Significant numbers

Question 1

E1/2t and clearnece of thiopental and methohexitol

Answer 1

• E1/2t and clearnace d/t hepatic metabolism
• Thiopentoal
  
  • E1/2 = 11.6 hours
  • Clearnace = 3.4 ml/kg/min
• Methohexitol
  
  • E1/2 = 3.9 hours
  • Clearnace = 10.9 ml/kg/min

Question 2

% nonionized at 7.4 for thiopental and methohexatol

Answer 2

Thiopentol = 61%

Methohexatol = 76%

Question 3

Relative dosages of methohexatol and thiopental

Answer 3

Thiopental Dose

1. IV: 3-5mg/kg
2. Elderly = Decrease
3. Peds IV: 5-6 mg/kg
4. Infants: 7-8 mg/kg

Methohexatol

1. IV: 1-2 mg/kg
2. Peds Rectal: 20-30 mg/kg

Question 4

1. pKA = 7.9
2. % NON-ionized at physoplogic pH = 23%

Answer 4

Morphine

Question 5

pKA = 8.5

% NON-ionized at physoplogic pH = 7%

Answer 5

Meperedine (Demerol)

Question 6

pKA = 8.4

% NON-ionized at physoplogic pH = 8.5%%

Answer 6

Fentanyl

Question 7

pKA = 8.0

% NON-ionized at physoplogic pH = 20%

Answer 7

Sufentanil

Question 8

pKA = 6.5

% NON-ionized at physoplogic pH = 89%

Answer 8

Alfentanil

Question 9

pKA = 7.3

% NON-ionized at physoplogic pH = 58%

Answer 9

Remifentanil

Question 10

Protein binding = 35%

Answer 10

Morphine

Question 11

Protein binding = 70%

Answer 11

Meperidine

Question 12

Protein binding = 84%

Answer 12

Fentanyl

Question 13

Protein binding = 93%

Answer 13

Sufentanil

Question 14

Protein binding = 92%

Answer 14

Alfentanil

Question 15

Protein binding = 66-93%

Answer 15

Remifentanil

Question 16

E1/2t = 3-5 hours

Answer 16

Meperedine (demerol)

Question 17

E1/2t = 0.17- 0.33 hours

Answer 17

Remifentanil

Question 18

E1/2t = 1.4 - 1.5 hours

Answer 18

Alfentanil

Question 19

E1/2t = 2.2-4.6 hours

Answer 19

Sufentanil

Question 20

E1/2t = 3.1 - 6.6 hours

Answer 20

Fentanyl

Question 21

E1/2t = 1.7-3.3 hours

Answer 21

Morphine

Question 22

Dosing of fentanyl

Answer 22

1. Wide ranges: 1-20 mcg/kg for pain and to blunt circulatory responses to DVL, or a chnage in circulatory stimulation
2. Lozenges: 5-20mcg/kg; 45 minutes prior to inducton
3. Transdermal Patch: 75-100 mcg/hour; peaks at 18-24 hours

Question 23

Sufentanil potency

Answer 23

10x fentanyl and 1000x morphine which parralles sufentanil’s greater affinity for opioid receptors compared to fentanyl

Question 24

Relative starting BOLUS doses of

1. Fentanyl
2. Remifentanil
3. Alfentanil
4. Sufentanil

Answer 24

1. Fentanyl = 1-3 mcg/kg
2. Remifentanil = 1-2 mcg/kg (same as fentanyl)
3. Alfentanil = 10-20 mcg/kg (5x fentanyl)
4. Sufentanil = 0.1-0.3 mcg/kg (1/10 fentanyl)

Question 25

Starting INFUSION doses of:

1. Fentanyl
2. Remifentanil
3. Alfentanil
4. Sufentanil

Answer 25

1. Fentanyl = 0.01-0.05 mcg/kg/min
2. Remifentanil = 0.05-0.25 mcg/kg/min (start at 5)
3. Alfentanil = 0.25 - 0.75 mcg/kg/min (5x upper fent)
4. Sufentanil = 0.0015 - 0.01 mcg/kg/min (lil > 1/10)

Question 26

Potency of opiods from lowest to higest

Answer 26

1. Meperedine (Demerol) (1/10)
2. Morphine
3. Hydropmorone (Dilaudid) (5x)
4. Alfentanil (10-20x morphine)(1/5 fentanyl)
5. Fentanyl (100x)
6. Remifentanil (100x)
7. Sufentanil (1000x morphine)(10x fentanyl)