Objectives. To determine the safety and efficacy of three different mydriatic regimens in premature infants referred for retinopathy of prematurity (ROP) screening using (1) multiple alternate instillations of 0.5% cyclopentolate hydrochloride and 2.5% phenylephrine (MAI), (2) single instillation of 0.5%/0.5% tropicamide + phenylephrine (SI) and (3) single instillation of 0.5%/0.5% tropicamide + phenylephrine with a cotton wick placed in the inferior fornix (SIW) in a Philippine tertiary hospital.

Methods. A randomized, double-blind, clinical trial included preterm infants for ROP screening at a Philippine tertiary hospital. After instillations via MAI, SI, and SIW, systolic blood pressure (SBP), diastolic pressure (DBP), mean arterial pressure (MAP), heart rate, and oxygen saturation were monitored. Pupillary dilation was also measured.

Results. Sixty preterm infants, 20 to each intervention, were included. The MAI group did not have significant changes relative to its baseline vital signs. The use of SI produced lower DBP (p<0.0106) and MAP (p<0.0027) compared to MAI. The use of SI produced lower DBP (p<0.01) and MAP (p<0.003) compared to MAI. The SIW group exhibited significant increases in SBP (p<0.002) and in MAP (p<0.04) compared to MAI. This increase in SBP exceeded the clinical normal values for <37 weeks old infants. Pupillary dilation did not have significant differences among groups (p=0.24).

Conclusion. Due to significant increase in SBP, it is recommended to discontinue SIW in preterm infants for ROP screening since it may promote the mydriatic's systemic absorption. Except for the clinically increased heart rate in infants aged ?37 weeks at examination, SI was found to be at par with the recommendation of the UK ROP Guidelines of May 2008.

Objective: To determine the characteristics and progress of the visual acuity and refractive state of schoolchildren in Huangzhong District, Xining City, Qinghai Province in China. Methods: Cohort study. Department of Ophthalmology, Beijing Children's Hospital carried out a cohort study by collecting the visual acuity and refractive state of Grade 1-5 schoolchildren among 16 primary schools in Huangzhong District, Xining City, Qinghai Province in September 2020 and July 2021. Cycloplegic retinoscopy with eye drop which contained tropicamide (0.5%) and phenylephrine hydrochloride (0.5%) was performed in children with low vision(<1.0). Myopia was defined as the spherical equivalent (SE) ≤-0.5 D after cycloplegic retinoscopy. Measurement data was analyzed by t-test and enumeration data was analyzed by χ² test. Multiple linear regression was used to analyze the influencing factors. Results: The 2 489 individuals with repeated tests in two years were included in the follow-up study, among whom the prevalence of myopia was 26.24%(653/2 489) in 2020, while 32.94% (820/2 489)respectively in 2021. The incidence of myopia in one school year from grades 1 to 5 was 11.19%(47/420), 5.44%(21/386), 6.39%(25/391), 11.52%(44/382) and 11.67%(30/257). The average SE of children in all grades in 2021 increased negatively from the previous year (Grade 1 to Grade 5 increased respectively: 0.40 D, 0.69 D, 0.62 D, 0.52 D and 0.37 D). Conclusions: The prevalence of myopia among schoolchildren in Huangzhong District, Xining City, Qinghai Province was relatively high. There were two peaks of myopia incidence in the first, fourth and fifth grades. Female, age, and the baseline of SE were the related influencing factors for myopia progression.
Child ; Cohort Studies ; Female ; Follow-Up Studies ; Humans ; Mydriatics ; Myopia/epidemiology* ; Ophthalmic Solutions ; Phenylephrine ; Prevalence ; Prospective Studies ; Tropicamide

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*

Free fatty acid (FFA) intake regulates blood pressure and vascular reactivity but its direct effect on contractility of systemic arteries is not well understood. We investigated the effects of saturated fatty acid (SFA, palmitic acid), polyunsaturated fatty acid (PUFA, linoleic acid), and monounsaturated fatty acid (MUFA, oleic acid) on the contractility of isolated mesenteric (MA) and deep femoral arteries (DFA) of Sprague–Dawley rats. Isolated MA and DFA were mounted on a dual wire myograph and phenylephrine (PhE, 1–10 µM) concentration-dependent contraction was obtained with or without FFAs. Incubation with 100 µM of palmitic acid significantly increased PhE-induced contraction in both arteries. In MA, treatment with 100 µM of linoleic acid decreased 1 µM PhE-induced contraction while increasing the response to higher PhE concentrations. In DFA, linoleic acid slightly decreased PhE-induced contraction while 200 µM oleic acid significantly decreased it. In MA, oleic acid reduced contraction at low PhE concentration (1 and 2 µM) while increasing it at 10 µM PhE. Perplexingly, depolarization by 40 mM KCl-induced contraction of MA was commonly enhanced by the three fatty acids. The 40 mM KCl-contraction of DFA was also augmented by linoleic and oleic acids while not affected by palmitic acid. SFA persistently increased alpha-adrenergic contraction of systemic arteries whereas PUFA and MUFA attenuated PhE-induced contraction of skeletal arteries. PUFA and MUFA concentration-dependent dual effects on MA suggest differential mechanisms depending on the types of arteries. Further studies are needed to elucidate underlying mechanisms of the various effects of FFA on systemic arteries.
Animals ; Arteries ; Blood Pressure ; Fatty Acids ; Fatty Acids, Unsaturated ; Femoral Artery ; Linoleic Acid ; Mesenteric Arteries ; Oleic Acid ; Oleic Acids ; Palmitic Acid ; Phenylephrine ; Rats ; Receptors, Adrenergic, alpha ; Vasoconstriction

