Effects of dexmedetomidine on systemic and coronary hemodynamics in the anesthetized dog.

In addition to central effects, which are the basis of their use in anesthesiology, alpha 2-adrenergic agonists have direct peripheral cardiovascular effects. Dexmedetomidine (DM) has been found to depress cardiac function in dogs, even after autonomic denervation. The present experiments evaluated the effects of DM on coronary flow, myocardial oxygen extraction, and cardiac function in intact, open chest dogs under enflurane anesthesia.

Effect of dexmedetomidine, an alpha 2-adrenergic agonist, in the isolated heart.

Dexmedetomidine (DM) was studied in the isolated dog heart in the form of a Starling heart-lung preparation, (HLP). Hearts were subjected to increased loading by (a) increasing cardiac output, and (b) increasing systemic resistance. Results are depicted by cardiac function curves, prepared by plotting left atrial pressure against either systemic cardiac output or mean arterial pressure.

Hemodynamic effects of dexmedetomidine, an alpha 2-adrenergic agonist, in autonomically denervated dogs.

The hemodynamic effects of the alpha 2-adrenergic agonist, dexmedetomidine (DM), were studied in eight anesthetized, autonomically denervated dogs. Autonomic block decreased mean arterial pressure (MAP) and cardiac index (CI) by approximately 20% to 95 +/- 8 mm Hg and 4.1 +/- 0.

Narcotic reversal in hypercapnic dogs: comparison of naloxone and nalbuphine.

Reversal of opioid effects by naloxone (NX) can lead to significant cardiovascular problems. We have reported previously that hypercapnic dogs develop greater increases in blood pressure and plasma catecholamine (CA) levels than hypocapnic ones when reversed with naloxone. We have also demonstrated differences between NX and nalbuphine (NBPH) in producing excitatory adrenergic responses when administered during normocapnia.