Search PubMed⌕ Search

Biomedical subjects

H B Wheeler

Publications and source records attributed to H B Wheeler.

At least 55 records · Page 3Linked to original sources

Humanities in surgery, a life threatening situation: communicating the diagnosis.

Surgeons should be able to communicate emotion-laden information to patients effectively. In most medical schools, there is an implicit assumption that students will learn communication skills through observation of appropriate role models. Young physicians often feel ill prepared to convey such information with sensitivity and understanding. University of Massachusetts Medical School's curriculum includes a program that addresses the communication skills involved in surgical practice and the ethical issues they raise. Videotaped vignettes of doctor-patient interactions culled from dramatic and documentary sources are viewed and discussed with students in small groups. These highly evocative vignettes are of live and role played doctor-patient encounters. The elements of communication are analyzed, as are psychosocial, existential, legal and ethical issues.

Communication↗

Traumatic pseudoaneurysm following blunt trauma.

Traumatic aneurysms of the superficial femoral (SFA) and superior medial geniculate artery (SMGA) demonstrated late expansion of previously well contained hematomas which were pulsatile and remarkable for the presence of bruits. Injury to the SFA resulted in a cool, pulseless distal extremity. Direct exploration of the pseudoaneurysm cavity following proximal and distal control of the main arterial segment resulted in optimal exposure and successful repair of the arterial defect. Blunt trauma may result in pseudoaneurysm formation. Persistent swelling at a focus of injury despite normal distal pulsation is an early indicator of major vascular injury.

Adolescent↗

Diagnostic approaches for deep vein thrombosis.

This article briefly reviews the advantages and limitations of currently available methods for the diagnosis of deep vein thrombosis (DVT). Clinical evaluation alone is inadequate but still useful in assessing the need for further testing. The medical history, especially the detection of risk factors for DVT, is as important as the physical examination. Confirmation by objective diagnostic tests is essential. Venography has been the traditional standard for determining the optimal management of DVT, but has significant limitations which are not widely appreciated. Noninvasive diagnostic methods for DVT are essential for effective management, but the optimal method for a particular hospital depends on the personnel and resources available.

Humans↗

Diagnosis of deep vein thrombosis. Review of clinical evaluation and impedance plethysmography.

This article has briefly reviewed the diagnosis of DVT by clinical evaluation and by impedance plethysmography. Clinical evaluation alone cannot be relied on for patient management, but when carefully performed, it remains useful in determining the need for additional testing. The medical history, especially the detection of risk factors for DVT, is as important as the physical examination. In 1,464 patients suspected of DVT, the incidence of this disease by impedance plethysmography was only 11 percent when there were no major risk factors present but increased to 50 percent when three risk factors were present. Impedance plethysmography is a widely used noninvasive test for the diagnosis of DVT. It has a sensitivity and specificity of 94 percent based on correlation with 2,561 venograms. The method is based on quantitation of the venous outflow from the calf after temporary venous occlusion in the thigh. It is particularly helpful in ruling out DVT in patients with suspicious signs or symptoms. Recent improvements in methods, including computer-assisted data analysis, appear likely to further extend its usefulness.

Computers↗

Noninvasive evaluation of arterial occlusive disease.

A procedure for observing blood flow during early reactive hyperemia, which uses prolonged venous occlusion following 3 min of arterial occlusion, is described. A mercury strain gauge was applied around the mid-calf and 3 tracings were simultaneously recorded during reactive hyperemia: the change in venous volume, its derivative and amplified pulse waves. The method was evaluated in animals, normal volunteers and in patients with symptoms of arterial insufficiency. This bedside procedure was found to be convenient and practical. Peak flow during reactive hyperemia was found to have an accuracy comparable to the ankle/arm pressure index in distinguishing between normal, stenotic or occluded lower extremity arterial systems. In addition, it proved more accurate than pressure measurements in diabetic patients with incompressible calcified vessels.

Animals↗

Transvenous interruption of the inferior vena cava.

Transvenous interruption of the inferior vena cava was successful in 45 of 47 consecutive patients treated during a 41/2-year period. Greenfield filters were used in 40, and Mobin-Uddin umbrellas in 5 others. Technical details of the insertion procedure are of particular importance for successful implantation of the Greenfield device. Follow-up data were available for 34 of 36 surviving patients and autopsy findings for 4 of the 11 who had died. Patency of the vena cava was assessed by radionuclide scan, venography, or autopsy. Of 33 patients with Greenfield filters who were evaluated, only one had an occluded filter, for a patency rate of 97%. One of the three patients with a Mobin-Uddin umbrella had caval thrombosis. Severe postoperative venous stasis was seen in one patient with a Greenfield filter and one with a Mobin-Uddin umbrella. Significant distal migration or angulation of Greenfield filters was observed in six patients and is a theoretical cause for recurrent embolization. The 30-day mortality rate for the patients who had transvenous procedures was 13%, but no deaths were attributed to the procedure itself. There were no clinically evident pulmonary emboli during the follow-up period. In the present study we have documented low operative morbidity and mortality rates as well as complete protection from recurrent pulmonary embolism using transvenous interruption of the inferior vena cava. Although the Greenfield filter is somewhat bulkier and more difficult to insert than the Mobin-Uddin umbrella, it has a clear advantage because of its superior long-term patency.

