Brimonidine.

Brimonidine is a highly selective 2-adrenoceptor agonist that lowers intraocular pressure (IOP) by decreasing aqueous humor production and increasing aqueous humor outflow via the uveoscleral route. Brimonidine is used to treat glaucoma and other eye conditions. Brimonidine is a topical medication that is used mainly to treat open-angle glaucoma and ocular hypertension in the eyelids. The purpose of this chapter is to provide a comprehensive discussion of Brimonidine's nomenclature, physiochemical properties, preparation methods, identification procedures, and numerous qualitative and quantitative analytical techniques, as well as its ADME profiles and pharmacological effects. In addition, the chapter contains numerous approaches for separating brimonidine from other medications in combination formulations utilizing chromatographic techniques and other spectroscopic approaches.

Systemic toxicity from subcutaneous brimonidine injection successfully treated with naloxone.

Brimonidine is a topical ophthalmic alpha-2 adrenergic agonist solution used to treat glaucoma. The toxidrome includes drowsiness, lethargy, hypotension, bradycardia, and respiratory depression when ingested in infants. We report a case of intentional subcutaneous injection of brimonidine in an elderly patient resulting in hypotension and CNS depression that responded to naloxone. A 73-year-old female with a past medical history significant for glaucoma, hypertension, and indwelling pacemaker presented to the emergency department after injecting her brimonidine tartrate ophthalmic solution subcutaneously (SQ). The patient was not taking any antihypertensive medications or opioids. Initial presentation consisted of lethargy, a paced rhythm of 60 bpm, and blood pressure of 91/24 mmHg with a MAP of 46. Due to central nervous system depression, 3 mg of intranasal naloxone was administered. The patient was treated with intravenous fluids and escalating doses of naloxone and required a continuous infusion. Mental status and vital signs subsequently improved. The patient was admitted to the ICU and naloxone was subsequently weaned over 12 h. Systemic central alpha-2 adrenergic agonist toxicity resulted from SQ brimonidine injection. Central alpha-2 adrenergic agonist overdoses present as sympatholytic effects including CNS depression, bradycardia, hypotension, and may mimic the opioid toxidrome. Brimonidine SQ injection has not previously been reported and this case has similar findings to other central alpha-2 adrenergic agonist poisonings. Naloxone has previously shown variable reversal of CNS depression in central alpha-2 overdose. In this case, high-dose naloxone was useful for reversing CNS depression and hemodynamic instability.

Oral clonidine as a pre-anesthetic medication in hair transplantation surgery-A pilot study.

BACKGROUND: Hair transplantation (HT) is a safe and rewarding procedure for a patient as well as the surgeon. Clonidine may be a good adjuvant in HT because of its analgesic, anxiolytic, and sedative effects. OBJECTIVE: To study efficacy of Clonidine as a preoperative medication in HT. METHODS & MATERIALS: The study was a prospective trial of 46 consecutive patients who underwent HT between January and May 2017. Patients with normal vital parameters on arrival were given Tab clonidine (0.1 mg) 30 min before starting of the procedure [Clonidine group (n = 30)]; rest were included in the control group (n = 16). Vitals were monitored every 30 min during surgery until the end. Patients were assessed for pain, level of sedation during surgery and for postoperative analgesia. RESULT: All patients who received clonidine, except one, were comfortable and experienced no pain throughout the duration of surgery; nine went into deep sleep. Of the 16 patients in the control group, no patients reported deep sleep, 3 felt restless, and 4 had mild pain. There were no untoward effects in both groups. CONCLUSION: Our study suggests that clonidine is useful as a pre-anesthetic medication in HT. However, this is a pilot study and further larger studies are needed.

Successful treatment of the face post acne erythema using a topically applied selective alpha 1-Adrenergic receptor agonist, oxymetazoline 1.5%, a controlled left to right face comparative trial.

