Ultrasonic Doppler Flow Detector Research Articles

The combined use of ultrasound examination of hemodynamics in the umbilical artery and urine microalbumin levels can predict adverse pregnancy outcomes in patients with severe preeclampsia

The aim of this study was to elucidate the application of ultrasound examination of umbilical artery (UA) hemodynamics with urine microalbumin (UmA) determination in evaluating the outcomes of sPE patients. Altogether 80 sPE patients and 75 healthy pregnant women were recruited. UmA, RI (resistance index) and PI (pulsatility index) were separately measured by ELISA and the ultrasonic Doppler flow detector. The correlation between parameters was analysed using Pearson’s coefficient method. The independent risk factors of sPE were identified using the Logistic regression model. sPE patients had increased UmA, RI and PI (all p < 0.05). UmA level was positively correlated with RI and PI in sPE patients. RI, PI and UmA were independent risk factors of sPE (all p < 0.05). sPE can predict adverse pregnancy outcomes. High UmA levels may increase the risk of poor prognosis. Overall, ultrasound examination of UA hemodynamics with UmA determination can predict the adverse pregnancy outcomes of sPE patients. IMPACT STATEMENT What is already known on this subject? Doppler ultrasound and urine microalbumin (UmA) measurement are important tools in assessing the clinical severity of severe preeclampsia (sPE). What do the results of this study add? This study aims to unravel the application of ultrasound examination of hemodynamics in the umbilical artery (UA) combined with the determination of UmA in evaluating the outcomes of sPE patients. What are the implications of these findings for clinical practice and/or further research? Ultrasound examination of hemodynamics in UA combined with the determination of UmA can predict the adverse pregnancy outcomes of sPE patients.

Systolic blood pressure measurements with Doppler ultrasonic flow detector and high-definition oscillometry are comparable on population level but show large intra-individual differences in apparently healthy elderly dogs.

Agreement of systolic blood pressure measurements (SBP) between noninvasive blood pressure devices in conscious dogs is poorly studied. Situational hypertension is expected in clinics, but studies are lacking. This study aimed to compare SBP measurements obtained with Doppler ultrasonic flow detector (Doppler) versus high-definition oscillometry (HDO) in clinics and at home and to estimate the prevalence of situational hypertension in conscious, apparently healthy elderly dogs. 122 apparently healthy elderly or geriatric dogs were prospectively recruited. Systolic blood pressure was obtained consecutively with Doppler and HDO techniques in a randomized order per dog, following a standardized protocol. An at-home measurement was advised for in-clinic hypertensive dogs (SBP ≥ 160 mmHg), also using both devices. Dual measurements were available in 102 dogs. Median SBP was 147.3 mmHg (range, 105 to 239 mmHg) for Doppler and 152.3 mmHg (range, 113 to 221 mmHg) for HDO. Forty-six percent (56/122) were hypertensive, of which 9% (11/122) were hypertensive with both methods. No significant difference was found between the 2 devices in the global study population or within the group of hypertensive dogs. Repeated at-home measurements were performed in 20/56 (35.7%) hypertensive dogs, resulting in a 10 and 26 mmHg lower median SBP value for Doppler and HDO, respectively (P > .05). In-clinic situational hypertension was presumed in 8/20 (40%) dogs. The choice of the noninvasive blood pressure device did not significantly impact SBP results, but large interindividual differences in SBP between techniques occurred. Situational hypertension was frequently observed in clinic.

Evaluation of prolonged immersion in tricaine methanesulfonate for juvenile goldfish (Carassius auratus) euthanasia.

