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Biomedical subjects

R R Lewis

Publications and source records attributed to R R Lewis.

At least 19 recordsLinked to original sources
PubMed2001

Prediction of hypertension in chronic hemodialysis patients.

BACKGROUND: There are no universally accepted criteria for the diagnosis of hypertension in hemodialysis (HD) patients. We sought to determine the clinical performance of predialysis and postdialysis systolic and diastolic blood pressure values (BPs) in diagnosing hypertension or assessing its control. METHODS: Seventy patients [77% African American, 46% females, mean age 59 +/- 17 (SD) years, 34% diabetics] on chronic HD underwent a single 44-hour interdialytic ambulatory blood pressure monitoring (ABPM) and concomitant recording of BP by conventional syphygmomanometer in the HD unit for two weeks. Hypertension was defined as systolic BP (SBP) > or =135 mm Hg or diastolic BP (DBP) > or =85 mm Hg on an average 44-hour ABPM. RESULTS: Average ABP was 144 +/- 22/81 +/- 11 mm Hg. Seventy-three percent of the patients had systolic hypertension; 40% had diastolic hypertension, and 24% were normotensive or had well-controlled BP. Area under the curve of receiver operating characteristic (ROC) curves exceeded 80% for all BPs, but the thresholds for best sensitivity and specificity were markedly different for predialysis and postdialysis BPs. A two-week averaged predialysis BP of > 150/85 mm Hg or a postdialysis BP of > 130/75 mm Hg had at least 80% sensitivity in diagnosing hypertension. Specificity of at least 80% was achieved if predialysis BP of > 160/90 mm Hg or postdialysis BP of > 140/80 mm Hg was used. There was poor agreement between HD unit BP and ABP values. CONCLUSIONS: HD unit BP values can be used to identify the presence or absence of hypertension, although prediction of ambulatory BPs from HD unit BP values cannot be made reliably in individual patients.

Adult↗
PubMed2001

Caregiving tasks among family caregivers of patients with lung cancer.

PURPOSE/OBJECTIVES: To describe family caregivers' perceptions of time spent and difficulty experienced with performing specific caregiving tasks for patients with lung cancer. To compare adult child and spousal caregivers in relation to time and difficulty of tasks. DESIGN: A secondary analysis of data from a study using a cross-sectional, descriptive, comparison design. SETTING: A university outpatient oncology center, two veterans administration outpatient clinics, and a private outpatient oncology practice. SAMPLE: 78 family caregivers of patients with lung cancer (62 spouses and 16 adult children). METHODS: Data that previously had been collected using a structured interview guide were analyzed using descriptive statistics, comparison of item means, and multivariate analysis of variance. MAIN RESEARCH VARIABLES: Time and difficulty with caregiving tasks. FINDINGS: The most time-consuming tasks for adult children and spouses were providing emotional support, transportation, and monitoring symptoms. The most difficult duties were emotional support, behavioral management, monitoring symptoms, and household tasks. Time and difficulty of tasks did not differ significantly between adult child and spousal caregivers. CONCLUSIONS: Some caregivers may require guidance in providing transportation, emotional support, behavioral management, and symptom management. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurses can make a significant impact in assisting family members in providing care by addressing the provision of transportation, emotional support, behavioral management, and symptom management.

Adult↗
PubMed2000

Acute confusion secondary to pneumocephalus in an elderly patient.

PRESENTATION: an 83-year-old man was admitted to hospital with acute confusion 3 days after a direct flight from Australia. OUTCOME: computed tomography (CT) brain scan and magnetic resonance imaging head scan revealed the cause to be pneumocephalus, apparently the result of barotrauma caused by Valsalva manoeuvres when he attempted to unblock his nose during the flight. After 5 days of nursing in the vertical position the patient's Abbreviated Mental Score returned to normal. A CT brain scan 6 weeks later showed complete resolution of the pneumocephalus.

Acute Disease↗
PubMed1998

Endoscopic retrograde cholangiopancreatography in elderly patients.

