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Biomedical subjects

E O'Brien

Publications and source records attributed to E O'Brien.

At least 145 records · Page 8Linked to original sources
PubMed1995

Diurnal blood pressure profile in older patients with isolated systolic hypertension. The SYST-EUR Investigators.

This study describes the diurnal blood pressure (BP) profile and identifies its correlates in older patients with isolated systolic hypertension (ISH). The ambulatory BP readings of 408 patients, aged > or = 60 years, with ISH on clinic measurement, enrolled in the placebo run-in phase of the Syst-Eur Trial were examined. The time-weighted 24 h BP, daytime and night-time BP and the cusum-derived crest and trough BP were computed to express the BP level. The daily alteration between the high and low BP span was estimated from the day-night BP difference, the cusum derived circadian alteration magnitude and plot height, as well as the amplitude of the Fourier curve. The 24 h SBP and DBP tended to be higher in men (150 +/- 15/82 +/- 9 mm Hg) than in women (147 +/- 17/79 +/- 10 mm Hg), but the sex difference was only significant for DBP. In multiple regression analysis, the 24 h SBP increased (P < 0.05) by 3 mm Hg for each 10 year increment in age and was also 10 mm Hg higher (P < 0.001) in smokers than in non-smokers; the 24 h DBP was 2 mm Hg higher (P < 0.05) in men than in women and decreased (P < 0.05) by 1.5 mm Hg for each 10 year increment in age. The day-night difference in SBP increased with 2 mm Hg for each 10 mm Hg increase in the conventional pressure, decreased with 5 mm Hg for each 10 year increment in age and was 6 mm Hg higher in smokers than in non-smokers; the day-night difference in diastolic pressure was 2 mm Hg greater in women than in men. We conclude that the main determinants of the diurnal BP variation in older patients with isolated systolic hypertension were sex, age, smoking habits and the level of pressure on conventional measurement.

Age Distribution↗
PubMed1995

Will mercury manometers soon be obsolete?

After a century of clinical use, the mercury sphygmomanometric technique of blood pressure (BP) measurement is under threat. There are three reasons for this: mercury is likely to be banned from hospital use because of the danger of toxicity, accurate automated devices are now available to replace the mercury sphygmomanometer and with the advent of 24 h ambulatory BP measurement into clinical practice, more reliance is being placed on BP behaviour rather than on casual measurements. The passing of the mercury sphygmomanometer from clinical practice raises two issues that merit deliberation. Without the mercury standard with which to compare measurements generated by algorithmic interpretation of BP, the clinician is dependent on the consistency and accuracy of such algorithms. If the millimetre of mercury is no longer the unit of measurement for BP, it will soon be replaced by the kilopascal thereby introducing, at least temporarily, the potential for uncertainty in clinical judgment.

Blood Pressure↗
PubMed1995

A new audiovisual technique for recording blood pressure in research: the Sphygmocorder.

OBJECTIVE: To devise a method of blood pressure measurement capable of being substituted for the fallible human observer in validation of blood pressure measuring devices. DESIGN: A number of components used to measure blood pressure have been combined innovatively with audiovisual recording technology to produce a system, named the Sphygmocorder, which consists of a mercury sphygmomanometer, an occluding cuff, an inflation source, a stethoscope, a microphone capable of detecting Korotkoff sounds, a camcorder and a display screen. METHODS: To determine the accuracy of the Sphygmocorder against the trained human observer, the Sphygmocorder has been validated in three separate studies in which three devices for self-measurement of blood pressure, the Omron HEM-705CP, the Phillips HP5332 and the Nissei DS-175, were being validated against two trained observers in 85 subjects with a wide range of blood pressure according to the protocol of the British Hypertension Society. RESULTS: The Sphygmocorder was as accurate as at least one of the observers in each of the validation studies and therefore allows replacement of trained observers by the new device. CONCLUSION: The Sphygmocorder, which retains the time-honoured technique of blood pressure measurement with a mercury sphygmomanometer and an auscultating observer, and provides, in addition, objective evidence of the measurement recorded, which can be stored and re-examined, can be used as a substitute for human observers in validation studies of blood pressure-measuring devices.

Blood Pressure Determination↗
PubMed1995

Factors influencing validation of ambulatory blood pressure measuring devices.

With the introduction of 24 h ambulatory blood pressure monitoring into clinical practice a vast market for ambulatory blood pressure monitoring devices has been created. To satisfy this market manufacturers are producing an array of ambulatory blood pressure monitoring devices. There is no obligation on manufacturers to have such devices validated independently, even though two national protocols, one from the British Hypertension Society (BHS) and the other from the Association for the Advancement of Medical Instrumentation (AAMI), call for independent validation and state the means of doing so. However, many factors can influence the validation procedure. They include compliance to the protocol being employed; the accuracy of the standard; establishing precisely the model being validated; the influences of blood pressure level, age and exercise on device accuracy; the provisions necessary for special populations, such as pregnant women, the elderly and children; the influence of oscillometric versus Korotkoff sound detection and electrocardiographic gating on comparative measurements; the assessment of performance as distinct from accuracy; and the relevance of general factors, such as the algorithm being employed and computer compatibility. Forty-three ambulatory blood pressure monitoring devices have been marketed for ambulatory blood pressure measurement and of those only 18 have been validated according to either the BHS or the AAMI protocol. The influence of the factors listed above on the validation studies of those devices will be considered and the relevance of validation procedures to the clinical use of ambulatory blood pressure monitoring devices will be discussed.