BACKGROUND: Post-inflammatory erythema (PIE) is a common sequalae of acne inflammation, persistent post acne erythema (PAE) is cosmetically unacceptable and sometimes its complete clearance could not be achieved. Oxymetazoline (OXZ) is a synthetic, direct-acting, sympathomimetic agonist that is highly selective for the 1α-adrenoceptor. It is a potent vasoconstrictor and well known for its ability to clinically 'get the red out'. AIM: The aim of this study was to evaluate the efficacy and safety of topical oxymetazoline (OXZ) 1.5% in treatment of post acne erythema (PAE) in a left to right face comparative study. METHODS: This study was conducted on 40 patients diagnosed with post acne erythema for at least 3 months, the left side of the face was treated with topical OXZ 1.5% in liposomal base and was compared to the right side to which topical lipogel was applied as a control. RESULTS: According to the investigator's global assessment of photographs and the analysis of erythema with image analysis software, topical OXZ was significantly effective in diminishing PAE when compared to topical placebo lipogel. CONCLUSION: Topical OXZ is a safe and effective treatment for post-acne erythema.

Extracorporeal Membrane Oxygenation for COVID-19-Associated Multisystem Inflammatory Syndrome in a 5-year-old.

Severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) is associated with multisystem inflammatory syndrome in children (MIS-C) that ranges from mild symptoms to cardiopulmonary collapse. A 5-year-old girl presented with shock and a rapid decline in left ventricular function requiring intubation. SARS-CoV-2 was diagnosed by viral Polymerase Chain Reaction (PCR), and she received remdesivir and COVID-19 convalescent plasma. Initial echocardiogram (ECHO) demonstrated low normal left ventricular function and mild left anterior descending coronary artery dilation. She remained hypotensive, despite high-dose epinephrine and norepinephrine infusions as well as stress-dose hydrocortisone. Admission SARS-CoV-2 IgG assay was positive, meeting the criteria for MIS-C. An ECHO 9 hours after admission demonstrated a severe decline in left ventricular function. Due to severe cardiogenic shock, she was cannulated for venoarterial extracorporeal support (ECMO). During her ECMO course, she was treated with remdesivir, intravenous methylprednisolone, intravenous immunoglobulin, and anakinra. She was decannulated on ECMO day 7, extubated the following day, and discharged home 2 weeks later without respiratory or cardiac support. The use of ECMO for cardiopulmonary support for pediatric patients with MIS-C is feasible and should be considered early as part of the treatment algorithm for patients with severe cardiopulmonary dysfunction.

Left ventricular-arterial coupling as a predictor of stroke volume response to norepinephrine in septic shock - a prospective cohort study.

BACKGROUND: Left ventricular-arterial coupling (VAC), defined as the ratio of arterial elastance (Ea) to left ventricular end-systolic elastance (Ees), is a key determinant of cardiovascular performance. This study aims to evaluate whether left VAC can predict stroke volume (SV) response to norepinephrine (NE) in septic shock patients. METHODS: This was a prospective cohort study conducted in an intensive care unit of a tertiary teaching hospital in China. We recruited septic shock patients who had persistent hypotension despite fluid resuscitation and required NE to maintain mean arterial pressure (MAP) > 65 mmHg. Those patients in whom the target MAP was not reached after NE infusion were ineligible. Echocardiographic variables were measured before (baseline) and after NE infusion. SV responder was defined by a ≥ 15% increase in SV after NE infusion. RESULTS: Of 34 septic shock patients included, 19 (56%) were SV responders. Before NE infusion, SV responders had a lower Ees (1.13 ± 0.24 mmHg/mL versus 1.50 ± 0.46 mmHg/mL, P = 0.005) and a higher Ea/Ees ratio (1.47 ± 0.40 versus 1.02 ± 0.30, P = 0.001) than non-responders, and Ea in SV responders was comparable to that in non-responders (1.62 ± 0.36 mmHg/mL versus 1.43 ± 0.28 mmHg/mL, P = 0.092). NE significantly increased Ea and Ees in both groups. The Ea/Ees ratio was normalized by NE administration in SV responders but unchanged in non-responders. The baseline Ea/Ees ratio was positively correlated with NE-induced SV increases (r = 0.688, P < 0.001). Logistic regression analysis indicated that the baseline Ea/Ees ratio was a predictor of SV increases induced by NE (odd ratio 0.008, 95% confidence interval (CI): 0.000 to 0.293), with an area under the receiver operating characteristic curve of 0.816 (95% CI: 0.646 to 0.927). CONCLUSIONS: The left VAC has the ability to predict SV response to NE infusion in septic shock patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900024031, Registered 23 June 2019 - Retrospectively registered, http://www.chictr.org.cn/edit.aspx?pid=40359&htm=4 .

