A simple oscillometric technique for determining new indices of arterial distensibility.

Recently, oscillometric devices have been developed that can measure blood pressure in the extremities and analyze pulse volume record. On the basis of the extremity pulse volume record, these devices can automatically determine three types of simply measured pulse wave velocity (PWV) (brachial PWV: heart to right upper arm; R-PWV: right upper arm-right ankle; and L-PWV: right upper arm-left ankle). The percent mean pulse volume record (%MPVR=the height that bisects the area of the pulse volume record/pulse pressure X100), a quantitative index of right brachial pulse volume record, can also be determined. To evaluate the usefulness of these new indices, we studied 1,067 consecutive subjects undergoing health checkups (648 men, 419 women; mean age, 50 +/- 9 years). In both sexes, age correlated positively with simply measured PWVs (men, brachial PWV: r=0.46, p<0.0001; R-PWV: r=0.46, p<0.0001; L-PWV: r=0.47, p<0.0001; women, brachial PWV: r=0.37, p<0.0001; R-PWV: r=0.47, p<0.0001; L-PWV: r=0.48, p<0.0001) and correlated negatively with %MPVR (men: r=-0.40, p<0.0001; women: r=-0.45, p<0.0001). Simply measured PWVs and %MPVR were significantly correlated with mean blood pressure. In a separate group of 60 patients, simply measured PWVs correlated positively with carotid PWV (heart to carotid) derived from an elastic vessel (brachial PWV: r=0.76, p<0.0001; R-PWV: r=0.43, p<0.01; L-PWV: r=0.43, p<0.01). %MPVR correlated negatively with carotid PWV (r=-0.35, p<0.01). In conclusion, simply measured PWVs and %MPVR are easier to determine than conventional PWV and may be useful as new indices of age-related changes in arterial distensibility.     

A radiopaque marker technique for measuring gastrointestinal transit in subjects with an ileostomy

We aimed to develop a simple, clinically useful technique for measuring gut transit time in patients with an ileostomy, in order to distinguish easily when patients have fast or slow transit. Seventeen healthy subjects (mean age, 55 years; range, 43–71 years; nine males) who had had a proctocolectomy for ulcerative colitis more than 1 year previously and without small intestinal resection were studied. Subjects were studied on 4 days after an overnight fast, two studies with and two without breakfast. A standard diet was used on all days. Twenty radiopaque markers were given at the start of each study day. Ileostomy effluent was collected over 24 hr and x-rayed to determine the number of retained markers. Studies with breakfast demonstrated greater intrasubject reproducibility. The mean transit time for passage of 50% of markers was 16.6 hr with, and 14.8 hr without, breakfast (p < 0.02). From the data obtained we suggest that the optimum time for taking a single abdominal radiograph in a patient with suspected fast transit is 6 hr after ingestion of markers, while the optimum time for a patient with suspected slow transit is 24 hr.     

A simple goniometer for measuring hip function.

A goniometer was designed and developed in an attempt to find an objective method of measuring hip flexion and extension in walking as as indication of hip function. Existing goniometers were found to be inadequate for clinical and research use because either they did not provide sufficient information or the information they provided was more than necessary, requiring bulky and time-consuming power devices. The present goniometer is a compromise, providing a quick and easy-to-use clinical and research tool which measures total flexion and extension in walking.     

Ventilatory effects of doxapram in conscious human subjects

The ventilatory effects of a bolus intravenous dose of doxapram (0.37 to 0.47 mg/kg) were studied in ten healthy normal subjects. An immediate significant (p less than 0.001) increase in minute ventilation (VE) was due, in equal part, to significant increases in tidal volume (VT) and frequency (f). The inspiratory (TI) and expiratory time (TE) per breath decreased significantly. Mouth occlusion pressure increased significantly, in association with the increase in VT; there was no change in the ratio of VE to mouth occlusion pressure, indicating that respiratory mechanics did not alter. These results indicate that doxapram increases ventilation in conscious, normal man by an increase in inspiratory neuromuscular drive and a change in central breath timing. The ventilatory and mouth occlusion pressure responses to progressive isocapnic hypoxia and progressive hyperoxic hypercapnia were significantly altered by an intravenous infusion of doxapram (1 mg/min) only in the elevations (Y-intercepts) of the slopes of VE and mouth occlusion pressure; the regression coefficients did not change significantly. These results indicate that in conscious normal subjects, doxapram acts on both the peripheral and central respiratory receptors.     

The international database of self-recorded blood pressures in normotensive and untreated hypertensive subjects.

OBJECTIVES: To pool data from individual subjects in an attempt to determine an operational threshold for making clinical decisions based on the self-recorded blood pressure (SRBP) and to examine how many hypertensive subjects, diagnosed by conventional blood pressure (CBP) measurement, would have a self-recorded blood pressure within the normotensive range if the proposed thresholds were applied. DATA SOURCES: Thirteen research groups studied 4668 untreated subjects. RESULTS: In total 2401 subjects were normotensive, 494 were borderline hypertensive and 1773 were definitely hypertensive. Hypertension had been diagnosed from the mean of 1-6 (median 3) CBP measurements obtained during 1-3 (median 1) visits. The reference values for SRBP measurements determined from the 95th percentiles of the distributions for normotensive subjects were 137 mmHg systolic and 85 mmHg diastolic. Of the subjects with systolic hypertension, 16% had systolic SRBP 相似文献   

A simple technique for processing of bone marrow for human marrow transplantation

Summary A simple stainless steel device is described for the processing of marrow for intravenous infusion to marrow graft recipients. The device can be cleaned easily and sterilized for re-use.     

