OBJECTIVETo investigate the effect of phenylephrine (an α-adrenergic agonist) on alveolar fluid clearance (AFC) in ventilator-induced lung injury and the possible mechanism involved.

METHODSA total of 170 male Wistar rats were randomly allocated into 17 groups (n=10) using random number tables. Short-term (40 minutes) mechanical ventilation with high tidal volume (HVT) was performed to induce lung injury, impair active Na+ transport and lung liquid clearance in the rats. Unventilated rats served as controls. To demonstrate the effect of phenylephrine on AFC, phenylephrine at different concentrations (1×10(-5), 1×10(-6), 1×10(-7), 1×10(-8), and 1×10(-9) mol/L) was injected into the alveolar space of the HVT ventilated rats. To identify the influence of adrenergic antagonists, Na(+) channel, and microtubular system on the effect of phenylephrine, phenylephrine at 1×10(-5) mol/L combined with prazosin (an α1-adrenergic antagonist, 1×10(-4) mol/L), yohimbine (an α2-adrenergic antagonist, 1×10(-4) mol/L), atenolol (a β1- adrenergic antagonist, 1×10(-5) mol/L), ICI-118551 (an β2-adrenergic antagonist, 1×10(-5) mol/L), amiloride (a Na+ channel blocker, 5×10(-4) mol/L), ouabain (a Na(+)/K(+)-ATPase blocker, 5×10(-4) mol/L), colchicine (a microtubular disrupting agent, 0.25 mg/100 g body weight), or β-lumicolchicine (an isomer of colchicine, 0.25 mg/100 g body weight) were perfused into the alveolar space of the rats ventilated with HVT for 40 minutes. AFC and total lung water content were measured.

RESULTSBasal AFC in control rats was (17.47±2.56)%/hour, which decreased to (9.64± 1.32)%/hour in HVT ventilated rats (P=0.003). The perfusion of phenylephrine at 1×10(-8), 1×10(-7), 1×10(-6), and 1×10(-5) mol/L significantly increased the AFC in HVT ventilated rats (all P<0.05). This effect of phenylephrine on AFC was suppressed by prazosin, atenolol, and ICI-118551 in HVT ventilated rats by 53%, 31%, and 37%, respectively (all P<0.05). The AFC-stimulating effect of phenylephrine was lowered by 33% and 42% with amiloride and ouabain, respectively (both P<0.05). Colchicine significantly inhibited the effect of phenylephrine (P=0.031).

CONCLUSIONPhenylephrine could increase the AFC in HVT-ventilated rats and accelerate the absorption of pulmonary edema.

Animals ; Male ; Phenylephrine ; therapeutic use ; Pulmonary Alveoli ; metabolism ; Rats ; Rats, Wistar ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Ventilator-Induced Lung Injury ; drug therapy ; metabolism ; pathology

BACKGROUND: Norepinephrine infusion decreases hypotension after spinal anesthesia during cesarean section. This study aimed to compare the efficacy of norepinephrine infusion and ephedrine bolus against post-spinal hypotension in parturients. METHODS: In this double-blinded, randomized controlled clinical trial, parturients scheduled for elective cesarean section were randomly allocated to receive norepinephrine infusion (0.05 μg·kg-1·min-1) just before spinal anesthesia continuing for 30 min or ephedrine bolus (0.15 mg/kg) just before spinal anesthesia. A rescue bolus (5 μg norepinephrine for the norepinephrine group, and 5 mg ephedrine for the ephedrine group) was administered whenever hypotension occurred. Our primary outcome was the incidence of hypotension within 30 min of spinal anesthesia administration. Secondary outcomes included maternal and neonatal outcomes 30 min after spinal block, and neonatal cerebral oxygenation 10 min after birth. RESULTS: In total, 190 patients were enrolled; of these patients, 177 were included in the final analysis. Fewer patients suffered hypotension in the norepinephrine group than in the ephedrine group (29.5% vs. 44.9%, odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.28-0.95, P = 0.034). Moreover, the tachycardia frequency was lower in the norepinephrine group than in the ephedrine group (OR: 0.22, 95% CI: 0.11-0.44, P < 0.001), and patients suffered less nausea and vomiting (OR: 0.28, 95% CI: 0.11-0.70, P = 0.004). There was no difference in Apgar scores and umbilical arterial blood gas analysis between the two groups. However, neonatal cerebral regional saturations were significantly higher after birth in the norepinephrine group than in the ephedrine group (mean difference: 2.0%, 95% CI: 0.55%-3.45%, P = 0.008). CONCLUSION: In patients undergoing elective cesarean section with spinal anesthesia, norepinephrine infusion compared to ephedrine bolus resulted in less hypotension and tachycardia, and exhibited potential neonatal benefits. TRIAL REGISTRATION ClinicalTrials.gov, NCT02542748; https://clinicaltrials.gov/ct2/show/record/NCT02542748.
Anesthesia, Spinal/adverse effects* ; Cesarean Section/adverse effects* ; Double-Blind Method ; Female ; Humans ; Hypotension/prevention & control* ; Infant, Newborn ; Phenylephrine ; Pregnancy ; Randomized Controlled Trials as Topic ; Vasoconstrictor Agents/therapeutic use*

