interpretation of monitoring data Flashcards
what usually causes hypernatremia?
Low total body water
what is considered hypernatremia?
Na+ > 145
what are signs and symptoms of hypernatremia?
- CNS changes
- mental status changes
- irritability
- hyperreflexia
- ataxia
- seizures
- hypotension after induction
- *think of AP, more Na+ available so it AP increases
what treatment and management are needed with hypernatremia?
- delay surgery if signs and symptoms present
- if volume depleted, may need CVP monitoring
- replace free water
- may need vasopressors and/or inotropic support with hypovolemia
- VOD of drugs decrease, so may be more sensitive and need a decreased dose
- if hypervolemic hypernatremia, give diuretics
what is considered hyponatremia?
Na+ < 135
what is commonly the cause of hyponatremia?
high total body water
- more common than hypernatremia and usually more serious
- seen often with CHF
what are signs and symptoms of hyponatremia?
- CNS changes
- lethargy
- cramps
- decreased reflexes
- seizures
- Na+ < 120 associated with 50% mortality rate
what treatment and management are needed with hyponatremia?
- delay if possible and necessary to allow s/sx to resolve
- if volume overloaded may need CVP monitoring
- HF may need inotropic support
- loop diuretics
- acute symptomatic: tx with hypertonic saline
what should hypertonic saline be infused at?
- 5-2 mEq/hr
* too rapid a correction with 3% saline may lead to demyelination of pontine neurons and a condition known as central pontine myelinolysis
what is considered hyperkalemia?
K+ > 5.5
when is hyperkalemia commonly seen?
- ESRD
- hemolysis (cell destruction releases K+)
- DKA
- drug therapy
what are signs and symptoms of hyperkalemia?
- usually deal with electrical conduction system of the heart
- K+ >6.0 can see prolonged PRI and peaked T waves
what is treatment and management of hyperkalemia?
- delay if needed
- avoid hypoventilation and high EtCO2 and acidosis
- for every 10 mmHg change in EtCO2, K+ changes 0.5 mEq (may not want to do MAC d/t hypoventilation)
- avoid Succs (increases K+ 0.5 mEq)
- D10 plus insulin (glucose drives K+ into cell)
- Ca++ (moves threshold higher away from rmp so wont see as many effects of hyperkalemia)
- Lasix can help excrete
what is considered hypokalemia?
K+ < 3.5
what are common causes of hypokalemia?
- diuretics
- N/V
- GI losses (NG suction)
what are signs and symptoms of hypokalemia?
- muscle weakness
- cramps
- PVCs
- U waves (right after T wave)
- flattened T waves
- low ST segment
- digoxin toxicity
what are treatment and management of hypokalemia?
- delay if needed
- avoid hyperventilation and low EtCO2 and alkalosis
- K+ replacement (20 mEq KCL over 30-45 min)
- watch for prolonged muscle relaxation form NMBs
- avoid glucose containing fluids
what are common causes of hypercalcemia?
- hyperparathyroid (PTH)
- cancer
- breast cancer alone causes 25-50% of cases
what are signs and symptoms of hypercalcemia?
- N/V
- decreased deep tendon reflexes
- hypotonia
- confusion
- lethargy
what are treatment and management of hypercalcemia?
- maintain hydration and UOP
- loop diuretics
- *avoid thiazide diuretics, they increase Ca++
- monitor muscle relaxation w/ nerve stimulator (enhances NMB)
what are common causes of hypocalcemia?
- decreased PTH
- decreased Mag (causes increased end-organ resistance to PTH)
- alkalosis (increased pH causes Ca++ bind to protein)
- massive blood transfusion (citrate binds Ca++)
- pancreatitis
- hypoparathyroidism
- accidental removal of parathyroid
what are signs and symptoms of hypocalcemia?
- tetany
- twitching
- laryngospasm
- tingling lips and fingers
- spontaneous APs are generated
how does Ca++ and K+ affect rmp and threshold?
- high K+ moves rmp up closer to threshold (more AP)
- low K+ moves rmp down away from threshold (less AP)
- high Ca++ moves threshold up away from rmp (less AP)
- low Ca++ moves threshold down away from rmp (more AP)
what are common causes of hypermagnesium?
- infusions like for preeclampsia and pheochromocytoma
* rare
what are signs and symptoms of hypermagnesium?
- lethargy
- loss of deep tendon reflexes
- paralysis
- hypotension
- heart block
- acidosis worsens
what are treatment and management for hypermagnesium?
- temporary dialysis
- loop diuretics
- reduce muscle relaxants
- adequate ventilation to avoid acidosis
what are common causes of hypomagnesium?
- poor GI absorption
- dialysis
- ETOH
what are signs and symptoms of hypomagnesium?
- ventricular dysrhythmias
- muscle weakness
- twitching
- tetany
what are treatment and management for hypomagnesium?
- supplemental Mag
- avoid diuretics (Mag follows Na+)
- caution with muscle relaxants
- *Mg++ helps treat and correct refractory hypocalcemia and hypokalemia
what is the FEV1 in pulmonary function tests?
volume forcefully exhaled in one second
what is the FVC in pulmonary function tests?
total volume that can be forcefully exhaled
how are FEV1 and FVC used in pulmonary function tests?
ration of FEV1/FVC used to distinguish between obstructive vs. restrictive pulmonary disease
what is indicative of obstructive disease?
- both FEV1 and FVC are low
- ratio is < 0.7
- mild = 0.6-0.7
- moderate = 0.4- 0.6
- severe = < 0.4
- cant get as much of what is taken in out
what is indicative of restrictive disease?
- both FEV1 and FVC are low
- ratio is > or equal to 0.7
- cant get in much but can get most of it out in good timing
what is mixed venous (SvO2) and central venous (ScvO2)monitoring?
indicator of balance between oxygen delivery and consumption
- normal range 68-80%
- normal extraction 25% (amount taken from blood to supply tissues, etc.)
what are the four primary factors that impact SvO2?
- oxygen consumption (VO2)
- hemoglobin level (hgb)
- cardiac output (CO)
- arterial oxygen saturation (SaO2)
how is O2 consumed?
- consumption varies by organ
- a lot taken up by coronary sinus
- a lot used for myocardium and skeletal muscle
when hgb, SaO2, and VO2 are stable, changes in SvO2 indicate what?
changes in CO
SVO2 < 30% usually indicates what?
anaerobic metabolism
how does the body compensate for increased VO2?
increasing CO
what decreases SVO2?
- increased VO2: fever, hyperthermia, stress, pain, shivering
- decreased hgb: anemia, hemolysis
- decreased SaO2
- decreased CO: MI, CHF, hypovolemia
what increases SVO2?
- decreased VO2: cyanide toxicity, CO poisoning, hypothermia, sepsis, analgesia, sedation, ventilation
- increased hgb: volume depleted
- increased SaO2
- increased CO: burns, inotropic drugs
why is there an increase in SVO2 with sepsis?
in severe late stage sepsis, mitochondria are essentially poisoned by endotoxin leading to a defect in oxygen utilization
what is the most reliable method of temperature monitoring?
bladder
what is ejection fraction?
- measures the degree of systolic dysfunction
- stroke volume/ end-diastolic volume
- typical SV approx. 70 ml, typical EDV approx. 120
- typical EF approx. 58%
- American society of echocardiology: normal EF 55% or >
what are the different grades of systolic dysfunction?
- mild = 45-54%
- moderate = 30- 44%
- severe = < 30%
what happens with a poor EF?
- drugs take longer to circulate, so pt. will take longer to induce
- propofol not a good drug with poor EF patients
