ANA 888 M3

epilepsy affects x% of global population

1-2%

recurrent seizures with abnormal EEG activity

epilepsy

factors that facilitate seizures (5)

1. hypoglycemia

2. hypoxia

3. electrolyte imbalance

4. stress

5. fatigue

Cisatracurium and epileptic patients?

NO, cisatracurium metabolizes down to laudosine and increases risk of seizures

Intervention most appropriate for seizure

1. Oxygen

2. give benzo (versed)

5 anti-epileptics that modify membrane ion conduction via Na+ channels

1. phenytoin

2. carbamazepine (PO only)

3. lamotrigine

4. topiramate

5. valproic acid

valproic acid (valproate) MOA 3

anti-epileptic that modifies membrane ion conduction via Ca++ channel, Na+ blocker, & enhances GABA transmission

anti-epileptic medications that enhance GABA transmission 5

-benzodiazepines (diazepam, clonazepam)

-barbiturates: (phenobarbital)

valproic acid

gabapentin

2 anti-epileptics that inhibit excitatory amino acids (EAA) transmission

felbamate & topiramate

3 anti-epileptic medications that induce CYP4A (↑ metabolism)

carbamazepine, phenytoin, phenobarbital

anti-epiletic that exerts its effects by stabilizing sodium channels and ↓ the release of glutamate and aspartate at synapses

lamotrigine

anti-epileptic that blocks sodium channels and inhibits high-frequency neuronal firing. It also ↓ synpatic transmission

carbamazepine (Tegretol)

anti-epileptic that ↓ release of glutamate from synapses

gapapentin

when does a gas embolism occur during laparoscopic surgery= EXAM

if the CO2 insufflation gas enters the circulatory cirulation

S/S of gas embolism 9= EXAM

1. ↓ ETCO2

2. ↓ ET nitrogen

3. hypoxia

4. Cyanosis

5. ↑ PA pressures

6. mill-wheel murmur

7. HoTN,

8. pulmonary edema

9. -detection of air via doppler ultrasound or TEE

treatment for gas embolism

left later decub position

4 hemodynamic changes during laparoscopic surgery that indicates gas embolism EXAM

Causes false stable BP

1. ↑ SVR,

2. ↑ MAP

3. ↑ HR

4. ↓ venous return (decreased CO/SV)

Anticonvulsants most effective in myoclonic but also in tonic-clonic and partial 7

1. benzos

2. barbiturate

3. valproic acid

4. gabapentin

5. vigabatrin

6. topiramate

7. felbamate

because they enhance GABA transmission:

anticonvulsant best for absence seizures

1. clonazepam (enhances GABA)

2. ethosuximide (CCB)

3. valproic acid (CCB)

anticonvulsants that are best for general tonic-clonic and partial seizures

Na+ channel blockers: phenytoin, carbamazepine, lamotrigine, topiramate, valproic acid

Cortisol 3

primary endogenous glucocorticoid

Mediates 95% of all glucocorticoid activty

majority of cortisol is secreted by zona fasciculata in adrenal cortes

intra-op uses for corticosteroids 3

-PONV

-inhibit swelling (ent, airway cases)

-chronic immunosuppression support

glucocorticoids 3

subtype of corticosteroids primarily involved in anti-inflammatory and immunosuppressive effects

-affect glucose metabolism

Cortisol is primary endogenous glucocorticoid

clinical examples and dosing with glucocorticoids (4)

1. prednisone (PO)

2. dexamethasone (IV) 4-10mg

3. methylprednisolone (IV) 4mg

4. hydrocortisone (PO/IV) 100mg

clinical uses of corticosteroids (11)

1. allergic therapy

2. asthma

3. antiemetic

4. addisons disease

5. OA/RA

6. cerebral & laryngeal edema

7. dermatitis

8. immunosuppression

9. IBS/UC

10. post-op pain/ pain injections

11. ocular/optic/nasal inflammation

SE of corticosteroids (9)= EXAM

1. dose & time dependent

2. HTN

3. induced psychosis

4. immunosuppression (single dose noncontributory)

5. Na retention; K secretion

6. GI bleeding

7. enhanced GERD

8. delayed wound healing

9. a/w hip avascular necrosis

corticosteroid and loop diuretic drug interactions

↑ hypokalemia

corticosteroid and NSAID drug interactions

↑ GI side effects

corticosteroid and Birth control/estrogen drug interactions

↓ metabolism

corticosteroid and phenytoin drug interaction= EXAM

↑ drug metabolism (d/t CYP450 inducer)

corticosteroid and sux drug interaction

↑ DOA

corticosteroid and ester LA drug interaction

↑ DOA

corticosteroid and antidiabetic meds drug interactions

↑ blood glucose

anesthetic implications of corticosteroids 4

1. -Dexamethasone ↓ N/V

2. ↓ pain & opioid needs

3. -long term users require stress dose preop to prevent crisis

4. -monitor sugars regularly

corticosteroid use w/ neuraxial 3

1. Effective for chronic back/joint pain

2. limited systemic effects

3. Decadron extends duration of block

How is cortisol secretion regulated?

