Halothane Pulmonary Effects
- 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
Halothane Physical Property: boiling point
50.2 C
Halothane Physical Property: SVP
243 mm Hg
Halothane Physical Property: MAC
0.74 %
Halothane Physical Property: Blood/Gas Coefficient
2.3
Halothane Physical Property: Brain/Blood coefficient
2.9
Halothane Physical Property: Muscle/Blood Coefficient
3.5
Halothane Physical Property: Fat/Blood Coefifcient
60
Halothane Cardiovascular Effects: most prominent effect
dose dependent arterial hypotension
Halothane Cardiovascular Effects: SVR
remains intact even with deep
Halothane Cardiovascular Effects: BP
decreased by dose dependent increase in CVP
Halothane Cardiovascular Effects: myocardial contractility
greater depressant than vasomotor tone and dose dependent decrease in CO
Halothane Cardiovascular Effects: inotropic
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
Halothane Cardiovascular Effects: SNS
indirect activation
Halothane Cardiovascular Effects: coronary blood flow
decreased coronary blood flow and decrease coronary artery vascular resistance, may be a response to decrease MVo2 secondary to decreased contractility and BP
Halothane Cardiovascular Effects: SA node
depression of SA node
- common to see AV junctional rhythms
- AV dissociation during halothane anesthesia
Halothane Cardiovascular Effects: treating AV junction rhythms
give atropine prior to inhalation agent
Halothane Cardiovascular Effects: ectopy
decreases threshold for catecholamines causing ventricular ectopy
Halothane Cardiovascular Effects: epinephrine administration
no more than 100 mcg of eli injected in less than 10 mins
-no more than 5 mcg/kg during injection
Halothane Cardiovascular Effects: increased injection of epi
cause hypercapnia
Halothane Cardiovascular Effects: epi injection insensitive
children
Halothane Neurological Effects: cerebral vasculature
don’t want additional water in the brain
-blunts auto regulatory response of cerebral vasculature
Halothane Neurological Effects: EEG
burst suppresion at greater than 3.5 MAC
halothane hepatic metabolism
20%