BACKGROUND: the presentation of common bile duct disease, value of investigations and treatment outcome in elderly patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) were assessed. METHODOLOGY: the clinical presentation, liver function tests, full blood counts, abdominal ultrasound and ERCP results were assessed retrospectively in 101 patients (59 women, 42 men; mean age 83 years, range 75-100) sequentially investigated for possible common bile duct disease. RESULTS: 59 patients had common bile duct gallstones, 35 had malignant biliary obstruction (13 with co-existing common bile duct stones) and seven had other outcomes. In the malignant-alone group 68% of those who had jaundice presented painlessly compared with 24% in the gallstones-alone group; 49% of the gallstones-alone group had pain compared with 28% of the malignant group. In the gallstones-alone group 43% had atypical presentations (non-specific symptoms or painless jaundice). Non-specific symptoms were found in 19% of the gallstones-alone group but in only 5% of the malignant group. Of the patients who had common bile duct stones, 18% had pancreatic or biliary malignancy. The co-existence of gallstones and malignancy was emphasized by eight patients in whom the clinical and ultrasound diagnosis was of common bile duct stones but malignancy was detected by ERCP. The sensitivity of ultrasound was 86% for detecting dilated common bile ducts was 86%, but only 69% for diagnosing gallstones within the common bile duct and 67% for diagnosing pancreatic masses. Ultrasound and ERCP were in agreement in 60 patients (60%). Endoscopic clearance of common bile duct gallstones was successful in 53 of 54 attempts (98%). Palliative ERCP treatment was performed in 30 patients who had malignant biliary obstruction and was successful in 22 (73%); in a further four patients (13%) an endoprothesis was successfully inserted percutaneously. The commonest complication of ERCP was cholangitis (four patients); pancreatitis and biliary perforation occurred in one patient each. Twenty-two patients (63%) who had malignancy died during follow-up, the mean survival being 11.3 weeks (range 3 days-2 years). Carcinoma of the ampulla was associated with a relatively good prognosis (three patients survived 18 months or more). CONCLUSION: in elderly patients, common bile duct stones often present atypically and co-existence with malignancy is not unusual; ampullary carcinoma has a relatively good prognosis and ERCP is a safe and effective procedure in the management of biliary obstruction.

Aged↗
PubMed1997

Comparison between reagent strips used for detection of urinary tract infection in the elderly.

A comparison was made between the accuracy of Ames and Boehringer reagent strips for detecting urinary tract infections in 100 elderly patients (50 acutely ill patients admitted to hospital and 50 attending the day hospital). The results for urinary nitrite, blood and protein for both strips were documented. Nitrite provided the highest sensitivities and specificities. In the acute hospital patients, the sensitivities were 83% for the Ames and Boehringer strips respectively, while for the day hospital patients the sensitivities were 90% for both strips. Specificities were 100% for both strips in each group of patients. There was thus little difference between the accuracy of the Ames and Boehringer reagent strips in detecting urinary tract infection.

Aged↗
PubMed1994

Comparison of indirect and direct blood pressure measurements with Osler's manoeuvre in elderly hypertensive patients.

Indirect (cuff) and direct (intra-arterial) BPs were measured in 15 normotensive (mean age 79 years, range 72-88 years) and 21 hypertensive (mean age 76 years, range 65-89 years) elderly patients. Osler's test and arm arterial compliance, measured using Doppler-shifted ultrasound, were also assessed. In the normotensive, cuff systolic pressures were less than the direct by > 20 mmHg in 10 of the 15 (mean cuff systolic 139 +/- 13: direct 160 +/- 20 mmHg, P < 0.001); there was no statistical difference between the cuff and direct mean diastolic pressures (mean cuff diastolic 75 +/- 8; direct 70 +/- 10 mmHg). In the hypertensives, one had pseudohypertension (cuff systolic 186: direct 152 mmHg). However, cuff systolic pressures were less than the direct by > 20 mmHg in 11 (mean cuff systolic 205 +/- 26: direct 224 +/- 31 mmHg, P < 0.05); cuff diastolic pressures were greater than the direct by > 10 mmHg in 10 (mean cuff diastolic 102 +/- 14; direct 93 +/- 16 mmHg, P < 0.05). There was no significant difference between cuff and direct mean arterial pressures or the compliance in the normotensive and hypertensive groups. Osler's test was negative in the pseudohypertensive patient while in the four positive tests cuff systolic pressures were less than the direct measurements. In elderly patients there was no significant difference between the mean BP for cuff and direct measurements; systolic pseudohypotension and diastolic pseudohypertension are common and Osler's test is misleading.

Aged↗
PubMed1992

Non-invasive assessment of the Circle of Willis using transcranial pulsed Doppler ultrasound with angiographic correlation.