Effects of Polymyxin B Hemoperfusion on Septic Shock Patients Requiring Noradrenaline: Analysis of a Nationwide Administrative Database in Japan.

INTRODUCTION: Polymyxin B hemoperfusion (PMX) reduces endotoxin in septic shock patients' blood and can improve hemodynamics and organ functions. However, its effects on the reduction of septic shock mortality are controversial. METHODS: Using the Japanese diagnosis procedure combination database from April 2016 to March 2019, we identified adult septic shock patients treated with noradrenaline. This study used propensity score matching to compare the outcome between PMX-treated and non-treated patients. The primary endpoint was 28-day mortality, counting from the day of noradrenaline initiation. The secondary endpoints were noradrenaline-, ventilator-, and continuous hemodiafiltration (CHDF)-free days at day 28. RESULTS: Of 30,731 eligible patients, 4,766 received PMX. Propensity score matching produced a matched cohort of 4,141 pairs with well-balanced patient backgrounds. The 28-day survival rate was 77.9% in the PMX group and 71.1% in the control group (p < 0.0001). Median days of noradrenalin-, CHDF-, and ventilator-free days were 2 days (p < 0.0001), 2 days (p < 0.0001), and 6 days (p < 0.0001) longer in the PMX group than in the control group, respectively. When stratified with the maximum daily dose of noradrenaline, the PMX group showed a statistically significant survival benefit in the groups with noradrenaline dose <20 mg/day but not in the noradrenaline group dose ≥20 mg/day. CONCLUSION: Analysis of large Japanese databases showed that septic shock patients who received noradrenaline might benefit from PMX treatment.

Timing of norepinephrine initiation in patients with septic shock: a systematic review and meta-analysis.

BACKGROUND: The effect of the timing of norepinephrine initiation on clinical outcomes in patients with septic shock is uncertain. A systematic review and meta-analysis was performed to evaluate the impact of early and late start of norepinephrine support on clinical outcomes in patients with septic shock. METHODS: We searched the PubMed, Cochrane, and Embase databases for randomized controlled trials (RCTs) and cohort studies from inception to the 1st of March 2020. We included studies involving adult patients (> 18 years) with septic shock. All authors reported our primary outcome of short-term mortality and clearly comparing early versus late norepinephrine initiation with clinically relevant secondary outcomes (ICU length of stay, time to achieved target mean arterial pressure (≥ 65 mmHg), and volume of intravenous fluids within 6 h). Results were expressed as odds ratio (OR) and mean difference (MD) with accompanying 95% confidence interval (CI). RESULTS: Five studies including 929 patients were included. The primary outcome of this meta-analysis showed that the short-term mortality of the early group was lower than that of the late group (odds ratio [OR] = 0.45; 95% CI, 0.34 to 0.61; P < 0.00001; χ2 = 3.74; I2 = 0%). Secondary outcomes demonstrated that the time to achieved target MAP of the early group was shorter than that of the late group (mean difference = - 1.39; 95% CI, - 1.81 to - 0.96; P < 0.00001; χ2 = 1.03; I2 = 0%). The volume of intravenous fluids within 6 h of the early group was less than that of the late group (mean difference = - 0.50; 95% CI, - 0.68 to - 0.32; P < 0.00001; χ2 = 33.76; I2 = 94%). There was no statistically significant difference in the ICU length of stay between the two groups (mean difference = - 0.11; 95% CI, - 1.27 to 1.05; P = 0.86; χ2 = 0.85; I2 = 0%). CONCLUSIONS: Early initiation of norepinephrine in patients with septic shock was associated with decreased short-term mortality, shorter time to achieved target MAP, and less volume of intravenous fluids within 6 h. There was no significant difference in ICU length of stay between early and late groups. Further large-scale RCTs are still required to confirm these results.

Managing Food Allergy in Schools During the COVID-19 Pandemic.