BACKGROUND: New complications associated with sugammadex have been increased since its widespread use. We report a case of an 80-year-old male who experienced profound bradycardia and sustained hypotension after administration of sugammadex. CASE: Following administration of 200 mg sugammadex after laparoscopic cholecystectomy, sudden bradycardia (29 beats/min) developed for 10 seconds and his train-of-four (TOF) ratio remained at 0.2 for 5 min. An additional 200 mg sugammadex was administered and profound bradycardia (21–30 beats/min) and hypotension (60/40 mmHg) developed. Atropine at 0.5 mg was administered, but the effect lasted only 30 s. Profound bradycardia occurred four more times at 30 s intervals, and ephedrine and phenylephrine were injected intermittently to increase the patient's heart rate and blood pressure. The TOF ratio became 0.9 about 10 min after administration of additional sugammadex. CONCLUSIONS: Awareness must be heightened regarding the possibility of sugammadexinduced bradycardia and hypotension, and more attention should be paid to patients with slow recovery times following muscle relaxation, despite the use of sugammadex.
Aged, 80 and over ; Atropine ; Blood Pressure ; Bradycardia ; Cholecystectomy, Laparoscopic ; Ephedrine ; Heart Rate ; Humans ; Hypotension ; Male ; Muscle Relaxation ; Neuromuscular Blockade ; Phenylephrine ; Postoperative Complications

BACKGROUND: Aortocaval compression by the gravid uterus is a known physiological phenomenon that is classically claimed to cause supine hypotension in full-term pregnant women. This study aimed to investigate the effects of fetal position on maternal hemodynamics after spinal anesthesia during cesarean delivery. METHODS: In total, 71 women with intrauterine pregnancy over 36 weeks of gestation who were scheduled for elective cesarean delivery under spinal anesthesia were enrolled in the study. Based on the fetal position, the women were divided into two groups: right position group (group R) and left position group (group L). Occurrence of hypotension, requirement for rescue bolus injections of phenylephrine, and the total amount of infused phenylephrine before delivery were recorded in each group. RESULTS: There was no statistically significant difference in the occurrence of hypotension between the two groups (P = 0.075); however, the amount of phenylephrine required before delivery was significantly greater in group R (P = 0.028). There was a statistically significant decrease in the systolic blood pressure compared with the baseline values in group R, and this change persisted until 15 min after spinal anesthesia. CONCLUSIONS: There was no difference according to fetal position in the number of patients who showed hypotension before delivery after spinal anesthesia.
Anesthesia, Spinal ; Blood Pressure ; Cesarean Section ; Female ; Hemodynamics ; Humans ; Hypotension ; Phenylephrine ; Physiological Phenomena ; Pregnancy ; Pregnant Women ; Uterus

BACKGROUND: Maternal hypotension is a common complication during obstetric spinal anesthesia. This study was conducted to investigate the role of autonomic function testing in predicting maternal hypotension during spinal anesthesia induced to conduct Cesarean sections (C-section). METHODS: This study was conducted on 32 parturients undergoing C-section under spinal anesthesia. Sympathetic function tests included measuring diastolic blood pressure changes in response to hand gripping and systolic blood pressure changes response to moving from a supine to a standing position. Sympathetic dysfunction is said to exist when there are abnormal responses to both sympathetic function tests. Parasympathetic function tests included measuring heart rate responses to deep breathing and heart rate responses to moving from a supine to a standing position. Parasympathetic dysfunction is said to exist when there are abnormal responses to both parasympathetic function tests. After the onset of spinal anesthesia, blood pressure was measured every minute until childbirth. RESULTS: Hypotension occurred in 22 of the 32 parturients. There was no correlation between sympathetic dysfunction and hypotension incidence, but 12 of the 12 (100%) of the positive group and 10 of the 20 (50%) of the negative group experiencing parasympathetic dysfunction, respectively, experienced hypotension with a significant difference of P = 0.004. The group experiencing parasympathetic dysfunction had statistically significantly higher phenylephrine requirements were also greater in the parasympathetic dysfunction positive group (P < 0.003). CONCLUSIONS: This study's findings suggested that the parasympathetic function tests may be useful methods for predicting the incidence of maternal hypotension during spinal anesthesia induced for C-section.
Anesthesia, Spinal ; Autonomic Nervous System ; Blood Pressure ; Cesarean Section ; Female ; Hand ; Hand Strength ; Heart Rate ; Humans ; Hypotension ; Incidence ; Parasympathetic Nervous System ; Parturition ; Phenylephrine ; Pilot Projects ; Posture ; Pregnancy ; Respiration ; Sympathetic Nervous System