Doses of buffered tricaine methanesulfonate (MS-222) up to 1000 mg/L for 15 minutes are reported inefficient to produce euthanasia in goldfish. The goal of this study was to determine if goldfish can be euthanized by more prolonged immersion in MS-222. 24 healthy goldfish (weight range: 1 to 10 g) were randomly assigned to 4 groups of 6 fish. The first group (G1) was exposed to 500 mg/L buffered MS-222 for 15 minutes then placed in freshwater for 3 hours. The second (G2) and third groups (G3) were exposed to 1000 mg/L of buffered MS-222 for 15 minutes then placed in freshwater for 3 hours and 18 hours respectively. The fourth group (G4) was exposed to 1000 mg/L of buffered MS-222 for 60 minutes then placed in freshwater for 3 hours. Time to cessation and return of operculation were recorded. If the goldfish did not resume operculation, heart rate was evaluated by Doppler ultrasonic flow detector. Median times to apnea were 35 seconds at 1000 mg/L and 65 seconds at 500 mg/L. Re-operculation occurred only in G1 in 5 out of 6 individuals. All fish from G1, 3 fish from G2, 0 fish from G3, 1 fish from G4 had remaining heartbeats at the end of the observation period. Overall, a dose of 1000 mg/L of buffered MS-222 for 15 minutes was efficient to euthanize juvenile goldfish at 20 °C. Different fish body mass and water quality parameters might explain different results compared to previous studies.

Cross-sectional survey of non-invasive indirect blood pressure measurement practices in cats by veterinarians.

This survey of small animal veterinarians endeavored to: (1) determine current methods of indirect blood pressure measurement; (2) detail techniques used to reduce situational hypertension; and (3) better understand the obstacles to performing blood pressure measurement in cats. An online survey was produced and circulated to members of the Veterinary Information Network. A total of 733 veterinarians who saw cats in their practice and had access to at least one indirect blood pressure device completed the entirety of the survey. Ninety-six percent (703/733) of veterinarians who completed the survey reported measuring indirect blood pressure in cats in their practice, with veterinary technicians conducting most (600/703; 85.3%) of these measurements. Few veterinarians (30/733; 4.1%) did not measure blood pressure, with these veterinarians citing several obstacles including: difficulty interpreting results with the occurrence of fear, anxiety and stress in cats (20/30; 66.7%); difficulty performing measurements in cats (17/30; 56.7%); and technical staff being uncomfortable performing measurements (12/30; 40.0%). Most veterinarians (300/435; 69.0%) in this survey preferred an ultrasonic Doppler flow detector with sphygmomanometry, with many (272/300; 90.7%) perceiving that the results obtained with this device were more trustworthy compared with results obtained with oscillometry. Ninety percent (633/703) of veterinarians employed techniques to reduce situational hypertension in cats. Techniques perceived to be most helpful among veterinarians included: using a quiet location (454/633; 71.7%); minimizing restraint (316/633; 49.9%); performing blood pressure prior to other procedures (eg, phlebotomy, cystocentesis) (302/633; 47.7%); avoiding other animals (219/633; 34.6%); and allowing time for acclimation (167/633; 26.4%). This survey study of veterinarians helps clarify obstacles to routine blood pressure measurement in conscious cats. Veterinarians reported several strategies that they felt reduced situational hypertension in cats. The data inform modifications of techniques to increase the frequency and perceived reliability of blood pressure measurement in at-risk cats.

EVALUATION OF POTASSIUM CHLORIDE ADMINISTERED VIA THREE ROUTES FOR EUTHANASIA OF ANESTHETIZED KOI (CYPRINUS CARPIO ).

