title: Effectiveness of Pulse Oximetry Versus Doppler for Tourniquet Monitoring.
abstract: BACKGROUND
  Pulse oximeters are common and include arterial pulse detection as part of their methodology. The authors investigated the possible usefulness of pulse oximeters for monitoring extremity tourniquet arterial occlusion.
  
  
  METHODS
  Tactical Ratcheting Medical Tourniquets were tightened to the least Doppler-determined occluding pressure at mid-thigh or mid-arm locations on one limb at a time on all four limbs of 15 volunteers. A randomized block design was used to determine the placement locations of three pulse oximeter sensors on the relevant digits. The times and pressures of pulsatile signal absences and returns were recorded for 200 seconds, with the tourniquet being tightened only when the Doppler ultrasound and all three pulse oximeters had pulsatile signals present (pulsatile waveform traces for the pulse oximeters).
  
  
  RESULTS
  From the first Doppler signal absence to tourniquet release, toe-located pulse oximeters missed Doppler signal presence 41% to 50% of the times (discrete 1-second intervals) and missed 39% to 49% of the pressure points (discrete 1mmHg intervals); fingerlocated pulse oximeters had miss rates of 11% to 15% of the times and 13% to 19% of the pressure points. On toes, the pulse oximeter ranges of sensitivity and specificity for Doppler pulse detection were 71% to 90% and 44% to 51%, and on fingers, the respective ranges were 65% to 77% and 78% to 83%.
  
  
  CONCLUSIONS
  Use of a pulse oximeter to monitor limb tourniquet effectiveness will result in some instances of an undetected weak arterial pulse being present. If a pulse oximeter waveform is obtained from a location distal to a tourniquet, the tourniquet should be tightened. If a pulsatile waveform is not detected, vigilance should be maintained.
authors.forename: Piper L
authors.initials: PL
authors.lastname: Wall
authors.forename: Charisse M
authors.initials: CM
authors.lastname: Buising
authors.forename: Lisa
authors.initials: L
authors.lastname: Grulke
authors.forename: Alexander
authors.initials: A
authors.lastname: Troester
authors.forename: Nicholas
authors.initials: N
authors.lastname: Bianchina
authors.forename: Shannon
authors.initials: S
authors.lastname: White
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Freymark
authors.forename: Ali
authors.initials: A
authors.lastname: Hassan
authors.forename: James W
authors.initials: JW
authors.lastname: Hopkins
authors.forename: Catherine Hackett
authors.initials: CH
authors.lastname: Renner
authors.forename: Sheryl M
authors.initials: SM
authors.lastname: Sahr
mesh_terms: D000293:Adolescent; D000328:Adult; D001132:Arm; D005260:Female; D064368:Healthy Volunteers; D006470:Hemorrhage / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008887:Military Medicine; D008991:Monitoring, Physiologic; D010092:Oximetry / Q000379:methods*; D011312:Pressure; D013848:Thigh; D014111:Tourniquets; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler / Q000379:methods*; D055815:Young Adult