Presentation is loading. Please wait.

Presentation is loading. Please wait.

Acid-Base Balance Interactive Tutorial Emily Phillips MSN 621 Spring 2009 All images imported from Microsoft Clipart &

Similar presentations


Presentation on theme: "Acid-Base Balance Interactive Tutorial Emily Phillips MSN 621 Spring 2009 All images imported from Microsoft Clipart &"— Presentation transcript:

1

2 Acid-Base Balance Interactive Tutorial Emily Phillips MSN 621 Spring 2009 E-mail: emmalemmaRN@hotmail.com All images imported from Microsoft Clipart & Yahoo Image gallery

3 How to navigate this tutorial:  To advance to the next slide click on the box  To return to the previous slide click on the box  To return to the Main Menu: click the box  Hover over underlined text for a definition/explanationunderlined text  To return to the last slide viewed click on the button  Click the for additional information

4 Objectives:  Define acid base balance/imbalance  Explain the pathophysiology of organs involved in acid base balance/imbalance  Identify normal/abnormal and compensated/uncompensated lab values  Explain symptoms related to acid base imbalances and compensated vs. uncompensated  Appropriate interventions and expected outcomes

5 Main Menu: Acid-Base PretestThe Buffer Systems ABG Interpretation & Case Studies Acid-Base Review test Diagnostic Lab Values Metabolic Distubances Respiratory DisturbancesAcid-Base Compensation

6 Acid-Base Pretest:  What is the normal range for arterial blood pH? 7.38 – 7.46 7.40 – 7.52 7.35 – 7.45

7 Incorrect  Close but not quite… try again. Next QuestionPrevious Question

8 Incorrect  Close, but no cigar… 7.52 would indicate alkalosis. Next QuestionPrevious Question

9 Correct!  This is the correct parameters for arterial blood pH with the extracellular fluid in the middle at 7.40… well done! Next QuestionPrevious Question

10 Acid-Base Pretest:  What 2 extracellular substances work together to regulate pH? Sodium bicarbonate & carbonic acid Carbonic acid & bicarbonate Acetic acid & carbonic acid

11 Incorrect  Sorry, but not exactly… although sodium bicarbonate plays a role as a buffer in acid-base balance it isn’t 1 of the extracellular substances that works to regulate pH Next QuestionPrevious Question

12 Correct!  Right on! Carbonic acid and bicarbonate are the two primary extracellular regulators of pH. pH is also further regulated by electrolyte composition within the intra & extracellular compartments. Next QuestionPrevious Question

13 Incorrect  Although carbonic acid is 1 of 2 extracellular substances that work to regulate pH, acetic acid is not; it’s simply a weak acid. Next QuestionPrevious Question

14 Acid-Base Pretest:  Characterize an acid & a base based on the choices below. Acids release hydrogen (H + ) ions & bases accept H + ions. Acids accept H + ions & bases release H + ions Both acids & bases can release & accept H + ions

15 Correct!  Acids are molecules that have the ability to release H + ions & bases are molecules that have the ability to accept or bind with H + ions. Next QuestionPrevious Question

16 Incorrect  Think this through and try again. Acids increase the concentration of H + ions & bases decrease the concentration. Think of an acid like a wet sponge & a base as a dry sponge. What happens when you squeeze a wet sponge? Likewise, what happens to a dry sponge when placed in a bucket of water? Next QuestionPrevious Question

17 Incorrect  If you think of an acid as wet sponge & a base as a dry sponge; what happens when a wet sponge gets squeezed & a dry sponge gets wet? Next QuestionPrevious Question

18 Acid-Base Pretest:  Buffering is a normal body mechanism that occurs rapidly in response to acid- base disturbances in order to prevent changes in what? HCO 3 - H 2 CO 3 H+H+

19 Incorrect  HCO 3 - is its own buffer system which is very important because HCO 3 - can be regulated by the kidneys & CO 2 by the lungs. Nice try, but think again… Next QuestionPrevious Question

20 Incorrect  The bicarbonate buffer system utilizes carbonic acid & sodium bicarbonate to buffer, but carbonic acid is NOT the major ion involved in acid-base balance. Next QuestionPrevious Question

21 Correct!  Excellent! H + ion concentration is most important to regulate in order to prevent acid-base balance disturbances. Next QuestionPrevious Question

