Oxygen Supply of the Myocardium

Frank, K.; Kessler, M.; Appelbaum, Kenneth A.; Dummler, W; Zündorf, Josef; Höper, J.; Klövekorn, W. P.; Sebening, F

doi:10.1007/978-1-4684-5643-1_62

Cited by 14 publications

(3 citation statements)

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“…Lightguide tissue spectrophotometry (O2C), a combination of laser Doppler spectroscopy and tissue spectrometry, is a relatively new approach for evaluating tissue oxygen supply (5). In previous investigations, this system was used to demonstrate the effect of postural changes in patients with chronic venous insufficiency (6) and for the early identification of diabetic foot ulcers that may require intervention (7).…”

Section: Diabetes Care 27:2863-2867 2004mentioning

confidence: 99%

The Impact of the Micro-Lightguide O2C for the Quantification of Tissue Ischemia in Diabetic Foot Ulcers

Witte²,

et al. 2004

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OBJECTIVE -Tissue oxygen supply is crucial for wound healing. Especially in diabetic foot lesions, the chances for healing are mainly dependent on the presence or absence of ischemia. This study investigates the impact of the tissue O2 analysis system "O2C" for noninvasive quantification of tissue oxygenation in diabetic foot ulcer patients.RESEARCH DESIGN AND METHODS -O2C assessed relative blood flow (flow), flow velocity (velo), and hemoglobin concentration (rHb) and hemoglobin oxygenation (SO 2 ) at 2 and 6 mm depth (means Ϯ SE). 1) Measurements were performed on intact skin of the forefoot and forearm of 20 healthy volunteers on 2 consecutive days. 2) Parameters were assessed on intact skin of the forefoot of diabetic foot ulcer patients (n ϭ 14). 3) Measurements were performed directly at the wound site in diabetic patients (n ϭ 14).RESULTS -1) Flow, velo, rHb, and SO 2 at 2 and 6 mm depth were not significantly different when measured at 2 consecutive days. 2) There were no significant differences between diabetic subjects and healthy volunteers. Only flow in 6 mm depth was significantly higher in diabetic subjects (75 Ϯ 13 vs. 51 Ϯ 0.4 arbitrary units [AU], P Ͻ 0.05). When diabetic foot ulcer patients were split into healers and nonhealers, initial readings of SO 2 at 2 mm (32 Ϯ 6 vs. 44 Ϯ 3%, P Ͻ 0.05) and flow in 6 mm (28 Ϯ 1 vs. 51 Ϯ 0.6 AU, P Ͻ 0.05) were significantly reduced in nonhealers compared with control subjects, whereas in healers flow in 6 mm (70 Ϯ 0.6 vs. 51 Ϯ 0.6 AU, P Ͻ 0.05) was significantly higher than that in control subjects. 3) Initial SO 2 , rHb, flow, and velo were significantly lower in nonhealing compared with healing wounds.CONCLUSIONS -O2C is a new reliable and valid method for noninvasive measurement of tissue oxygenation and microvascular blood flow in patients with diabetic foot ulcers. Diabetes Care 27:2863-2867, 2004F oot ulcers are severe long-term complications in diabetic patients. In addition to local wound therapy, adequate tissue oxygenation is crucial for healing since oxygen is necessary for collagen formation, bactericidal activity of neutrophils, and endothelial cell function. Prognosis of diabetic foot lesions is mainly dependent on the presence or absence of tissue ischemia. However, quantitative assessment of peripheral perfusion and microcirculation is still challenging. Different methods like Doppler ultrasound or angiography are able to evaluate macrocirculation, but a reliable, easy technique to assess microcirculation, i.e., tissue perfusion, is not available. Previous studies have shown that healing might be predictable by measurement of transcutaneous oxygen tension (TcPO 2 ) (1-3). If TcPO 2 is Ͻ30 mmHg, complete healing cannot be expected (4). However, TcPO 2 is only a qualitative, not a quantitative, approach for evaluating peripheral perfusion and has a main limitation due to the need for heating the skin before measurement. This affects the resistance of skin vasculature and attenuates reflex mechanisms.Lightguide tissue spectrophotometry (O2C), ...

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Section: Diabetes Care 27:2863-2867 2004mentioning

confidence: 99%

The Impact of the Micro-Lightguide O2C for the Quantification of Tissue Ischemia in Diabetic Foot Ulcers

Witte²,

et al. 2004

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“…The technique uses a small (<2 mm) diameter fibre optic lightguide to transfer light to and from the surface of tissues. It has been used to measure intravascular oxygen saturation (HbO 2 ) in a wide variety of tissues including human heart (Frank et al 1989a), skin (Harrison et al 1992a) and brain (Höper and Gaab 1994), but not in peripheral nerve. When used in combination with an endoscope the technique allows the measurement of oxygen saturation in relatively inaccessible tissues under direct visual control.…”

Section: Introductionmentioning

confidence: 99%

Combined microlightguide spectrophotometry and microendoscopy for measurement of oxygen saturation in peripheral nerves

Ibrahim¹,

Laude²,

Bee³

et al. 1999

Physiol. Meas.

