Effect of local cold provocation on systolic blood pressure and skin blood flow in the finger.

Demonstration of increased vascular cold reactivity in patients with Raynaud's syndrome is difficult. For medico-legal reasons, it is important to get objective measures of vasospasm in these patients. Evaluation of the degree of vasospasm also provides prognostic information which is useful for patient management. In this study, we compare two methods of arterial circulation measurement. The laser Doppler scanning is a new method, which uses the recently developed laser Doppler perfusion imaging (LDPI) instrument. The aim of the present study was to compare the effect on finger skin blood flow measured with LDPI with changes in finger systolic blood pressure during local cold provocation. The effect of such provocation, skin blood flow and systolic blood pressure, were studied in 15 healthy controls. Six patients with known traumatic vasospastic disease (TVD) were also tested with both methods. Finger skin blood flow was measured with LDPI on the distal phalanx of the index finger of the left hand, every minutes during 6 min of local heating at 40 degrees C followed by local cooling for 3 min at 15 degrees C and then for 3 min at 10 degrees C. Finger systolic blood pressure was measured with strain-gauge method before and after local cooling to 10 degrees C with a cuff perfused with water of desired temperature. The test was performed in the same finger within a week of the laser Doppler scanning. Local finger cooling to 15 degrees C and 10 degrees C caused a significant decrease in blood flow, most marked at 10 degrees C. There was, however, no correlation between the decrease in blood flow and blood pressure. In the TVD-patients decreases in skin blood flow were similar compared with the healthy controls. In contrast, the changes in systolic blood pressure, were outside normal range (systolic quotient <0.65) in five of the six patients (83%), and also in 11 of the 15 healthy controls (73%). In conclusion, there is no correlation between the decrease in finger skin blood flow and systolic blood pressure during local cold provocation. For diagnosis of traumatic vasospastic disease (TVD), local cold-induced changes in finger systolic blood pressure seems superior to changes in skin blood flow, but the ideal clinical method for demonstrating increased cold-induced vasospasm is, however, still lacking.

Sympathetic skin vasoconstriction--further evaluation using laser Doppler techniques.

The aim of this study was to quantify the reflex sympathetic vasoconstriction in skin at different depths. Twenty healthy subjects were studied. Finger skin blood flow was measured using laser Doppler perfusion imaging (LDPI) and laser Doppler perfusion monitoring (LDPM). In LDPM, a probe with fibres separated 0.25 mm (deep) and 0.14 mm (superficial) from the illuminating fibre was used. Local heating (40 degrees C) was achieved with a Peltier element, and reflex vasoconstriction induced by immersion of the contra-lateral hand and forearm for 3 min in water at 15 degrees C. The change in skin blood flow was measured and a vasoconstriction index (VAC: cooling/before cooling) calculated. VAC indices of LDPI, LDPM-0.25 and LDPM-0.14 were 0.60, 0.59 and 0.60, respectively. The two components of the LDPM perfusion value, blood cell velocity and concentration, were studied separately. Their contributions in LDPM-0.25 were roughly the same, whereas the velocity component dominated in LDPM-0.14, although their relative responses in the two channels were similar. We conclude that sympathetic skin vasoconstriction does not significantly differ in two compartments, as probed with fibres separated by 0.25 and 0.14 mm. Blood cell velocity is influenced in a proportional way, as is concentration.

Sympathetic dysfunction in patients with primary Sjögren's syndrome.

OBJECTIVE: To investigate autonomic nervous system function in patients with primary Sjögren's syndrome (SS) and relate the findings to clinical variables. METHODS: Autonomic nervous system function was determined in 30 patients with primary SS using the finger skin blood flow test [vasoconstrictory (VAC) index], deep-breathing test [expiration/inspiration (E/I) ratio], and the tilt table (orthostatic) test [acceleration index (AI), brake index (BI), and orthostatic blood pressure]. The results were compared with age matched control materials (finger skin blood flow test, n = 80, and deep-breathing and tilt table tests, n = 56). RESULTS: The VAC index was found to be significantly increased and the E/I ratio significantly decreased in patients compared to controls, indicating both a sympathetic and a parasympathetic dysfunction. Further, the patients, especially the anti-SSA and anti-SSB antibody seropositives, were found to have an abnormal blood pressure reaction to tilt compared to controls. No correlations were found between autonomic nerve function variables measured and the clinical ophthalmologic or the oral tests, performed at the time of diagnosis. CONCLUSION: Patients with primary SS show signs of both sympathetic and parasympathetic dysfunction. Further, immunological mechanisms seem to influence blood pressure in patients with primary SS.