1. Regulated by HPA axis through negative feedback loop

2. hypothalamus secretes CRH→

3. CRH stimulates anterior pituitary to release ACTH

4. ACTH stimulates zona fasciculata of adrenal cortex to produce and release Cortisol.

what is the HPA axis

hypothalamus-pituitary-adrenal axis

stimulates or inhibits continued production of steroids

negative feedback

HPA axis suppression may result in

adrenal crisis

cortisol is secreted at a rate of x mg/day from adrenal cortex

20mg/day

stress can increase cortisol secretion to

150-300mg/ day

synthetically produced cortisol replacement potencies are measured against

hydrocortisone

standard stress dose of hydrocortisone

100mg

actions of synthetically produced cortisol

both glucocorticoid & mineralocorticoid actions

4 subtypes of histamine receptor antagonists

1. H1 (1st & 2nd generation): allergic response, bronchial and vascular smooth muscle

2. H2: gastric acid secretion, heart

3. H3, H4: CNS & immune cells (no anesthetic relevance)

antipsychotic that works by blocking dopamine receptors in the brain; action helps reduce the sensation of N/V

prochlorperazine

H1 (1st generation) examples 5

1. -diphenhydramine (benadryl)

2. -dimenhydrinate (dramamine)

3. -promethazine (phenergan)

4. -hydroxyzine (vistaril)

5. -prochlorperazine (generic only)

general uses of H1 blockers 3

1. motion sickness

2. pruritus

3. PONV

side effects/precautions for H1 blockers 3

-crosses BBB: sedative effects,

caution in outpatient clinics and elderly

-extrapyramidal effects: restlessness, agitation

benadryl commonly used for

allergic reactions

dramamine commonly used in which surgeries

eye and ear surgery

4 examples of 2nd generation H1 blockers

-cetirizine (Zyrtec)

-loratadine (Claritin)

-fexofenadine (allegra)

-levocetirizine (xyzal)

What is the main use of 2nd generation H1 blockers

allergic rhinitis (minimal CNS, non-sedation)

MOA of H2 blockers

selective, reversible inhibition of H2 receptors on gastric parietal cells→ H2 blocks Gs receptor that normally stimulates cAMP and increases acid secretion

H2 blockers= decrease cAMP=decrease acid secretion

H2 effects on histamine release

NONE

rank potency of H2 blockers

cimetidine < ranitidine < nizatidine < famotidine

T/F is an interaction of cimedetine impairment of hepatic metabolism= EXAM

True

MOA of prokinetics such as reglan 4

acts via cholinergic stimulation and dopamine receptors antagonism

-↑ LES tone

-enhances peristaltic contractions

-accelerates rate of gastric emptying

pharmacokinetics of reglan 3

half-life: 2-4 hours

Crosses BBB (extrapyramidal effects)

adjust with renal impairment

indications for reglan 3

1. -diabetic gastroparesis

2. Preoperative; GERD (hx gastroparesis)

3. -antiemetic

contraindications to reglan 3

1. -parkinson's disease

2. -restless legs syndrome

3. -dopamine inefficiencies

4. SBO= EXAM

MOA of oral antacids 3

1. neutralize HCl

2. raises pH

3. inactivates pepsin

common oral antacids

-sodium bicarb

-magnesium hydroxide

-calcium carbonate

-aluminum hydroxide

sodium bicarb 3

1. antacid that works quickly,

2. but causes acid rebound

3. ↑ sodium load

magnesium hydroxide 3

antacid w/ fast-acting laxative effect,

causes diarrhea,

avoid in renal failure

calcium carb 2

antacid that can cause acid rebound and

hypercalcemia

aluminum hydroxide

antacid that causes constipation,

hypophosphatemia, and

potential neurotoxicity in renal disease

sodium citrate 4

nonparticulate antacid

preferred preop in pregnant or aspiration risk patients

dose= 15-30 mL of 0.3mol/L, 15-30 min pre-induction

DOES NOT PREVENT ASPIRATION- JUST NEUTRALIZES/RAISES PH

complications a/w sodium citrate 3

-metabolic acidosis

-GI effects: constipation, diarrhea, gas formation

-aluminum & mag toxicity in renal impairment

antacids + which 3 medications increase absorption

salicylates, NSAIDS, indomethacin

antacids + which 3 medications decrease absorption

tetracyclines, digoxin, cimetidine

increases diazepam bioavailability

aluminum

anesthesia implications w/ antacids 2

1. evaluate renal, hepatic, and cardiac function

2. monitor electrolyte shifts

best practices w/ herbal supplements

D/C 1-2 weeks pre-op→ may interact with anesthetic agents, ↑ sedation, bleeding, or cardiac complications

EXAM= matching herb with interaction

Herbal	Use	Toxicity/Interactions
Ginkgo biloba	Memory, dementia	Bleeding, seizures, ↑ warfarin effect
Garlic Ginger	HTN, Lipids Vertigo, nausea	GI upset, ↑ bleeding with warfarin ↑ bleeding with warfarin
Ginseng	Fatigue, diabetes	HTN, ↑ HR, ↓ warfarin effect
St. John’s Wort	Depression	Drug interactions, ↑ anesthesia effect, delayed emergence
Kava, Valerian	Anxiety, insomnia	Sedation, prolonged emergence
Echinacea	Immune booster	Hepatotoxicity, hypersensitivity

what was ephedra used for

1. weight loss aids

2. stimulants

3. decongestant

4. bronchodilators

active agent in ephedra

ephedrine (sympathomimetic, amphetamine-like)

6 adverse effects a/w ephedra

1. -HTN

2. -cardiac arrhythmias

3. -prolonged QTc

4. -MI

5. -stroke

6. -sudden death

(4-6 is why it was banned in 2004)

risk a/w ephedra is how many times greater than other supplements

100x