PURPOSE: Although penile duplex Doppler ultrasonography (PDDU) is a common and integral procedure in a Peyronie's disease workup, the intracavernosal injection of vasoactive agents can carry a serious risk of priapism. Risk factors include young age, good baseline erectile function, and no coronary artery disease. In addition, patients with Peyronie's disease undergoing PDDU in an outpatient setting are at increased risk given the inability to predict optimal dosing. The present study was conducted to provide support for a standard protocol of early administration of phenylephrine in patients with a sustained erection after diagnostic intracavernosal injection of vasoactive agents to prevent the deleterious effects of iatrogenic priapism. MATERIALS AND METHODS: This was a retrospective review of Peyronie's disease patients who received phenylephrine reversal after intracavernosal alprostadil (prostaglandin E1) administration to look at the priapism rate. Safety was determined on the basis of adverse events reported by subjects and efficacy was determined on the basis of the rate of priapism following intervention. RESULTS: Patients with Peyronie's disease only had better hemodynamic values on PDDU than did patients with Peyronie's disease and erectile dysfunction. All of the patients receiving prophylactic phenylephrine had complete detumescence of erections without adverse events, including no priapism cases. CONCLUSIONS: The reversal of erections with phenylephrine after intracavernosal injections of alprostadil to prevent iatrogenic priapism can be effective without increased adverse effects.
Alprostadil/adverse effects/diagnostic use ; Drug Evaluation/methods ; Humans ; Male ; Middle Aged ; Penile Erection ; Penile Induration/*ultrasonography ; Phenylephrine/*therapeutic use ; Pilot Projects ; Priapism/chemically induced/*prevention & control ; Retrospective Studies ; Ultrasonography, Doppler, Duplex/adverse effects/methods ; Vasoconstrictor Agents/*therapeutic use ; Vasodilator Agents/adverse effects/diagnostic use

OBJECTIVETo observe the therapeutic effect of glucose-6-phosphate polyclonal antibody (G-6-P pAb) on vasogenic brain edema (VBE) in rats.

METHODSSixty Wistar rats were randomly divided into normal control group, VBE group, mannitol-treated edema group, and G-6-P pAb-treated edema group. After establishment of rat models of VBE by intraperitoneal injection of phenylephrine in the latter 3 groups, mannitol was injected through the femoral vein in mannitol group and G-6-P pAb injected intraperitoneally in G-6-P pAb group. The permeability of the blood-brain barrier (BBB) was determined by Evans blue (EB) extravasation method, and the brain water content in the gray and white matter measured with a moisture analyzer.

RESULTSG-6-P pAb administration significantly reduced the permeability of BBB as well as the water content in the white matter in comparison with mannitol treatment (P<0.01), but the two treatments showed no obvious difference in reducing the water content in the gray matter (P>0.05).

CONCLUSIONChanges in G-6-P activity results in BBB permeability alteration in the condition of VBE, and G-6-P pAb has a selective therapeutic effect against VBE, especially white matter edema.

Animals ; Antibodies, Monoclonal ; immunology ; therapeutic use ; Blood-Brain Barrier ; drug effects ; physiopathology ; Brain Edema ; chemically induced ; drug therapy ; physiopathology ; Capillary Permeability ; drug effects ; Female ; Glucose-6-Phosphate ; immunology ; Male ; Phenylephrine ; Random Allocation ; Rats ; Rats, Wistar