22 Acid-Base Pretest:  What are the two systems in the body that work to regulate pH in acid-base balance & which one works fastest? The Respiratory & Renal systems Renal The Respiratory & Renal systems Respiratory The Renal & GI systems Renal

23 Incorrect  These two systems do work together to regulate pH in acid-base imbalance, however, the renal system works over a matter of days as opposed to hours… think it over & try again. End PretestPrevious Question

24 Correct!  Great work! Both the respiratory & renal systems work to regulate pH in acid- base imbalance; the respiratory system works in a matter of minutes & is maximal within 12-24 hours while the renal (kidneys) system continues to function for days to restore pH within normal limits (WNL). End PretestPrevious Question

25 Incorrect  The renal system does work to regulate pH in acid-base imbalance, but the GI system does not… try again. End PretestPrevious Question

26 Acid-Base Balance:  Homeostasis of bodily fluids at a normal arterial blood pH Homeostasis pH  pH is regulated by extracellular carbonic acid (H 2 CO 3 ) and bicarbonate (HCO 3 - )carbonic acid (H 2 CO 3 ) bicarbonate (HCO 3 - )  Acids are molecules that release hydrogen ions (H + )  A base is a molecule that accepts or combines with H + ionsbase

27

28 Acids and Bases can be strong or weak:  A strong acid or base is one that dissociates completely in a solution dissociates - HCl, NaOH, and H 2 SO 4HCl, NaOH, and H 2 SO 4  A weak acid or base is one that dissociates partially in a solution -H 2 CO 3, C 3 H 6 O 3, and CH 2 OH 2 CO 3, C 3 H 6 O 3, and CH 2 O

29

30 The Body and pH:  Homeostasis of pH is controlled through extracellular & intracellular buffering systems extracellular intracellular buffering systems  Respiratory: eliminate CO 2CO 2  Renal: conserve HCO 3 - and eliminate H + ionsHCO 3 - H +  Electrolytes: composition of extracellular (ECF) & intracellular fluids (ICF) - ECF is maintained at 7.40 Protein Buffer system HCO 3 - Buffer system K + - H + Exchange

31 Protein Buffer Systems:  Largest buffer system in the body  Amphoteric: can function as acids or bases  Contain several ionizable groups able to bind or release H +  Largely located in cells; H + & CO 2 diffuse across cell membranes for buffering by Albumin & plasma globulins Albumin & plasma globulins Previous Slide

32 Bicarbonate Buffer System:  Uses NaHCO 3 as its weak base & H 2 CO 3 as its weak acidNaHCO 3H 2 CO 3  The HCO 3 - /CO 2 buffer system can readily add or remove components from the body  An ample supply of CO 2 provided via metabolism, replaces H 2 CO 3 lost when excess base is added  In turn, the kidneys conserve or form new HCO 3 - in the presence of excess acid & excrete HCO 3 - in the presence of excess base Previous Slide

33

34 Plasma Potassium-Hydrogen Exchange:  Both positively charged ions move freely between IC & EC compartmentsIC & EC  Decreases in plasma K + cause movement of K + from ICF to ECF & movement of H + from ECF to ICFK +  With an EC decrease in K +, K + moves out & is replaced by H +  As a result, changes in EC K + levels affect acid-base balance & vice versa Previous Slide

35 Quick Review: Click the Boxes A donator of H + ionsAn acceptor of H + w/ pH 7.0 Regulated by EC Controlled by EC H 2 CO 3 & HCO 3 - & IC buffer systems Eliminates CO 2 Conserves HCO 3 - Eliminates H + ions An Acid is:A Base is: pH is: Respiratory System: pH is: Renal System:

36 Respiratory Control Mechanisms:  Works within minutes to control pH; maximal in 12-24 hours  Only about 50-75% effective in returning pH to normal  Excess CO 2 & H + in the blood act directly on respiratory centers in the brain  CO 2 readily crosses blood-brain barrier reacting w/ H 2 O to form H 2 CO 3  H 2 CO 3 splits into H + & HCO 3 - & the H + stimulates an increase or decrease in respirations

37 Renal Control Mechanisms:  Don’t work as fast as the respiratory system; function for days to restore pH to, or close to, normal  Regulate pH through excreting acidic or alkaline urine; excreting excess H + & regenerating or reabsorbing HCO 3 -  Excreting acidic urine decreases acid in the EC fluid & excreting alkaline urine removes base H+ elimination & HCO3- conservation

