data lap

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data lap
2011-11-13 15:09:38
exam midterm

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  1. who maintain the acid base balance
    • lungs
    • kidneys
    • complex systems of buffers
  2. princible buffer and the other buffers
    • princible buffer is carbonic acid/ bicarbonate system
    • other buffers are proteins, phosphate and HB
  3. ph : ???
    lower: ??
    higher ??
    • ph: 7.36- 7.44
    • lower acidemia
    • higher alkalemia
  4. PaCO2
    • Provides information about the adequacy of lung function
    • in excreting CO2. Increase CO2 reflects inadequate ventilation.
  5. PO2 (100 mm hg)
    has to relate the result ot the oxygen-hgb dissociation curve
  6. serum CO2
    this reflect bicarbonate so it is a measure of a base
  7. chloride
    reflects alteration in fluid status or acid- base balance.
  8. lactate
    is a byproduct of anaerobic metabolism of glucose. in patients with inadequate tissue perfusion or increased tissue metabolic rates anaerobic metabolism predominates. lactate level increases
  9. metabolic acidosis
    • low ph, low serum bicarbonate, body compensate by hyperventilation and low PaCo2.
    • causes are:
    • renal failure
    • ketoacidosis (DM, starvation, ethanol)
    • lactic acidosis( shock, liver disease)
    • intoxication (salicylates)
    • drugs( amphotericin, li, carbonic anhydrase inhibitors )
  10. metabolic alkalosis
    • high PH, high serum bicarbonate, compansate by hypoventilation
    • causes :
    • vomiting
    • mineralcorticoid excess
    • hypokalemia
    • alkali administration
    • diuretic therapy
  11. respiratory acidosis
    • decrease ph, increase PaCO2, increase bicarbonate
    • cause is hypoventilation either :
    • CNS disorder,
    • neuromuscular disorder ( mysthemia gravis)
    • lung disorder( airway obstruction, asthma, COPD, pulmonary edema)
  12. respiratory alkalosis
    • increase ph, decrease CO2, decrease bicarbonate
    • causes:
    • hypoxemia
    • lung disease( pneumonia)
    • CNS stimulation (CvA, Fever, anxiety)
  13. myocardial dysfunction due to:
    • AMI
    • hypertensive
    • valvular heart disease
    • congenital heart disease
    • cardiomyopathy
  14. creatinine kinase
    • Normal values vary depending on the individual muscle mass. Males tend to have higher
    • values
    • Levelsrise sharply 6-8 hours after AMI.

    They can also increase after trauma, IM injection, surgery, vigorous excercise.

    • There are 3 CK isoenzymes. Elevated CK-MB is
    • relatively specific for MI.
  15. Lactate dehydrogenase (LDH) & other tests
    • High LDH concentration occur in skeletal muscle, liver, RBC, kidneys, & heart.
    • After AMI LDH does not increase until 12 hours after chest pain. It peaks at 3-4 days.
    • LDH has 5 isoenzymes. In the heart LDH1 & to a lesser extent 2 predominate.
    • Other blood tests: AST, Myoglobin(Within 2hours & clear rapidly).
    • CRPwill be also elevated in acute MI.
  16. Troponin
    • cardiac troponins I & T This chemical is present in heart muscle cells. Damage to heart muscle cells releases troponin into the bloodstream. with an MI, the blood level of troponin increases within 3-12 hours from the onset of chest
    • pain, peaks at 24-48 hours, and returns to a normal level over 5-14 days.
    • Very specific to cardiac tissue, 100% of AMI will have elevated levels, considered best marker
    • due to high specificity.
  17. Diagnosis of AMI
    • •Two biochemical markers should be used for routine diagnosis.
    • •With definitive ECG changes no need for markers (T-wave inversion or elevation, ST
    • elevation, appearance of Q-waves.

    •In the absence of definitive ECG changes do serial tests.
  18. Electrocardiography & other exams
    • •ECG: Diagnosis &
    • location of MI. Cardiac rhythm.

    •Echocardiography:Visualize structural anatomy & assess LV ejection fraction. (Wall thickness & motion).

    • •Cardiac angiography. (Diagnose presence of CAD, visualize coronary arteries, estimate cardiac & valvular performance)
    • •Myocardial perfusion imaging

    •CT scan ,MRI, PET scan.
  19. The liver
    • •It is the largest solid organ in the body. Weighing between 1200 7 1500 g. It is
    • located in the right upper quadrant of the abdomen.
    • •It produces bilirubin, a product of Hgb breakdown, excreted via the bile duct.
    • •Plays a major role in AA & carbohydrate metabolism. (Coagulation factors & albumin)
    • •Most lipids & lipoprotein including cholesterol are synthesized in the liver.