Phasic right coronary artery blood flow in conscious dogs with normal and elevated right ventricular pressures.

We studied phasic right coronary blood flow in well trained normal dogs and dogs with pulmonic stenosis. We installed electromagnetic flow transducers and pressure tubes under anesthesia to monitor right coronary blood flow, cardiac output, central aortic blood pressure, and right ventribular pressure. In normotensive dogs, systolic flow amplitude equaled early diastolic flow levels. The ratio of systolic to diastolic flow at rest was substantially greater in the right coronary bed (36+/-1.3%) than in the left circumflex bed (13+/-3.6%). Right diastolid flow runoff, including the cove late in diastole, resembled left circumflex runoff. Blood flow to the normotensive right (37+/-1.1 ml/min 100(-1) g) and the left (35+/-1.0 ml/min(-1) g) ventricular myocardium indicated equal perfusion of both cardiac walls. Throttling of systolic flow was related directly to the right ventricular systolic pressure level in the dogs with pulmonic stenosis. Retrograde systolic flow occurred in severe right ventricular hypertension. The late diastolic runoff pattern in dogs with pulmonic stenosis appeared the same as for the normotensive dogs. We obtained systolic to diastolic flow ratios of 1/3 the value of normotensive hearts in high and severe pulmonic hypertension. Electrocardiograms and studies of pathology suggested restricted blood flow to the inner layers of the right myocardium in the dogs with severe and high right ventricular hypertension. Normotensive and hypertensive peak hyperemic flow responses were similar, except for an increased magnitude of diastolic flow, with proportionately less systolic flow in hypertensive states.     

A simple technique for securing tubes

The brief task of inserting a tube, such as a central venous catheter or a chest tube, is usually followed by the longer task of ensuring that the tube will not be inadvertently pulled out. Various methods for securing tubes have been described, and yet these tubes continue to be pulled out with frustrating predictability. The author describes a technique for securing tubes which is simple, effective, requires no special equipment or assistance, and which is applicable to any flexible tube or catheter inserted at a site suitable for placement of an anchoring suture. After the anchoring suture is secured to the skin, an easily mastered knot is performed which, because it will not slip when tightened, allows an indentation to be made in the tube. Once this indentation is further secured with a square knot, it will not allow the tube to slip through it.     

Normal and borderline ambulatory arterial pressures. A new method for establishing reference values

Ambulatory arterial pressures, both systolic (SAP) and diastolic (DAP), together with heart rate were measured every 15 minutes during 24 hours, using a Spacelabs 5200 apparatus, in 168 male subjects of mean age 21 +/- 1 years. According to the WHO criteria, 72 subjects had normal arterial pressure (clinical DAP less than or equal to 90 mmHg, clinical SAP less than or equal to 140 mmHg), and 86 subjects had untreated borderline arterial hypertension (abnormal clinical pressures, with clinical DAP less than or equal to 95 mmHg and clinical SAP less than or equal to 160 mmHg). On the basis of the WHO criteria, a sizeable part of pressure profiles in the normal and hypertensive groups overlapped. The Mc Queen method, derived from cluster analysis, considerably reduces this overlap. The method defines and objective criterion which enables the subjects to be reclassified in cases where clinical and ambulatory pressures "contradict each other". Such reclassification applied in about 20% of our subjects. This leads to a new definition of reference groups based on both clinical pressure and ambulatory pressure profile. The WHO criteria remain the basis for this classification. The Mc Queen method may be used to define normal and borderline arterial pressure profiles in male and female subjects of different age-groups.     

A simple technique for preparation of young red cells for transfusion from ordinary blood units

We have developed a rapid and simple method for the isolation of relatively young cells from ordinary fresh or previously frozen blood units, using the IBM-2991 Blood Cell Processor. Based on in vitro measurements of red cell pyruvate kinase activity, the resolution of the method is excellent, comparable to that of the stractan discontinuous gradient system. In splenectomized patients with thalassemia major, the administration of the "youngest" 50% of blood units yielded 51Cr survival times of 40 and 42 days for fresh packed red cells and 41 and 43 days for previously frozen red cells.     

A simplified method for measuring critical pressures during sleep in the clinical setting

Upper airway critical pressure measurements correlate with the degree of upper airway obstruction during sleep and may have a role in the diagnosis and treatment of obstructive sleep apnea. Nevertheless, the utility of the critical pressure has not yet been realized in the clinical setting because significant technical expertise is still required for the acquisition and analysis of pressure-flow data. Using segmented regression, we developed and validated a simplified approach to analyze the pressure-flow relationship and to determine the effects of protocol-related factors in 44 subjects with sleep apnea. When compared with expert visual analysis, segmented regression method was found to accurately determine the critical pressure (-0.98 +/- 2.47 cm H(2)O vs. -1.07 +/- 2.47 cm H(2)O, respectively; p = 0.46). Furthermore, it was found that two series of measurements acquired at varying nasal pressure levels with two or more breaths per level were sufficient to determine the critical pressure with a minimum of variability. Therefore, this analytic approach has the potential for standardizing and simplifying the ascertainment of the critical pressure for studies examining the effect of therapeutic devices and agents on upper airway collapsibility during sleep.     

A simple assay technique for pancreatic lipase

A simple and inexpensive procedure is described to include pancreatic lipase in the protocol for evaluation of pancreatic function by duodenal aspiration. The method involves dilution with an albumin solution, a 2-hr incubation with a commercially available substrate mixture, and manual titration with a burette. Results comparable to assay with a pH-stat were obtained. Assay for pancreatic lipase is recommended as a part of the diagnostic procedure of duodenal aspiration.