BACKGROUND: Vasoplegic syndrome is an increasingly recognized disease in perioperative medicine and is characterized by severe hypotension, normal or elevated cardiac output, and decreased systemic vascular resistance. It occurs commonly after cardiopulmonary bypass but may also occur after other types of surgery.CASE: Vasoplegic syndrome developed in our patient during posterior lumbar interbody fusion because of administering nicardipine after phenylephrine. However, the blood pressure did not increase as expected despite simultaneous use of norepinephrine and vasopressin to increase the reduced systemic vascular resistance.CONCLUSIONS: We present a case of vasoplegic syndrome that developed during posterior lumbar interbody fusion and was treated successfully with methylene blue.
Blood Pressure ; Cardiac Output ; Cardiopulmonary Bypass ; Humans ; Hypotension ; Methylene Blue ; Nicardipine ; Norepinephrine ; Phenylephrine ; Vascular Resistance ; Vasoplegia ; Vasopressins

BACKGROUND: Hydroxyethyl starch (HES), a class of synthetic colloid solutions, has been widely used to treat perioperative hypovolemia. The use of HES, however, is associated with the risk of allergic reactions.CASE: An 83-year-old man was scheduled to undergo an open reduction and internal fixation of a pertrochanteric fracture under spinal anesthesia. He had no history of allergy. Five minutes after HES administration, hypotension, agitation, and skin rash were developed. HES infusion was terminated due to a suspected anaphylactic reaction. The vital signs recovered following administration of phenylephrine, dexamethasone, and hydrocortisone. Serum tryptase and total immunoglobulin E levels were elevated in plasma samples collected following the commencement of the allergic reaction during surgery.CONCLUSIONS: In the present report, the risk of anaphylactic reaction with HES and the laboratory tests needed to support the diagnosis are highlighted.
Aged, 80 and over ; Anaphylaxis ; Anesthesia ; Anesthesia, Spinal ; Colloids ; Dexamethasone ; Diagnosis ; Dihydroergotamine ; Exanthema ; Humans ; Hydrocortisone ; Hypersensitivity ; Hypotension ; Hypovolemia ; Immunoglobulin E ; Immunoglobulins ; Phenylephrine ; Plasma ; Starch ; Tryptases ; Vital Signs

PURPOSE: The urinary bladder (UB) is innervated by both sensory and autonomic nerves. Recent studies have shown that sensory neuropeptides induced contractions in the detrusor muscle. Therefore, in a mouse model, we investigated the presence of interactions between the submucosal sensory nerves and the autonomic nerves that regulate the motor function of the detrusor muscle. METHODS: UB samples from male C57BL/6 mice were isolated, cut into strips, and mounted in an organ bath. Dose-response curves to norepinephrine and phenylephrine were studied in UB strips with and without mucosa, and the effects of preincubation with a receptor antagonist and various drugs on relaxation were also studied using tissue bath myography. RESULTS: Phenylephrine-induced relaxation of the UB strips showed concentration-related effects. This relaxation appeared in both mucosa-intact and mucosa-denuded UB strips, and was significantly inhibited by lidocaine, silodosin, and guanethidine (an adrenergic neuronal blocker). Meanwhile, phenylephrine-induced relaxation was inhibited by pretreatment with propranolol and calcitonin gene-related peptide (CGRP)–depletory capsaicin in UB strips with and without mucosa. CONCLUSIONS: The present study suggests that phenylephrine activates the α-1A adrenergic receptor (AR) of the sensory nerve, and then activates capsaicin-sensitive sensory nerves to release an unknown substance that facilitates the release of norepinephrine from adrenergic nerves. Subsequently, norepinephrine stimulates β-ARs in the detrusor muscle in mice, leading to neurogenic relaxation of the UB. Further animal and human studies are required to prove this concept and to validate its clinical usefulness.
Adrenergic Neurons ; Animals ; Autonomic Pathways ; Baths ; Calcitonin Gene-Related Peptide ; Capsaicin ; Guanethidine ; Humans ; Lidocaine ; Male ; Mice ; Mucous Membrane ; Myography ; Neuropeptides ; Norepinephrine ; Phenylephrine ; Propranolol ; Receptors, Adrenergic ; Receptors, Adrenergic, alpha-1 ; Relaxation ; Urinary Bladder*