Anesthesiology
-
Clinical studies have implicated surgery in promoting infections and compromising immune functions, including natural killer cell activity. Animal studies indicate that surgery-induced suppression of natural killer cell activity also promotes tumor metastasis. Hypothermia, a common surgical complication, has been suggested to underlie some of the deleterious consequences of surgery. This study evaluated the effect of hypothermia on the activity and number of blood natural killer cells and on host susceptibility to metastasis. The involvement of adrenergic mechanisms was also considered. ⋯ Hypothermia under thiopental anesthesia suppresses natural killer cell activity and compromises host resistance to metastatic formation, possibly via adrenergic mechanisms. Such suppression may place patients with metastasizing tumors or dormant viral infections at greater risk for complications after intraoperative hypothermia.
-
To learn more about pain mechanisms produced by surgery, responses of wide dynamic range (WDR) and high threshold (HT) dorsal horn neurons were studied before and after an incision. For this study, an incision was made in a mechanically insensitive area of the receptive field (RF) of the dorsal horn neuron in the plantar aspect of the foot and changes in mechanical response properties were studied. ⋯ These results suggest that incisions in mechanically insensitive areas of the RF of dorsal horn neurons produced little change in background activity; expansion of pinch RFs outside the injury was common. Changing a mechanically insensitive area of the RF of WDR neurons to a mechanically sensitive area by an incision could contribute to pain behaviors that indicate primary mechanical hyperalgesia in behavioral studies.