STRUBE TIPS Flashcards
Methemoglobin absorbs light in a manner equal to. As a result,
oxyhemoglobin
How does the methemoglobinemia affect oxygen saturation?
If the oxygen saturation is over 85%,methemoglobinemia will cause the pulse oximeter to falsely underestimate the hemoglobin saturation. If the oxygen saturation is under 85%, it will cause it to falsely overestimate it
Placement of the transducer below the level of the heart will ______over/underestimate the actual blood pressure and vice-versa.
overestimate
If the NIBP cuff is not level with the heart, what should be done?
then a correction must be made to compensate for the difference between arm and systemic pressure.
How do you compensate BP arm and systemic?
For every 10 cm the cuff is above the level of the heart, you must add 7.5 mm Hg to estimate the systemic pressure accurately.
Likewise, for every 10 cm the NIBP cuff is below the level of the heart, you must
subtract 7.5 mm Hg to correctly estimate the systemic pressure.
Placing a blood pressure cuff that is too loose, too small, or positioned below the level of the heart will result in a blood pressure that
overestimates the actual blood pressure.
These actions lower intracranial hypertension and cerebral edema, which in turn lower the ICP
Fluid restriction, diuretics, corticosteroids, CSF drainage, propofol, MAP reduction, and hyperventilation.
The Cushing reflex consists of (3) .
bradycardia, hypertension, and respiratory irregularity
When ICP levels rise so significantly, what happens?
Brain stem herniation occurs.
Nicardipine and Cerebral Blood flow
Nicardipine preserves cerebral blood flow.
Where does the preganglionic sympathetic nervous system fibers originate?
between the T-1 and L-2 nerve roots.
The choroid plexuses are located in the
four ventricles.
Neurons and its glycogen supply
The neurons only contain about a 2-minute supply of glycogen.
Which 2 choroid plexuses provides the greatest quantity of CSF?
The ones located in the two lateral ventricles produce the greatest quantity of cerebrospinal fluid.
The brain % of the body mass occupies?
about 2% of body mass but receives about 15% of the cardiac output.
How much of the Cardiac output does the brain receive?
15%
The left and right carotid arteries and
Look up
left and right vertebral arteries
Look up
What is the normal blood flow of brain ? In the average adult? At about 2.0 MAC, the EEG may temporarily exhibit electrical silence. This is referred to as burst suppression.
The normal blood flow to the brain is about 50-65 milliliters per 100 grams of brain tissue per minute (50-60ml/100g/min) This amounts to about 750-900 milliliters/minute in the average adult.
Volatile anesthetics effects on EEG?
All volatile anesthetics suppress the electroencephalogram (EEG) in a dose-dependent manner
When a volatile agent is administered, How does it affect amplitude and frequency?
there is an initial increase in amplitude followed by a decrease in both amplitude and frequency.
DAF,IL
MAC at which there is electrical silence? What is is referred to as ?
At about 2.0 MAC, the EEG may temporarily exhibit electrical silence. This is referred to as burst suppression.
What is the most serious side effect of chronic amiodarone administration?
is pulmonary toxicity resulting in alveolitis (pneumonitis).It is believed that amiodarone increases the production of free radicals that results in pulmonary toxicity.
What % of people treated with amiodarone develop pulmonary toxicity ?
5-15% of patients treated with amiodarone.
How do you provide Oxygen therapy during anesthesia for a patient on Amiodarone?
Because of this, it is recommended to avoid high inspired oxygen concentrations during general anesthesia for these patients as oxygen increases the production of free radicals.
Nitroprusside action on veins and arteries.
causes dilation in both veins and arteries (an increase in vessel diameter). The result is a reduction of both preload and afterload which causes a reduction of cardiac filling pressures.
WHAT IS THE ONLY ANALOGUE OF LIDOCAINE?
The antiarrhythmic MEXILETINE is an orally administered analogue of lidocaine.Electrophysiological, it is most similar to lidocaine.
ONLY ORAL ANALOGUE OF lidocaine and It is used for the chronic treatment of ventricular arrhythmias
MEXILETINE
Amiodarone and cardiac death ?
reduces the risk of sudden cardiac death by 29% in patients with congestive heart failure. Therefore, it is the best alternative for patients who refuse or are not candidates for an AICD.
Best alternative for patients who refuse or are not candidates for an AICD.
Amiodarone
ACE inhibitors and angiotensin?
decreased angiotensin II production.
ACEI on sodium and water retention?
sodium and water retention are decreased and aldosterone levels are reduced.
Reduction of aldosterone put the patient at risk for which electrolyte abnormality?
The reduction in serum aldosterone levels place the patient at increased risk for hyperkalemia.