Effects of transcutaneous nerve stimulation on the microcirculation in chronic leg ulcers.

The purpose of this study was to find out to what extent transcutaneous electrical nerve stimulation (TENS) affects the blood flow in and around chronic lower leg ulcers, as measured with a new technique, laser Doppler imaging (LDI). Fifteen patients, mean age 73 years (range 38-85) with chronic leg ulcers of various causes participated in the study. The duration of the ulcers ranged from 3 months to 16 years. Low-frequency (2 Hz; 10-45 mA) TENS was given for 60 minutes. The changes in blood flow were measured every 5 minutes by LDI. After 60 minutes, mean blood flow had increased in the ulcer by 35%, and in the intact skin surrounding the ulcer by 15%. Even 15 minutes after the TENS had finished there was still a mean blood flow increase of 29% in the ulcer and 9% in the skin. The present results show that TENS has a stimulating effect on local blood circulation in and around chronic ulcers.

Detection of autonomic sympathetic dysfunction in diabetic patients. A study using laser Doppler imaging.

OBJECTIVE: To study signs of the disturbed reflex autonomic sympathetic nerve function in type 1 and type 2 diabetic patients. RESEARCH DESIGN AND METHODS: Measurements were made on 15 type 1 (duration 13-32 years) and on 50 recently diagnosed type 2 diabetic patients (duration 3-4 years). The vasoconstrictor responses in the distal phalanx of the middle finger (locally heated to 40 degrees C) to the cooling of the contralateral arm were measured using Laser Doppler Imaging (LDI). A vasoconstriction index (VAC) was calculated taking age into account and was compared with reference values obtained in 80 control subjects. The diabetic patients were also studied with deep-breathing tests (i.e., the heart-rate variation expressed as the expiration-to-inspiration [E/I] ratio, a test of parasympathetic nerve function). RESULTS: The vasoconstrictor responses to indirect cooling (VAC) were significantly reduced in the fingers of the diabetic patients, both type 2 (0.77 +/- 0.02 V; P < 0.01) and type 1 (0.83 +/- 0.04 V; P < 0.001), compared with the healthy control subjects (0.65 +/- 0.01); the age-corrected VAC (VACz) was slightly more impaired in type 1 than in type 2 diabetic patients. The frequency of an abnormal VACz corresponded well to the frequency of an abnormal E/I ratio in type 1 diabetic patients (approximately 50%), whereas the frequency of an abnormal VACz was significantly higher than an abnormal E/I ratio among type 2 diabetic patients (11/50 vs. 4/50; P < 0.05). CONCLUSIONS: Both type 1 and type 2 diabetic patients have impaired cutaneous blood flow regulation. The VAC index seems to be a promising tool for detection of subclinical changes in autonomic sympathetic function.

Finger skin blood flow in response to indirect cooling in normal subjects and in patients before and after sympathectomy.

Finger skin blood flow was measured in 80 healthy subjects, using laser Doppler imaging during basal vasodilatation at a local temperature of 40 degrees C. The response to cooling of the contralateral hand at 15 degrees C was studied. A vasoconstriction index was calculated in all subjects and a nomogram was constructed, taking age into consideration. Compared with these normal subjects, four patients operated on with transthoracic endoscopic sympathectomy due to hand hyperhidrosis showed clearly attenuated responses. The results indicate that the test can be used to assess disturbances in the sympathetic regulation of the peripheral blood flow.

Skin temperature changes and changes in skin blood flow monitored with laser Doppler flowmetry and imaging: a methodological study in normal humans.

The aim of the present study was to elucidate the interrelation between changes in skin temperature and changes in skin blood flow, as measured by laser Doppler techniques. Therefore, 17 healthy volunteers were studied upon immersion of both feet in water of 15 degrees C for 10 min followed by body warming for 30 min. Measurements using laser Doppler flowmetery (LDF) were performed from the nailfold of the big toe, while measurements using laser Doppler imaging (LDI) were performed from the dorsum of the foot. Temperatures were recorded simultaneously from the toe tip and the dorsal foot skin. Temperatures at the toe tip were significantly lower than at the dorsal foot skin. Cooling caused decreased values in all parameters, with restitution during indirect heating. There was an exponential interrelation between LDF and temperature readings from the toe owing to very high LDF values at the end of indirect heating. On the dorsum of the foot, relative changes in LDI and temperature showed a linear relationship (rs = 0.65), although LDI values were consistently higher than temperatures. It is concluded that temperature readings constitute an ambiguous measure of skin blood flow. On the toe tip, blood flow through opened arteriovenous shunts during indirect heating does not correlate with temperature. Cooling of the foot decreases skin temperature, mainly by heat conduction, whereas skin blood flow is only slightly reduced.

