Pulse oximetry: a new non-invasive assessment of peripheral arterial occlusive disease

Frequency of lower extremity artery disease in type 2 diabetic patients using pulse oximetry and the ankle-brachial index

Objectives: To determine the of undiagnosed lower extremity artery disease using the pulse oximetry in a type 2 diabetic population sample. Methods: Observational, cross-sectional, descriptive study that included 594 type 2 diabetic patients, with no previous history of lower extremity artery disease. Medical history, physical examination, determination of the ankle-brachial index (portable Doppler) and measurement of oxygen saturation in upper and lower extremities (pulse oximeter) were performed. Results: Frequency of lower extremity artery disease determined by ankle-brachial index was 18.4%. No significant correlations were detected between oxygen saturation and the ankle-brachial index except for the relationship between ankle-brachial index vs. oxygen saturation at 30 cm lower limb elevation vs. the supine position at no elevation (0 cm) in subjects under the age of 40. Pulse oximetry showed little diagnostic value in the screening of lower extremity artery disease. A relationship between lower extremity artery disease and age has been found. Its diagnosis was associated with a lower body mass index and lower systolic blood pressure in the lower extremities and higher in the upper extremities. Conclusions: We conclude that pulse oximetry is not useful in the screening for asymptomatic lower extremity artery disease in type 2 diabetics.

Ankle Fractures in Diabetic Patients: Report of Two Cases

Although ankle fractures are very common cases for orthopedic surgeons with an easy diagnosis and very good outcomes either with conservative or with operative treatment, in diabetic patients, these fractures can be complex with difficult solutions. We report two cases with ankle fractures in diabetic patients from our department with demanding diagnostic or therapeutic approaches and poor outcomes. The first case, a 65-year-old man with undiagnosed diabetes mellitus and neglected ankle fracture dislocation because of diabetic neuropathy, underwent open reduction internal fixation with additional external fixation. Early after the operation, he presented with pin-tract infection, and later after the operation, he developed osteomyelitis which led to salvage below-knee amputation. In the second case, a 70-year-old woman with diabetes mellitus and severe coexisting medical comorbidities underwent open reduction internal fixation plus external fixation for an acute fracture-dislocation of the left ankle. Early after the operation, she developed ischemic lesions of the toes with worsened status despite the vascular surgeon's instructions. Although a below-knee amputation could be an acceptable choice, she denied it. As a result, systematic complications led to her death. It is very important for surgeons to follow an algorithm when they have to manage ankle injuries in diabetic patients because, in these patients, ankle fractures are very demanding and misdiagnosed cases with difficult treatment algorithms and often poor outcomes. 

Correlation Between Ankle Brachial Index and Lower Limbs Digital Pulse Oximetry: A Referral Center Experience, Prevalence Study

Objective

Ankle-brachial index (ABI) is widely recommended and used to evaluate peripheral arterial disease. The oxygen saturation (SpO₂) has been associated with ABI, showing a promising clinical practice utility; however, little literature regarding this matter has been reported. This study aims to assess the correlation between pulse oximetry and ABI. 

Methods

A cross-sectional study was conducted using ABI measuring devices, such as the MESI® Ankle Brachial Pressure Index (ABPI) (MESI, Ltd., Slovenia, EU) and pulse oximetry. We compared the SpO₂ distribution by using the Wilcoxon test and evaluated its correlation by using logistic regression. 

Results

From a total of 86 patients, 54 were males (62.8%) and the median age was 54 years old (interquartile range (IQR) = 37 - 65 yrs.). Regarding ABI measurements of the right lower limb (RLL), a total of 20 patients (22.3%) had an abnormal classification. On the other hand, a total of 21 patients (22.1%) had an abnormal classification of the left lower limb (LLL) ABI measurements. The distribution of SpO₂ in relation to ABI categories was not statistically different (RLL p = 0.2433; LLL p = 0.1242). The SpO₂ classification of ABI and abnormal pulse oximetry for the RLL was at 76.7% and at 77.9% in the LLL (Pearson’s goodness-of-fit test: RLL = p < 0.001 and LLL = p < 0.001). 

Conclusion

Although we didn’t observe any statistical differences in the SpO₂ distribution regarding ABI measurements, in their correlation, there seems to be a different tendency. The SpO₂ might be a useful non-invasive tool to assess asymptomatic patients with risk factors for peripheral arterial disease (PAD).