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Microlightguide measurements of the spectral composition of backscattered light may be used to determine local tissue oxygen saturation and monitor tissue perfusion using intravenous injection of fluorescein dye as a contrast agent. We have used a combination of microlightguide spectrophotometry and microendoscopy to measure intravascular oxygen saturation (HbSaO2%) and monitor blood flow in the sciatic nerve of 12 healthy male Sprague-Dawley rats. The microlightguide and endoscope combination is a relatively new measurement technique. The aims of this study were to determine whether microlightguide spectrophotometry and microendoscopy could be used to measure HbO2 and blood flow in peripheral nerves and to compare the measurements made using the flexible lightguide with the endoscope-lightguide combination. We found no significant difference between the two types of measurement over similar regions of the nerve. mean SaO2% values 77.1% (95% CI = 75.4-78.8) and 78.8% (95% CI = 77.5-80.1) respectively. During a period of hypoxia there was a similar fall in both arterial and nerve oxygen saturation. Following injection of fluorescein, the rate of increase in nerve fluorescence was used as a measure of perfusion. The combination of microlightguide spectrophotometry and microendoscopy allows the exact site of measurement to be directly visualized. The minimally invasive nature of this technique may allow its application to the study of peripheral nerves in human subjects in conditions such as diabetic neuropathy where vascular factors are thought to have an important role in aetiology.

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“…4 Investigations have been made using micro-lightguide spectrophotometer measurements in various organs. [5][6][7][8][9][10][11][12][13] The method's ability to predict ulcer healing in patients with diabetes has been studied, 14,15 as well as the method's ability to predict healing after amputation. 16 Consecutive measurements in healthy volunteers have provided reproducible data.…”

mentioning

confidence: 99%

Micro-lightguide spectrophotometry for tissue perfusion in ischemic limbs

Jørgensen

Schroeder

2012

Journal of Vascular Surgery

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To validate micro-lightguide spectrophotometry (O2C) in patients with lower limb ischemia and to compare results with those obtained from toe blood pressure. Methods: We prospectively examined 59 patients, 24 of whom complained of claudication, 31 had critical ischemia, and four were asymptomatic. Diabetes was present in 19 (32%) patients. Saturation (SO 2) and flow measured with O2C were determined with the limb in the horizontal position followed by a 55-cm elevation. Toe pressures were determined in the horizontal position only. In addition, 13 patients were examined before and, on average, 3 days after revascularization. Results: Median SO 2 was 62% (25%-75% percentile: 37%-75%) with the limb in the horizontal position and 16% (3%-41%) with the limb elevated. Comparing the individual toe pressures with SO 2 values measured in the horizontal position and elevated position revealed a significant correlation (r s ‫؍‬ 0.40; P < .01 and r s ‫؍‬ 0.56; P < .01, respectively). A low SO 2 (ie, <40% in the horizontal position and <20% in the elevated position) was highly predictive of a toe pressure of 40 mm Hg or less. In the horizontal position, the positive predictive value was 100%, whereas the negative predictive value was 47%. The similar figures in the elevated position were a positive predictive value of 97% and a negative predictive value of 68%. Postoperatively, SO 2 increased significantly from 27% (P25%-75%: 11%-75%) to 79% (68%-87%) in the horizontal position (P ‫؍‬ .008) and from 14% (P25%-75%: 2%-39%) to 55% (30%-73%) in the elevated position (P ‫؍‬ .011), respectively. Looking at the individual 13 cases in which revascularization was performed, three patients had a partial reconstruction (ie, superficial femoral artery occlusion distal to a central reconstruction or reconstruction to a popliteal blind segment). These patients had significantly lower postoperative SO 2 as well as toe pressure compared with the 10 patients with unobstructed flow to the foot. Conclusions: O2C was easy to use, fast, and painless. The most useful finding was the high predictive value of a low saturation and the rise in O2C values after successful revascularization.

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Oxygen Supply of the Myocardium

Cited by 14 publications

References 1 publication

The Impact of the Micro-Lightguide O2C for the Quantification of Tissue Ischemia in Diabetic Foot Ulcers

The Impact of the Micro-Lightguide O2C for the Quantification of Tissue Ischemia in Diabetic Foot Ulcers

Combined microlightguide spectrophotometry and microendoscopy for measurement of oxygen saturation in peripheral nerves

Micro-lightguide spectrophotometry for tissue perfusion in ischemic limbs

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