Acid Base Disorders Flashcards
Compensation for a metabolic disorder occurs via the __ and takes approximately __ hours
Lung: 12-24 hours
During acidosis, serum potassium
increases
During alkalosis, serum potassium
decreases
a patient with nasogastric suctioning output exceeding 2L a day is likely to manifest
metabolic alkalosis
acidemia
pH <7.35
alkalemia
pH >7.45
normal blood pH range
7.35-7.45
pCO2 normal range
35-45
normal bicarbonate range
23-25
how to correct metabolic acidosis with parenteral nutrition ?
increase acetate
PN metabolites that are acidic
arginine, lyseine, histidine, methionine, cysteine
Metabolic acidosis is associated with _____kalemia
hyperkalemia ; correction of metabolic acidosis re distributes potassium into the intracellular space to correct hyperkalemia
when a patient is hyperkalemic, what can be given to correct it?
bicarbonate as the body is in a state of acidosis
Decrease pH, Increased PCO2, Normal Bicarb indicates which acid base disorder
respiratory acidosis
How to correct respiratory acidosis in PN
avoid overfeeding to prevent excessive CO2 production , less carbohydrate
Causes of respiratory acidosis
HYPOventilation, sleep apnea, pneumothorax, COPD, ARDS, hypophosphatemia
Causes of respiratory alkalosis
HYPERventilation (lost all your CO2), anxiety, pneumonia, high altitude, catecholamines (compromised lung function)
Normal Anion Gap
10-12
Causes of normal anion gap metabolic acidosis
providing high amounts of chloride in blood (ie IVF)
Bicarbonate loss from high output fistula or ileostomy or excessive diarrhea
Impaired renal function
D-Lactic acidosis
What metabolites are used to calculate Anion Gap?
Sodium - Chloride + Bicarb
what are causes of high anion gap metabolic acidosis
renal failure, thiamine deficiency (build up of lactate), ketoacidosis, SIBO, diuretic use
If HCO3 and pH move in the same direction it is a _____ disorder
metabolic disorder
If PCO2 and pH move in opposite directions it is a ____ disorder
respiratory disorder
First line of defense in acid base imbalance
Buffers
Second line of defense in acid base imbalance
Lungs
Primary buffer in the body
bicarbonate
a mixed acid base disorder occurs when pCO2 and HCO3 move in the ____ direction (s)
Opposite
a simple acid base disorder occurs when pCO2 and HCO3 move in the ______direction (s)
Same
How to alter PN in the setting of respiratory alkalosis
None
In respiratory acidosis, pCO2 _____ and pH ____
increases, decreases
pH and hydrogen ions move in ___ direction (s)
Opposite
In respiratory alkalosis, pCO2 ___ and pH ___
decreases, increases
In metabolic acidosis HCO3 ___ and pH ___
decreases, decreases
What can you alter in PN in the setting of metabolic acidosis
Increase acetate
acidic IVF solutions
D5W and D5w 1/2 NS
In metabolic alkalosis HCO3 ___ and pH ___
increases, increases
IVF treatment of metabolic alkalosis
Isotonic saline + KCl
During acidosis, hydrogen ions are prominent in the serum. In order to correct the acidosis, Hydrogen ions are pumped _____ the cell, in exchange for ____ which exits the cell. Therefore the patient becomes hyper______
into the cell, potassium, hyperkalemic
During alkalosis potassium moves _______ the cell while hydrogen ions move ____ of the cell. Therefore the patient becomes hypo_____
into the cell, out of the cell, hypokalemic
Case: a 42 year old male is admitted with dizziness and weakness. He has a normal blood pressure of 120/80 mmHg while sitting but a low blood pressure while standing (100/64 mmHg) . This suggests orthostatic hypotension. He has had a history of vomiting. Sodium is 129, Potassium is 2.5, chloride is low, bicarbonate is 58, Creatinine is 1.9, BUN is 32, pH is 7.52, pCO2 is 63, pO2 is 68. What disorder is this? What is the cause? What is the expected compensation? What is the proposed treatment?
Metabolic Alkalosis caused by loss of hydrochloric acid from the stomach due to vomiting, it is expected that he will decrease his respiratory rate to increase is concentration of PCO2 (hypo ventilate). He can be treated with Normal saline with KCl as potassium is also low, Normal saline is an acidic IVF solution.
Case: a 31 year old male is admitted with abdominal pain and weakness. He has a respiratory rate of 24 breaths per minute (normal is 13-16) and has a history of chronic IV drug use. His sodium is 136, potassium of 5.1, chloride of 100, HCO3 of 14, creatinine of 10, BUN of 120, pH of 7.28, pCO2 of 30 , pO2 of 100 and HCO3 13. What disorder is this? What is the cause? What is the expected compensation? What is the proposed treatment?
Metabolic acidosis caused by kidney failure. It is expected that his respiratory rate will increase to get rid of acidic CO2 in order to compensate (hyperventilation). Treatment would be dialysis, NaHCO3
total body water for an adult male is __%
60%
total body water for females is __%
50%
which conditions would increase a person’s fluid requirements
ileostomy, high output fistula, fever
the older you are the ____ muscle mass you have there fore less% body water
lower
functions of water in the body
metabolic functions
maintains temperature
circulatory function
if the abnormal accumulation of fluid occurs in the ICF compartment or body cavities, the following is most likely to occur
edema
the component of plasma that is the principal determinant of colloid oncotic pressure
albumin
the number of osmotically active particles per KG of solvent is known as
osmolality
the body’s normal osmolality range
290-310 mOsm/L
the direction and extent of water movement between fluid compartments is determined by the
osmolality
during osmosis, fluids will shift from an area of lower concentration to an area of higher concentration until the water by
osmosis
in addition to osmosis the regulation of body fluid compartments also occurs via (3 items)
diffusion, filtration and sodium potassium pumps
which organs maintain the composition and volume of body fluid (6)
heart, lungs, kidneys, pituitary glands, adrenal gland, parathyroid gland
As ADH increases, water retention _____
increases
the majority of sensible water losses occur via
urine
the majority of insensible losses of fluid come from the _____ and _____
skin and lungs
third spacing, polyuria, and excessive GI losses are potential losses of
fluid
3 potential causes of fluid overload include
heart failure, cirrhosis, steroid therapy
estimated fluid needs for patients in critical illness and sepsis
30-40mL/kg/day
a patient getting PN that provides NaCl 50mEq/L, KCl 20mEq/L, K Phos 30mEq/L with lab values Na 140, K 4.0, Cl 119, CO211, what is an appropriate adjustment for this PN
Change NaCL to Na acetate, add acetate
in providing PN to a patient with metabolic alkalosis, the clinician should pay careful attention to the provision of salts as
acetate