In the wake of the COVID-19 pandemic and massive disruptions to daily life in the spring of 2020, in May 2020, the Centers for Disease Control (CDC) released guidance recommendations for schools regarding how to have students attend while adhering to principles of how to reduce the risk of contracting SARS-CoV-2. As part of physical distancing measures, the CDC is recommending that schools who traditionally have had students eat in a cafeteria or common large space instead have children eat their lunch or other meals in the classroom at already physically distanced desks. This has sparked concern for the safety of food-allergic children attending school, and some question of how the new CDC recommendations can coexist with recommendations in the 2013 CDC Voluntary Guidelines on Managing Food Allergy in Schools as well as accommodations that students may be afforded through disability law that may have previously prohibited eating in the classroom. This expert consensus explores the issues related to evidence-based management of food allergy at school, the issues of managing the health of children attending school that are acutely posed by the constraints of an infectious pandemic, and how to harmonize these needs so that all children can attend school with minimal risk from both an infectious and allergic standpoint.

Current pharmacotherapy for tic disorders.

Introduction: Though many unanswered questions about the pathophysiology of Tourette Syndrome remain, several pharmacotherapies for tics have been studied, with varying results in terms of efficacy and the strength of evidence.Areas covered: This literature review encompasses pharmacotherapies for tics. The pharmacotherapies discussed in this review include: alpha agonists, antipsychotics, topiramate, botulinum toxin, and dopamine depleters.Expert opinion: Once the presence of tics is confirmed and psychoeducation and support are provided to patients and caregivers, one must examine the degree of tic-related impairment and the presence of psychiatric comorbidities. These factors influence treatment decisions as the presence of comorbidity and related impairment may shift the treatment target. When selecting a medication for tics, the presence of ADHD (the most frequent comorbidity) strengthens the case for choosing an alpha agonist. The case for antipsychotic medications is strongest when tic-related impairment is severe and/or the tics are refractory to more conservative measures. All medications require drug safety monitoring procedures and reevaluation over time.

Prescribing trends of glaucoma drugs in six major cities of China from 2013 to 2017.

OBJECTIVE: To evaluate the prescribing trends of glaucoma drugs in six major cities of China from 2013 to 2017. METHODS: A descriptive analysis using pharmacy prescription data was conducted. Outpatient prescription data was extracted from the Hospital Prescription Analysis Cooperative Project. Prescribing patterns, trends of visits, and corresponding expenditures for glaucoma medications were analyzed. RESULTS: A total of 84297 ambulatory prescriptions were included in the current study. Visits by glaucoma patients increased from 13808 in 2013 to 20060 in 2017. Over the same period, the yearly expenditure for glaucoma drugs increased from 2.33 million to 3.95 million Chinese Yuan (CNY). Among all the six classes of glaucoma drugs (prostaglandin analogues, carbonic anhydrase inhibitors, α-receptor agonists, ß-receptor antagonists, cholinergic agonists and fixed combinations), ß-receptor antagonists were the most commonly prescribed in 2013, accounting for 34.3% of patients, but gradually decreased to 27.1% in 2017. Prostaglandin analogues became the most frequently prescribed drugs in 2017, accounting for 30.2% of the visits. Prostaglandin analogues are the most expensive and yielded a total expenditure of 2.34 million CNY in 2017, followed by carbonic anhydrase inhibitors, α-receptor agonists, ß-receptor antagonists, fixed combinations, and cholinergic agonists. Combination therapy became increasingly prescribed in 2017. CONCLUSION: Glaucoma prescribing practices exhibited substantial changes over the study period. The number of glaucoma prescriptions continuously increased from 2013 to 2017, leading to increased prescription costs. These findings implied a similar trend observed in previous studies, as well as recommendations in the appropriate guidelines.

Treatment of Erythematotelangiectatic Rosacea With Pulsed-Dye Laser and Oxymetazoline 1.0% Cream: A Retrospective Study.

