The measurement of cortisol in saliva has become a reliable tool for both thc scientist and the clinician for studying adrenal cortical function in the adult. We have measured salivary cortisol in samples from 138 healthy infants, children, and adolescents, and from 14 adults. Saliva samples were obtained at home using a cotton swab and a saliva-collecting tube at 800, 1300, and 1800 h before meals. Cortisol was measured using a time-resolved fluorcsccnt irnmunoassay. Cortisol levels in saliva ranged from less than 2 nmol/L up to more than 100 nmol/L. Cortisol levels were age-dependent. Intcrcstingly, after thc age of 6 y, cortisol levcls corrclated significantly with pubertal stages (analysis of variance). No sex difference was found. In addition, cortisol morning levels and daily cortisol levels (area under the curve from three measurements) increased with body weight and body mass index. The highest cortisol levels were measured in saliva of children younger than 1 y. No circadian variation was evident before thc agc of 9 mo. After 1 y of age, salivary cortisol levels varied in a circadian fashion. The measurement of salivary cortisol levels is an attractive way of testing adrenal function in infants and children. It provides a rcliable tool for the determination of the physiology and developmental characteristics of cortisol metabolism. (Pediatr Res 37: 502-506, 1995)The measurement of cortisol in saliva provides a reliable cents and from 1 4 adults to obtain more insight into regulatory tool for investigations of hypothalamus-pituitary-adrenal axis mechanisms of adrenal function throughout childhood and activity (1-1 1). Saliva samples can be obtained stress-free. In adolescents. addition, salivary cortisol reprcsents the free fraction of cortisol in plasma and does not depend on salivary sccretion rate (flow rate) nor on salivary protein content (4, 5, 9, 11). About METHODS 5-10% of total plasma cortisol is not bound to cortisol-binding Subjects and study protocol. Saliva samples were obtained globulin (= free plasma and diffuses into in the home setting at 800, 1300, and 1800 h before meals. saliva. Salivary cortisol measurements have been extensively Saliva samples were sent to the laboratory by surface mail. A used in psychobiologic, psychiatric, and endocrine re-complete medical examination was performed, and height, search. Surprisingly, relatively little information is available on weight, and pubertal stages were recorded by means of a the use of salivary cortisol determinations in children and standardized examination form. adolescents. Importantly, relatively few studies deal with the Height, weight, and body mass index values of the subjects diurnal variation of cortisol levels in children, developmental were all within the third to 97th percentile range (26). A total and physiologic aspects of function in young age, and of 178 healthy subjects were recruited from an inner city influ' ' ' ' of and pubertal On neighborhood (Munich, Germany), the local kindergarden, and cortisol levels (12)(13)(14)...

Arterial blood pressure (BP) is a fundamental cardiovascular variable, is routinely measured in perioperative and intensive care medicine, and has a significant impact on patient management. The clinical reference method for BP monitoring in high-risk surgical patients and critically ill patients is continuous invasive BP measurement using an arterial catheter. A key prerequisite for correct invasive BP monitoring using an arterial catheter is an in-depth understanding of the measurement principle, of BP waveform quality criteria, and of common pitfalls that can falsify BP readings. Here, we describe how to place an arterial catheter, correctly measure BP, and identify and solve common pitfalls. We focus on 5 important steps, namely (1) how to choose the catheter insertion site, (2) how to choose the type of arterial catheter, (3) how to place the arterial catheter, (4) how to level and zero the transducer, and (5) how to check the quality of the BP waveform.

Since both, hypotension and hypertension, can potentially impair the function of vital organs such as heart, brain, or kidneys, monitoring of arterial blood pressure (BP) is a mainstay of hemodynamic monitoring in acutely or critically ill patients. Arterial BP can either be obtained invasively via an arterial catheter or non-invasively. Non-invasive BP measurement provides either intermittent or continuous readings. Most commonly, an occluding upper arm cuff is used for intermittent non-invasive monitoring. BP values are then obtained either manually (by auscultation of Korotkoff sounds or palpation) or automatically (e.g., by oscillometry). For continuous non-invasive BP monitoring, the volume clamp method or arterial applanation tonometry can be used. Both techniques enable the arterial waveform and BP values to be obtained continuously. This article describes the different techniques for non-invasive BP measurement, their advantages and limitations, and their clinical applicability.

Background The optimal method for blood pressure monitoring in obese surgical patients remains unknown. Arterial catheters can cause potential complications, and noninvasive oscillometry provides only intermittent values. Finger cuff methods allow continuous noninvasive monitoring. The authors tested the hypothesis that the agreement between finger cuff and intraarterial measurements is better than the agreement between oscillometric and intraarterial measurements. Methods This prospective study compared intraarterial (reference method), finger cuff, and oscillometric (upper arm, forearm, and lower leg) blood pressure measurements in 90 obese patients having bariatric surgery using Bland–Altman analysis, four-quadrant plot and concordance analysis (to assess the ability of monitoring methods to follow blood pressure changes), and error grid analysis (to describe the clinical relevance of measurement differences). Results The difference (mean ± SD) between finger cuff and intraarterial measurements was −1 mmHg (± 11 mmHg) for mean arterial pressure, −7 mmHg (± 14 mmHg) for systolic blood pressure, and 0 mmHg (± 11 mmHg) for diastolic blood pressure. Concordance between changes in finger cuff and intraarterial measurements was 88% (mean arterial pressure), 85% (systolic blood pressure), and 81% (diastolic blood pressure). In error grid analysis comparing finger cuff and intraarterial measurements, the proportions of measurements in risk zones A to E were 77.1%, 21.6%, 0.9%, 0.4%, and 0.0% for mean arterial pressure, respectively, and 89.5%, 9.8%, 0.2%, 0.4%, and 0.2%, respectively, for systolic blood pressure. For mean arterial pressure and diastolic blood pressure, absolute agreement and trending agreement between finger cuff and intraarterial measurements were better than between oscillometric (at each of the three measurement sites) and intraarterial measurements. Forearm performed better than upper arm and lower leg monitoring with regard to absolute agreement and trending agreement with intraarterial monitoring. Conclusions The agreement between finger cuff and intraarterial measurements was better than the agreement between oscillometric and intraarterial measurements for mean arterial pressure and diastolic blood pressure in obese patients during surgery. Forearm oscillometry exhibits better measurement performance than upper arm or lower leg oscillometry. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New