The Predictive Value of Pulse Oximeters for Pulse Improvement after Angiography in Infants and Children

Background

Information from pulse oximeter waves confirms the presence of a pulse and helps obtain waves from tissue when the supplying artery is not readily accessible.

Objectives

This study determined the predictive value of pulse oximeters for detecting improved arterial pulses after angiography.

Patients and Methods

This cross-sectional, multi-center study included 467 4-day-old to 12-year-old patients and was conducted from January 2012 to January 2016. Angiographies were performed on 12-year-old or younger children for various medical reasons using venous, arterial, or both types of paths. The posterior malleolar or dorsalis pedis were palpated in punctured lower extremities. In the absence of a pulse, pulse oximetry was performed to identify pulse curves at 1 hour, 6 hours, and 12 hours after each angiography.

Results

Pulse oximetry displayed the pulses of 319 patients immediately following each angiography. Of these, 262 patients had palpable pulses at 6 hours after angiography (P < 0.0001), while 57 patients had no palpable pulse. Of these 57 patients, 15 had no palpable pulse at 12 hours after angiography (P < 0.0001). The odds of pulse improvement in children 6 hours after catheter angiography were 76% for the arterial path, 90% for the venous path, and 83.2% for both paths. At 12 hours after catheter angiography, these values increased to 91.6% for the arterial path, 100% for the venous path, and 95.9% for both paths.

Conclusions

The pulse oximeter can display the pulse curve immediately (1 hour) after angiography and indicate pulse improvement at 12 hours maximally following an angiography. In this case, heparin alone may be used instead of thrombolytic agents.

Diabetic ankle fractures: a review of the literature and an introduction to the Adelaide fracture in the diabetic ankle algorithm and score

Diabetics who have acquired an ankle fracture may be easily missed given their atypical presentation. As such, it is not infrequently seen that these patients are either initially misdiagnosed or ineffectively managed resulting in unnecessary hospital length of stay and procedures. Multiple review articles and retrospective studies have been previously published in the literature, but complete guidelines to assist in accurate diagnosis and cost-effective management for this complex problem do not currently exist. Through a critical analysis of the current literature, a proposed diagnostic and management algorithm and scoring system that can be used to quantify risks in the surgical management are presented for consideration.

[Use of pulse oximetry as screening method for peripheral arterial disease in patients admitted to a general medicine service]

INTRODUCTION

Ankle-brachial index measured by a continuous wave Doppler device remains as the reference method for office diagnosis of peripheral arterial disease. This method is time consuming, requires an appropriate device and training of the examiner. We evaluated the usefulness of pulse oximetry as an easier method to screen for peripheral arterial disease.

METHODS

A total of 110 subjects were selected by opportunistic sampling among patients admitted to a general medicine service. Entry criteria were age older than 50 years and having an additional cardiovascular risk factor. Patients with known cardiovascular disease were excluded. We measured oxygen saturation (SaO2) by means of a pocket finger tip pulse oximeter at 4 limbs. SaO2 was measured at right and left index fingers and great toes with patient lying and after elevating the foot 30 cm above the bed. We considered as abnormal a difference in SaO2 greater than 2% between fingers and toes. Brachial index was estimated by means of a handheld Doppler device.

RESULTS

The prevalence of peripheral arterial disease was 10% (95% confidence interval [CI], 6%-14%). Pulse oximetry has sensitivity 12% (95%CI, 4%-37%), specificity 67% (95%CI, 60%-74%), positive likelihood ratio 0.43 (95%CI, 0.11-1.19), negative likelihood ratio 1.27 (95%CI, 0.91-1.45) and area under the receiving operating characteristics curve 0.75 (95%CI, 0.67-0.82).

CONCLUSIONS

Pulse oximetry showed low accuracy as screening method for peripheral arterial disease. Simpler and more accurate devices than ankle-brachial index measured by Doppler are necessary to ease the screening of peripheral arterial disease.

The role of pulse oximetry in chiropractic practice: a rationale for its use

OBJECTIVE

Pulse oximetry is used regularly to assess oxygen saturation levels. The objective of this commentary is to discuss a rationale for using pulse oximetry in chiropractic practice.

