Effects of acetazolamide and furosemide on ventilation and cerebral blood volume in normocapnic and hypercapnic patients with COPD

Study objectives: Effects of chronic metabolic alkalosis and acidosis and their relation to central chemoregulation may differ between normocapnic and chronic hypercapnic patients with COPD. The relationship between responses of inspired ventilation …

New methods for monitoring cerebral oxygenation and hemodynamics in patients with subarachnoid hemorrhage

Radiographic cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) do not reflect cerebral hemodynamics and oxygenation and may occur in the absence of clinical deficit and vice-versa. This report is to describe preliminary findings in further …

Nonuniform quadriceps O2 consumption revealed by near infrared multipoint measurements

Single location muscle monitoring does not reflect the heterogeneous activation of the muscle group(s) during a given exercise. Vastus lateralis and rectus femoris O2 consumption (VO2) was investigated, non-invasively, at rest and during maximal …

Can cerebral blood volume be measured reproducibly with an improved near infrared spectroscopy system?

In some circumstances, cerebral blood volume (CBV) can be used as a measure for cerebral blood flow. A new near infrared spectroscope was used for determining the reproducibility of CBV measurements assessed by the O2-method. Twenty-seven healthy …

Reproducibility of orthostatic changes in cerebral oxygenation in healthy subjects aged 70 years or older

In the elderly, standing can frequently be accompanied by blood pressure (BP) changes and cerebral symptoms such as dizziness, fall, or even syncope, but this may vary from day-to-day. Therefore, we aimed to investigate the reproducibility of …

Systemic circulation and cerebral oxygenation during head-up tilt in spinal cord injured individuals

Objective: To compare tilt-induced alterations in cardiovascular homeostasis and cerebral oxygenation of spinal cord-injured (SCI) to able-bodied (AB) individuals. Design: Subjects underwent 10 min supine rest followed by 10 min 70°head-up tilt. The …

Human motor cortex oxygenation changes induced by cyclic coupled movements of hand and foot

Near-infrared spectroscopy (NIRS) was used to assess human motor-cortex oxygenation changes in response to cyclic coupled movements of hand and foot. Using a highly sensitive NIRS instrument, we showed that it was possible to detect reproducible …

Muscle O2 consumption by NIRS: A theoretical model

In the past, the measurement of O2 consumption (Ȯ2) by the muscle could be carried out noninvasively by near-infrared spectroscopy from oxyhemoglobin and/or deoxyhemoglobin measurements only at rest or during steady isometric contractions. In the …

Reproducibility of the alterations in circulation and cerebral oxygenation from supine rest to head-up tilt

Cardiovascular stability, as affected by several diseases, may be assessed by head-up tilt testing. Follow-up studies are essential in both evaluating interventions and assessing progression. However, data on the reproducibility of the changes in …

Cerebral and circulatory haemodynamics before vasovagal syncope induced by orthostatic stress

Vasovagal syncope is usually described as a sudden and transient loss of consciousness that resolves spontaneously. Cardiocirculatory changes are well described during and before syncope. However, changes in the cerebral oxygenation are not well …

Measurement of the blood supply to the abdominal testis by means of near infrared spectroscopy

Cryptorchidism is the most common male sexual disorder. In the case of an abdominal testis there is no objective criterion to choose between autotransplantation or orchiopexy after ligation of the spermatic vessels with. subsequent development of …