In the US, BETA BLOCKERS that are available in intravenous form.
propranolol, metoprolol, and esmolol
Because of its alpha-adrenergic blocking capability, labetalol produces _______ ? There in risk of
less bradycardia than pure beta-adrenergic blockers, but has an increased incidence of orthostatic hypotension.
Beta blockers administration in parturients? Effects on placenta, newborn
Beta-adrenergic blockers administered to a parturient cross the placenta and can produce bradycardia, hypoglycemia, and hypotension in the newborn. Beta-blockers are also likely to pass into breast milk.
How does Esmolol administration help with skin incision . What is the dose ?
Esmolol administered as 1 mg/kg IV followed by a 250 mcg/kg/min infusion substantially reduces the dosage of propofol required to prevent patient movement upon skin incision. There is no known pharmacokinetic reaction between the two drugs that explains this phenomenon.
Propranolol and LA
Propranolol decreases the clearance of amide local anesthetics, but not ester anesthetics such as Chloroprocaine.
Fentany and propranolol: you should know?
The pulmonary uptake of fentanyl, however, is substantially decreased in patients taking propranolol. As a result, plasma concentrations shortly after injection can be 2-4 times higher than normal.
Selective phosphodiesterase inhibitors are (2)
amrinone and milrinone
Selective phosphodiesterase inhibitors are such as amrinone and milrinone: on CO, cardiac contractility and SVR
increase the cardiac output primarily by increasing cardiac contractility and decreasing systemic vascular resistance.
Selective phosphodiesterase inhibitors are such as amrinone and milrinone: on LVEDP, filling pressure, venous return, SVR, and Mean PAP
They produce increased cardiac output, decreased LVEDP, decreased filling pressure, decreased venous return to the heart, decreased systemic vascular resistance, and decreased mean pulmonary artery pressures.
Phosphodiesterase inhibitors MOA
inhibit phosphodiesterase.This results in a decrease in the hydrolysis of cAMP (and subsequent elevated levels of cAMP within the myocardial and vascular smooth muscle cells).
Phosphodiesterase inhibitor and cAMP
decrease in the hydrolysis of cAMP (and subsequent elevated levels of cAMP within the myocardial and vascular smooth muscle cells
Dopamine and Immune system. .
can negatively affect the immune system by its effects on hormones and lymphocyte function.
Dopamine and HPA system
Can depress the hypothalamic-pituitary system in a manner similar to that seen in chronic stress and critical illness.
Dopamine and prolactin levels.
It also reduces prolactin levels, which is a regulator of T and B lymphocytes
Dopamine is a fairly nonspecific agonist of
alpha, beta, dopamine-1, and dopamine-2 receptors. The vasodilatory effects seen with low dose infusions are attributed to its effects on the dopamine-1 and dopamine-2 receptors
Epinephrine and cerebral effects, if any?.
has few cerebral effects because it is not very lipid-soluble, making it difficult for the drug to cross the blood-brain barrier
Under periods of high demand what occurs with some sustances?,
Vasodilating substances such as Adenosine, Potassium ions, Carbon dioxide, hydrogen ions, and prostaglandins can dilate the coronary arteries and increase blood flow by three to four hundred percent.
3 endogenous agents with vasoconstrictive properties.
Thromboxane, ATP, and endothelin
Sodium nitroprusside and CO
preserves cardiac output well,
Sodium Nitroprusside side effects you should:
Reflex tachycardia
Rebound hypertension
Pulmonary shunting
risk of cyanide toxicity.
One caution is that nitroprusside may
increase intracranial pressure and therefore must be used cautiously in the treatment of hypertensive crises associated with encephalopathy.
SVO2/ETCO 2 All result in a decreased ETCO2.
Hypothermia hypothyroidism hyperventilation hypoperfusion Pulmonary embolism
Factors that result in an increased SVO2 include
cyanide toxicity
Left-to-right shunts
Sepsis, a wedged pulmonary artery catheter, and hypothermia
Factors that result in a decreased SVO2 include
hyperthermia, shivering, hemorrhage, decreased cardiac output, and a decrease in the pulmonary transport of oxygen.
A patient with COPD, the following would be seen in a PFT? name 3
FEV1/FVC ratio to Somewhat decreased
FEV 25-75 to Markedly decreased
FRC to Increased.
Factors that increase the metabolic rate and subsequently, the amount of carbon dioxide produced.
Hyperthermia, sepsis, malignant hyperthermia, shivering, and hyperthyroidism
What are non-metabolic causes of an increased ETCO2.
Hypoventilation and rebreathing
The accuracy of an SpO2 monitor can be adversely affected by.
pathologic hemoglobin forms (carboxyhemoglobin, methemoglobin), intravenous dyes (methylene blue, indigo carmine), motion artifact, nail polish, ambient light, and even electrocautery.