Immersion in tricaine methanesulfonate (MS-222) is insufficient for euthanasia in at least one species of fish. The current study investigated the effectiveness of potassium chloride (KCl) to euthanize anesthetized koi (Cyprinus carpio). Twenty-eight healthy koi were anesthetized via immersion in 500 mg/L of buffered MS-222 for 10-12 min, manually removed to room air, and randomly administered 10 mEq/kg KCl (333 mg/ml) via one of three routes-intracardiac injection (IC) (n = 7), intracoelomic injection (ICe) (n = 7), or topical instillment over the gill filaments bilaterally (T) (n = 7)-or received no treatment (control, C) (n = 7). A Doppler ultrasonic flow detector was placed over the heart, and sounds were assessed continuously from immediately prior to treatment until 5 min posttreatment and every 5 min thereafter until Doppler sound cessation, resumption of operculation, or 30 min. Time to Doppler sound cessation or resumption of operculation was recorded. Doppler sound cessation occurred in 7/7 fish in IC (median 0.08, range 0-2.75 min) and 1/7 fish in T (10 min). In T, ICe, and C, 6/7, 7/7, and 7/7 fish, respectively, maintained Doppler sounds to 30 min. All fish in ICe (7/7) and C (7/7) resumed operculation with median (range) times of 22 (7-30) min and 16 (9-29) min from treatment, respectively. Intracardiac KCl at 10 mEq/kg rapidly ceases Doppler sounds and is a successful technique for euthanasia of anesthetized koi. Intracoelomic and topical KCl at 10 mEq/kg were not effective for euthanasia of koi.

Effects of various factors on Doppler ultrasonographic measurements of radial and coccygeal arterial blood pressure in privately owned, conscious cats.

OBJECTIVE To assess the effects of age, body condition score (BCS), and muscle condition score (MCS) on radial and coccygeal systolic arterial blood pressure (SAP) in cats. DESIGN Prospective randomized trial. ANIMALS 66 privately owned cats enrolled between May and December 2010. PROCEDURES BCS and MCS of cats were assessed by 2 investigators; SAP was measured via Doppler ultrasonic flow detector, with cats positioned in right lateral or sternal recumbency for measurements at the radial or coccygeal artery, respectively, with order of site randomized. Associations among variables were assessed through correlation coefficients, partial correlation coefficients, and ANCOVA. RESULTS Interrater reliability for BCS and MCS assessment was high (correlation coefficients, 0.95 and 0.83, respectively). No significant effect was identified for order of SAP measurement sites. Coccygeal and radial SAP were positively correlated (ρ = 0.45). The median difference in coccygeal versus radial SAP was 19 mm Hg, but differences were not consistently positive or negative. Radial SAP was positively correlated with age (ρ = 0.48) and negatively correlated with MCS (ρ = -0.30). On the basis of the correlation analysis, the association between radial SAP and MCS reflected the confounding influence of age. Coccygeal SAP was not significantly correlated with age, BCS, or MCS. CONCLUSIONS AND CLINICAL RELEVANCE Use of the coccygeal artery is recommended to reduce the confounding effects of age and sarcopenia on Doppler ultrasonographic SAP measurements in cats. Additionally, monitoring for changes in MCS is recommended for cats undergoing serial SAP measurement.

Measuring level of agreement between values obtained by directly measured blood pressure and ultrasonic Doppler flow detector in cats

To determine if blood pressure measured with an ultrasonic Doppler flow detector (Doppler) is in good agreement with directly measured blood pressures in anesthetized cats. Prospective observational study. University veterinary teaching hospital. Thirty-nine cats undergoing routine neutering. Cats were divided into 2 groups; 19 cats enrolled in Group A had a 24-Ga catheter inserted into a dorsal pedal artery; 20 cats in Group B had a 20-Ga catheter placed in a femoral artery. In both groups, systolic, diastolic, and mean arterial pressures were directly measured using a validated pressure measurement system. Indirect values were compared against direct blood pressure measurements. There was no difference between groups. Overall, there was poor agreement with a significant bias observed between Doppler and directly measured blood pressures. For the systolic arterial pressure the bias was -8.8 with limits of agreements (LOA) of -39.3 and 21.7. For the mean arterial pressure, the bias was 14.0 with LOA of -13.9 and 41.9. For the diastolic arterial pressure, the bias was 27.9 with LOA of -4.4 and 60.2. Methodology, weight, sex, and replicates did not have a significant effect on the difference between indirect and direct measurements in any model. Results suggest poor agreement between Doppler values and directly measured blood pressures in anesthetized cats. Use of Doppler in cats could be misleading and readings should be interpreted with caution in a clinical context.