The ability of transcranial pulsed Doppler ultrasound (TCD) to provide a dynamic assessment of the functional capability of the Circle of Willis was assessed using conventional cerebral angiography for anatomic correlation. Eleven patients had normal four-vessel cerebral angiography prior to being investigated with ultrasound. Angiography and ultrasound both demonstrated a functional anterior communicating artery in nine of the eleven patients, giving complete agreement between the two techniques. Posterior communicating arteries were visualized angiographically in all eleven patients. Ultrasound identified bilateral functional vessels in nine, the other two patients having non-functional vessels. In these latter two patients, angiography demonstrated three of the four posterior communicating arteries to be hypoplastic and it was uncertain whether these vessels carried significant blood flow. The fourth posterior communicating artery was shown to have an absent proximal segment of the ipsilateral posterior cerebral artery, with a persistent fetal posterior communicating artery. This anatomical variation is a potential limitation of ultrasound for assessing functional posterior communicating arteries. These preliminary results indicate that a combination of the anatomical (angiographic) and dynamic (ultrasonic) data may prove to be complementary for assessing the Circle of Willis.

Adult↗
PubMed1991

Incidence of loss of consciousness during automatic implantable cardioverter-defibrillator shocks.

OBJECTIVE: To determine the incidence of loss of consciousness occurring in association with shocks delivered by automatic implantable cardioverter-defibrillators (AICD) in patients who had undergone implantation as treatment for ventricular tachycardia or ventricular fibrillation. DESIGN: Cohort study. SETTING: Two major tertiary medical care facilities. PATIENTS: A total of 180 patients who had undergone implantation of an AICD for treatment of ventricular tachycardia or ventricular fibrillation. INTERVENTION: Implantation of an AICD that delivered only high-energy shock. MEASUREMENTS: During a mean (+/- SD) follow-up period of 16 +/- 12 months, the incidence of loss of consciousness occurring in association with spontaneous AICD shocks was determined. Various clinical factors were analyzed to identify predictors of loss of consciousness that occurred during AICD shocks. MAIN RESULTS: Of the 180 patients who received an AICD, 106 patients (59%) experienced AICD shocks during follow-up. Sixteen of the 180 patients (9%) experienced loss of consciousness; 13 of these 16 patients had syncope and 3 died suddenly, in association with AICD shocks. The absence of syncope during one AICD shock did not always predict the absence of syncope during subsequent shocks. Syncope could not be predicted by age, sex, history of syncope, left ventricular function, type of underlying heart disease, electrophysiologic findings, rate of ventricular tachycardia, antiarrhythmic medications, and type of pulse generator implanted. CONCLUSIONS: Patients with sustained ventricular tachycardia or ventricular fibrillation who receive an AICD that delivers only high-energy shock therapy are at moderate risk for experiencing loss of consciousness during AICD shocks. No clinical variables were found to be predictors of syncope. Therefore, driving and other activities that require patients to be extra vigilant should not be assumed to be safe after implantation of an AICD that delivers only high-energy shock.

Adult↗
PubMed1991

Effect of antiarrhythmic drug therapy on the incidence of shocks in patients who receive an implantable cardioverter defibrillator after a single episode of sustained ventricular tachycardia/fibrillation.

Seventy-four patients (16 women, 58 men, age 58 +/- 11 years, mean +/- standard deviation) who received an implantable cardioverter defibrillator (ICD) after experiencing a single episode of ventricular tachycardia or ventricular fibrillation were followed to determine if antiarrhythmic drug therapy affects the incidence of ICD discharges. Thirty-three patients (group A) were treated with an antiarrhythmic drug that was either untested or previously demonstrated during electropharmacological testing to be ineffective in suppressing the induction of ventricular tachycardia. Forty-one patients (group B) were not treated with an antiarrhythmic drug. There were no significant differences between the two groups in regards to age, sex, incidence of coronary artery disease, left ventricular function or the type of ICD pulse generator used. During a mean follow-up of 14 months for the entire cohort, 15 patients (46%) in group A and 18 patients (44%) in group B experienced at least one ICD shock. The time to the first appropriate shock (5 +/- 5 months in both groups) and the frequency of ICD shocks (0.3 +/- 0.2/month in group A vs 0.4 +/- 0.5/month in group B) were similar in both groups. The incidence of syncope at the time of ICD discharge was higher in group A than group B patients (31% vs 5%, P less than 0.05). In conclusion, antiarrhythmic drugs that are untested or have failed electropharmacological testing do not appear to reduce the probability of ICD discharge over a short-term (mean 14 months) follow-up in patients who have had only one clinical episode of VT/VF and may increase the risk of syncope during ICD discharge.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Arrhythmia Agents↗