Anemia and SPO2 monitor.
Anemia can result in an overestimation of the oxygen saturation
Optical interference and SPO2
Optical interference caused by ambient lights flickering at a frequency similar to the pulse oximeter LED can cause erratic readings.
Nail polish and intravenous dyes SPO2
can result in an underestimation of the oxygen saturation.
A decrease in arterial oxygen content or an increase in arterial oxygen extraction will _____the PvO2.
reduce
Severe anemia and SPO2
overestimation of the SpO2, particularly at low oxygen saturations.
Non-hypoxic SaO2 and anemic patients
normal in anemic patients
Prominent venous pulsations and injection of certain dyes such
as indigo carmine, lymphazurin, nitrobenzene, indocyamine green, methylene blue, and patent blue can result in underestimation of the SpO2.
Volatile anesthetics exhibit what on the cardiac system? How?
cardiac preconditioning effects. They appear to alter mitochondrial electron transport in myocardial cells.
It is estimated that about 30-40% of the cardioprotective effects of volatile anesthetics occurs by
reducing the overload of calcium within the cardiac cells and improving contractility.
Sevoflurane has been shown to demonstrate late preconditioning for how long? When does this effect begins?
24-48 hours after administration. The effects begin at 1 MAC with a dose of 1.5 MAC needed for maximum benefit.
Normally, cerebral blood flow is regulated through a range of mean arterial pressures from about
50 mmHg to 150 mmHg (some sources cite a narrower range of 60-140 mmHg).
With sevoflurane, cerebral autoregulation is
maintained up until about 1 MAC. Even at 1.5 MAC, autoregulation is maintained more effectively by sevoflurane than isoflurane or desflurane
Inhalation agents on respiratory? .
depress the respiratory system in a dose-dependent fashion
Inhalation agents on respiratory depress the respiratory system in a dose-dependent fashion? ..
The tidal volume is primarily affected, followed by the respiratory rate.
TV and concentration of agent relationship? Down/up
The tidal volume is decreased as the concentration of the agent increases. The respiratory rate increases, but this is typically insufficient to prevent increases in arterial CO2 due to hypoventilation.
Burst suppression on the EEG usually occurs
between 1.5 and 2.0 MAC with desflurane and around 2.0 MAC with isoflurane and sevoflurane.
Sevoflurane and seizure history
can enhance seizure activity and needs to be used with caution in patients with a history of epilepsy.
What is ventilation-perfusion deficit effect on speed of induction?
Where is the effect the greatest?
slows the speed of induction.
The effect is greatest in agents with a low blood: gas partition coefficient.
What is the blood: gas partition coefficient of desflurane?
0.42
The blood: gas partition coefficient of nitrous oxide it is
0.47
The blood: gas partition coefficient of sevoflurane
0.6
The blood: gas partition coefficient of isoflurane it is
1.4
A ventilation-perfusion deficit slows the speed of induction. The effect may be more visible in which gases?
Visible in nitrous oxide than in desflurane despite the difference in blood: gas partition coefficients because of the extremely high concentrations of nitrous oxide normally used compared to that of desflurane.
Effects of sevoflurane on normal CO2?
In the normotensive patient with a normal CO2, sevoflurane has no significant effects on cerebral physiology.
Increasing age effect on MAC
decreases MAC
Hypoxia, metabolic acidosis, on MAC
decreases MAC
Hypothermia, hyponatremia on MAC
Decreases MAC
Hypo-osmolality on MAC
Decreases MAC
Pregnancy, acute ethanol intoxication on MAC
Decreases MAC
Anemia, lidocaine administration effect on MAC
Decreases MAC
Decreased central neurotransmitter levels on MAC
Decreases MAC
Blood: gas partition coefficient relationship to cardiac output.
The higher the blood: gas partition coefficient is, the more the onset will be slowed by an increase in cardiac output.
Active scavenging disposal uses a what kind of system? Requires what kind of vacuum?
dedicated evacuation system such as the wall suction and requires a vacuum capability of 30 liters per minute (30 L/min). The exhaust port of the system has to be an adequate distance from healthcare workers.
Factors that can result in rSO2 desaturation include:
The administration of IV indigo carmine, cardiac arrest, hypothermia, blood steal syndromes, hypoxia, ischemia/embolic strokes, Trendelenburg position (leads to cerebral venous congestion), unilateral or bilateral cerebral atherosclerosis ,and the interference of hair, scalp, or hair follicles. A left-shifted curve can create false positives, and some patients have normal neurological function, yet have low baseline values.
An rSO2 value of 70% would be considered abnormal or normal?
normal because this encompasses both venous, arterial, and capillary blood.
Cerebral oxygen saturation is related to three factors:
- The light intensity at the source
- The detector
- The length of the light path through the tissue according to the Beer law
What does the Beer law states?
