BACKGROUND The impact of blood sampling in sitting vs supine positions on measurements of plasma metanephrines for diagnosis of pheochromocytoma is unknown. METHODS We compared plasma concentrations of free metanephrines in samples from patients with primary hypertension obtained after supine rest with those obtained in the sitting position without preceding rest. We also assessed the effects...

We examined the effects of postural change on the concentrations of plasma cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, apolipoproteins (apo) A-I and B, and lipoprotein(a) [Lp(a)] in six volunteers who fasted 12 h before blood sampling. Baseline samples were drawn in the standing position; the subjects then assumed the supine or sitting position, and additional blood s...

This study looked at the effects of posture on the morning/evening expiratory flows and airway responsiveness to methacholine. Fourteen nonsmoking subjects with stable asthma (eight men, six women) were included in the study. Subjects were randomly allocated to spend 4 h in the supine or seated position on separate days, in the morning from 8 to 12 AM and in the evening from 8 to 12 PM. The FEV...

In the prone knee-chest position the spread of plain 0.5% bupivacaine in the cerebrospinal fluid and associated haemodynamic changes may be different compared with the horizontal position. A randomized comparison was performed in 40 ASA I-II patients, aged 24-61 yr, undergoing lumbar disc surgery. Subarachnoid injection (27-gauge needle) at the L2-3 interspace with 3 ml of 0.5% bupivacaine was ...

BACKGROUND It is well known that upper airway resistance increases with postural change from a sitting to supine position in patients with obstructive sleep apnoea (OSA). It is not known, however, how the postural change affects the ventilatory and occlusion pressure response to hypercapnia in patients with OSA when awake. METHODS The responses of minute ventilation (VE) and mouth pressure 0....

The relationship between lung volume and regional distribution of ventilation measured by the single breath oxygen test has been found to be similar in the upright and supine positions. When subjects breathe at progressively smaller lung volumes there is an increase in the slope of the alveolar plateau indicative of a redistribution of ventilation to the uppermost parts of the lung. On assuming...

BACKGROUND Early stage breast cancer patients are long-term survivors and finding techniques that may lower acute and late radiotherapy-induced toxicity is crucial. We compared dosimetry of wedged tangential fields (W-TF), tangential field intensity-modulated radiotherapy (TF-IMRT) and multi-beam IMRT (MB-IMRT) in prone and supine positions for whole-breast irradiation (WBI). METHODS MB-IMRT,...

OBJECTIVES Intra-abdominal pressure (IAP) is most commonly measured via the bladder with the patient in the supine position. In the ICU, patients are nursed with the head of the bed elevated at 30° (HOB30) to reduce the risk of ventilator-associated pneumonia. This study investigated whether gastric pressure at HOB30 can be used as a surrogate measure of IAP via the bladder in the supine positi...

It is presently unclear how the fast and slow components of pulmonary oxygen uptake (VO(2)) kinetics would be altered by body posture during heavy exercise [i.e., above the lactate threshold (LT)]. Nine subjects performed transitions from unloaded cycling to work rates representing moderate (below the estimated LT) and heavy exercise (VO(2) equal to 50% of the difference between LT and peak VO(...

OBJECTIVES The accidental puncture of the renal cavities and the performance of anterograde pyelogram by Goodwin in 1955 gave way to the beginning of modern endourology. The possibility to insert thick caliber catheters in the excretory system through the renal parenchyma had led to the current state of percutaneous surgery techniques in the treatment of urinary lithiasis. Percutaneous nephroli...