keywords:
Bookmark and Share



Front Back
What are the seven ways to treat hyperkalemia?
1.  Give calcium gluconate
2.  Give glucose/insulin
3.  Give sodium bicarbonate
4.  Give diuretics (to increase excretion)
5.  Give kayexalate (potassium exchange resins)
6.  Use hemodialysis
7.  Hyperventilate the patient
How do plasma K+ and PaCO2 correlate?
[K+] decreases 0.5 mEq1/L for each 10 mm Hg decrease in PaCO2
What should be given to the hyperkalemic patient when ventricular dysrhythmias appear?
Calcium
What are the six physiologic functions that require Ca?
1.  Action potentials in smooth and cardiac muscle
2.  Blood coagulation
3.  Bone formation
4.  Muscle contraction
5.  Membrane excitability (Ca controls threshold)
6.  Neurotransmitter release
What results from a rapid decrease in plasma Ca?
Skeletal muscle spasm (laryngospasm) and tetany
What are the nine S/S of Hypocalcemia?
1.  Numbness
2.  Circumoral paresthesia
3.  Confusion
4.  Seizures
5.  Hypotension
6.  Increased LV filling pressures (due to decreased contractility)
7.  Prolonged QT interval
8.  Skeletal muscle weakness
9.  Fatigue
What sign is a monitor for hypocalcemia?
Chvostek's sign (contracture of facial muscle with tapping)
What ECG changes are seen with hypocalcemia?
1.  Prolonged QT interval
2.  Increased ST segment duration
3.  Flat or inverted T-waves   
What are the functions of Magnesium?
(It both resembles and antagonizes Ca)
1.  Functions as a cofactor in many enzyme pathways
2.  Regulates the Na/K pump
3.  Regulates adenylate cyclase
4.  Regulates slow Ca channels
5.  It antagonizes Ca (an endogenous Ca channel blocker)
6.  Controls the threshold potential (membrane stabilizer)
7.  Regulation of the release of acetylcholine from nerve terminals
Three S/S of Hypermagnesemia?
1.  Coma
2.  Hypoventilation
3.  Hypotension
Where are the heat loss and heat gain centers located?
Loss: Anterior (preoptic) hypothalamus
Gain: Posterior hypothalamus
What is hypothermia associated with?
Incresed SVR and myocardial depression (decreased CO).  It is also associated with increased blood viscosity, left shift of O2Hgb curve, impaired coagulation, and thrombocytopenia.  It is further associated with decreased drug elimination 2nd to decreased hepatic blood flow and metabolism.  Decreased renal blood flow and clearance slow renal excretion of drugs.
What are the eight physiologic effects of hypothermia?
1.  Decreased O2 consumption (decreased CO2 production)
2.  Increased SVR
3.  Cardiac dysrhythmias
4.  L O2Hgb curve shift
5.  Coagulopathy
6.  Increased blood viscosity
7.  Impaired renal function
8.  Decreased drug metabolism
What are the eleven clinical manifestations of MH?
1.  Hypercarbia
2.  Tachycardia
3.  Tachypnea
4.  Hyperthermia
5.  Hypertension
6.  Cardiac dysrhythmias
7.  Acidosis (metabolic)
8.  Hyperkalemia
9.  Skeletal muscle rigidity
10.  Myoglobinemia
11.  Hypoxemia
What is the earliest sign of MH?  How does it progress?
Incresed ETCO2 is the earliest sign; Temp may increase 1-2 C every 5 min.  Sux and volatile agents trigger.  MMR is an early sign.  <1% of children experience MMR after exposure to halothane and sux.  CPK > 20,000 confirms the dx after MMR.  Halothane-caffeine contracture is the standard dx test, but has too many false positives.
Eight actions for initial management of MH?
1.  Discontinue inhaled agents & Sux
2.  Hyperventilate with 100% O2
3.  Administer dantrolene
4.  Treat acidosis with NaHCO3 (1-2 mmoles/kg)
5.  Decrease body temp to 38 C
6.  Replace anesthesia circuit and CO2 absorber
7.  Monitor ETCO2 & ABGs
8.  Treat hyperkalemia and dysrhythmias if necessary    
How is dantrolene dosed?  How does it work?
It decreases the release of Ca from the SR in skeletal muscle and causes relaxation.  Initial dose is 2.5 mg/kg followed by 1-2 mg/kg boluses to a max of 10 mg/kg.  Therapeutic blood level is 2.5 mg/mL.  Vials contain 20 mg and is mixed with 60 mL of sterile distilled H20.  Repeat every 10-15 hours for three days.
What are five complications after dantrolene treatment of MH?
1.  Reoccurence
2.  DIC
3.  Myoglobinuric renal failure
4.  Skeletal muscle weakness
5.  Electrolyte abnormalties
What is the best method to decrease temp in MH?
Gastric lavage
What is the best antiarrhythmic for MH?
Procainamide 15 mg/kg
What are the incidences and mortality rate of MH?
1:15,000 children, 1:50,000 adults
Mortality rate is 10%
What is neuroleptic malignant syndrome?
May mimic MH, but onset and recovery are different.  Patients treated with antipsychotic drugs such as haldol, prolixin, or thorazine are susceptible to NMS.  FEVER is the cardinal sign.
What are the five second messengers?
1.  cAMP
2.  Calcium ions
3.  Calmodulin
4.  cGMP
5.  Inositol triphosphate (IP3)
What is the therapeutic index?
LD50/ED50
What is the ED50?
The dose that is effective in 50% of patients
What is the elimination half time?
Time taken for the plasma concentration to fall by one-half.  T1/2 is directly related to Vd and inversely related to Clearance (Cl)