There is a logarithmic dependence between the transmission of light through a substance and the product of the absorption coefficient of the substance, and the distance the light travels through the material.)
A disadvantage of active disposal is that the
wall suction may not be strong enough to serve anesthesia, the surgeon, and the scavenging system.
Passive disposal routes for waste anesthetic gas utilize a
through-the-wall conduit or the operating room ventilation system.
Passive disposal routes there is a through-the-wall disposal system , waste gas exits
towards the outside through a duct in the floor, ceiling, wall, or window. This is achieved due to the preferential flow of gases into these disposal ducts because of the slightly positive pressure of the operative room created by OR ventilation.
Passive disposal routes there is a through-the-wall disposal system , waste gas exits
towards the outside through a duct in the floor, ceiling, wall, or window. This is achieved due to the preferential flow of gases into these disposal ducts because of the slightly positive pressure of the operative room created by OR ventilation.
Cerebral Oximetry
Cerebral oximetry is a monitor that uses).
near-infrared optical spectroscopy (NIRS) to noninvasively measure the regional blood hemoglobin oxygenation saturation (rSO2
Cerebral oximetry is useful in patient populations at risk for stroke such as
vascular or cardiac surgery patients, patients with a history of stroke, and neurosurgical patients. The technology used in cerebral oximetry is similar to that used in pulse oximetry.
How is the cerebral oximeter used?
A noninvasive sensor is placed over the forehead, but away from the hair and scalp. The sensor can be placed on the right, left, or both frontal-temporal regions (preferable).
Cerebral oximeter sensor emits low intensity light that penetrates the 4 things ? It is then reflected back to the
skin, skull, dura, and CSF into the blood located within the cerebral cortex.
skin sensor where the rSO2 is determined based upon the light intensity changes as it passes through the brain.
The 2 lights emitted with cerebral oximeter?
The light emitted is of 2 wave-lengths, 730 nm and 805 nm, emitted in alternating fashion through two light-emitting diodes.
Positive pressure caused by winds can interfere with what? Blockage of the exhaust port by birds, insects, and ice can also do what?
Can interfere with this disposal route; hinder proper functioning of the passive disposal route.
The OR ventilation system can also be used for the passive disposal of waste gas.
nonrecirculating (recirculating systems partially recirculate stale air), and it must also satisfy requirements set forth by the American Institute of Architects.
Recirculating system should be To avoid inadvertent
blockage of the hose connecting the scavenging interface to the ventilation outflow port, the hose should not be left on the floor.
rsO2 and left shifted
A left-shifted curve can create false positives, and some patients have normal neurological function, yet have low baseline values.
rsO2 and curve shift
A left-shifted curve can create false positives, and some patients have normal neurological function, yet have low baseline values.
What drugs can cause Serotonin syndrome?
SSRIs
MAOI’s
TCAs and atypical antidepressants
Cough medicines, drugs used to treat migraine headaches, weight reduction drugs, opiates, and illicit drugs such as ‘Ecstasy’.
Serotonin syndrome Symptoms are related to autonomic _________and include which five symptoms?
hyperreactivity Hyperreflexia Delirium Clonus Agitation Hyperthermia.
When exposed to a cold environment, what happens to core body temperature?
there is a reduction in core and/or skin temperature. (A 1-degree reduction in skin temperature is equal to an approximate 0.2-degree reduction in core body temperature.)
End stage liver disease is generally associated with what few signs? ( comment on SV, CI, and mixed venous oxygen saturation)
Very low SVR
Increased cardiac index
Increased mixed venous oxygen saturation.
What is the role of Phospholipase A2 with inflammatory pathways?
which is the rate-limiting enzyme in the conversion of arachidonic acid into prostaglandins and leukotrienes, is the primary inflammatory mediator implicated in disc herniation
What is the action of Corticosteroids injected into the epidural space?
inhibit cytokine release, inhibit phospholipase A2 activity, and exert a local anesthetic-like action on C fibers (but specifically, not A-beta fibers).
The central termination of visceral afferent fibers synapse spinal neurons in what laminae?
I, II, V, and X and deliver visceral sensation information to supraspinal sites through the contralateral spinothalamic tract or the ipsilateral dorsal column.
Pyloric stenosis rThe body trades K+ for Na+ in order to hold on to water and fight hypovolemia.
results in fulminant, and often projectile, vomiting.Gastric acid (HCl) is lost during this process; this is the reason for the hypochloremia and alkalosis exhibited by the patient.
Pyloric Stenosis metabolic disturbances?
Hypochloremic metabolic alkalosis
Why do patients with pyloric stenosis develop hypochloremic metabolic alkalosis?.