38

39 H+ Elimination & HCO3- Conservation:  Begins with Na + /H + transport systemNa + / H + secreted in tubular fluid & Na + reabsorbed in tubular celltubular fluid tubular cell Secreted H + couples w/ filtered HCO 3 - & CO 2 & H 2 O result H 2 O secreted in urine & CO 2 diffuses into tubular cell combining w/ H 2 O to form HCO 3 - via a carbonic anhydrase-mediated reactioncarbonic anhydrase-mediated reaction HCO 3 - is reabsorbed into the blood along w/ Na +, & newly generated H + is secreted into tubular fluid beginning a new cycle Previous Slide

40 Mechanisms of Acid-Base Balance:  The ratio of HCO 3 - base to the volatile H 2 CO 3 determines pHvolatile  Concentrations of volatile H 2 CO 3 are regulated by changing the rate & depth of respiration  Plasma concentration of HCO 3 - is regulated by the kidneys via 2 processes: reabsorption of filtered HCO 3 - & generation of new HCO 3 -, or elimination of H + buffered by tubular systems to maintain a luminal pH of at least 4.5tubular systems luminal pH Phosphate Buffer system Ammonia Buffer system

41 The Phosphate Buffer system:  Uses HPO 42 - and H 2 PO 4 - present in tubular filtrateHPO 42 - and H 2 PO 4 -  Both become concentrated in the fluid due to relatively poor absorption & reabsorption of H 2 O from tubular fluid  H + combines w/ HPO 42 - to form H 2 PO 4 - giving the kidneys the ability to increase secretion of H + ions  When H + ions in the bloodstream decrease, pH increases & vice versa  Subsequently hydrogen phosphate either accepts or releases H + ions to maintain pH within the bloodstream Previous Slide

42 The Ammonia Buffer System:  This buffer system is the more complex of the two  The generation of HCO 3 - & excretion of H + by this system occurs in 3 steps: 1) synthesis of NH 4 + from glutamine, an amino acid in the proximal tubule, thick ascending loop of Henle & distal tubulesNH 4 +proximal tubulethick ascending loop of Henle distal tubules 2) recycling & reabsorption of NH 3 in the kidney’s medulla, &NH 3 3) buffering of H + ions by NH 3 in the collecting tubules. Previous Slide

43 Acid-Base Balance Review test:  The kidneys regulate pH by excreting HCO 3 - and retaining or regenerating H + TRUE FALSE

44 Incorrect  Actually the kidneys work to regulate pH through the regeneration or reabsorption of HCO 3 - & excretion of H + Next QuestionPrevious Question

45 Correct!  You’re absolutely right! The kidneys actually do the opposite in order to regulate pH. Nicely done. Next QuestionPrevious Question

46 Acid-Base Review test:  H 2 CO 3 splits into HCO 3 - & H + & it is the H + that stimulates either an increase or decrease in the rate & depth of respirations. TRUE FALSE

47 Correct!  You got it! This is because H +, along with CO 2 in the blood stream, act directly on respiratory centers in the brain. Next QuestionPrevious Question

48 Incorrect  The correct answer is TRUE. Please review the Respiratory Control Mechanisms slide as needed. Next QuestionPrevious Question

49 Acid-Base Review test:  Plasma concentration of HCO 3 - is controlled by the kidneys through reabsorption/regeneration of HCO 3 -, or elimination of buffered H + via the tubular systems. TRUE FALSE

50 Correct!  Yes! Reabsorption of filtered HCO 3 - or generation of new HCO 3 - & or H + ion elimination via phosphate & ammonia buffer systems help the kidneys regulate plasma concentrations of HCO 3 -. Next QuestionPrevious Question

51 Incorrect  Please review Mechanisms of Acid-Base balance if needed. Next QuestionPrevious Question

52 Acid-Base Review test:  The ratio of H + to HCO 3 - determines pH. TRUE FALSE

53 Incorrect  The answer is false. It’s the ratio of HCO 3 - to volatile H 2 CO 3 that determines pH. Next QuestionPrevious Question

54 Correct!  You’re right, the answer is false. REMEMBER: concentrations of volatile H 2 CO 3 are regulated by changing the rate & depth of respirations. Next QuestionPrevious Question

55 Acid-Base Review test:  Secreted H + couples with filtered HCO 3 - & CO 2 & H 2 O result. TRUE FALSE

56 Correct!  Well done! If you look back at the H + Elimination & HCO 3 - Conservation slide, this is part of the Na + /H + transport system. End Post testPrevious Question

