Halothane

Question 1

Halothane Pulmonary Effects

Answer 1

• respiratory depression
• dose dependent manner, alveolar hypoventilation resulting in hypercapnia
• rapid and shallow respiratory pattern
• blunts ventilatory response to hypercapnia
• subanesthetic of halothane abolish ventilatory response to hypoxemia and why it is important to administer O2 to your patients after extubation
• increase A-a gradient as result of atelectasis in dependent regions of lungs and blunting hypoxia pulmonary vasoconstrictor response
• surgical stimulation tends to increase respiratory drive and counteract some of the respiratory depressant effects of halothane
• unrecognized apnea during deep halothane can be catastrophic

Question 2

Halothane Physical Property: boiling point

Answer 2

50.2 C

Question 3

Halothane Physical Property: SVP

Answer 3

243 mm Hg

Question 4

Halothane Physical Property: MAC

Answer 4

0.74 %

Question 5

Halothane Physical Property: Blood/Gas Coefficient

Answer 5

2.3

Question 6

Halothane Physical Property: Brain/Blood coefficient

Answer 6

2.9

Question 7

Halothane Physical Property: Muscle/Blood Coefficient

Answer 7

3.5

Question 8

Halothane Physical Property: Fat/Blood Coefifcient

Answer 8

60

Question 9

Halothane Cardiovascular Effects: most prominent effect

Answer 9

dose dependent arterial hypotension

Question 10

Halothane Cardiovascular Effects: SVR

Answer 10

remains intact even with deep

Question 11

Halothane Cardiovascular Effects: BP

Answer 11

decreased by dose dependent increase in CVP

Question 12

Halothane Cardiovascular Effects: myocardial contractility

Answer 12

greater depressant than vasomotor tone and dose dependent decrease in CO

Question 13

Halothane Cardiovascular Effects: inotropic

Answer 13

greater negative inotropic effect except for enflurane

• alters intracellular Ca homeostasis secondary to inhibiting calcium influx through slow Ca channel
• decrease availability of calcium activation of contraction
• decreased storage of calcium

Question 14

Halothane Cardiovascular Effects: SNS

Answer 14

indirect activation

Question 15

Halothane Cardiovascular Effects: coronary blood flow

Answer 15

decreased coronary blood flow and decrease coronary artery vascular resistance, may be a response to decrease MVo2 secondary to decreased contractility and BP

Question 16

Halothane Cardiovascular Effects: SA node

Answer 16

depression of SA node

• common to see AV junctional rhythms
• AV dissociation during halothane anesthesia

Question 17

Halothane Cardiovascular Effects: treating AV junction rhythms

Answer 17

give atropine prior to inhalation agent

Question 18

Halothane Cardiovascular Effects: ectopy

Answer 18

decreases threshold for catecholamines causing ventricular ectopy

Question 19

Halothane Cardiovascular Effects: epinephrine administration

Answer 19

no more than 100 mcg of eli injected in less than 10 mins

-no more than 5 mcg/kg during injection

Question 20

Halothane Cardiovascular Effects: increased injection of epi

Answer 20

cause hypercapnia

Question 21

Halothane Cardiovascular Effects: epi injection insensitive

Answer 21

children

Question 22

Halothane Neurological Effects: cerebral vasculature

Answer 22

don’t want additional water in the brain

-blunts auto regulatory response of cerebral vasculature

Question 23

Halothane Neurological Effects: EEG

Answer 23

burst suppresion at greater than 3.5 MAC

Question 24

halothane hepatic metabolism

Answer 24

20%

Question 25

halothane hepatitis

Answer 25

secondary to reductive metabolism of halothane in presence of hepatocyte hypoxia