The hypokalemia is due to potassium excretion in the kidney
Adenoidal hyperplasia can result in
nasopharyngeal obstruction resulting in obligate mouth breathing.
2 associated and linked with sleep apnea.
Both adenoidal and tonsillar hyperplasia are linked to sleep apnea with the potential for cor pulmonale and failure to thrive.
What is the Mechanism of action of Baclofen?
Baclofen agonizes the GABA-B receptor to suppress neuronal transmission in the CNS.
The major risk factors contributing to apnea after anesthesia in preterm infants are 3 things
1) the type of anesthetic
2) post-conceptual age
3) the presence of anemia.
Dilate the pupils –> drops
to Phenylephrine
Mannitol and IOP
Decrease intraocular pressure to Mannitol.
Pilocarpine drops on pupils
Constrict the pupils
Obesity is characterized by an
increased glomerular filtration rate, increased renal tubular resorption, and impaired sodium excretion which further worsens hypertension.
Hepatocellular syndrome (HPS) is characterized by the triad of (HPP):
Hypoxemia
portal hypertension
pulmonary vascular dilatations.
For pregnant patient, as the patient gets closer to term, what happens to the diaphragm ?
rises and shifts the heart upward and leftward.
For pregnant women, what happens to heart on xray? ECG changes related to pregnancy?
This makes the heart appear larger on chest Xray and produces a left axis shift on the ECG.
In the third trimester, there is also an increased tendency for what ECG changes?
Premature atrial contractions
Supraventricular tachycardia
Ventricular dysrhythmias.
The term ‘Cushing’s disease’ refers to Cushing’s syndrome that is caused by the
over secretion of ACTH by a pituitary tumor.
Symptoms of Cushing’s syndrome are:
Sudden onset of weight gain Thickening of the facial fat giving a rounded shape to the face Facial telangiectasias Glucose intolerance Hypertension Decreased libido in men Oligomenorrhea Spontaneous bruising
Patients with Cushing’s disease have _____in serum ______resulting in Hypokalemia….
increased serum cortisol levels resulting in hypokalemia, hyperglycemia, and skeletal muscle relaxation which may require a decreased non-depolarizing muscle relaxant dose.
A low-dose infusion of etomidate may be helpful in patients with
Cushing’s disease
Because patients undergoing bilateral adrenalectomy exhibit rapid decrease of
serum cortisol levels, steroid replacement therapy should be initiated prior to or during surgery
Because patients undergoing bilateral adrenalectomy exhibit rapid decrease of serum cortisol levels, what should be initiated prior and during surgery?
steroid replacement therapy should be initiated prior to or during surgery.
Because of the tendency toward skeletal muscle weakness, it is recommended that patients with Cushing’s disease be
mechanically ventilated whenever possible.
About 85% of pheochromocytomas are located in theT
medulla of one of the adrenal glands.
Pheochromocytomas can also be found in ?
Spleen, broad ligament of the ovary, right atrium, or at the bifurcation of the aorta.
What is the preferred for the treatment of hypertension (systolic pressures over 200 mmHg are common) during surgical excision of pheochromocytomas?
Nitroprusside
what Typically occurs following ligation of the vein draining the pheochromocytoma tumor?
Hypotension
For pheochromocytoma resection, To prevent hypotension, the patient should undergo volume expansion until a
pulmonary capillary wedge pressure of 16-18 mmHg is reached prior to ligation of the vein.
For pheochromocytoma resection, vasopressors should be utilized only after —-
after adequate volume expansion has been achieved.
What are the agents of choice if it is primarily an epinephrine-secreting tumor?.
Esmolol or labetalol
Advantage of esmolol during a pheochromocytoma resection?
short duration of action
Pheochromocytomas typically release______ norepinephrine and_______epinephrine
85% ; 15% epinephrine.
The parathyroid glands release______hormone which regulates?
parathyroid hormone which regulates calcium balance.
Condition that stimulate the release of parathyroid hormone.
condition that results in even a slight decrease in calcium ion concentration in the extracellular fluid
The parathyroid glands become hyperactive and hypertrophied in conditions such as
rickets, pregnancy, and lactation.
The parathyroid______ phosphate by increasing the renal excretion of phosphate.
decreases
Parathyroid hormone______ serum calcium levels by _______bone resorption of calcium, ________and ______________
increases; increasing
limiting its renal excretion, and enhancing the gastrointestinal absorption of calcium by regulating vitamin D metabolism.
Parathyroid hormone increases bone resorption of calcium and phosphate in two stages:
- the first stage begins within minutes and increases the resorption activity of osteoclasts.
- The second stage is much slower and may require several days or weeks as it stimulates the increased production of osteoclasts.
Parathyroid hormone can cause a rapid loss of
phosphate ions in the urine by its effect on the proximal tubule.