DISCUSSION

Pulse oximetry may offer doctors of chiropractic a way to monitor patients' oxygen saturation levels. Quantification of saturation values with heart rate may give clinical aid to the management of chiropractic patients. Markedly reduced saturation levels may necessitate medical referral, whereas mildly reduced levels could lead to changes in chiropractic management.

CONCLUSIONS

Pulse oximetry has the potential to be an integral part of chiropractic practice.

A CMOS Camera-Based Pulse Oximetry Imaging System

In this paper a CMOS camera-based system for non-contact pulse oximetry imaging in transmission mode is described. Attention is drawn to the current uses of conventional pulse oximetry and the potential application of pulse oximetry imaging to developing objective wound assessment systems.

Utility of digital pulse oximetry in the screening of lower extremity arterial disease

Purpose

The aim of this study was to evaluate screening methods in the lower extremities by measurement of the digital pulse oximetry (oxygen percent saturation [SpO₂]) of toes for peripheral arterial disease (PAD).

Methods

A prospective study was performed among 49 patients (98 limbs) with lower extremity arterial occlusive disease. We attempted to measure the ankle-brachial index (ABI), digital pulse oximetry (SpO₂), and computerized tomographic angiography (CTA). Patients were divided into three groups by the traditional Fontaine classification system by symptom and CTA criteria: 1) Critical limb ischemia (Fontaine III and IV), 2) Claudication; (Fontaine II), and 3) asymptomatic limbs (Fontaine I).

Results

The sensitivity, specificity, positive and negative predictive values between active treatment groups (group I and II; endovascular and open surgery) and conservative group (group III) are all statistically significant. ABI; 55.09%, 94%, 96.7%, 39.02% (R = 12.54, P < 0.000) SpO₂; 87.06%, 87.8%, 84.3%, 90% (R = 40.11, P < 0.000). Pre-SpO₂ and pre-ABI all show statistically significant correlation in group I vs. group II, symptomatic PAD (group I and II) vs. asymptomatic PAD (group III), and the total PAD comparison. The Pearson's correlation coefficient between SpO₂ and ABI all show significant correlation in group II. Pre-SpO₂ vs. Pre-ABI show strong positive correlation except asymptomatic group (group III).

Conclusion

Digital pulse oximetry can be a useful, simple, noninvasive screening device as well as ABI in PAD.

Diagnostic importance of pulse oximetry in the determination of the stage of chronic arterial insufficiency of lower extremities

INTRODUCTION

Chronic arterial insufficiency (CAI) of lower extremities is important socio-economical and healthcare problem, due to its high incidence of morbidity, disability and mortality.

OBJECTIVE

The aim of our work was to determine the diagnostic importance of pulse oximetry in the early detection of stage of lower extremities CAI based on peripheral arterial oxygen saturation of haemoglobin (SpO2).

METHODS

Prospectively, we analyzed a group of 50 patients, admitted at the Vascular Department of Surgical Clinic in Nis during the period from September 2006 to October 2007, with evident symptoms and signs of different stages of lower extremities CAI verified by ultrasonography. In patients with lower extremity disorder of tissue arterial capillaries, SpO2 was determined by pulse oximetry.

RESULTS

Using pulse oximetry, depending on the of stage of lower extremities CAI, we revealed a considerable difference in the stages of functional ischemia SpO2: Fontaine I - 95.33 +/- 1.41%, Fontaine IIa - 92.14 +/- 2.27% and Fontaine IIb - 79.67 +/- 2.73%; in stage critical ischemia SpO2: Fontaine III - 62.54 +/- 4.39% and Fontaine IV - 47.67 +/- 6.16%. In 3 patients with gangrenous foot and fingers SpO2 was immeasurable and progressive decrease in SpO2 of arterial capillaries (p < 0.01 between stages).

CONCLUSION

Due to the reliability and simplicity of pulse oximetry it can be a routinely used diagnostic device for patients with early determined stage of lower extremities CAI.