    • •The primary location for most drug & hormonal metabolism including barbituates, certain
    • tranquilizers, sex hormones, H2-blockers,& many narcotics.
    • •It is affected by many systemic diseases, but is capable of regeneration.
  20. Tests of liver synthetic capabilities
    • •Total protein is the
    • sum of Albumin & globulin.
    • •Albumin: 3.5-5 g/dL. Important in maintaining plasma oncotic pressure. Symptoms when it is less than 2. & in cases where the synthetic ability of the liver is affected. Other causes is malabsorption, nephrotic syndrome, malnuitrition.
    • •Globulin increase in inflammation.
    • •Prothrombin time: Many factors synthesized in the liver.
  21. Cholestatic liver disease
  22. •Alkaline phosphatase: Normal values vary with age, bone disorders can increase its level.
    • •5’nucleotide. It is elevated only in liver diseases.
    • •Gamma GT: No origin in bone or placenta. Can be elevated in non liver disease, but a
    • marked elevation points to liver.
  23. Hepatocellular injury
    • •Aminotransferases are the most frequent measured indicators of hepatic diseases. Both AST (SCOT), & ALT (SCPT) are very sensitive indicators.
    • •Markedly high levels indicate: viral hepatitis, severe drug toxicity, or ischemic hepatitis.
  24. Bilirubin
    • •Jaundice becomes visible when total bilirubin is 2-4 mg/dL.urine may be dark.
    • •Uncojugated/indirect: Increase in hemolytic process. Large hematoma, transfusion of old blood, hemolytic anemia, neonatal jaundice.
    • •Conjugated/Direct :reflect liver disease.
  25. Pancreas
    • •Amylase, an enzyme, helps break starch into its glucose molecules. Found in pancreas & salivary glands. It is the single most useful biochemical test to diagnose acute pancreatitis. It could be elevated in Alcholism, drugs, gallstone, hypercalcemia, trauma.
    • •Lipase increase in acute pancreatitis less sensitive but more specific.
  26. Helicobacter pylori
    •IT is a Gram-negative, microaerophilic bacterium that can inhabit various areas of the stomach, particularly the antrum. It causes a chronic low-level inflammation of the stomach lining and is strongly linked to the development of duodenal and gastric ulcers, stomach cancer. Over 80 percent ofindividuals infected with the bacterium are asymptomatic.
  27. Hyponatremia
    • •Normal serum Na: 136-145 mEq/L
    • •When encounter an asymptomatic patient the clinician should suspect an error.
    • •Agitation,anorexia, disorientation, depressed DTR, seizures.
    • •Hyponatremia with low body Na: vomiting, diarrhea, pancreatitis, diueritics.
    • •With normal body Na: dilutional type,hypothyroidism, glucocorticoid deficiency, increase water adminstration

    •High total Na: e.g. Chronic heart failure, cirrhosis,CRF.
  28. Hypernateremia
    •It is less common than hyponateremia

    • •Found in those with impaired thirst mechanism(neurohypophyseal lesion), or inability to replace water depleted from skin, respiration, renal, & GI.
    • •Manifestation is primarily neurological.
  29. Hypokalemia
    •Normal range: 3.5-5.0 mEq/mL.

    • •Intracellular shifting: Alkalosis, insulin.
    • •K loss: From kidney or GI
    • •GI:vomiting, diarrhea, laxative abuse, intestinal fistula.
    • •Decrease intake: e.g. K-free IV fluid.
    • •Renal: Corticosteroids, Amphotericin B, Diuretics, Hyperaldosteronism, Cushing syndrome, licorice abuse.
    • •Primarily concerned on cardiac rhythm also muscle arreflxia.
  30. Hyperkalemia
    • •Extracellular shifting: metabolic acidosis.
    • •Increased intake: Hemolysis, rhabdomyolysis, muscle crushinjuries, burns, Salt substitutes.
    • •Decrease output: Chronic renal failure, deficiency of adrenal steroids, addison’s disease.
    • •Drugs:K-sparing diuretics, NSIDs, heparin,Angiotensin- converting enzyme inhibitor.
    • •The main signs & symptoms are cardiological