Comparison of arterial blood pressure measurements and hypertension scores obtained by use of three indirect measurement devices in hospitalized dogs

To evaluate the agreement of blood pressure measurements and hypertension scores obtained by use of 3 indirect arterial blood pressure measurement devices in hospitalized dogs. Design-Diagnostic test evaluation. 29 client-owned dogs. 5 to 7 consecutive blood pressure readings were obtained from each dog on each of 3 occasions with a Doppler ultrasonic flow detector, a standard oscillometric device (STO), and a high-definition oscillometric device (HDO). When the individual sets of 5 to 7 readings were evaluated, the coefficient of variation for systolic arterial blood pressure (SAP) exceeded 20% for 0% (Doppler), 11 % (STO), and 28% (HDO) of the sets of readings. After readings that exceeded a 20% coefficient of variation were discarded, repeatability was within 25 (Doppler), 37 (STO), and 39 (HDO) mm Hg for SAP. Correlation of mean values among the devices was between 0.47 and 0.63. Compared with Doppler readings, STO underestimated and HDO overestimated SAP. Limits of agreement between mean readings of any 2 devices were wide. With the hypertension scale used to score SAP, the intraclass correlation of scores was 0.48. Linear-weighted inter-rater reliability between scores was 0.40 (Doppler vs STO), 0.38 (Doppler vs HDO), and 0.29 (STO vs HDO). Results of this study suggested that no meaningful clinical comparison can be made between blood pressure readings obtained from the same dog with different indirect blood pressure measurement devices.

Cardiovascular Risk Factors and Distributions of the Ankle-Brachial Index among Type 2 Diabetes Mellitus Patients

Background. The aim of present study is to observe the association between the levels of ankle-brachial index (ABI) and cardiovascular risk factors among people with type 2 diabetes mellitus in north India. A cross-sectional study was carried out at a centre for heart and diabetic clinic in the state of Punjab on 1121 subjects (671 males and 450 females) with type 2 diabetes mellitus. History of symptoms related to cardiovascular diseases was noted, and blood pressure and anthropometric measurements were recorded. Ankle-brachial index (ABI) was measured using ultrasonic Doppler flow detector. Subjects with ABI ≤0.9 and ≥1.30 were classified as having low and high ABI, respectively. Females had a higher BMI and brachial-ankle pulse wave velocity (P < 0.001). Whereas, males had higher diastolic blood pressure and duration of type 2 diabetes mellitus. The differences of systolic blood pressure and ankle-brachial index were not found significant between the sexes. The prevalence of low ABI (<0.9) was 4.47% in men and 4.67% in women and high ABI (≥1.30) was prevalent in 14% of men and 10.45% of women. Age, BMI, baPWV, and blood pressures were significantly associated with ABI value in both sexes. The results suggested that the ABI might be used as a strong indicator for cardiovascular risk factors in type 2 diabetic subjects.

Precision of Repeated, Doppler-Derived Indirect Blood Pressure Measurements in Conscious Psittacine Birds

Although the use of indirect methods for measuring blood pressure has become commonplace in dogs and cats, it is uncertain whether these methods can be extended to avian species with any proven accuracy or precision. To evaluate the precision of indirect blood pressure measurement in conscious psittacine birds by the Doppler flow method, 25 psittacine birds, weighing between 230 and 1263 g and representing 17 commonly kept species, were examined. Birds were manually restrained, and indirect blood pressure measurements were obtained by placing a cuff around the limb proximal to a Doppler ultrasonic flow detector held over either the basilic or cranial tibial artery. Three sets of 3 measurements were obtained from each wing and leg site, with cuff size and site based on pilot study data identifying the selection criteria of cuff placement with the least variance among repeated measurements. A mixed-effects linear regression analysis was performed to evaluate the differences among mean blood pressure measurements in the individual bird, obtained from the wing versus leg site as well as from 3 different cuff placements at each site. Results showed variation attributable to the limb was not significant. However, blood pressure measurements varied significantly between cuff placements on the same limb from the same bird and among individual birds. The precision of these indirect blood pressure measurements was poor. From these results, the meaning and value of Doppler-derived indirect blood pressure measurements obtained in psittacine birds remains in question, warranting further research.