Cutaneous vasomotor responses in young type I diabetic patients.

Abnormal skin temperature reactions have been reported in type I diabetic patients. Whether this is due to a primary vascular disturbance or autonomic neuropathy is unclear. The aim of this study was to clarify this issue by evaluating cutaneous circulatory reactions before and after provocation. Seventeen type I diabetic patients and 17 age-matched controls were studied by recording blood flow (laser Doppler technique) on the dorsum of the hand (before, during, and after arterial occlusion), blood flow and skin temperatures on the dorsum of the foot and on the toe (before and after cooling followed by indirect body heating) and autonomic nerve function (heart rate reaction to deep breathing and to tilting). The results showed that before [4.6 +/- 0.5 perfusion units (PU) versus 6.1 +/- 0.7 PU; p = 0.0356] and after arterial occlusion (17.5 +/- 1.6 PU versus 25.3 +/- 1.7 PU; p = 0.0024), hand skin blood flow was significantly lower in patients than in controls. On the dorsum of the foot, skin temperatures was significantly lower in patients than in controls before cooling (29.2 degrees C +/- 0.3 degrees C versus 30.5 degrees C +/- 0.4 degrees C; p = 0.0107) whereas toe temperature and toe blood flow were similar before and after cooling in patients and controls. After body heating, however, toe temperature (after 30 min: 25.2 degrees C +/- 1.4 degrees C versus 30.9 degrees C +/- 1.2 degrees C; p = 0.0022) and toe blood flow (after 30 min: 10.9 +/- 2.5 degrees C versus 22.9 +/- 4.9 PU; p = 0.0313) were significantly lower in patients than in controls, especially in patients with parasympathetic neuropathy (i.e., patients with abnormal heart rate reactions to deep breathing). In conclusion, type I diabetic patients demonstrated a vascular disturbance in their skin that seemed to be exaggerated by parasympathetic neuropathy.

Is vibration-induced white finger a reversible syndrome if vibration is stopped?

The purpose of the study was to investigate if vibration-induced white finger may be a reversible symptom after cessation of vibration exposure. Fifty-nine welders, previously employed by a ship building company and who had shown various levels of vibration-induced vasospastic symptoms in the hand were interviewed 5 to 6 years after closure of the company. Out of the 43 patients exposed to no or insignificant vibration subsequently, 28 claimed improvement, 11 claimed unchanged problems and four complained of worse problems. Twelve of these patients had the cold provocation test repeated at follow up. One patient showed the same result as 5 years earlier, six showed improvement and five showed much improvement. Of 16 patients with continued vibration exposure none showed subjective improvement, nine claimed unchanged problems while seven patients were worse. It is concluded that vibration-induced white finger is not a progressive condition following cessation of exposure to vibration. On the contrary it may be static or even reversible to some extent.

A new device combining laser Doppler perfusion imaging and digital photography.

We describe a new method for acquisition and analysis of skin perfusion images acquired by laser Doppler scanning and digital photographs of the area scanned. Photographs are obtained with a commercial digital still video camera. A commercial software package is used to handle the perfusion image file and the digital photo. We describe software developed to assess blood flow distribution in detail in relation to the visual appearance of the skin, palpatory findings and other clinical signs. Possible clinical applications of the method described by case reports are post-operative evaluation of vascularized grafts and monitoring of treatment of chronic skin ulcers.

Wound healing after total elbow replacement in rheumatoid arthritis. Wound complications in 50 cases and laser-Doppler imaging of skin microcirculation.

Wound healing complications, predisposing to deep infection, are common following prosthetic surgery of the elbow. 50 capitellocondylar elbow prostheses were inserted, using a lateral approach, in 42 patients with rheumatoid arthritis. The first 5 elbows were immobilized postoperatively for 5 days and the following 45 elbows for 12 days, because of delayed wound healing in 2 of the first 5 elbows. No wound healing complications were recorded in elbows immobilized for 12 days and elbow motion was not compromised. 5 elbows were investigated with laser-Doppler imaging (LDI) technique, both pre- and postoperatively. Postoperative LDI values were considerably higher than preoperative ones, indicating no impairment of local skin microcirculation. The authors conclude that the lateral approach is safe to use in prosthetic surgery on the elbow. Early mobilization can delay wound healing, but this can be prevented by 2 weeks of postoperative immobilization.

