Halothane Flashcards
Halothane boiling point
50.2 C
Halothane saturated vapor pressure
243 mmHg
Halothane MAC
0.74 vol%
Halothane blood/gas coefficient
2.3
Halothane brain/blood coefficient
2.9
Halothane muscle/blood coefficient
3.5
Halothane fat/blood coefficient
60
Halothane Pulmonary effects
Medium(but more than N2O) decrease in tidal volume and increase in end tidal CO2 (same as sevo).
Respiratory depressant.
Alveolar hypoventilation causes arterial hypercapnia- rapid & shallow breaths.
Profoundly blunts ventilatory response to hypercapnia.
Subanesthetic concentrations abolish response to hypoxemia.
Increases arterial-alveolar gradient.
Unrecognized apnea during deep halothane anesthesia can be catastrophic.
Surgical stimulation increases respiratory drive and counteracts some respiratory depressant effects of halothane.
Halothane CV effects
Dose dependent arterial hypotension, causing increase CVP (significant depressant of myocardial contractility)– dose dependent decrease in cardiac output = decreased MVO2
SVR stays intact
Most amount of negative inotropic effect (inhibits calcium influx through slow channel, decreases availability of calcium for activation of contraction * decreased storage)
No activation of sympathetic nervous system
Decreases coronary blood flow and vascular resistance
Common to see slow AV junctional/dissociation rhythms
Halothane recommendations with epinephrine
Decreases ectopy threshold- recommended that no more than 100 mcg of epi be injected in less than 10 minutes and no more than 5mcg/kg during injection process – WORSE WITH HYPERCAPNIA (children less sensitive)
Halothane burst suppression at what MAC
3.5
Halothane hepatic metabolism effects
Bromide metabolism can cause somnolence & confusion if >6 MeQ/L, hepatitis due to reductive metabolism in presence of hepatocyte hypoxia
Halothane liver:blood coefficient
2.1
Halothane kidney:blood coefficient
1.2