BACKGROUND AND OBJECTIVES: Pulsed-dye laser (PDL) and oxymetazoline 1.0% cream are each used for the treatment of erythematotelangiectatic (ET) rosacea. PDL targets oxyhemoglobin and can reduce facial erythema and telangiectasias. Oxymetazoline 1.0% cream is an α adrenergic agonist, which has shown to reduce facial erythema. The aim of this study was to determine the degree of erythema improvement and telangiectasia clearance after combination treatment with PDL plus oxymetazoline 1.0% cream. STUDY DESIGN/MATERIALS AND METHODS: This retrospective study was conducted at two sites. Pre- and post-treatment cross-polarized images from subjects on combination treatment with PDL and oxymetazoline 1.0% cream were graded by a board-certified dermatologist at each practice. Blinded images were analyzed using the Clinical Erythema Assessment (CEA) Scale (0 = clear and 4 = severe). Unblinded images were analyzed using the five-point Telangiectasia Scale to determine the degree of improvement post-treatment compared with baseline (1 = <5% clearance and 5 = 75-100% clearance). RESULTS: Thirty-one subjects (20 females, 11 males) of age 51 ± 13 years (mean ± standard deviation) were included in the study after an average of 4 months (range: 1-13) of daily oxymetazoline 1.0% cream and two (range: 1-4) PDL treatments. At baseline, 87% of subjects had CEA Grade 2 (mild erythema) or higher. For erythema, 55% of subjects improved by at least one CEA grade and 13% achieved two grades of improvement post-treatment. For telangiectasias, 90% of subjects achieved at least a two-point clearance (5-25%), 62% at least a three-point clearance (25-50%), and 41% at least a four-point clearance (50-75%) post-treatment. Compared with subjects with baseline CEA Grade 1-2 (almost clear to mild erythema), significantly more subjects with baseline CEA Grade 3-4 (moderate to severe erythema) achieved at least one CEA grade of improvement (P = 0.021) and two grades of CEA improvement (P = 0.041). A higher percentage of baseline CEA Grade 3-4 subjects achieved at least a two-point clearance in telangiectasias (P = 0.055). CONCLUSIONS: Combination treatment with PDL and daily oxymetazoline 1.0% cream can safely and effectively reduce erythema and telangiectasias. Limitations include the retrospective design of the study, small sample size, and lack of a control group. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Dexmedetomidine infusion overdose during anesthesia: A case report.

A 12-kg infant was given intravenous dexmedetomidine 0.2 µg kg-1  min-1 as an adjunct for general anesthesia. The 60-fold increase in dexmedetomidine infusion rate caused a biphasic response with initial hypertension followed by bradycardia and hypotension requiring inotropic support. No postoperative or long-term sequelae were noted. Dexmedetomidine infusion is usually delivered as µg kg-1  h-1 .

Microvascular Effects of Pulsed Dye Laser in Combination With Oxymetazoline.

BACKGROUND AND OBJECTIVE: Oxymetazoline, an α-1A agonist, is approved by the United States Food and Drug Administration (FDA) for treatment of persistent facial erythema associated with rosacea and induces vasoconstriction by interacting with α receptors. The objective of our study was to study the microvascular effects of oxymetazoline and pulsed dye laser (PDL). MATERIALS AND METHODS: A dorsal window chamber was surgically installed on 20 mice. Each animal was assigned to one of four experimental groups: saline alone, oxymetazoline alone (10 µl applied once daily × 7 days), saline + PDL (saline applied 5 minutes before PDL irradiation [10 mm spot, 1.5 ms pulse duration, 7 J/cm2 delivered to epidermis]), or oxymetazoline + PDL (10 µl oxymetazoline applied 5 minutes before PDL and then once daily × 7 days). Brightfield and laser speckle imaging were performed for 7 days to monitor vascular architectural and functional changes. RESULTS: We observed persistent blood flow in all of the saline-only and oxymetazoline-only experiments. A higher rate of vascular shutdown was observed with oxymetazoline + PDL (66.7%) compared with saline + PDL alone (16.7%). Oxymetazoline application increased venule diameter at 5 minutes post-application and decreased both arteriole and venule diameters at 60 minutes post-application. CONCLUSION: The combination protocol of oxymetazoline + PDL induces persistent vascular shutdown observed 7 days after irradiation. This result may be associated with the acute vascular effects of oxymetazoline. Oxymetazoline + PDL should be evaluated as a treatment for cutaneous vascular disease, including rosacea and port wine birthmarks. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Pharmacological Strategies for Presbyopia Correction.

PURPOSE: To summarize the pharmacological strategies that are being explored for presbyopia correction. METHODS: The review concentrates on pharmacologically induced pupillary miosis to increase depth-of-focus and lens softening or other measures to restore active accommodation. RESULTS: Several studies suggest that near vision improves and distance vision is unaffected for many hours after either monocular or binocular instillation of any one of several drug combinations that cause miosis. Unfortunately, in most studies, measurements were limited to photopic visual acuity for near and distance vision, whereas it is anticipated that pupil constriction may have adverse effects on mesopic and scotopic vision. It is not clear whether improved near vision was due entirely to increased depth-of-focus, or whether, for example, a drug-induced myopic shift in refraction was also involved. Currently, no study has provided direct evidence for drug-induced restoration/enhancement of true accommodation involving an ocular power change. CONCLUSIONS: Although it is possible that, in the future, pharmacological drops may offer a safe and reliable solution for presbyopia correction, more evidence of their effectiveness and limitations is required. [J Refract Surg. 2019;35(12):803-814.].

