title: Accuracy of laser Doppler capillary flow measurements for predicting blood loss from skin incisions in pigs.
abstract: This study assesses the clinical applicability of laser Doppler capillary flow measurements for predicting blood loss from a surgical incision. To produce a wide range of blood flows, we injected lidocaine 1%, lidocaine 1% plus octapressin (0.03 IU.ml-1), and lidocaine 1% plus epinephrine (5 micrograms.ml-1) subcutaneously into three separate sites on the flank of each animal (N = 6). Laser Doppler flow measurements were made before and 10 minutes after injection Subcutaneous injection of lidocaine tended to increase cutaneous blood flow (96 +/- 13 to 153 +/- 30 mV, mean +/- SE, P = 0.09). Blood flow tended to decrease after injection of lidocaine with epinephrine (101 +/- 13 to 57 +/- 10 mV, P = 0.03) or octapressin (108 +/- 20 to 58 +/- 11 mV, P = 0.08). Laser Doppler measurements were higher after the injection of plain lidocaine than after that of lidocaine with either epinephrine or octapressin (P = 0.004). A standard incision was performed at each site and blood loss measured over the subsequent 10 minutes. Laser Doppler measurements correlated with the amount of bleeding from the surgical incision (R = 0.69, P less than 0.001). We conclude that the laser Doppler is a useful tool for evaluating the ability of subcutaneously injected local anesthetics (vasodilators) or vasoconstrictors to alter bleeding from skin incisions.
authors.affiliation: Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA 98111.
authors.forename: R L
authors.initials: RL
authors.lastname: Carpenter
authors.forename: D J
authors.initials: DJ
authors.lastname: Kopacz
authors.forename: D C
authors.initials: DC
authors.lastname: Mackey
mesh_terms: D000818:Animals; D002196:Capillaries / Q000503:physiopathology; D004837:Epinephrine / Q000494:pharmacology; D005069:Evaluation Studies as Topic; D005259:Felypressin / Q000494:pharmacology; D006470:Hemorrhage / Q000175:diagnosis*; D008012:Lidocaine / Q000494:pharmacology; D012867:Skin / Q000098:blood supply*; D013552:Swine; D014463:Ultrasonography
chemical_list: D005259:Felypressin; D008012:Lidocaine; D004837:Epinephrine