Psychiatric Disorders (2)

Question 1

What percent of the U.S. population takes a prescription medication for their mental health?

Answer 1

15.8%

Question 2

Of prescriptions, what is the most prescribed drug?

Answer 2

Lyrica

Question 3

Discontinuation syndrome signs and symptoms:

Answer 3

~ Nausea
~ Abdominal pain and diarrhea
~ Sleep disturbances (insomnia, vivid dreams and nightmares)
~ Somatic symptoms (sweating, lethargy and headaches)
~ Affective symptoms (low mood, anxiety and irritability

Question 4

Discontinuation syndrome when do signs and symptoms begin?

Answer 4

Symptoms begin abruptly within a few days of stopping the antidepressant

Question 5

Continuation of medications:

Answer 5

With the exception of MAOIs (where debate exists) continue all antidepressants throughout the perioperative period

Question 6

MAOI continuation during surgery

Answer 6

Continuation of MAOIs carries risks, but with careful anesthetic technique, these risks can be minimized and must be balanced against the risks of relapse and discontinuation syndrome

Question 7

Psychiatric disease - Mood disorders include and involve:

Answer 7

Depression, Bipolar disorder, Schizophrenia
~ Imbalance of NTs (Norepinephrine [NE], Serotonin [5-HT], Dopamine [DA])
~ Treatments - potential drug interactions, anesthesia considerations

Question 8

Depression dx:

Answer 8

Most common psychiatric disorder
~ Lifetime prevalence of between 10 and 20%
~ Diagnosis requires presence of at least 5 of the following symptoms for a period of 2 weeks
- depressed mood
- markedly diminished interest or pleasure in almost all activities
- fluctuations in body weight and appetite
- insomnia or hypersomnia
- restlessness
- fatigue
- feelings of worthlessness or guilt
- decreased ability to concentrate
- suicidal ideations

Question 9

***What causes depression?

Answer 9

Imbalance in endogenous amines (5-HT or NE) in the CNS

Question 10

***Depression: Classification of antidepressants base on MOA structure

Answer 10

~ MAOIs inhibit amine (NE or 5-HT) metabolism
~ TCAs (and heterocyclics) non selectively inhibit both NE and 5-HT
~ Selective Serotonin Reuptake Inhibitors (SSRIs) selectively inhibit 5-HT reuptake
~ Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) selectively inhibit reuptake of both 5-HT and NE

Question 11

Depression treatment:

Answer 11

~ Initial (primary) therapy - antidepressant drugs (70-80* of patients respond to antidepressant pharmacologic therapy)
~ Psychotherapy
~ Electroconvulsive therapy (ECT) - (50% who do not respond to antidepressants do respond favorably to ECT

Question 12

MAOIs and Tyramine

Answer 12

When taken together, MAOIs and Tyramine can cause a sudden increase in blood pressure, called the tyramine pressor response, which can be dangerous and even life-threatening

Question 13

Tyramine containing foods:

Answer 13

Meat - wine - cheese

Question 14

***What is the most common adverse side effect of MAOIs?

Answer 14

*** Orthostatic hypotension

Question 15

Tricyclic Antidepressants (TCAs) side effects:

Answer 15

~ Anticholinergic: dry mouth, blurred vision, urinary retention, consitpation
~ A-blockade: postural hypotension
~ Sedation (blockade of histominergic and a-adrenoceptors)

Question 16

MAOIs and TCAs have largely been replaced by what drugs?

Answer 16

SSRIs (due to side effects - sedation, anticholinergic and a-adrenoceptor)

Question 17

Low dose TCAs (amitryptyline and imipramine are currently used in the treatment of what?

Answer 17

Chronic pain: Structural similarities to local anesthetics (Na+ channel blocking properties)

Question 18

***What are the most commonly prescribed type of antidepressants?

Answer 18

***SSRIs

Question 19

How do SSRIs work?

Answer 19

Block reuptake of serotonin at presynaptic membranes but have relatively little effect on adrenergic, cholinergic or histaminergic systems, therefor they are associated wit few side effects

Question 20

Most prescribed SSRIs

Answer 20

Citalopram (Celexa)
Fluoxetine (Prozac)
Paroxetine (Paxil)
Sertraline (Zoloft)
Escitalopram (Lexapro)
Fluvoxamine (Luvox)

Question 21

Use extreme caution when giving what medications to patients who are on serotonergic drugs (SSRIs, SNRIs, MAOIs, TCAs)

Answer 21

~ Penylpiperidiens - Opioids (Fentanyl, Meperidine, Dextromethorphan)
~ Anti-emetics
~The potential to cause serotonin syndrome exists.

Question 22

Serotonin Syndrome Anesthetic Concerns:

Answer 22

~ May occur with therapeutic drug use, overdose, or interaction between serotonergic drugs.
~ In contrast to neuroleptic malignant syndrome, serotonin syndrome develops within 24 hours
~ Potentially life threatening

Question 23

Mnemonic used for Serotonin Syndrome symptoms

Answer 23

HARM
H - Hyperthermia
A - Autonomic instability (delirium)
R - Rigidity
M - Myoclonus

Question 24

St John’s Wort, what is it?