Lanarkshire Oximetry Index as a Diagnostic Tool for Peripheral Arterial Disease in Type 2 Diabetes: A Pilot Study

We evaluated the Lanarkshire Oximetry Index (LOI) for the diagnosis of peripheral arterial disease (PAD) in type 2 diabetic patients, using the Ankle-Brachial Index (ABI) as gold standard. We included 161 patients (71 men, mean age 63.1 ± 9.8 years). Peripheral arterial disease was defined as ABI < 0.9. Two cut-off values of LOI (<0.9 and <0.8) were assessed for the diagnosis of PAD. Sensitivity and specificity for PAD were 93.3% and 89.1%, respectively, using a LOI cut-off value of 0.9, while they were 40% and 99.3%, respectively, using a LOI cut-off value of 0.8. Agreement between LOI and ABI was moderate (P < .001). There was a significant positive correlation between ABI and LOI (r = .377, P < .001). Lanarkshire Oximetry Index is a potentially useful alternative diagnostic test for PAD in type 2 diabetes. A cut-off value of 0.9 has high sensitivity and modest specificity. Agreement between LOI and ABI is moderate.

[Usefulness of pulse oximetry in screening of carotid atherosclerosis in patients with type 2 diabetes mellitus]

BACKGROUND AND OBJECTIVE

Pulse oximetry of the toes has been suggested in the screening of peripheral arterial disease. We studied the uselfuness of pulse oximetry in detection of type 2 diabetic patients with carotid atherosclerosis.

SUBJECTS AND METHODS

105 patients with type 2 diabetes mellitus (DM) without previous clinical peripheral arterial disease were enrolled. All patients had (1) ankle-brachial index (ABI) measurement, (2) pulse oximetry to measure SaO(2) of their index fingers and big toes in the supine position and at elevated 30cm and (3) a carotid ultrasound [carotid artery intima-media thickness (IMT) and carotid plaques (CP) measurements]. The ABI was considered abnormal when it was <0.9 and when the pulse oximetry showed a decrease in SaO(2) of >2% of the finger compared to foot or to 30cm foot elevation.

RESULTS

60 patients were men (age of 62+/-7 years, HbA(1c) of 6.9+/-1.0); 58.1% had CP. There were no differences in anthropometric and biochemical results between patients with or without CP. The ABI was <0.9 in 49% and 25% of patients with and without CP, respectively. Neither were there differences in pulse oximetry in patients with CP or in those with ABI <0.9. The IMT did not change in relation to pulse oximetry, but it was higher in patients with CP and with ABI <0.9 than in patients without alterations. These results were independent of the presence of previous clinical macroangiopathy.

CONCLUSION

Pulse oximetry is not a useful screening method of carotid atherosclerosis in type 2 DM.

Ankle fractures in diabetic neuropathic arthropathy

Between 2000 and 2006 we performed salvage tibiotalar arthrodesis in 17 diabetic patients (17 ankles) with grossly unstable ankles caused by bimalleolar fractures complicated by Charcot neuro-arthropathy. There were ten women and seven men with a mean age of 61.6 years (57 to 69). A crossed-screw technique was used. Two screws were used in eight patients and three screws in nine. Additional graft from the malleoli was used in all patients. The mean follow-up was 26 months (12 to 48) and the mean time to union was 5.8 months (4 to 8). A stable ankle was achieved in 14 patients (82.4%), nine of whom had bony fusion and five had a stiff fibrous union. The results were significantly better in underweight patients, in those in whom surgery had been performed three to six months after the onset of acute Charcot arthropathy, in those who had received anti-resorptive medication during the acute stage, in those without extensive peripheral neuropathy, and in those with adequate peripheral oxygen saturation (> 95%). The arthrodesis failed because of avascular necrosis of the talus in only three patients (17.6%), who developed grossly unstable, ulcerated hindfeet, and required below-knee amputation.

Measuring sub-bandage pressure: comparing the use of pressure monitors and pulse oximeters

OBJECTIVE

To test the use of low-cost sub-bandage pressure monitors and pulse oximeters as part of a quality-control measure for graduated compression bandaging in leg ulcer clinics.

METHOD

Twenty-five healthy volunteers (mean age 40 years) providing 50 limbs were bandaged with a four-layer compression bandaging system. The ankle systolic pressure (ASP) was measured using a pulse oximeter (Nellcor NBP-40) before applying the graduated compression bandages. Interface pressure was measured by placing pressure sensors on the skin at three points (2cm above the medial malleolus; the widest part of the calf; and a point midway between them) in the supine and standing positions. The ASP was measured again with the pulse oximeter after the bandage had been applied, and the effect of the bandage on the ASP was recorded. The actual pressure created by the bandage was compared with the required pressure profile.

