules of Nephrons  It leaves the body via urine  Table 07.T02: Components of the Nephron and Their Function Chiras, D. (2011). Human biology (7th ed.). Sudbury, MA: Jones & Bartlett Learning.  Figure 07.F03: Nephrons of the kidney. Part of the nephron is located in the cortex, and part is located in the medulla. The electron micrograph to the left of the illustration is of a glomerulus from a human nephron. Courtesy of Kenjiro Kimura, MD, PhD/Story, L. (2012). Pathophysiology: A practical approach. Jones & Bartlett Learning: Burlington, MA.  Ammonia Excreted through urine by adding a H+ (NH3) Helps neutralizes urine acids S/S  Lethargy Causes of Elevated Levels  Severe ETOH  ALOC  Cirrhosis  N/V  Liver diseases  Sz  Liver damage TX  Reye syndrome  Oxygen, Cardiac monitor  Metabolic disorders  Sz precautions  Sz disorder (Epilepsy)  Correcting the Etiology  Dialysis  Table 07.T03: Important Metabolic Wastes and Substances Excreted From the Body Story, L. (2012). Pathophysiology: A practical approach. Jones & Bartlett Learning: Burlington, MA.  Metabolic vs. Respiratory  Two influencing factors to pH 1. Metabolic related to Kidney function (HCo3-) 2. Respiratory related to Lung function (CO2)  Derangements caused by multiple factors  Test by Arterial Blood Gas (ABG) or Venous Blood Gas (VBG)  Treatment is to find the underlying condition  pH is used as a tool to evaluate treatement regimens  Both can be acid or base  Table 06.T03: Normal Serum Arterial Blood Gas Values Story, L. (2012). Pathophysiology: A practical approach. Jones & Bartlett Learning: Burlington, MA.  Base Excess / Base Deficit (-2 - +2)  Is the amount of strong acid that must be added to each fully oxygenated blood to return the pH to 7.40 at a temperature of 36.5 and a pCO2 of 35-45 mmHg  The amount of BASE present in the blood (extracellular)  Defines the Metabolic Component or Bicarbonate levels  This will immediately respond to changes in the Protein Buffering System (hemorrhaging) Causes: Trauma  Ig: The more negative = severe (m) acidosis = fluid behind = no preload = Shock +2 Base BE -2 ACID pH < 7.35  Video Reminder  Review ABG Base Excess and Deficit video on Canvas.  Make sure to leave commits.  Base Excess or Base Deficit Explained +10 Resuscitation Pearls 1. BE of -9 had a 100% sensitivity for MTP +8 2. eTCO2 is surrogate to Lactic Acid +4 +2 0 -2 Common Causes of Metabolic Acidosis -4 Hemorragic Shock or moderate blood loss Lactic Acidosis related to hypoxia and Sepsis -6 Diabetic Keto Acidosis (DKA) Chronic Renal Failure -8 Diarrhea Poisons (Aspirin Overdose) -10  ACID-BASE BALANCE PaO2 (90-100 mmHg)  Tissue Consumption of available O2  Perfusion status  Similar to Spo2 (pulse oximetry) 90-100  100 = tissues not utilizing O2  Sepsis  Tissue injury and illness  Clinical indication of organ death  Death  Acid / Base Balance ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY Controlled by Kidneys Controlled by Lungs HCO3- pCO2 22 26 35 45 BASE ACID ACID BASE  Respiratory Acidosis ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY HCO3- PaCO2 22 26 35 45 BASE ACID ACID BASE  Respiratory Acidosis Causes and S/S TX  Hypoxia  ALOC  Increase ventilations  Cardiac arrest (pEtCO2 Co2 low)?  Passive airway TX  Hypoventilation / Respiratory Arrest  High fowlers  COPD  Bronchospasm  High flow O2  Asthma  Aggressive airway TX  Over dose  Intubation  Respiratory diseases  ARDS  CPAP  PE Sodium Bicarbonate is contraindicated  Chest Trauma H+ + HCO3- mirrors H2O + CO2  Lactic Acidosis  Renal Failure  Cervical Cord Injury  Respiratory Alkalosis ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY HCO3- PaCO2 22 26 35 45 BASE ACID ACID BASE  Respiratory Alkalosis Causes and S/S TX  Hypoxia  Hyperventilation’s  Decrease respirations  Anemia  ALOC  Decrease ventilations  Anxiety  Increase CO2 uptake  Hysteria  C/P  Sedation medication  Sepsis  Pain management  Dyspnea  PE  Finding the underlying  Dizziness cause  Carpal pedal spasms  Altitude acclimation  Metabolic Acidosis ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY HCO3- PaCO2 22 26 35 45 BASE ACID ACID BASE  Metabolic Acidosis Causes and S/S TX  Medically sick  High flow oxygen  Severe Trauma  Aggressive airway  Sepsis management if needed  DKA  ASA OD  Finding the underlying  Cardiac Arrest causes  Respiratory distress  Sodium Bicarbonate IV  Carbon monoxide exposure infusion or push  Hyperkalemia (controversial)  V/D  Metabolic Alkalosis ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY HCO3- PaCO2 22 26 35 45 BASE ACID ACID BASE  Metabolic Alkalosis Causes and S/S TX  N/V/D  Fluid replacement  Antacid OD  Electrolyte replacement  Cushing's syndrome  Identifying the cause  Hypokalemia  Complete Acidosis ACID 7.35 - 7.45 BASE METABOLIC RESPIRATORY HCO3- PaCO2 22 26 35 45 DEATH BASE ACID ACID BASE  Figure 06.F12: Mixed acid–base disorders Baumberger-Henry, M. (2008). Quick Look Nursing: Fluids and Electrolytes (2nd ed.). Sudbury, MA: Jones & Bartlett Learning