Cl = Vd/T1/2
What does the brain uptake of anesthetics depend on?
1.  Blood solubility
2.  Cardiac output
3.  Alveolar ventilation
4.  Inspired concentration
What are the three ways to increase the speed of equilibrium?
1.  Increase inspired anesthetic concentration
2.  Second gas effect
3.  Increased alveolar ventilation
What are the two most important factors for increasing alveolar partial pressure?
1.  Inspired concentration
2.  Blood solubility
List partial pressures greatest to least (body sites)
Inspired > Alveolar > Arterial blood > Brain

Reversed during emergence!
What does the Meyer-Overton Theory explain?
The anesthetic potency of volatile agents directly correlates with their lipid solubilities.
What is MAC?
The "minimum alveolar concentration" of anesthetic at one atmosphere that produces immobility in 50% of patients exposed to a noxious stimulus.  MAC is inversely proportional to potency.

MAC = ED50 of non-inhalational drugs
1.3MAC = ED95

MAC is decreased 1% for every 1% of N2O delivered.
What are the seven factors that decrease MAC?
1.  Increasing age
2.  Hypothermia
3.  CNS depressants
4.  Acute ethanol intoxication
5.  Alpha-2 agonists (Clonidine)
6.  Pregnancy
7.  Decreased levels of CNS neurotransmitters
What are three factors that increase MAC?
1.  Hyperthermia
2.  Hypernatremia
3.  Increased levels of CNS neurotransmitters
Where are volatile anesthetics metabolized?
In the liver by cytochrome P-450 hepatic microsomes
How much are the volatiles metabolized?
Halothane 15-20%
Enflurane 2.4%
Isoflurane 0.2%
Desflurane 0.02%
Sevoflurane 3.0%
What is responsible for hepatotoxicity with halothane?
An oxidative trifluoroacetyl metabolite (in susceptible individuals).  Reduced metabolism occurs with hypoxia.  Thymol is the preservative in halothane.
What is the most clinically important metabolite of enflurane?  What are common metabolites of halothane and enflurane?
Fluoride; inorganic fluoride and chloride
Which is the only inhalational agent without a halogen?
N2O
What is the acceptable exposure level of N2O + Volatile?  Volatile alone?
N2O 25 ppm
Volatile 0.5 ppm

Volatile 2 ppm (alone)
Where is N2O metabolized?
In the intestine by reductive anaerobic metabolism (to N2)
What are the six contraindications to N2O use?
1.  Venous air embolism
2.  Malignant hyperthermia
3.  Ear surgery (middle ear)
4.  Closed pneumothorax
5.  Potential pneumocephalus
6.  Bowel obstruction
What are the four adverse side effects of N2O?
1.  Aplastic anemia
2.  Congenital anomalies
3.  Spontaneous abortion
4.  CNS toxicity
What happens when N2O is added to high dose opioids?
Decrease in BP and CO
What are the normal effects of N2O?
Increases PVR and PA blood pressure due to mild sympathomimetic effects.  It will support fire, but is neither flammable nor explosive.
What are three renal changes associated with volatile anesthetics?
1.  Decreased RBF
2.  Decreased GRF
3.  Decreased UO
Which volatile agent least potentiates NDMRs?
Halothane
Which volatile agents produce the greatest myocardial depression?
Halothane and Enflurane
Which volatile agents most depress the baroreceptr reflex (No increase in HR despite decreases in BP)?
Halothane and Sevoflurane
How does Isoflurane affect temperature regulation?
It depresses the temperature-regulating center in the hypothalamus.
x of y cards Next > >> >|