57 Incorrect  Sorry, but the correct answer is true. End Post testPrevious Question

58 Metabolic Disturbances:  Alkalosis: elevated HCO 3 - (>26 mEq/L) Causes include: Cl - depletion (vomiting, prolonged nasogastric suctioning), Cushing’s syndrome, K + deficiency, massive blood transfusions, ingestion of antacids, etc.  Acidosis: decreased HCO 3 - (<22 mEq/L) Causes include: DKA, shock, sepsis, renal failure, diarrhea, salicylates (aspirin), etc.DKA  Compensation is respiratory-related

59 Metabolic Alkalosis:  Caused by an increase in pH (>7.45) related to an excess in plasma HCO 3 - Caused by a loss of H + ions, net gain in HCO 3 -, or loss of Cl - ions in excess of HCO 3 -  Most HCO 3 - comes from CO 2 produced during metabolic processes, reabsorption of filtered HCO 3 -, or generation of new HCO 3 - by the kidneys  Proximal tubule reabsorbs 99.9% of filtered HCO 3 - ; excess is excreted in urine

60 Metabolic Alkalosis Manifestations:  Signs & symptoms (s/sx) of volume depletion or hypokalemiahypokalemia  Compensatory hypoventilation, hypoxemia & respiratory acidosis  Neurological s/sx may include mental confusion, hyperactive reflexes, tetany and carpopedal spasm  Severe alkalosis (>7.55) causes respiratory failure, dysrhthmias, seizures & coma

61 Treatment of Metabolic Alkalosis:  Correct the cause of the imbalance May include KCl supplementation for K + /Cl - deficits  Fluid replacement with 0.9 normal saline or 0.45 normal saline for s/sx of volume depletion  Intubation & mechanical ventilation may be required in the presence of respiratory failure

62 Metabolic Acidosis:  Primary deficit in base HCO 3 - (<22 mEq/L) and pH (<7.35)  Caused by 1 of 4 mechanisms Increase in nonvolatile metabolic acids, decreased acid secretion by kidneys, excessive loss of HCO 3 -, or an increase in Cl -  Metabolic acids increase w/ an accumulation of lactic acid, overproduction of ketoacids, or drug/chemical anion ingestion

63

64 Metabolic Acidosis Manifestations:  Hyperventialtion (to reduce CO 2 levels), & dyspneadyspnea  Complaints of weakness, fatigue, general malaise, or a dull headache  Pt’s may also have anorexia, N/V, & abdominal painN/V  If the acidosis progresses, stupor, coma & LOC may declineLOC  Skin is often warm & flush related to sympathetic stimulation

65 Treatment of Metabolic Acidosis:  Treat the condition that first caused the imbalance  NaHCO 3 infusion for HCO 3 - <22mEq/L  Restoration of fluids and treatment of electrolyte imbalances  Administration of supplemental O 2 or mechanical ventilation should the respiratory system begin to fail

66 Quick Metabolic Review:  Metabolic disturbances indicate an excess/deficit in HCO 3 - ( 26mEq/L  Reabsorption of filtered HCO 3 - & generation of new HCO 3 - occurs in the kidneys  Respiratory system is the compensatory mechanism  ALWAYS treat the primary disturbance

67 Respiratory Disturbances:  Alkalosis: low PaCO 2 (<35 mmHg) Caused by HYPERventilation of any etiology (hypoxemia, anxiety, PE, pulmonary edema, pregnancy, excessive ventilation w/ mechanical ventilator, etc.)PE  Acidosis: elevated PaCO 2 (>45 mmHg) Caused by HYPOventilation of any etiology (sleep apnea, oversedation, head trauma, drug overdose, pneumothorax, etc.)  Compensation is metabolic-related

68 Respiratory Alkalosis:  Characterized by an initial decrease in plasma PaCO 2 (<35 mmHg) or hypocapnia  Produces elevation of pH (>7.45) w/ a subsequent decrease in HCO 3 - (<22 mEq/L)  Caused by hyperventilation or RR in excess of what is necessary to maintain normal PaCO 2 levelsRR

69

70 Respiratory Alkalosis Manifestations:  S/sx are associated w/ hyperexcitiability of the nervous system & decreases in cerebral blood flow  Increases protein binding of EC Ca +, reducing ionized Ca + levels causing neuromuscular excitabilityEC Ca +  Lightheadedness, dizziness, tingling, numbness of fingers & toes, dyspnea, air hunger, palpitations & panic may result

71 Treatment of Respiratory Alkalosis:  Always treat the underlying/initial cause  Supplemental O 2 or mechanical ventilation may be required  Pt’s may require reassurance, rebreathing into a paper bag (for hyperventilation) during symptomatic attacks, & attention/treatment of psychological stresses.