RESULTS

Interface pressures varied with change of position and movement. With the operator blinded to the pressure monitors while applying the bandages, the target pressure of 35-40mmHg at the ankle was achieved in only 36% of limbs ([mean +/- 95% confidence interval]; 32.3 +/- 1.6mmHg [supine]; 38.4 +/- 2.4mmHg [standing position]). With the help of the pressure monitors, the target pressure was achieved in 78% of the limbs. There was no correlation between the pressure monitors and pulse oximeter pressures, demonstrating that the pulse oximeter is not a useful tool for measuring sub-bandage pressures.

CONCLUSION

The results suggest a tool (interface pressure monitors) that is easy to operate should be available as part of quality assurance for treatment, training of care providers and education.

Pulse oximetry vascular assessment in patients with leg ulcers

Arterial screening of the lower limbs is recommended before compression therapy is initiated in patients with ulceration or dermatitis. Hand-held Doppler ABPI is the accepted assessment tool but has limitations. Pulse oximeters have potential as alternative screening instruments with some advantages over Doppler. This article reviews the mode of action, application and limitations of pulse oximeters. A pulse oximetry toe/finger arterial screening index, which may be used as an alternative to Doppler ABPI, is described. Case studies are reported in which arterial blood flow which was easily detected by pulse oximetry could not be detected by Doppler.

Pulse oximetry: a new tool to assess patients with leg ulcers

The objective of the study was to investigate pulse oximetry as a guide to assessing patients with leg ulcers before treatment. Graduated elastic compression is the treatment of choice for uncomplicated venous leg ulcers, but is contra-indicated in patients with significant arterial disease. The standard assessment of arterial insufficiency by Doppler ultrasound ankle branchial pressure index (ABPI) has shortcomings which prompted this investigation of pulse oximetry as a possible additional, or alternative, method of assessment of patients with leg ulcers, prior to treatment with compression. The study, carried out on a population of patients attending hospital leg ulcer clinics, was designed to evaluate pulse oximetry assessment in the selection and monitoring of patients with venous leg ulceration leading to a prospective controlled study of ulcer healing in groups of patients with reduced and normal ABPI, selected for compression therapy by pulse oximetry criteria. Outcome measurement required follow-up of patients selected for compression therapy by pulse oximetry to record time to healing and rate of healing of leg ulcers. Results from the study show a fair correlation between the toe-finger oximetry index (TFOI) and Doppler ABPI. There is no difference between ulcer healing in patients with reduced and normal ABPI selected for treatment on the basis of pulse oximetry maximum compression pressure (MCP). In conclusion, pulse oximetry is an aid to the selection of patients who will benefit from compression therapy, but would be excluded on the basis of Doppler ABPI.

Use of subcutaneous terbutaline to reverse peripheral ischemia

Four cases are presented, one involving extravasation of a dopamine and dobutamine solution in the arm and three involving accidental digital injection of epinephrine into the thumb. In three cases, local infiltration of terbutaline resulted in dramatic reversal of vasospasm and ischemia. In the remaining case the use of terbutaline resulted in minor clinical improvement. These are the first reported cases involving the successful treatment of peripheral ischemia with subcutaneous terbutaline. This experience suggests that terbutaline may be an effective alternative for treatment of peripheral ischemia when phentolamine is not available.

Pulse oximetry in the evaluation of peripheral vascular disease

The role of pulse oximetry in the evaluation of peripheral vascular disease (PVD) was investigated. In addition, the value of elevating the limb to improve the sensitivity of detection of PVD by the pulse oximeter was also determined. Pulse oximetry reading in the toes were obtained in 40 young, healthy volunteers and in 40 randomly selected patients referred to the vascular investigation laboratory over a period of two months. All 40 healthy volunteers had normal pulse oximetry readings. Normal pulse oximetry reading in the toes was defined as > 95% O2 Sat and +/-2 of finger pulse oximetry reading. In all 40 patients, pulse oximetry readings were either normal or not detected at all. Since there was no gradation in decrease in the pulse oximetry reading with severity of disease or with elevation of the patient's lower extremity, an absent or no reading was considered as an abnormal result from the test. The frequency of abnormal pulse oximetry readings increased significantly in groups with abnormal ankle-brachial pressure index (ABPI) and also varied significantly with elevation of the patients' lower limbs. In patients with no PVD detected by Doppler (ABPI > 0.9), pulse oximetry readings were normal in all. However, in patients with moderate PVD (ABPI, 0.5-0.9), 84% of the patients' lower limbs had normal pulse oximetry readings and 16% had an abnormal reading at baseline level (flat). An additional 12% of the lower limbs in this group had an abnormal reading on elevation of the limb to 12 inches. In patients with severe PVD (ABPI < 0.5), 54% of the patients' lower limbs had an abnormal reading at baseline and an additional 23% had an abnormal reading at elevation of the limb to 12 inches. In conclusion, pulse oximetry was not a sensitive test for detecting early PVD.