As more phosphate is excreted, calcium is
retained.
The increased calcium reabsorption takes place primarily where in the nephron?
collecting tubules and the late distal tubules.
Cardiac signs and symptoms of hyperparathyroidism:
Hypertension, prolonged PR interval, and a shortened QT interval.
Neuromuscular signs hyperparathyroidism:
Skeletal muscle weakness
Bone demineralization
Vertebral collapse
Pathologic fractures.
Your anesthetic with hyperparathyroidism should be aimed at dealing with underlying –>
hypercalcemia
Your anesthetic with hyperparathyroidism should be aimed at dealing with underlying, because of this , 2 things are essential?
hydration with normal saline
Monitoring of urinary output
Hypercalcemia and anesthetic requirements
Because hypercalcemia is associated with somnolence, the anesthetic requirement may be decreased.
If personality changes due to chronic hypercalcemia are present, then what medication should be avoided?
ketamine may need to be avoided.
Baseline skeletal weakness may necessitate a decreased dose of_______; however you should know that the _________
nondepolarizing muscle relaxants; however, the increased calcium can antagonize muscle relaxants–in short, hyperparathyroidism is associated with an increased sensitivity to succinylcholine and a resistance to nondepolarizing muscle relaxants.
Increased calcium and effects of dosing of succinylcholine and NDNMBs
associated with an increased sensitivity to succinylcholine and a resistance to nondepolarizing muscle relaxant
Acidosis and serum calcium
Acidosis increases the serum calcium level, so hypoventilation should be avoided.
Hypercalcemia–> It is important to position patients because there is risk of
risk of pathologic fractures
During parathyroidectomy, As with thyroidectomy, there is a risk of damage to the______nerve; what must be used?
recurrent laryngeal nerve during surgery, so a Nim(Registered) tube or similar device should be used to monitor nerve function during surgery.
Hypercalcemia (hyperparathyroidism) preferred fluid?
Normal saline is preferred over Lactated Ringer’s solution for fluid management.
Signs and symptoms of hypoparathyroidism:
prolonged QT interval
muscle spasms
hypotension
decreased responsiveness to beta agonists
The treatment of hypoparathyroidism is aimed at
restoring low calcium levels to normal.
Hypocalcemia , an infusion of
10 mL of calcium gluconate 10% IV should be administered until signs of neuromuscular irritability resolve.
Hypocalcemia , an infusion of
10 mL of calcium gluconate 10% IV should be administered until signs of neuromuscular irritability resolve.
How does thiazide diuretics help with hypocalcemia?
Thiazide diuretics may be helpful as they result in sodium depletion without the loss of potassium which tends to increase calcium levels.
Patients with aortic valve stenosis have a fixed obstruction, whereas about 25% of patients with hypertrophic cardiomyopathy exhibit a _______obstruction
a dynamic obstruction which peaks in mid-to-late systole, can vary from beat to beat, and can worsen with enhanced ventricular contractility, decreased ventricular volume, and decreased left ventricular afterload.
Patients with hypertrophic cardiomyopathy typically suffer from
diastolic dysfunction which is exhibited by increased left ventricular end-diastolic pressures despite an often hyperdynamic left ventricular function.
With hypertrophic cardiomyopathy, the diastolic stiffness is due to the
increased muscle mass of the left ventricle which is typically concentrated in the upper septum just below the aortic valve.
Many patients are asymptomatic, but those that do exhibit symptoms exhibit
dyspnea on exertion, fatigue, syncope, or angina.
With hypertrophic cardiomyopathy, patients often exhibit what kind of obstruction? What other signs and symptoms will you see?
dynamic left ventricular outflow tract obstruction mitral regurgitation Diastolic dysfunction Myocardial ischemia Dysrhythmias.
Paradoxical embolus is the transfer of
an embolus from the venous system to the arterial system and often to the brain via a patent foramen ovale or atrial septal defect.
Hypertrophic cardiomyopathy involves
enlargement of the interventricular septum which results in left ventricular outflow obstruction.
The obstruction seen with hypertrophic cardiomyopathy is worsened by
increased heart rate or increased myocardial contractility as well as decreases in preload or afterload. Anesthesia is usually maintained by controlled myocardial depression using volatile anesthetics.
The obstruction seen with hypertrophic cardiomyopathy is worsened by __________ or _______
increased heart rate or increased myocardial contractility as well as decreases in preload or afterload. Anesthesia is usually maintained by controlled myocardial depression using volatile anesthetics.
With hypertrophic cardiomyopathy, as flow through the mitral valve opening into the left ventricle is decreased
(thus decreasing the left ventricular volume), left atrial pressure increases, resulting in left atrial hypertrophy and distention. The increased pressure is transmitted into the pulmonary vasculature as the volume of pulmonary blood increases.