72 Respiratory Acidosis:  Occurs w/ impairment in alveolar ventilation causing increased PaCO 2 (>45 mmHg), or hypercapnia, along w/ decreased pH (<7.35)  Associated w/ rapid rise in arterial PaCO 2 w/ minimal increase in HCO 3 - & large decreases in pH  Causes include decreased respiratory drive, lung disease, or disorders of CW/respiratory muscles CW

73

74 Respiratory Acidosis Manifestations:  Elevated CO 2 levels cause cerebral vasodilation resulting in HA, blurred vision, irritability, muscle twitching & psychological disturbancesHA  If acidosis is prolonged & severe, increased CSF pressure & papilledema may resultCSF  Impaired LOC, lethargy/coma, paralysis of extremities, warm/flushed skin, weakness & tachycardia may also result

75 Treatment of Respiratory Acidosis:  Treatment is directed toward improving ventilation; mechanical ventilation may be necessary  Treat the underlying cause Drug OD, lung disease, chest trauma/injury, weakness of respiratory muscles, airway obstruction, etc.  Eliminate excess CO 2

76 Quick Respiratory Review:  Caused by either low or elevated PaCO 2 levels ( 45mmHg)  Watch for HYPOventilation or HYPERventilation; mechanical ventilation may be required  Kidneys will compensate by conserving HCO 3 - & H +  REMEMBER to treat the primary disturbance/underlying cause of the imbalance

77 Compensatory Mechanisms:  Adjust the pH toward a more normal level w/ out correcting the underlying cause  Respiratory compensation by increasing/decreasing ventilation is rapid, but the stimulus is lost as pH returns toward normal  Kidney compensation by conservation of HCO 3 - & H + is more efficient, but takes longer to recruit

78 Metabolic Compensation:  Results in pulmonary compensation beginning rapidly but taking time to become maximal  Compensation for Metabolic Alkalosis: HYPOventilation (limited by degree of rise in PaCO 2 )  Compensation for Metabolic Acidosis: HYPERventilation to decrease PaCO 2 Begins in 1-2hrs, maximal in 12-24 hrs

79

80 Respiratory Compensation:  Results in renal compensation which takes days to become maximal  Compensation for Respiratory Alkalosis: Kidneys excrete HCO 3 -  Compensation for Respiratory Acidosis: Kidneys excrete more acid Kidneys increase HCO 3 - reabsorption

81

82 DIAGNOSTIC LAB VALUES & INTERPRETATION

83 Normal Arterial Blood Gas (ABG) Lab Values:  Arterial pH: 7.35 – 7.45  HCO 3 - : 22 – 26 mEq/LmEq/L  PaCO 2 : 35 – 45 mmHg  TCO 2 : 23 – 27 mmol/Lmmol/L  PaO 2 : 80 – 100 mmHg  SaO 2 : 95% or greater (pulse ox) SaO 2  Base Excess: -2 to +2  Anion Gap: 7 – 14

84 Acid-Base pH and HCO 3 -  Arterial pH of ECF is 7.40 Acidemia: blood pH < 7.35 (increase in H + ) Alkalemia: blood pH >7.45 (decrease in H + ) If HCO 3 - levels are the primary disturbance, the problem is metabolic Acidosis: loss of nonvolatile acid & gain of HCO 3 - Alkalosis: excess H + (kidneys unable to excrete) & HCO 3 - loss exceeds capacity of kidneys to regenerate

85 Acid-Base PCO 2, TCO 2 & PO 2  If PCO 2 is the primary disturbance, the problem is respiratory; it’s a reflection of alveolar ventilation (lungs)PCO 2 PCO 2 increase: hypoventilation present PCO 2 decrease: hyperventilation present  TCO 2 refers to total CO 2 content in the blood, including CO 2 present in HCO 3 - TCO 2 >70% of CO 2 in the blood is in the form of HCO 3 - PO 2 also important in assessing respiratory function PO 2

