Man - ACID BALANCE and Shapiro hypertension Flashcards
Blood pH range compatible with life
6.8 - 7.8
The normal physiological pH
7.35 - 7.45
Primary change in metabolic acidosis/alkalosis
[HCO3-]
Major change in respiratory acidosis/alkalosis _____
PCO2
Normal [HCO3-]
23-25 mEQ/L
24
Normal Pco2
35-45mmHg
40
3 defense mechanism for pH maintenance
Extracellular and intracellular buffering
Adjustments in Pco2 by alterations in ventilatory rate
Adjustments in renal acid excretion
Metabolic disorders are buffered primarily in the
Extracellular fluids
What are other extracellullar buffers besides bicarb?
HPO4
Protein
Inside the cells, H+ is titrated by ?
Phosphate and proteins
Renal response to metabolic acidoses takes _____ to complete
Several days.
The renal response to acidosis is ?
Increase secretion of hydrogen ions
Reabsorb the entire filtered load of bicarb
Increase production and excretion of NH4
The renal response to alkalosis?
Decrease secretion of H ions
Decrease HCO3 reabsorption
What kind of defense mechanisms are used in respiratory disorders?
ICF buffers
Renal NAE changes
What kind of defense mechanisms are there in metabolic disorders?
ICF and ECF buffers
Ventilatory changes
NAE changes
A graph that helps predict the different disorders in acid base balance and their compensation. Based on the blood pH and the amount of bicarb in solution
Davenport diagram
Low plasma bicarbonate and pH
Due to addition of nonvolatile acid
The removal of a nonvolatile alkali
Or the failure of the kidneys to excrete sufficient net acid
Metabolic acidosis
Unmeasured anions are
Proteins, phosphates, sulfates, etc.
Unmeasured cations are
Calcium, magnesium, minerals, etc.
A way of approximating the total concentration of anions other than Cl- and HCO3- in the plasma.
The sum of the “routinely measured” cations minus the sum of the ‘routinely measured’ anions in the blood
Anion gap
Normal value for anion gap??
If K is not used to calculate?
16mEq/L
Less than or equal to 12 if K is not used
Causes of metabolic acidosis with high anion gap ?
Diabetic ketoacidosis
Saolicylate poisoning
Lactic acidosis
Metabolic acidosis with normal anion gap
Decreased bicarbonate is replaced by Cl-
Metabolic acidosis with ____ anion gap has decreased bicarbonate replaced by ‘unmeasured anions’
High
A high anion gap tells you that ?
An acid has been added!
Characterized by increased plasma pH and [HCO3-]
Can develop by the addition of nonvolatile alkali to the body (ingestion of antacids)
Or
The loss of nonvolatile acid (vomit)
Metabolic alkalosis
Characterized by elevated pCO2 and reduced plasma pH
Can develop by inadequate ventilation (brain centers suppressed)
Or
Impaired gas diffusion (pulmonary edema)
Respiratory acidosis
What are the responses for respiratory acidosis?
Increased renal excretion of NH4 and acids, and increased reabsorption of bicarbonate
Intracellular compartment buffering
Characterized by reduced pCO2 and increased pH
Can be caused by stimulation of the respiratory centers
Respiratory alkalosis
Compensation for respiratory alkalosis?
Buffering ICF
Renal compensation; decrease NH4 excretion, increase Bicarb excretion
A second acid-base disturbance compounding the first acid-base disturbance
Combined simple
Respiratory failure followed by renal failure is an example of ?
A combined simple
Respiratory acidosis and renal failure
People with hypertension are ___- times more likely to get CAD
3
People w/ hypertension are ___ times more likely to develop CHF
6
People with hypertension are ____ times more likely to develop stroke`
7
The closest link between hypertension and another disease is with _____
Stroke
Usual clue is hypokalemia
Hypokalemia in face of ACE inhibitor is red flag
Goal is to demostrate suppressed renin and non-suppressible aldosterone
Try to stimulate renin with diuretic and suppress aldosterone with volume expansion
Evaluation for hyperaldosteronism
Type of renovascular hypertension.
Seen in :
Young
Female > male
Familial history
Responds well to correction
UNCOMMON in people of african descent
Fibromuscular dysplasia
Who should be evaluated for Secondary Hypertension?
Hypertension presenting “early”
Hypertension w/o family history
Severe or difficult to control hypertension
Medical injury
Evidence for acute vascular injury in context of hypertension
Generally evidence for acute vascular injury is found on the retinal examination
Actual number may not be all that high.
Malignant hypertension
The vast majority of hypertension is ________
Essential (primary)
The most common cause of secondary hypertension?
Sleep apnea (as high as 50% of secondary)
___________ is necessary to produce sustained hypertension
Renal involvement
Altered renal _______ necessary to maintain hypertension
Set point
Risk factors for atherosclerosis:
Smoking
Dyslipidemia (high LDL or low HDL)
Age > 60
Male or postmenopausal female
Family history
JNC 7 recommendation for uncomplicated hypertension
Diuretics
JNC 7 agent recommendations for hypertension w/ diabetes
ACE inhibitors or ARB if proteinuria present
JNC 7 agent recommendations for hypertension w/ Myocardial infarction
Beta blocker
JNC 7 agent recommendations for systolic heart failure
ACE inhibitors or ARB