Agreement between direct and indirect blood pressure measurements obtained from anesthetized Hispaniolan Amazon parrots

To determine the level of agreement between direct and indirect blood pressure measurements obtained from healthy Hispaniolan Amazon parrots (Amazona ventralis) anesthetized with isoflurane. Validation study. 16 healthy adult Hispaniolan Amazon parrots. Parrots were anesthetized, and a 26-gauge, 19-mm catheter was placed percutaneously in the superficial ulnar artery for direct measurement of systolic, mean, and diastolic arterial pressures. Indirect blood pressure measurements were obtained with a Doppler ultrasonic flow detector and an oscillometric unit. The Bland-Altman method was used to compare direct and indirect blood pressure values. There was substantial disagreement between direct systolic arterial blood pressure and indirect blood pressure measurements obtained with the Doppler detector from the wing (bias, 24 mm Hg; limits of agreement, -37 to 85 mm Hg) and from the leg (bias, 14 mm Hg; limits of agreement, -14 to 42 mm Hg). Attempts to obtain indirect blood pressure measurements with the oscillometric unit were unsuccessful. Results suggested that there was substantial disagreement between indirect blood pressure measurements obtained with a Doppler ultrasonic flow detector in anesthetized Hispaniolan Amazon parrots and directly measured systolic arterial blood pressure.

Left Basilar Systolic Murmur in Retired Racing Greyhounds

Nineteen of 28 (67%) Greyhounds enrolled in the Blood Donor Program at The Veterinary Teaching Hospital, The Ohio State University (Columbus, OH), had a left basilar systolic murmur. Ten Greyhounds with murmurs and 9 without murmurs were evaluated to gain knowledge about the pathogenesis of this murmur. Echocardiograms were performed without sedation by means of a GE Vivid 7 Echocardiographic System with a continuous ECG; systolic arterial blood pressure (SABP) was measured with an Ultrasonic Doppler Flow detector model 811-B. The mean peak aortic velocity in the Greyhounds with murmurs (2.15 m/s; range, 1.8-2.2 m/s) was significantly higher than in the Greyhounds without murmurs (1.89 m/s; range, 1.6-2.0 m/s) (P < .001); there were no significant differences between groups for aortic valve or annulus diameter, fractional shortening, pulmonic velocity, SABP, hematocrit, serum protein concentration, or red blood cell counts. In this study, Greyhounds with soft, left basilar systolic murmurs had mildly (but significantly) higher mean peak aortic velocities than similar dogs without murmurs. In the dogs with murmurs (and higher velocities), we could not identify structural abnormalities, such as valvular lesions or other congenital defects. There was no inverse correlation between the systolic murmur and the higher hematocrit and red blood cell counts observed in this breed. This 1-2/6 basilar systolic murmur is common in Greyhounds, and it does not appear to be of any clinical consequence.

Left Basilar Systolic Murmur in Retired Racing Greyhounds

Nineteen of 28 (67%) Greyhounds enrolled in the Blood Donor Program at The Veterinary Teaching Hospital, The Ohio State University (Columbus, OH), had a left basilar systolic murmur. Ten Greyhounds with murmurs and 9 without murmurs were evaluated to gain knowledge about the pathogenesis of this murmur. Echocardiograms were performed without sedation by means of a GE Vivid 7 Echocardiographic System with a continuous ECG; systolic arterial blood pressure (SABP) was measured with an Ultrasonic Doppler Flow detector model 811‐B. The mean peak aortic velocity in the Greyhounds with murmurs (2.15 m/s; range, 1.8‐2.2 m/s) was significantly higher than in the Greyhounds without murmurs (1.89 m/s; range, 1.6‐2.0 m/s) (P &lt; .001); there were no significant differences between groups for aortic valve or annulus diameter, fractional shortening, pulmonic velocity, SABP, hematocrit, serum protein concentration, or red blood cell counts. In this study, Greyhounds with soft, left basilar systolic murmurs had mildly (but significantly) higher mean peak aortic velocities than similar dogs without murmurs. In the dogs with murmurs (and higher velocities), we could not identify structural abnormalities, such as valvular lesions or other congenital defects. There was no inverse correlation between the systolic murmur and the higher hematocrit and red blood cell counts observed in this breed. This 1–2/6 basilar systolic murmur is common in Greyhounds, and it does not appear to be of any clinical consequence.