86 Base Excess or Deficit:  Measures the level of all buffering systems in the body – hemoglobin, protein, phosphate & HCO 3 -  The amount of fixed acid or base that must be added to a blood sample to reach a pH of 7.40  It’s a measurement of HCO 3 - excess or deficit

87 Anion Gap:  The difference between plasma concentration of Na + & the sum of measured anions (Cl - & HCO 3 - )  Representative of the concentration of unmeasured anions (phosphates, sulfates, organic acids & proteins)  Anion gap of urine can also be measured via the cations Na + & K +, & the anion Cl - to give an estimate of NH 4 + excretion

88 Anion Gap  The anion gap is increased in conditions such as lactic acidosis, and DKA that result from elevated levels of metabolic acids (metabolic acidosis) A low anion gap occurs in conditions that cause a fall in unmeasured anions (primarily albumin) OR a rise in unmeasured cationsanionsalbumincations A rise in unmeasured cations is seen in hyperkalemia, hypercalcemia, hyper- magnesemia, lithium intoxication or multiple myeloma hyperkalemia, hypercalcemia, hyper- magnesemia

89

90 Sodium Chloride-Bicarbonate Exchange System and pH:  The reabsorption of Na + by the kidneys requires an accompanying anion - 2 major anions in ECF are Cl - and HCO 3 -Cl  One way the kidneys regulate pH of ECF is by conserving or eliminating HCO 3 - ions in which a shuffle of anions is often necessary  Cl - is the most abundant in the ECF & can substitute for HCO 3 - when such a shift is needed.

91 Acid-Base Interpretation Practice:  Please use the following key to interpret the following ABG readings.ABG  Click on the blue boxes to reveal the answers  Use the button to return to the key at any time  Or use the “Back to Key” button at the bottom left of the screen

92 Acid-Base w/o Compensation: Parameters: pH PaCO 2 HCO 3 - Metabolic Alkalosis Normal Metabolic Acidosis Normal Respiratory Alkalosis Normal Respiratory Acidosis Normal

93 Interpretation Practice:  pH: 7.31 Right!  PaCO 2 : 48 Try Again  HCO 3 - : 24 Try Again  pH: 7.47 Try Again  PaCO 2 : 45 Right!  HCO 3 - : 33 Try Again Back to Key Resp. Acidosis Resp. Alkalosis Metabolic Acidosis Resp. Alkalosis Metabolic Alkalosis Metabolic Acidosis

94 Interpretation Practice:  pH: 7.20Try Again  PaCO 2 : 36Try Again  HCO 3 - : 14 Right!  pH: 7.50 Try Again  PaCO 2 : 29 Right!  HCO 3 - -: 22 Try Again Metabolic Alkalosis Resp. Acidosis Metabolic Acidosis Metabolic Alkalosis Resp. Alkalosis Resp. Acidosis Back to Key

95 Acid-Base Fully Compensated: Parameters: pH PaCO 2 HCO 3 - Metabolic Alkalosis Normal >7.40 Metabolic Acidosis Normal <7.40 Respiratory Alkalosis Normal >7.40 Respiratory Acidosis Normal <7.40

96 Interpretation Practice:  pH: 7.36Try Again  PaCO 2 : 56Try Again  HCO 3 - : 31.4 Right!  pH: 7.43 Right!  PaCO 2 : 32Try Again  HCO 3 : 21Try Again Compensated Resp. Alkalosis Compensated Metabolic Acidosis Compensated Resp. Acidosis Compensated Resp. Alkalosis Compensated Metabolic Alkalosis Compensated Metabolic Acidosis Back to Key

97 Acid-Base Partially Compensated: Parameters: pH PaCO 2 HCO 3 - Metabolic Alkalosis Metabolic Acidosis Respiratory Alkalosis Respiratory Acidosis

98 Interpretation Practice:  pH: 7.47 Right!  PaCO 2 : 49Try Again  HCO 3 - : 33.1Try Again  pH: 7.33Try Again  PaCO 2 : 31Try Again  HCO 3 - : 16 Right! Partially Compensated Metabolic Alkalosis Partially Compensated Resp. Alkalosis Partially Compensated Metabolic Acidosis Partially Compensated Metabolic Alkalosis Partially Compensated Resp. Acidosis Partially Compensated Metabolic Acidosis Back to Key