Adult↗

Suspected deep vein thrombosis. Management by impedance plethysmography.

Controversy exists as to whether patients suspected of having deep vein thrombosis (DVT) can be studied safely without venography, with its attendant expense, inconvenience, and potential risk. We used impedance plethysmography (IPG) in 1,464 consecutive patients suspected of having DVT, with 96% of these patients with normal IPGs, there were no fatal pulmonary emboli (PE). The incidence of nonfatal PE was 1%. In 284 outpatients suspected of having DVT, but discharged without treatment because of normal IPGs, only one patient returned with subsequent symptoms of DVT (0.4%). Noninvasive testing with IPG is a safe and highly cost-effective alternative to venography for routine management of patients suspected of DVT.

Adolescent↗

Noninvasive detection of carotid stenosis following endarterectomy.

Noninvasive diagnostic studies (oculoplethysmography, pulsed Doppler arteriography, and phonoangiography) were used to follow the postoperative courses of 172 patients who had 199 carotid endarterectomies. There were 24 restenotic arteries in 21 patients who underwent 29 operations. Fifteen restenotic lesions in 14 patients were detected solely by noninvasive testing. These patients are being observed closely and remain asymptomatic. One has been operated on for progression of disease. Either transient or permanent neurologic deficits developed in nine as the initial indication of recurrent stenosis or occlusion; three of these subsequently have undergone reoperation. Patients with bilateral disease are at increased risk of restenosis. Routine testing of all patients undergoing carotid endarterectomy is recommended 1, 3, and 12 months postoperatively to detect and observe stenosis on both the side operated on and the contralateral side before clinical symptoms develop.

Aged↗

Applicability and interpretation of electrocardiographic stress testing in patients with peripheral vascular disease.

Electrocardiographically monitored arterial stress testing was performed before surgery in 130 patients with peripheral vascular disease. When limitations of claudication or pain at rest precluded treadmill exercise, arm ergometry was employed. The electrocardiographically monitored arterial stress test proved a cost-effective, easily applicable means of screening for coronary artery disease in this group of patients. Unlike statistical analyses of historical risk factors, the electrocardiographically monitored arterial stress test evaluates the current functional state of the myocardium. We believe that preoperative electrocardiographic exercise testing should be employed more widely and should be considered in any patient facing major surgery in whom coronary artery disease is suspected on the basis of past history or known risk factors. In patients who have an ischemic response to exercise, particularly at less than 75 percent of the maximum predicted heart rate, coronary angiography and possibly coronary revascularization should be considered before elective major surgery is performed.

Aged↗

Assessment of operative risk with electrocardiographic exercise testing in patients with peripheral vascular disease.

Doppler ankle blood pressures were performed inere obtained in 100 consecutive patients with peripheral arterial insufficiency after treadmill exercise. A twelve lead electrocardiogram was monitored during and after exercise. Despite a restricted ability to exercise because of peripheral vascular insufficiency, forty-six patients had ventricular dysrhythmia or ischemia, or both, usually without associated symptoms. Electrocardiographic monitoring during treadmill exercise proved a useful predictor of postoperative complications. Thirty-two vascular operations were performed in patients with no electrocardiographic evidence of ischemia. No patient had a postoperative myocardial infarction or died. Sixteen vascular procedures were performed in patients with ischemic responses on exercise electrocardiography. Six patients had postoperative myocardial infarctions, two of which were fatal. Electrocardiographic monitoring during treadmill exercise for peripheral vascular insufficiency in recommended (1) to assess the severity of coronary artery disease and the likehood of postoperative complications, and (2) as a precautionary measure to identify potentially dangerous dysrhthmias or ischemia during exercise before the development of clinical symptoms.

Aged↗

Impedance plethysmography: correlation with contrast venography.

Impedance plethysmography is a noninvasive, indirect test for deep venous occlusion in the lower limbs. The results of ascending contrast venography impedance plethysmography have been compared in 315 limbs. Impedance plethysmography was positive in 77 of 79 limbs with acute deep vein thrombosis proximal to the calf. It was positive in 6 of 27 limbs with clot isolated in the calf. Only 7 false-positive plethysmograms were found in 161 normal contrast venograms. The clinical implications of these data are discussed.

False Positive Reactions↗