    • •Fictitious Hyperkalemia in hemolyzed sample.
    • •Also if sample clotted.
  31. Magnesium
    • •Normal range: 1.5-2.2 mEq/L
    • •Hypo:more common than hyper, result from GI or kidney loss, poor intestinal absorption, chronic alcohol consumption. Manifestation weakness, tremor, tetany, personality problems & cardiac.
    • •Hyper:Increase intake e.g. Antacids, rapid infusion. Neuromuscular signs
  32. Calcium
    • •8.5-10.8 mEq/mL
    • •Plays an important role in N-M activity, endocrine functions, blood coagulation, & bone metabolism.
    • •Ca is regulated by PTH, serum P, vit.D, & target organ
    • •Found as complex bound (6%), Protein bound (40%), Free (54%)
  33. Hypocalcemia
    • •Medications: Calcitonin, Clucocorticoids, loop diuretics,
    • phosphate salts
    • •Hyperphosphatemia, hypoalbuminemia, hypomagnesemia, hypoparathyroid, pancreatitis, renal
    • failure, secondary hyperpara. Vit D deficiency.
    • •Finger numbness, burning of extremities, tetany.
  34. Hypercalcemia
    • •Malignancy, primary hyperparathyroidism.
    • •Thiazide
    • •Calcium supplements, immobilization, Excess vit D, Estrogen, progesterone
    • •Lethargy, psychosis
    • •Factitious results if tourniquet is left too long or if albumin is very high
  35. Phosphate
    • •Normal: 2.6-4.5
    • •Hypo:Increase renal excretion, intracellular shifting, decrease phosphate or vit. D intake. Neurological irritability occurs when P is less than 2 mEq/mL.

    • •Hyper: Decrease renal excretion (CRF), extracellular shifting, Increase vitD or phosphate
    • intake.. Symptoms are primarily hypocalcemia
  36. The
    • •They filter about 180L of fluid each day; of this amount they excrete 1.5L as urine. Thus, more than 99% of the glomerular filtrate is absorbed back into the blood
    • stream as urine. Many solutes that are not reabsorbed are concentrated in the urine e.g. creatinine, urea.
    • •GFRis the volume of water filtered out of plasma per minute through the
    • surrounding capillary walls into Bowman’s spaces.
  37. Blood urea nitrogen (BUN)
    • •Normal range: 8-20 mg/dL.
    • •BUN is the concentration of N in the serum & not blood. It reflects GFR but not ideal. It depends also on urea production in the liver& tubular reabsorption.
    • •BUN can be used to assess hydration status, renal function, protein tolerance,& catabolism in numerous clinical settings
    • •Azotemia: other than renal failure may be caused by a high protein diet, upper GI bleeding (blood being digested), administration of corticosteroids, tetracycline or any other drug with antianabolic effects.
    • •Decreased BUN does not have pathophysiological consequences.
  38. Common causes of BUN elevation
    • 1-Prerenal: Decreased renal perfusion secondary to blood loss, dehydration or shock.
    • Increase protein breakdown: GI bleed, crash
    • injury, burn, excess protein intake, corticosteroid, tetracycline.
    • 2- Intrarenal: Acute & chronic renal failure
    • 3- Postrenal: Obstruction of ureter or bladder.
  39. creatinine
    • •Normal range: 0.7-1.5 mg/dL.
    • •Non protein nitrogenous biochemicals of the blood. After synthesis in the liver , creatinine is taken by muscle
    • cells & is stored as creatinine phosphate.
    • •A rise in SCr. Almost always indicates worsening renal function.
    • •Muscle mass, & some dugs affect Scr. levels
  40. Drugs reported to cause increase serum creatinine

    • •Amphotericin
    • B


    •Cisplatin, methotrexate

  41. BUN /Cr. ratio
    • •Ratio greater than 20/1 suggest prerenal causes.
    • •Ratio 10/1 to 20/1 suggest intrinsic renal damage..
    • •Both types may occur simultaneously confounding typical interpretations.
  42. Creatinine clearance
    • •Crcl provides the best approximation of the GFR.
    • •Tests asked to assess kidney function, moniter patients on nephrotoxic drugs, or for dosage adjustment.
    • •Crcl= UV/P x 1.73/BSA
    • •U: Creatinine in urine
    • •V: Urine volume
    • •P: Plasma creatinine

    • •BSA: Body surface area (Standard normogram).
    • •Unadjusted clearance: Ucr. x 0.07 / SCr.