99 Case Study 1:  Mrs. D is admitted to the ICU. She has missed her last 3 dialysis treatments. Her ABG reveals the following: pH: 7.32Low, WNL = 7.35-7.45 PaCO 2 : 32Low, WNL = 35-45mmHg HCO 3 - : 18Low, WNL = 22-26mEq/L  Assess the pH, PaCO 2 & HCO 3 -. Are the values high, low or WNL?WNL The pH is: The PaCO 2 is: The HCO 3 - is:

100 Case Study 1 Continued:  What is Mrs. D’s acid-base imbalance? Right! Try Again  Remember the difference between full & partial compensation. Go back & use the appropriate key if necessary. Partially Compensated Metabolic Acidosis Fully Compensated Resp. Acidosis

101 Case Study 2:  Mr. M is a pt w/ chronic COPD. He is admitted to your unit pre-operatively. His admission lab work is as follows: pH: 7.35WNL = 7.35-7.45 PaCO 2 : 52High, WNL = 35-45mmHg HCO 3 - : 50High, WNL = 22-26mEq/L  Assess the above labs. Are they abnormal or WNL? The pH is: The PaCO 2 is: The HCO 3 - is:

102 Case Study 2 Continued:  What is Mr. M’s acid-base disturbance? Try Again Right!  Think about appropriate interventions- if the problem is metabolic, the respiratory system compensates & vice versa Fully Compensated Metabolic Acidosis Fully Compensated Resp. Acidosis

103 Case Study 3:  Miss L is a 32 year old female admitted w/ decreased LOC after c/o the “worst HA of her life.” She is lethargic, but arouseable; diagnosed w/ a SAH.c/oSAH. Her ABG reads: pH: 7.48High; WNL = 7.35-7.45 PaCO 2 : 32Low; WNL = 35-45mmHg HCO 3 - : 25High; WNL = 22-26mEq/L  What is the significance of her ABG values? The pH is: The PaCO 2 is: The HCO 3 - is:

104 Case Study 3 Continued:  What is Miss L’s imbalance? Right! Try Again  Great Job! You’ve reached the end of the tutorial & I hope you found it helpful. Thank you! Resp. Alkalosis Metabolic Alkalosis

105 REFERENCES: http://www.healthline.com/galecontent/acid-base- balance?utm_medium=ask&utm_source=smart&utm_campaign=article &utm_term=Acid+Base+Equilibrium&ask_return=Acid-Base+Balancehttp://www.healthline.com/galecontent/acid-base- balance?utm_medium=ask&utm_source=smart&utm_campaign=article &utm_term=Acid+Base+Equilibrium&ask_return=Acid-Base+Balance. Retrieved 3/5/09. Porth, C.M. (2005). Pathophysiology Concepts of Altered Health States (7 th ed.). Philadelphia: Lippincott Williams & Wilkins. http://en.wikipedia.org/wiki/Dissociation_(chemistryhttp://en.wikipedia.org/wiki/Dissociation_(chemistry). Retrieved 3/6/09. http://www.clt.astate.edu/mgilmore/pathophysiology/Acid and Base.ppt#1http://www.clt.astate.edu/mgilmore/pathophysiology/Acid and Base.ppt#1. Retrieved 3/6/09. http://www.uhmc.sunysb.edu/internalmed/nephro/webpages/Part_E.htmhttp://www.uhmc.sunysb.edu/internalmed/nephro/webpages/Part_E.htm. Retrieved 3/6/09. http://medical-dictionary.thefreedictionary.com/Volatile+acidhttp://medical-dictionary.thefreedictionary.com/Volatile+acid. Retrieved 3/6/09.

106 REFERENCES http://wiki.answers.com/Q/How_does_the_phosphate_buffer_system_help_ in_maintaining_the_ph_of_our_bodyhttp://wiki.answers.com/Q/How_does_the_phosphate_buffer_system_help_ in_maintaining_the_ph_of_our_body. Retrieved 3/10/09. Alspach, J.G. (1998). American Association of Critical-Care Nurses Core Curriculum for Critical Care Nursing (5 th ed.). Philadelphia: Saunders. http://medical-dictionary.thefreedictionary.comhttp://medical-dictionary.thefreedictionary.com. Retrieved 4/14/09. Acid-Base Balance & Oxygenation Power Point. (2007). Milwaukee: Froedtert Lutheran Memorial Hospital Critical Care Class.


Download ppt "Acid-Base Balance Interactive Tutorial Emily Phillips MSN 621 Spring 2009 All images imported from Microsoft Clipart &"

Similar presentations


Ads by Google