With hypertrophic cardiomyopathy, the increased pulmonary vascular pressure represents an increase in
right ventricular afterload and will cause right ventricular hypertrophy and failure. As pulmonary venous pressure increases above about 25 mmHg, fluid can leak into the pulmonary interstitial space resulting in a decrease in pulmonary compliance and increased work of breathing. If the change in pulmonary venous pressure occurs over a long period of time, an increase in pulmonary lymph flow can partially compensate for the fluid accumulation.
Coarctation of the aorta to
Widened pulse pressure in the arms
Aortic stenosis murmur Is to
Systolic murmur over the 2nd right interspace
Patent ductus arteriosus can be treated with
treated with cyclooxygenase inhibitors
Eisenmenger’s syndrome to Reversal of a
left-to-right shunt.
Kussmaul’s sign and pulsus paradoxus are both indicative of
ventricular discordance (also known as ventricular dyssynchrony) that occurs due to the opposing response of the ventricles to filling during the respiratory cycle.
Pericarditis is often due to a
viral illness
This condition may often occur 1-3 days after a myocardial infarction.
Pericarditis
Pericarditis , what worsens the pain
Deep inspiration
What often relieves the pain of pericarditis?
Sitting forward
The ECG changes seen in acute pericarditis occur in
four stages.
In stage I of acute pericarditis, there is and
diffuse ST segment elevation and depression of the PR segment.
In stage 2 during pericarditis, what happens to the ST and PR changes
the ST and PR changes normalize
What happens in pericarditis In stage 3?
the T wave inverts,
What happens in pericarditis in stage 4?
he T waves normalize.
If no other associated pericardial disease is present, acute pericarditis does or does not affect cardiac function ?
Does not alter cardiac function.
The choroid plexuses are located where?
An increase in hydrogen ion concentration depresses neuronal activity. It also causes an increase in blood flow to the brain. By doing so, it will help ‘wash away’ the hydrogen ions, carbon-dioxide, and other acid precursors away from the brain which returns the hydrogen ion concentration back to normal.
in the four ventricles.
Which ventricles produce the greatest quantity of CSF?
The ones located in the two lateral ventricles produce the greatest quantity of cerebrospinal fluid. When lying in a horizontal position, the normal cerebrospinal fluid pressure is about 130 mm of water or 10 mmHg.
When lying in a horizontal position, the normal cerebrospinal fluid pressure is about
130 mm of water or 10 mmHg.
The brain only comprises about ____of body mass but receives about____ of the cardiac output.
2%; 15%
What vessels supply the blood to the brain?
The left and right carotid arteries and left and right vertebral arteries
Rexed laminae I through laminae VI are located in the
dorsal horn of the spinal column.
Laminae ____, ____ and ____comprise the ventral horn.
VII, VIII, and IX
Normally, the body maintains a constant cerebral blood flow between mean arterial pressures of
60 and 140 mmHg.
Chronic hypertension on the CBF
will shift both the upper and lower limits of the cerebral autoregulation curve to the right.
Secretion of cerebrospinal fluid by the choroid plexus is dependent upon the
active transport of sodium through the epithelium of the choroid plexus.As the sodium is transported out, chloride is pulled outward as well because of its electrochemical attraction to sodium.
The combination of sodium and chloride increases the osmotic pressure on the outside of the plexus which results in the
osmosis of water through the plexus membrane. It is the fluid that forms the principal constituent of cerebrospinal fluid.
The preganglionic sympathetic nervous system fibers originate between the
T-1 and L-2 nerve roots.
Central nervous system symptoms of hyponatremia such as
confusion, restlessness, nausea, and vomiting begin to appear at about 120 mEq/L, with ECG changes occurring at 115 mEq/L, and
Ventricular tachycardia and fibrillation occurring below what sodium levels?
100 mEq/L.
What are the regions involved in the emotional and motivational aspect of pain sensation?
The limbic and paralimbic regions (anterior cingulate cortex and insular cortex)
The SI and SII somatosensory cortices are involved in determining the location and intensity of pain sensations.
1816
RX: 1123178
The major ascending spinal pathways involved in the transmission of nociceptive information include t
spinothalamic, spinohypothalamic, spinomedullar, and spinobulbar tracts.
What is the most important for the transmission of pain, temperature, and itch sensations?
The spinothalamic tract (SPI sensation, pain, itch)
What is the most important in integrating pain information with homeostasis and behavior mechanisms of the tracts?
The spinobulbar tract
What is the most important tract involved in the autonomic, neuroendocrine, and emotional aspects of pain?
The spinohypothalamic tract
The central termination of visceral afferent fibers synapse spinal neurons in what laminae? And what do they do?
