Irradiation is a fundamental treatment modality for head and neck malignancies. However, a significant drawback of irradiation treatment is the irreversible damage to salivary glands in the radiation field. Although the protective effect of phenylephrine pretreatment on salivary glands following irradiation has previously been demonstrated, the exact mechanism remains unclear. In this study, we...

BACKGROUND Prevention of hemodynamic instability during cesarean delivery during spinal anesthesia has been the aim of several studies. Noninvasive monitoring has been used in all previous studies. This is the first study in healthy pregnant women with continuous invasive recording of arterial blood pressure, cardiac output, and systemic vascular resistance. The aim of this randomized trial was...

Several techniques have been proposed to prevent hypotension in obstetric patients. Ephedrine and phenylephrine are individually used to prevent maternal hypotension; however, each has its own drawbacks. Some researchers have reported that the infusion of combined ephedrine and phenylephrine immediately after spinal anesthesia for cesarean delivery reduces the incidence of maternal hypotension....

Carvalho, Paula, William H. Thompson, and Nirmal B. Charan. Comparative effects of a-receptor stimulation and nitrergic inhibition on bronchovascular tone. J Appl Physiol 88: 1685–1689, 2000.—Adrenergic agonists are known to influence bronchial blood flow and bronchovascular resistance. Recently, the nitrergic system has also been implicated in the control of bronchovascular tone. In this study...

A constant intravenous infusion of phenylephrine (0.74 +/- 0.41 micrograms/kg/min) was given to 10 patients to cause a continuous augmentation in reflex vagal tone. After the infusion, the diastolic blood pressure increased from 76 +/- 7 to 89 +/- 11 mm Hg (p less than 0.01). The sinus cycle length and atrial-His (AH) interval were measured, and incremental atrial pacing was performed before an...

Mitochondria are dynamic organelles and continuously undergo fission and fusion processes. Mitochondrial fission is involved in multiple physiological or pathological processes, but the role of mitochondrial fission of smooth muscle cells in artery constriction is unknown. The role of mitochondrial fission of smooth muscle cells in arterial function was investigated by measuring the tension of ...

A 76-year-old man presented with fluctuating right-hand clumsiness and mild right-leg weakness. MRI revealed a left anterior cerebral artery (ACA) infarct with perfusion/diffusion mismatch. Gradient echo imaging showed a left ACA clot, and magnetic resonance angiography showed left A2 occlusion (figure, A). The patient’s symptoms recurred the next morning, when mean arterial pressure (MAP) was ...

PURPOSE OF REVIEW Hypotension remains one of the most researched subjects in obstetric anaesthesia. The purpose of this study is to review the most recent published articles on the use of vasopressors during spinal anaesthesia for caesarean section. RECENT FINDINGS Despite continued research indicating advantages of phenylephrine over ephedrine, practitioners in some countries continue to fav...

PURPOSE OF REVIEW Historically, ephedrine has been recommended as the best vasopressor in obstetrics because animal studies showed it caused less reduction in uterine blood flow compared with alpha-agonists. Recent clinical evidence, however, suggests that this is not as important as initially thought. This review evaluates current data with a focus on spinal anesthesia for cesarean section. ...

During development, there are changes in the response of automatic cardiac fibers to a-adrenergic agonists. In neonatal rat ventricle, in vitro phenylephrine (1 X 10~* M) induces an increase in automatic rate from 115 ± 12 (mean ± SEM) to 168 ± 10 beats/min, P < 0.05. In contrast, in adult rat ventricle, the rate decreases from 36 ± 8 to 12 ± 12 beats/min, P < 0.05. At both ages, the response i...