Guidelines for Obese patients

Question 1

Midazolam dose for obese patients

Answer 1

0.6mg/kg

Question 2

What dose of hydroxyzine to be used with N2O on obese patients?

Answer 2

up to 2mg/kg

Question 3

What can be given to obese patients prior to sedation to prevent aspiration that have a history of vomiting during sedation?

Answer 3

H2 blockers (best to refer to hospital for treatment)

Question 4

Should post-op opioids be used for obese patients that have been sedated?

Answer 4

Should be avoided due to potential for respiratory depression and arrest. Obese pt take longer to recover from sedative drugs due the the lipophilic sequestering of the sedative drugs

Question 5

Percentage of children in US that are obese?

Answer 5

17% and rising

Question 6

What ratio of overweight preschool age children and school-age children remain obese into adulthood?

Answer 6

1/3 of preschool age children

1/2 of school age children

Question 7

How does obesity impose a restrictive ventilation defect?

Answer 7

Excess weight added to the thoracic cage and abdomen impedes motion of the diaphragm, especially in the supine position

Question 8

What decreases in lung capacity are seen with obese patients?

Answer 8

Functional reserve capacity, expiratory reserve volume. Also a reduction in chest wall compliance and increase respiratory airway resistance. (more tissue to imped airflow)
Morbidly obese-vital capacity and total lung volume

Question 9

How much reduction in functional residual capacity occurs in obese patients when in supine position?

Answer 9

There is a 50% reduction in functional residual capacity (FRC) in obese. Even with pre-oxygenation, cessation of breathing can quickly lead to arterial hypoxemia.
Non obese have a 20% reduction.

Question 10

What occurs to the myocardium when obese patients are placed in the supine position?

Answer 10

Tend to have an increase cardiac output. Leads to potential myocardial hypoxia due to decreased respiratory function and cardiac workload, especially in sedated patients.

Question 11

What increases the chances of aspiration during sedation of obese patients?

Answer 11

Increased gastric volumes, increased intra-abdominal pressure.

Question 12

What pharmacokinetics deviations occur in the obese patients?

Answer 12

Drug absorption, distribution, metabolism, and excretion are all affected by increase BMI

Question 13

What classification are most sedation drugs considered to be?

Answer 13

Lipophilic

Question 14

Why do obese patients take longer for complete recovery from sedation drugs?

Answer 14

Sequestering of drugs into fat and away from brain. Takes more drugs to induce due to fat but then quicker to recover. Fat tissues then release sedative and complete recovery is longer after drug delivery has stopped.

Question 15

Most complications seen in which type of patient during sedation?

Answer 15

ASA III
Those with cerebral palsy, followed by those with autism.
Airway obstruction seen in those with cerebral palsy.
Vomiting with those that had learning disability

Question 16

What was the concluding results of the study of sedation on patients with special needs?

Answer 16

Dental sedation on special needs patients is safe and complications are only mild. Mild airway obstruction.

Question 17

Goals of sedation in dentistry

Answer 17

1) Guard the patient’s safety and welfare
2) minimized physical discomfort and pain
3) control anxiety and maximize the potential for amnesia
4) control behavior in order for safe completion of treatment
5) return patient to a state in which safe discharge from medical supervision is possible

Question 18

Why is meperidine a desirable agent for OCS

Answer 18

sedative and analgesic properties.
It has a metabolite (normeperidine) that is CNS stimulant that can cause agitation, tremors and seizures.
Some clinics have banned meperidine and use morphine now, but little research into its use. Morphine shown to cause post-discharge excessive somnolence, nausea, and emesis.

Question 19

Benefits of combining sedative drugs

Answer 19

Synergistic sedative effect that allows for reduce dosing of the single agents but giving desired sedative effect.

Question 20

sedative effects of benzos

Answer 20

sedative and anxiolytic, amnesia

Question 21

Hydroxyzine sedative effects

Answer 21

anti-histamine producing antiemetic, anxiolytic, sedative,

Question 22

AAPD indications for OCS

Answer 22

• fearful patient whom basic behavioral techniques have not been successful
• patient unable to cooperate due to lack of psychological or emotional maturity
• desire to protect the patient’s developing psyche or desire to reduce medical risk

Question 23

What outcome on sedation does the patient’s willingness to drink the medication and the effectiveness of sedation?

Answer 23

Likelihood of successful sedation appt

Question 24

What success rate was seen in the triple combination of midazolam, hydroxyzine and oral morphine on sedation appts according to the study?

Answer 24

80% success rate with the triple combination use.

Question 25

For what medical history is it contraindicated to administer opioids (meperidine, morphine) for OCS?

Answer 25

history of asthma, wheezing
If occurs during sedation, treat with albuterol
The use of hydroxyzine can help prevent the histamine release caused by Opioids

Question 26

What age and weight should you reconsider OCS?

Answer 26

Under 15kg and age 3 or under

Question 27

Ideal tidal volume?

Answer 27

6-8ml/kg

average 500ml

Question 28

An SpO2 of 95% indicates a partial pressure PaO2 of what?

Answer 28

80mmHg PaO2

Question 29

A SpO2 of 90% indicates partial arterial pressure ( PaO2) of what?

Answer 29

60mmHg

Question 30

How to calculate sedation drugs when no preweight is known

Answer 30

use 50th percentile range for pt age and sex

Question 31

Should you use a consistent dose of sedative drugs for all patients?

Answer 31

No, dosage should be individually dose

Also based on temperament, age, weight, and amount of dentistry needed to be complete.

Question 32

What affect do benzodiazepines have on on local anesthetic toxicity effects?

Answer 32

They reduce the clinical signs of LA toxicity making it more difficult to diagnosis

Question 33

What age group are at the greatest risk for adverse events during sedation appointments?

Answer 33

Age 3 and younger

Question 34

Prilocaine MRD

Answer 34

6mg/kg

Max dose 400mg

Question 35

Role of red blood cells

Answer 35

1) transport oxygen
2) transport carbon dioxide
3) buffer for acid/base system

Question 36

Normal oxidized state of RBD porphyrin rings

Answer 36

2+ ferrous state

has 4 porphyrin rings

Question 37

What happens to RBC in methemoglobin state?

Answer 37

It is oxidized further to ferric state (3+).
Higher affinity for already bound oxygen but doesn’t bind additional oxygen.
Doesn’t release oxygen to tissues or transport carbon dioxide to lungs.

Question 38

Normal levels of methemoglobin in blood?

Answer 38

0-2%

Question 39

Signs of methemoglobin

Answer 39

cyanosis, chocolate brown blood,
Mental status change- headache, dizziness, syncope, confusion
Tachycardia, tachypnea, acidosis,

Question 40

Local anesthetic that has shown to cause methemoglobinemia

Answer 40

Benzocaine and prilocaine

Question 41

Factors that increase chance of methemoglobin?

Answer 41

Female gender
young age
higher concentration of prilocaine
higher dose

Question 42

Should prilocaine be used with caution when a patient is receiving other oxidizing agents?

Answer 42

Yes,
General anesthesia, oxygen
care must be taken in patients with hemoglobinopathies

Question 43

When was peak methemoglobin development for prilocaine and lidocaine

Answer 43

Both peak at 60 minutes after administration.

Can occur at home!!!