Laminae I, II, V, and X and deliver visceral sensation information to supraspinal sites through the contralateral spinothalamic tract or the ipsilateral dorsal column
The majority of visceral afferent fibers are
A-delta and unmyelinated C fibers with a tiny portion of them being A-beta fibers in the mesentery.
Group C fibers are
unmyelinated
Blockade of which branch can relieve pain from sacroiliac joint syndrome?
Blockade of the medial branch of the dorsal rami of L5 and S1-S3 via a facet joint injection
An _______in hydrogen ion concentration depresses neuronal activity. What else happens?
increase. It also causes an increase in blood flow to the brain. By doing so, it will help ‘wash away’ the hydrogen Common gas outlet.ions, carbon-dioxide, and other acid precursors away from the brain which returns the hydrogen ion concentration back to normal.
The low-pressure system on an anesthesia machine contains the (FCHUP).
Flowmeters Common gas outlet Hypoxia prevention devices Unidirectional valves Pressure relief device
The intermediate pressure system of an anesthesia machine contains the.
pneumatic part of the master switch
pipeline inlet connections and pressure indicators
the gas power outlet, oxygen flush valve, oxygen pressure failure devices, and flow control valves
What is the only machine safety device that evaluates the integrity of the low-pressure circuit in an ongoing fashion?
The oxygen analyzer
It is the only machine monitor that can detect problems downstream from the flow control valves.
The oxygen analyzer
The ‘pumping effect’, an intermittent back pressure caused by __________OR caused by ____________ and results in _______
It is more prominent with low flows, low vaporizer dial settings, low levels of anesthetic in the vaporizer chamber,
positive pressure ventilation or use of the oxygen flush valve results in elevated vaporizer output
Pumping effect: more prominent with what kind of flow? (high or low) ? more prominent What kind of vaporizer dial settings?
Low flows; Low vaporizer dial settings
Pumping effect: more prominent with what kind of anesthetic level in the vaporizer chamber?
low levels of anesthetic
2 HIGHS that are associated with pumping effect are
high respiratory rates
high peak inspiratory pressures.
Both hypothermia and hypothyroidism will the ______ETCO2 during anesthesia.
decrease
What is the possible complications from overfilling a vaporizer?
liquid agent entering the fresh gas line and potentially delivering a lethal dose of agent to the patient or complete failure of the vaporizer.
Some vaporizers have the filling port positioned so that overfilling cannot occur, but if the vaporizer is tipped , wha t can happen?
overfilling is still a possibility.
Thoracic neuraxial anesthesia will produce what effect on the gut?
a contracted gut with hyperperistalsis.
During thoraxic neuraxial anesthesia, what happnes to the Renal and hepatic blood flow?
decrease in parallel with the reduction in mean arterial pressure.
During thoraxic neuraxial anesthesia, what happens to the vital capacity? Who is the effect more prominent?
It will decrease relative to the degree of abdominal and thoracic muscle paralysis from the anesthetic. The decrease in vital capacity is more pronounced in obese patients.
Both spinal and epidural anesthetics exert their primary action on the
nerve root.
Epidurally administered drugs reach their destination by
coursing along the epidural space and then diffuse through the meninges and the DURAL CUFF to reach the nerve root.
If LMWH is planned postoperatively, the epidural catheter should be removed at least how long before the first dose?
2 hours before the first dose.
An epidural catheter should be advanced how far in the epidural space?
about 5 cm into the epidural space.
Advancing the epidural catheter further than will increase the likelihood that a complication will result such as the
Puncturing the dura.
Entering a vein
Catheter forming a knot
Because different neurons have a different susceptibility to local anesthetics, specific sensations exhibit inhibition at different dermatome levels. This is referred to as
differential block.
With regards to spinal anesthesia, what is the difference in the dermatome level in regard to light touch/cold sensation than pinpricK?
light touch or cold sensation is inhibited at a higher dermatome level than pinprick sensation
What two factors determine the duration of action of the block?
The anesthetic drug used, and the total dose given
The major ascending spinal pathways involved in the transmission of nociceptive information include the.
spinothalamic
spinohypothalamic
spin medullar
Spinobulbar tracts.
Of these, What is the tract that is most important for the transmission of pain, temperature, and itch sensations.
the SPInoThalamic (PIsT)
The spinobulbar tract is important in integrating
pain information with homeostasis and behavior mechanisms
The spinohypothalamic tract is involved in the
autonomic, neuroendocrine, and emotional aspects of pain.
The obese patient should be in the______ position when the epidural is placed to help in identifying landmarks.
Sitting
Because rostral spread of the anesthetic is______ prevalent in obese patients and they are more prone to suffer respiratory symptoms as a result, you should have them Do what?
more ;
sit up for a longer period of time after injection.