Intramuscular laser-Doppler flowmetry in the supraspinatus muscle during isometric contractions.

To study the regulation of microvascular blood flow in a compartment muscle, laser-Doppler measurements of muscle microcirculation were recorded in the supraspinatus muscle in eight volunteers during and following submaximal isometric muscle contractions. The subjects performed isometric shoulder abductions at five contraction levels from 5% to 50% maximal voluntary contraction for 1 min each and a sustained 30 degrees shoulder abduction for 20 min. The subjects' perceived exertion increased from "no perceived exertion" to "near maximal exertion" during the 20-min period with 30 degrees shoulder abduction. Microcirculation increased during all 1-min contractions. Following the contractions at 20%, 30% and 50% MVC post-exercise reactive hyperaemia was seen for a period of at least 1 min. The reactive hyperaemia increased in magnitude in response to increasing contraction level. The results showed the same time-history of the blood flow at microvascular level as previously seen in larger peripheral vessels in response to muscle contractions. During the 20-min contraction microcirculation increased in line with the findings during the brief contractions. However, in contrast to the brief contractions no postexercise reactive hyperaemia occurred following the prolonged contraction. Lack of postexercise reactive hyperaemia following the prolonged shoulder abduction would suggest insufficient regulation of the vascular resistance. Alternatively, lack of hyperaemia could be taken as an indication of sufficient microcirculation during the preceding contraction. From previous studies on intramuscular pressure and metabolism the latter alternative would seem unlikely.

Laser Doppler imaging of finger skin blood flow in patients after microvascular repair of the ulnar artery at the wrist.

Laser Doppler imaging is a new, non-invasive technique allowing the spatial distribution and the temporal variation of the skin blood flow to be monitored. A mean blood flow value over an area, such as the finger-tip in the present study, can also be calculated. Recordings from 12 patients with a sutured ulnar artery following trauma did not significantly differ from those obtained in 14 controls. Four patients with a ligated ulnar artery, however, showed a slower restitution of blood flow values after cold provocation. All sutured ulnar arteries were found to be patent, which confirms that microvascular reconstruction of an injury to the ulnar artery at the wrist is worthwhile.

Evaluation of port wine stain perfusion by laser Doppler imaging and thermography before and after argon laser treatment.

Thirteen patients with port wine stains (PWS) were treated with argon laser therapy. Before and at different points in time following treatment, skin blood perfusion and temperature were mapped with laser Doppler imaging and thermography. In nine patients no elevation in blood perfusion was observed in the PWS in comparison with the surrounding normal skin before treatment. In the remaining four patients a significantly (p less than 0.01) higher blood flow was recorded within the PWS. Immediately after treatment nine patients showed elevated perfusion within the PWS. During the first two days following treatment, all patients showed a gradually decreasing hyperperfusion in the borderline between the PWS lesion and surrounding skin. Immediately after treatment 10 patients had a significantly (p less than 0.01) higher temperature in the PWS than in normal skin. During the first 24 h following treatment, an elevated perfusion was in general accompanied by a tissue temperature increase. Three and a half months after argon laser treatment, three patients showed excellent clinical results with no remaining PWS spots or scarring. Two of these patients had had both elevated perfusion and temperature in the PWS prior to treatment.

Thermography and laser-Doppler flowmetry for monitoring changes in finger skin blood flow upon cigarette smoking.

Haemodynamic changes after smoking two 1.1 mg nicotine cigarettes were monitored in 24 smokers on two different occasions. Smoking caused an increase in heart rate and arterial blood pressure, whereas finger temperature as measured by thermography and finger skin blood flow as measured by laser-Doppler flowmetry (LDF) decreased. Lowest values were seen within 15 min by LDF, and after 30 min by thermography. Changes in the two methods correlated closely, however, when maximum responses during a 45-min period after smoking were compared. The wider distribution of LDF values would seem to be due to the small measuring volume which is susceptible to differences in vascular anatomy and reactivity. In both methods, responses showed a high degree of reproducibility.

Leg showering therapy in patients with intermittent claudication.