Sigmoidal ischaemia after aortic grafting, detected by endoluminal pulse oximetry

Colonic ischaemia after abdominal aortic grafting is a severe complication. Late detection of transmural ischaemia will result in a high mortality rate. No simple specific methods are available to detect the early stage. The aim of this pilot study was to detect and monitor sigmoidal ischaemia after aortic surgery with a new endoluminal sigmoidal probe, based on pulse oximetry. Twelve patients with sigmoidal ischaemia were included, the endoluminal probe being introduced into the sigmoid at least 25 cm proximal to the anal verge. It is shown that with this method, mucosal and transmural ischaemia can be graded and differentiated. Patients who showed no wave-form had transmural ischaemia; those with mucosal ischaemia showed reliable wave-forms with oxygen saturation from 40-85%. Colonic ischaemia after aortic grafting can be detected by endoluminal pulse oximetry but the clinical outcome will only improve by early detection in the preclinical stage.

Pulse oximeter analysis of peripheral cyanosis distal to an AV fistula

Arteriovenous (AV) fistulas are routinely constructed for hemodialysis in patients with renal failure. The case of a hemodialysis patient with cyanosis of the hand distal to an AV fistula is described. Pulse oximeter analysis found a saturation of 72% in the cyanotic hand with a normal saturation of 97% in the opposing hand. Evaluation of 11 additional patients with AV fistulas and no cyanosis or symptoms found no difference in oxygen saturation between extremities. Pulse oximetry was found to be useful for evaluating the oxygenation status distal to an AV fistula, and in asymptomatic patients with an AV fistula, the oxygenation status distal to the fistula should be no different from that of the opposing extremity.

Pulse Oximetry in the Diagnosis of Non-Critical Peripheral Vascular Insufficiency

Pulse oximetry was used to detect return of pulsatile flow in 27 subjects during reactive hyperaemia following 3 min of total limb ischaemia induced by above knee tourniquet occlusion. Fourteen patients with exercise induced leg pain had 18 symptomatic limbs tested. Thirteen controls had 25 limbs tested. Return of pulsatile flow during reactive hyperaemia occurred within 20 s of tourniquet release in the 25 control limbs which was then regarded as normal. The mean time for return of pulsatile flow in 18 symptomatic limbs was 53±37 s ( P > 0.05 versus controls). Three limbs had a normal value, two of which did not have peripheral vascular disease. Pulse oximetry correctly identified all 25 asymptomatic limbs and 15 of 16 patients with claudication secondary to peripheral vascular disease (PVD). This modification of the reactive hyperaemia test using the pulse oximeter is simple and quick to perform. It has potential as a non-invasive screening test for PVD, suitable for outpatient assessment.

Failure of pulse oximetry in the assessment of raised limb intracompartmental pressure

Pulse oximetry has been proposed as an aid to monitoring raised intracompartmental pressures (ICPs). ICP and percentage haemoglobin oxygen saturation in the affected limb were studied in 10 consecutive patients with raised ICP. Compartment pressures ranged from 28 to 64 mmHg (mean 40.9 mmHg). In two patients with absent pulses, pulse oximetry failed to detect pulsatile flow and recorded 0 per cent saturation. The remaining eight patients, including four with absent peripheral pulses, all had percentage haemoglobin saturations within 2 per cent of the opposite normal limb. Arterial haemoglobin desaturation was not associated with raised ICP. The presence of an oximeter signal and a normal reading does not necessarily imply adequacy of tissue perfusion. Pulse oximetry does not appear to be a reliable aid in the diagnosis or monitoring of impaired perfusion due to raised ICP.