Answer 24

An herbal supplement that claims to promote positivity and good overall mood. Can inhibit the reuptake of dopamine, norepinephrine, and serotonin. Therefor there is a potential to have synergistic effects of dangerously elevating these neurotransmitter levels regardless of wether patients are taking other antidepressants. will also increase metabolism and reduce efficacy of orally administered midazlolam IV agents may show increased metabolism. will also diminish effects of warfarin and some NSAIDS

Question 25

St Johns Wort synopsis:

Answer 25

~ Inhibits - serotonin, norepinephrine, and dopamine reuptake ~ Can lead to serotonergic syndrome ~ Significantly increases metabolism of many commonly administered drugs such as - alfentanyl, midazlolam, and lidocaine ~ Reduced effect of warfarin and NSAIDs

Question 26

St Johns Wort when to stop prior to surgery?

Answer 26

Pharmacokinetic data suggests that St John's Wort should be stopped for at least 5 days before surgery

Question 27

How effective is St Johns Wort?

Answer 27

St Johns Wort has been found to be equivalent to TCAs in the treatment of mild to moderately sever depressive disorders

Question 28

Bipolar disorder, what is it?

Answer 28

Characterized by episodes of mania or hypomania separated by periods of depression or of "normal" mood (euthymia)

Question 29

Bipolar disorder: what percent of patients who have depression are likely to be bipolar (missed diagnosis)

Answer 29

15%

Question 30

Bipolar disorder: family history is a major risk factor. What % increase is associated with first-degree relatives?

Answer 30

19%

Question 31

Bipolar disorder: what is the first-line treatment

Answer 31

Lithium

Question 32

Bipolar disorder: possible treatments

Answer 32

Lithium Valproate Carbamazepine Olanzapine Risperidone Benzodiazepines SSRIs Bupropion Venlafaxine

Question 33

Lithium MOA

Answer 33

~ Being smaller than sodium it passes through the fast voltage-sensitive sodium channels easily, but the NA+k+ATPase pump does not readily extract lithium from the cells ~ Accumulated intracellular concentration impairs re-entry of potassium after depolarization and reduces the transmembrane potential and facilitates neuronal depolarization

Question 34

Lithium Therapeutic window:

Answer 34

Therapeutic/toxic ratio is narrow (0.8 to 1.2 mEq/L) (small therapeutic window)

Question 35

Lithium toxicity correlated with plasma levels:

Answer 35

Mild toxicity ~ Sedation ~ Skeletal muscle weakness ~ ECG changes (T wave and QT interval) Concentrations greater than 2 mEq/L ~ Hypotension ~ Dysrhythmias - heart block ~ Seizures

Question 36

Schizophrenia, what is it?

Answer 36

Major psychotic mental disorder (abnormal reality testing or thought process), thought to be related to an excess of dopaminergic activity in the brain

Question 37

Schizophrenia treatment

Answer 37

Two generations of antipsychotic drugs: ~ DA receptor antagonists (first generation - typical) cause extrapyramidal side effects (EPSE) acute dystonia, akathisia, Parkinsonism and tar dive dyskinesia ~ 5-HT-DA antagonists (second generation - atypical) less likely to cause EPSE

Question 38

Schizophrenia anesthesia concerns:

Answer 38

~ Continue medication ~ A-adrenergic blockade causing postural hypotension with compensatory tachycardia ~ Expect prolongation of QT intervals - tornadoes and sudden death occurs in 10-15 of 10,000, which is almost twice as often as in normal populations ~ Antipsychotic induce glucose intolerance (impairs action of insulin) ~ Temperature regulation impaired (direct effect on hypothalamic thermoregulation by DA blockade)

Question 39

Neuroleptic malignant syndrome, what is it?

Answer 39

Complication of treatment with DA antagonists

Question 40

Neuroleptic malignant syndrome causes what issues?

Answer 40

~ Blockade of D2 receptors in the hypothalamus may lead to hyperthermia and other signs of autonomic dysfunction due to reduced tonic inhibition of the sympathetic nervous system. ~ Blockade of DA receptors in the nigrostriatal pathways can result in increased muscle rigidity and tremor via extrapyramidal pathways

Question 41

Neuroleptic malignant syndrome: clinical manifestations

Answer 41

~ Hyperthermia - higher than 38 degrees Celsius, even higher than 40 degrees ~ Rigidity - typical: "lead pipe rigidity" ~ Mental status changes - agitated delirium with confusion ~ Autonomic instability - tachycardia, tachypnea, labile or high BP

Question 42

Neuroleptic malignant syndrome: incidence

Answer 42

1 in every 5,000; 82% of patients develop symptoms within 1 week of starting antipsychotics

Question 43

Neuroleptic malignant syndrome: comparison to MH

Answer 43

~ Shares many clinical similarities with MH, to include treatment with Dantroline ~ MH-susceptible mutations of the ryanodien receptor gene have not been detected in NMS patients and there has been no association between NMS and MH based on halothane-caffeine contracture studies. However, when patients with a history of NMS require anesthesia, they probably should be anesthetized with same precautions as MH-susceptible patients

Question 44

Pre-Op Bottom Line:

Answer 44

~ Pay particular attention to the therapeutic regimen used ~ Chronic psychiatric meds must be continued ~ Abrupt withdrawal can lead to exacerbation of illness ~ These patients have an increased risk of developing postoperative cognitive deficits, and postoperative delirium ~ Preoperative mini-mental examination - if the score is lower than allowed, re-evaluate decisions regarding the risk/benefits of suggested techniques and informed consent