Open AccessEchogenic Emboli upon Tourniquet Release During Total Knee Arthroplasty
Author(s) -
Jonathan L. Parmet,
Jan C. Horrow,
Robert A. Singer,
ARNOLD T. BERMAN,
Henry Rosenberg
Publication year - 1994
Publication title -
anesthesia and analgesia
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.404
H-Index - 201
eISSN - 1526-7598
pISSN - 0003-2999
DOI - 10.1213/00000539-199411000-00021
Subject(s) - medicine , tourniquet , anesthesia , hemodynamics , thrombus , echogenicity , vascular resistance , central venous pressure , surgery , cardiology , blood pressure , heart rate , ultrasonography
Echogenic venous emboli accompany tourniquet deflation during total knee arthroplasty. The associated pulmonary hemodynamic alterations and determined embolic composition were measured in 34 patients, undergoing 35 procedures. Ten patients received a femoral venous catheter on the operative side. Hemodynamic variables, heart rate and mixed venous oximetry, end-tidal CO2 and nitrogen tensions, and transesophageal echocardiograms were recorded after induction of anesthesia (baseline), after tourniquet inflation, after cementing, and for 15 min after tourniquet deflation. Echocardiograms revealed either showers of miliary echogenic material (Group S, 9 patients), or large echogenic masses superimposed on the showers (Group MS, 26 patients). In Group MS only, pulmonary vascular resistance index increased above baseline (205 +/- 16 [SEM] dyne.s.cm-2) beginning 5 min after tourniquet deflation (maximum 328 +/- 29, P < 0.05). Mean pulmonary arterial pressure increased above baseline (20 +/- 1.0 mm Hg) for both Groups S and MS beginning 3 min after tourniquet deflation (27 +/- 1.0, P < 0.05). Cardiac index did not change. Five of 10 patients demonstrated fresh thrombus from the catheter in the operative limb. Echogenic emboli occurred in all patients upon tourniquet deflation during knee arthroplasty. Pulmonary vascular resistance index increased only in patients with large echogenic material. Our data suggest that these emboli represent fresh thrombus formation during tourniquet inflation. Heparin administration prior to tourniquet inflation may diminish embolic showers.