Appendicular arterial tumor embolization in two cats with pulmonary carcinoma

A 13-year-old neutered male Persian cat and an 11-year-old neutered female Persian cat were examined because of an acute onset of lameness. In both cats, conscious proprioception and reflexes were diminished in the affected limb. In 1 cat, no blood flow was detected in the left brachial artery with a Doppler ultrasonic flow detector, whereas blood flow in the right brachial artery was easily documented. In the other cat, the right femoral pulse was not palpable. Neither cat had any echocardiographic evidence of cardiac disease. In both cats, treatment was primarily supportive. One cat died, and the other was euthanatized. At necropsy, lung lobe consolidation was seen. Microscopically, there was multifocal infiltration of the lung parenchyma with cuboidal to columnar neoplastic epithelial cells. Neoplastic epithelial cells of similar morphology were identified in nodular masses in sections of muscle, and intravascular tumor emboli were identified obliterating small and large arterioles. Immunohistochemical staining of pulmonary and muscular tissue for pan-cytokeratin antigen revealed intense cytoplasmic staining of neoplastic cells. Staining for factor VIII-related antigen confirmed that clusters of neoplastic cells represented intravascular emboli. Clinical signs in the cats were attributed to arterial occlusion by tumor emboli.

The ankle-brachial index in normal neonates and infants is significantly lower than in older children and adults

Vascular trauma from accidental or iatrogenic causes is becoming more common in children. In early infancy, the most common arterial injuries are caused by diagnostic or interventional cardiac catheterizations. Doppler arterial pressure measurements and the computed ankle-brachial pressure index (ABI) are the most helpful diagnostic modalities in the assessment and follow-up of the ischemic extremity. Because normative ABI data in small children are not available, an ABI of 0.9 or less (based on data obtained from an adult population), is used to indicate limb ischemia in young infants. The purpose of this study was to define the normal values of ABI in newborns and infants. Materials and Methods: Three hundred and fifty patients were divided into two groups: group 1 (n = 200; male-to-female ratio, 1:1) were full-term (gestational age 40 ± 1.3 weeks, surface area 0.22 ± 0.02 m 2) healthy newborns following uneventful pregnancy and delivery. Group 2 (n = 150) were healthy patients aged 2 weeks to 2.5 years admitted for elective hernia repair. All the patients underwent a complete physical examination, which excluded any cardiovascular pathology. The systolic blood pressure (BP) was measured bilaterally over the brachial, tibialis posterior, and dorsalis pedis arteries. All BP data were obtained in the supine position, using an ultrasonic Doppler flow detector, an appropriately-sized pneumatic cuff and a sphygmomanometer. The chosen cuff size was long enough to completely encircle the circumference and wide enough to cover 75% of the length of the upper arm. The same cuff was applied around the ankle above the malleoli. BP values were expressed as mean ± SD in mm Hg. If there was a difference between the BP in the two arms, the higher pressure was used for calculation of the ABI. Results: The BP measurements in newborns (group 1) were left brachial, 98 ± 11; right brachial, 90 ± 10 ( P < .001), left and right tibialis posterior and left and right dorsalis pedis were 83, 81, 84, and 82 mm Hg, respectively. The mean computed ABI was 0.88 ± 0.11. Fifty eight percent of the newborns had an ABI less than 0.9 (lower limit of normal in adults). The ABI values in patients belonging to group 2 increased with age and surface area. The mean ABI was 1.0, 1.1, and more than 1.1 in patients aged 1, 1.5, and 2 years with surface areas of 0.4, 0.5 and 0.6 m 2, respectively ( P < .001 compared with group 1). Conclusion: The normative ABI in newborns and infants is significantly lower than in older children and reaches normal (adult) values during the second year of life. These data may be used as a reference when assessing lower extremity ischemia caused by trauma in young patients.