Ten patients with intermittent claudication were treated using a recently constructed "chair" in which the seated patient has alternately warm and cool water flushed over the legs and feet. A trial treatment was given for 25 minutes, three times a week for 5 weeks. Ankle/arm index, skin perfusion pressure and calf blood flow all remained unchanged immediately after such a series of treatment. Even at follow-up 6 months later, values were unchanged but for a minute increase in ankle/arm index in the poorer leg. Walking capacity was additionally measured and an improvement was seen, also after 6 months. The role of the contrast temperature treatment in this improvement is, however, unclear.

Acute effects of doxazosin and atenolol on smoking-induced peripheral vasoconstriction in hypertensive habitual smokers.

The acute effects of selective alpha 1 inhibition with doxazosin (0.5-0.7 mg intravenously) and beta 1-blockade with atenolol (0.1 mg/kg body weight, intravenously) on smoking-induced peripheral vasoconstriction were investigated in 24 hypertensive habitual smokers. Forearm blood flow was measured by venous occlusion plethysmography and skin blood flow was estimated by thermography and laser doppler flowmetry. After the patients had smoked two cigarettes, plasma adrenaline elevations were similar under basal conditions and after drug administration; plasma noradrenaline remained unchanged. The smoking-induced increase in the heart rate was attenuated by atenolol compared with basal values. The smoking-induced increase in systolic blood pressure was more marked after atenolol and doxazosin (P less than 0.05) than before the drug administration. The smoking-induced increase in diastolic blood pressure was enhanced by atenolol (P less than 0.05) but unchanged by doxazosin. Smoking increased forearm vascular resistance under basal conditions (P less than 0.05) and after atenolol (P less than 0.01) but not after doxazosin. Similarly, skin temperature was significantly reduced by smoking under basal conditions and after the administration of atenolol (P less than 0.001) but not doxazosin. The smoking-induced reduction in skin blood flow was attenuated by doxazosin compared with atenolol (P less than 0.05). Thus, smoking-induced muscular and cutaneous vasoconstriction was inhibited by doxazosin as opposed to atenolol in hypertensive habitual smokers. This may reflect unmasked beta-adrenoceptor mediated vasodilation in addition to attenuated alpha 1-adrenoceptor mediated vasoconstriction.

Skin perfusion pressure assessed by measuring the external pressure required to stop blood cell flux.

Laser Doppler flowmetry (LDF) was used to determine the point at which blood flow cessation is achieved under circumferentially applied external counter pressure at the ankle level. In 13 individuals with a normal ankle index, the flow of cessation external pressure (FCEP) was, on average, 28 mmHg lower than the systolic ankle pressure (range: 7-62). In 19 patients with an ankle index below 1.0, FCEP correlated with the ankle pressure (rs = 0.76) and even more closely with the ankle index (rs = 0.82). In patients with a more pronounced degree of arterial occlusive disease, FCEP can be equal to or even higher than the ankle pressure. This may be due to a release of sympathetic vasoconstrictor tone and possibly to the presence of a collateral circulation supplying the skin. Individual LDF values from the skin at rest do not reflect the degree of peripheral circulatory insufficiency.

Venous haemodynamics of the upper extremity after subclavian vein thrombosis.

Late post-thrombotic complaints after subclavian vein thrombosis are reported with highly varying frequencies (8-80% severe disability). The therapeutic approach depends partly on this frequency. With the aim to evaluate late sequelae a questionnaire was answered by 26 patients with arm-shoulder symptoms leading to arm phlebography, but where the examination did not reveal any thrombi. 65% had remaining symptoms 2-9 years after the examination. 3 had to change profession. 36 patients with phlebographically shown subclavian vein thrombosis answered the same questionnaire. Only 9 (25%) had remaining symptoms and in 4 it was classified as mild, in 4 as moderate and only in 1 patient as severe leading to change of profession. Venous haemodynamics in the upper extremity were also studied in 3 groups of patients; I) healthy volunteers (n = 16 arms), II) patients with arm-shoulder disabilities with negative arm phlebography (n = 7 disabled arms, n = 7 non-disabled arms), III) patients with phlebographically verified subclavian vein thrombi (n = 10 arms with DVT, n = 8 arms without DVT). Strain gauge plethysmography was used measuring venous capacity and maximal venous outflow. Venous pressure measurements were made both with the arms in a resting position and in a military position with and without work-load. Repeat phlebography of arms with symptoms were made. Maximal venous outflow was significantly lower in arms with previous subclavian vein thrombi (p less than 0.05) and venous pressure measurements with the arm in military position was significantly higher in those arms. However, no correlation between these measurements and the degree of arm disability was noted.(ABSTRACT TRUNCATED AT 250 WORDS)