Dependence of transcutaneous O2 partial pressure on cutaneous blood flow

Abstract

Transcutaneous PO2 was measured using a transcutaneous PO2 electrode heated to 45 degrees C on the forearm of 19 healthy volunteers. Cutaneous blood flow (CBF) was estimated indirectly from the heating power of the electrode (HP) and with an 8-MHz bidirectional ultrasonic probe by Doppler shift in a fingertip at 45 degrees C (DF). Blood flow was regulated by an upper arm cuff. Mean transcutaneous PO2 during air respiration was 86.0 +/- 6.2 Torr, and the correlation to arterial PO2 (Pao2) was 0.96 at normal blood flow. The arterial inflow was intermittently reduced in 10-15% stages of effective perfusion pressure (Peff). There was a hyperbolic decrease in PO2 when CBF was restricted in stages. A linear dependence between Peff, HP, and DF was found, which means that there is no autoregulation in the capillary bed at 45 degrees C. Transcutaneous PO2 can be also taken as an indication of CBF. The transcutaneous index, transcutaneous PO2/Pao2, is helpful for estimating local O2 availability.

Skin oxygen tension is improved by immersion in oxygen‐enriched water

“…PskO 2 was measured with the electrode temperature set to 44°C to induce local hyperaemia. This ensured that any increase in PskO 2 was due to O 2 absorption from water rather than from increased arterial O 2 delivery [26,27]. Similar to previous findings in healthy adults [28], the PskO 2 on the plantar surface of the foot was approximately 75 mmHg for all groups prior to water immersion.…”

“…The process and equipment used in the laboratory to increase the oxygen content of water follows Henry's Law; however, the water produced holds more oxygen at atmospheric pressure than would generally be predicted. This ensured that any increase in PskO 2 was due to O 2 absorption from water rather than from increased arterial O 2 delivery [26,27]. O 2 for N 2 ) during the oxygenation process and because the nature of the fibrous filter allows formation of extremely small microbubbles (<50 microns) to enter solution which are somewhat stable at atmospheric pressure.…”

Exploring the influence of skin perfusion on transepidermal water loss

“…tcpO 2 has been used as a tissue metabolism indicator in soft and skeletal tissue injuries caused by infection and/or ischaemia (8, 31, 32). tcpO 2 measurement value was suggested to be more accurate than other non‐invasive strategies such as the measurement of local skin perfusion pressures, and the tc index (tcpO 2 /paO 2 ) has been applied to the estimation of local oxygen availability (29, 33). Measurement of microcirculation by LDF, provided an additional mean to quantitatively describe peripheral vascular disease and limb ischemia, and have been implemented as an amputation criteria (8, 9, 14, 34).…”

“…Measurement of microcirculation by LDF, provided an additional mean to quantitatively describe peripheral vascular disease and limb ischemia, and have been implemented as an amputation criteria (8, 9, 14, 34). However, the possibility to correlate local blood flow dynamics with tissue oxygenation and/or other related indicators has only been partially explored (16, 33, 35).…”

Monitoring Carbon Dioxide Tension and Arterial Oxygen Saturation by a Single Earlobe Sensor in Patients With Critical Illness or Sleep Apnea

“…8,9 However, in adults, transcutaneous partial pressure of oxygen depends heavily on local skin perfusion and does not reliably reflect systemic Pao 2 . 10 Recently, a novel combined sensor for the measurement of both Ptcco 2 and pulse oximetric saturation (Spo 2 ) [TOSCA; Linde Medical Sensors; Basel, Switzerland] has been developed. It contains an electrochemical electrode (for Ptcco 2 measurement), a light emitter/sensor (for Spo 2 measurement), and a heating element (to increase local perfusion).…”