Association↗
PubMed1994

Game, set and MRCP.

Explore the source record for details and available documents.

Clinical Competence↗
PubMed1994

Cloning of the glucose 6-phosphate dehydrogenase gene from Plasmodium falciparum.

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is one of the human genetic traits that confer relative resistance against malaria caused by Plasmodium falciparum. It has been previously shown that this organism, during its intraerythrocytic development, produces its own G6PD, which has properties different from those of human G6PD. In order to investigate the role of this enzyme in parasite-host cell interactions, we have isolated the G6PD gene from Plasmodium falciparum as a set of overlapping lambda gt11 clones. By sequence analysis we have found a single open reading frame, uninterrupted by introns, coding for a protein of 910 amino acids, almost twice as long as any previously sequenced G6PD molecule. The P. falciparum G6PD mRNA is 5.1 kb in size and has an exceptionally long 5' untranslated region of some 1000 nucleotides. We have mapped the G6PD gene to chromosome 14. The C-terminal portion of the predicted protein, from amino acid 310-910 (except for an 'insert' of 62 amino acids), has 39% homology to human G6PD, with a number of characteristic, fully conserved peptides. The N-terminal portion of the predicted protein has no homology to G6PD, but it contains a peptide in which 7 out of 12 amino acids are identical to the putative glutathione binding site of human glutathione S-transferase.

Amino Acid Sequence↗
PubMed1994

Using Hawksley random zero sphygmomanometer as a gold standard may result in misleading conclusions.

We combined a database of paired blood pressure measurements taken using the Hawksley random-zero sphygmonanometer and a standard mercury sphygmomanometer and a database of paired measurements made on a SpaceLabs 90202 ambulatory blood pressure recorder and standard sphygmomanometer to determine how the SpaceLabs 90202 would have fared if it had been assessed against the Hawksley random-zero sphygmomanometer instead of a standard sphygmomanometer. The pooled database contained 255 triplicate readings. Using the standard sphygmomanometer as gold standard, the Spacelabs had a median error of 2 mm/Hg for both systolic and diastolic. Against the Hawksley random-zero sphygmomanometer, median error was -3 mm systolic and -6 mm diastolic. The proportion of errors > 10 mm rose from 11% (systolic) and 9% (diastolic) with the standard sphygmomanometer to 16% and 29% with the Hawksley random-zero sphygmomanometer. Because it underestimates systolic and diastolic pressures, the use of the Hawksley random-zero sphygmomanometer as a gold standard may have resulted in misleading conclusions about performance of some automated BP recorders.

Adult↗
PubMed1994

Thoracic and lumbar spine injuries in children: different than in adults.

A study of 38 patients, ages birth through 17 years, is reported that was performed to identify patterns of thoracic and lumbar spine injuries and healing in children in order to make appropriate treatment recommendations and avoid unnecessary surgery. This retrospective/prospective study, which is the largest review of children's thoracic and lumbar spine injuries in the orthopaedic literature, supports several accepted concepts regarding children's spine fractures. In addition, the periosteal sleeve fracture mimicking lumbar dislocations in small children, which has not been reported previously in the clinical setting, is described. Thoracic and lumbar spine injuries in children have distinct differences from these injuries in adults, and the treatment should take these differences into consideration.

Adolescent↗
PubMed1994

A comparison of the British Hypertension Society and Association for the Advancement of Medical Instrumentation protocols for validating blood pressure measuring devices: can the two be reconciled?

BACKGROUND: Experience with the original protocols of the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) for validating blood pressure has provided valuable insight into the methodological problems associated with device validation and has influenced both the BHS and the AAMI in revising their protocols. OBJECTIVES: To review the revisions of the original BHS and AAMI protocols; to compare the protocols; and, using the BHS protocol as a framework for validation, to determine how it should be modified to a protocol that will fulfil the criteria of both the AAMI and the BHS. CONCLUSIONS: The revised protocols have many similarities but there are some important differences. These differences merit consideration so as to facilitate manufacturers seeking to validate devices for acceptance in both Europe and the United States. Of the two protocols, the BHS protocol is the more elaborate in that (1) it takes particular care to ensure that observers are trained to a very high standard, (2) it makes provision for special group validation and (3) it recommends in-use validation of all devices. By modifying the BHS protocol, it is possible to validate blood pressure measuring devices (ambulatory devices require special consideration) to satisfy the criteria of both protocols.

Blood Pressure Determination↗
PubMed1994

Supporting parental bonding in the NICU: a care plan for nurses.

New and improved technology in the NICU has assisted in supporting critically ill neonates, especially those born at very low birth weights. These small patients require the dedicated hand of the NICU staff, but also the love and support of their parents. Family bonding in the NICU is often a very difficult process, which is interrupted by separation of parent and child at birth and continued by the physical constraints of this highly complex critical care environment. Neonatal nurses are most often the front line managers and coordinators of family care in the NICU. They are charged with the challenge of understanding and providing "state of the art" technological care in an environment that must also adapt to the ever changing needs of parents and families who cannot be considered visitors, but an integral part of their infants' care and survival. Each infant and family in the NICU requires individualized assessment and nursing care. This article reviews the process of parental bonding as it relates to the premature or ill infant and provides for nurses a plan of care written to foster and support family bonding in the NICU. Stages of bonding with a sick or premature infant are explored in the context of a theoretical framework of adaptation provided by Sister Callista Roy.

Humans↗