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R Jones

Publications and source records attributed to R Jones.

1,161 records · Page 65Linked to original sources
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A hydrostatic method assessing accuracy and reliability while revealing asymmetry in blood pressure measurements.

This study describes a method for noninvasive hydrostatic validation of blood pressure devices. It is based on the hydrostatic pressure exerted by a column of blood. The mid-position of an upward-held wrist blood-pressure cuff marks the top of the column, and a cuff on the opposite wrist pointed downward similarly determines the bottom of the column. Twenty-one healthy subjects comprising 12 right-handed and nine left-handed men and women entered this study. Each repeatedly alternated the arm positions ten times. Linear regression analysis yielded correlation coefficients for comparison of the Dinamap devices against the hydrostatic differences of 0.57, 0.70, and 0.70 for systolic pressure (SP), diastolic pressure (DP), and mean pressure (MP), respectively. These coefficients combined with the results of the graphic method of Altman and Bland demonstrated the best results for DP and matched least for SP. Overall results presented mean errors (ME: Dinamap-hydrostatic) +/- standard deviations (SD) of 9.3 +/- 10.1, -1.0 +/- 5.6, and 6.3 +/- 6.7 mmHg for SP, DP, and MP, respectively. These results are numerically comparable to some of the prior reports of ME +/- SD analysis of Dinamap devices by conventional validation studies. Numerically, DP is within and MP is close to the AAMI standards. The results of ME +/- SD, however, revealed a remarkable asymmetry for SP. The results of all the left-arm-up/right-arm-down position had ME +/- SD 12.3 +/- 11.1, -0.6 +/- 5.8, and 7.2 +/- 7.1 mmHg for SP, DP, and MP, respectively. The results of the opposite positioning were 6.3 +/- 7.9, -1.3 +/- 5.5, and 5.4 +/- 6.2 mmHg, respectively. This asymmetry of the SP differences seems independent of handedness (left or right) and gender, and may be related to the reflectance caused by intrathoracic vasculature asymmetry, which suggests that for validation purposes, the left-arm-down/right-arm-up position should be used. The alternative position may be used to detect and/or study this asymmetry. Such detection should have important clinical consequences for patient blood pressure monitoring. During surgery, if both arms must be placed shoulder-high, for instance, the right arm should provide more accurate and reliable blood pressure measurement.

Adult↗
PubMedDate not supplied

The management of rectal bleeding.

Rectal bleeding is a common symptom in the general population; it may signal the presence of serious gastrointestinal disease but more frequently is caused by minor and self-limiting local ano-rectal conditions. Appropriate and accurate evaluation of rectal bleeding requires an investigative approach which balances an appreciation of the need to provide an adequate explanation for the bleeding against over-investigation, excessive referral and wasted resources. As doctors of first contact, general practitioners (GPs) are frequently faced with difficult questions concerning the optimum management of rectal bleeding. This paper was prepared as a result of a series of interactive meetings with over 1,000 GPs from throughout the UK, which revealed wide variations in the possession and use of investigative equipment in the surgery, access to secondary care facilities, estimates of the prevalence and potential seriousness of rectal bleeding and the management strategies adopted in response to a series of case histories. We highlight a number of unresolved issues about the roles of GPs and hospital specialists in the management of rectal bleeding and the need for research directed at answering outstanding questions. In addition, a management strategy is proposed which might form the basis for a protocol for care, shared between general practice and the hospital.

Attitude of Health Personnel↗
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The practice of obstetrics by Army family physicians.

BACKGROUND: There has been a dramatic decline nationwide in family physicians practicing obstetrics. This study describes the practice of obstetrics by Army family physicians in an environment relatively free of malpractice liability and other financial concerns. METHODS: A questionnaire was mailed to every family physician on active duty in the Army (n = 334) in 1993, with a final response rate of 79 percent (n = 265). RESULTS: Nearly 73 percent of Army family physicians practice obstetrics. Almost all believed they were adequately prepared to provide routine prenatal care (98 percent) and complicated obstetric care (84 percent). More than 95 percent of those assigned to a teaching facility delivered babies. Obstetric procedures that the majority performed included normal vaginal deliveries (100 percent), repair of third-degree (98 percent) and fourth-degree (93 percent) tears, insertion of fetal scalp electrodes (96 percent) and intrauterine pressure catheters (98 percent), interpretation of nonstress tests (97 percent) and contraction stress tests (83 percent), vacuum extractions (93 percent), pudendal or paracervical blocks (88 percent), first assist in Cesarean sections (80 percent), amnioinfusions (76 percent), and low-forceps deliveries (53 percent). Those who currently practice obstetrics were more satisfied with being a family physician compared with those who did not practice obstetrics (95 percent vs 86 percent, P < 0.02). CONCLUSIONS: The majority of Army family physicians perform a wide spectrum of obstetrics care. Those who practiced obstetrics were generally more satisfied with family practice than were those who did not practice obstetrics.

Adult↗
PubMedDate not supplied

Malaria in a captive emu (Dromaius novaehollandiae) from Florida.

Severe anemia and intraerythrocytic stages of an unusual Plasmodium sp. were identified in the blood of a 5-month-old female emu (Dromaius novaehollandiae) that had a 4-week history of malaise. Examination of blood taken 3 days prior to the death of the bird revealed a packed cell volume of 10%. Erythrocytes showed a marked regenerative response. Approximately 4% of erythrocytes had intracytoplasmic inclusions, mainly within immature cells, resembling malarial parasites. The schizonts were a combination of the Haemamoeba and Huffia subgenera type with 8-16 merozoites in mature forms. The gametoctyes were elongate. The abnormal morphology was probably a reflection of a new host-parasite relationship. Exoerythrocytic parasite stages were not identified at necropsy. The anemia was tentatively attributed to the Plasmodium infection.

Animals↗
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A new approach to reproducibility assessment: clinical evaluation of SpaceLabs Medical oscillometric blood pressure monitor.

The SpaceLabs Medical oscillometric blood pressure monitor was evaluated in both neonatal and adult populations according to the 1992 AAMI SP-10 standard for electronic or automated sphygmomanometers. For the neonatal study, the umbilical artery pressure was used as a reference. Fifteen newborn ICU patients were enrolled in the study, yielding a total of 150 pairs of comparison readings. For the adult study, the first and fifth phases of the Korotkoff sounds were used as a reference. One hundred twelve adults were enrolled in the study, yielding a total of 336 pairs of comparison readings. Accuracy was analyzed by the AAMI SP-10 standard. For systolic and diastolic pressures, respectively, the mean differences +/- standard deviations of oscillometric accuracy were 0.1 +/- 4.3 and 2.7 +/- 4.8 mmHg for the neonatal study and -0.6 +/- 5.9 and 0.9 +/- 6.4 mmHg for the adult study, which are within the AAMI SP-10 accuracy standard. Reproducibility was analyzed by a new approach developed from the sequential technique of the 1990 British Hypertension Society protocol. For systolic and diastolic pressures, respectively, the mean differences +/- standard deviations of the oscillometric reproducibility were estimated to be -0.1 +/- 3.3 and 0.1 +/- 3.4 mmHg for the neonatal study and -0.3 +/- 3.2 and 0.1 +/- 3.5 mmHg for the adult study.

Adult↗