Use of an ultrasonic Doppler flow detector for determining tissue viability in a dog

Use of an ultrasonic Doppler flow detector for determining tissue viability in a dog

Assessment of non-invasive techniques for measuring blood pressure in preterm infants of birthweight less than or equal to 750 grams

Non-invasive techniques for measuring systolic blood pressure (BP) were evaluated in 10 very preterm infants, median gestational age 24 weeks, who were all of birthweight ≤ 5750 g. Systolic BP measurements were attempted in all infants using a Doppler technique (Ultrasonic Doppler Flow Detector) and two oscillometers (Sentry and EME). Using each technique five separate measurements were attempted over a 10-min period. The systolic BP measurements for each device were then compared to results obtained from intra-arterial catheters which had an undamped waveform. BP measurements were possible on all 10 infants using the Doppler technique, but only in seven using the EME oscillometer and four using the Sentry oscillometer. The mean difference in measurements from those obtained using the arterial catheter were 0.27 mmHg using the Doppler technique and, in those infants in whom measurements were possible, 1.34 mmHg using the Sentry oscillometer and 1.34 mmHg using the Sentry oscillometer. We conclude that the Doppler technique provides the most useful and reliable non-invasive method of assessment of systolic BP in immature infants of birthweight ≤ 750 g.

Noninvasive Doppler blood pressure monitoring in the monoplace hyperbaric chamber

We describe a noninvasive method of monitoring blood pressure in the monoplace hyperbaric chamber. A standard blood pressure cuff was placed on the patient's arm. A Doppler probe, linked to an ultrasonic Doppler flow detector outside the chamber, was secured over the patient's radial artery. Cuff inflation tubing and the Doppler probe wires were passed into the chamber by modifying a standard disposable hyperbaric intravenous pass-through. Blood pressure readings were determined by inflating and slowly deflating the cuff from outside the chamber while observing the sphygmomanometer within the chamber and listening for the first audible flow signal from the Doppler detector, corresponding to the systolic blood pressure. To minimize the risk of fire in the oxygen-filled monoplace hyperbaric chamber, the patient, Doppler detector, and chamber were grounded. Doppler readings obtained from nine normal subjects whose arterial pressures were being measured with indwelling radial arterial catheters (approved as part of another study by the hospital's Investigational Review Board) compare closely with the subject's blood pressures measured with this noninvasive method: 114 +/- 7.6 mm Hg (mean +/- 1 SD) compared to 112 +/- 8.1 mm Hg, respectively (n = 92 measurements in 8 subjects). We conclude that this noninvasive method of monitoring blood pressure within the monoplace hyperbaric chamber is accurate and suitable for monoplace clinical purposes.

The use of Doppler ultrasound to locate "pulseless" femoral arteries.

Percutaneous transluminal angioplasty (PTA) is now an established technique, and is particularly useful for the dilatation of iliac stenoses. One of the problems encountered is that the femoral artery to be punctured may not have a palpable pulse because of proximal disease. (Cumberland, 1982). We describe the use of a Doppler ultrasonic flow detector as a non-invasive and accurate method of detecting the position of a “pulseless” femoral artery.

Testicular torsion: Management with ultrasonic doppler flow detector

The use of the ultrasonic Doppler flow detector in the management of acute testicular torsion is described. The Doppler can be used to diagnose torsion accurately and also to monitor manual detorsion. In this series detorsion was a reliable procedure which avoided emergency exploration in 5 of 8 patients with acute torsion. The advantages and limitations of the Doppler flow detector are presented.