Early Use of Norepinephrine Improves Survival in Septic Shock: Earlier than Early.

BACKGROUND: The timing of initiation of Norepinephrine (NEP) in septic shock is controversial. AIM OF THE STUDY: We evaluated the impact of early NEP simultaneously with fluids in those patients. METHODS: We randomized 101 patients admitted to the emergency department with septic shock to early NEP simultaneously with IV fluids (early group) or after failed fluids trial (late group). The primary outcome was the in-hospital survival while the secondary outcomes were the time to target mean arterial pressure (MAP) of 65 mmHg, lactate clearance and resuscitation volumes. RESULTS: There was no significant difference between the two groups regarding the baseline characteristics. NEP infusion started after 25 (20-30) and 120 (120-180) min in the early and late groups (p = 0.000). MAP of 65 mmHg was achieved faster in the early group (2 [1-3.5] h vs. 3 [2-4.75] h, p = 0.003). Serum lactate was decreased by 37.8 (24-49%) and 22.2 (3.3-38%) in both groups respectively (p = 0.005). Patients with early NEP were resuscitated by significantly lower volume of fluids (25 [18.8-28.7] mL/kg vs. 32.5 [24.4-34.6] mL/kg) in the early and late groups (p = 0.000). The early group had survival rate of 71.9% compared to 45.5% in the late group (p = 0.007). NEP started after 30 (20-120 min) in survivors vs. 120 (30-165 min) in non-survivors (p = 0.013). CONCLUSIONS: We concluded that early Norepinephrine in septic shock might cause earlier restoration of blood pressure, better lactate clearance and improve in-hospital survival.

Alternatives to Opioid Analgesia in Small Animal Anesthesia: Alpha-2 Agonists.

Alpha-2 agonists have potent analgesic effects, in addition to their sedative actions. Alpha-2 agonists provide analgesia through any of several routes of administration, including parenteral, oral, epidural or intrathecal and intraarticular, because of spinal and supraspinal actions. Systemic doses are short acting, whereas local administration at the site of action result in longer analgesic effects. The potent cardiovascular and respiratory effects of alpha-2 agonists should be considered when used as analgesics.

Dexmedetomidine reduces norepinephrine requirements and preserves renal oxygenation and function in ovine septic acute kidney injury.

Norepinephrine exacerbates renal medullary hypoxia in experimental septic acute kidney injury. Here we examined whether dexmedetomidine, an α2-adrenergic agonist, can restore vasopressor responsiveness, decrease the requirement for norepinephrine and attenuate medullary hypoxia in ovine gram-negative sepsis. Sheep were instrumented with pulmonary and renal artery flow probes, and laser Doppler and oxygen-sensing probes in the renal cortex and medulla. Conscious sheep received an infusion of live Escherichia coli for 30 hours. Eight sheep in each group were randomized to receive norepinephrine, norepinephrine with dexmedetomidine, dexmedetomidine alone or saline vehicle, from 24-30 hours of sepsis. Sepsis significantly reduced the average mean arterial pressure (84 to 67 mmHg), average renal medullary perfusion (1250 to 730 perfusion units), average medullary tissue pO2 (40 to 21 mmHg) and creatinine clearance (2.50 to 0.78 mL/Kg/min). Norepinephrine restored baseline mean arterial pressure (to 83 mmHg) but worsened medullary hypoperfusion (to 330 perfusion units) and medullary hypoxia (to 9 mmHg). Dexmedetomidine (0.5 µg/kg/h) co-administration significantly reduced the norepinephrine dose (0.8 to 0.4 µg/kg/min) required to restore baseline mean arterial pressure, attenuated medullary hypoperfusion (to 606 perfusion units), decreased medullary tissue hypoxia (to 29 mmHg), and progressively increased creatinine clearance (to 1.8 mL/Kg/min). Compared with vehicle time-control, dexmedetomidine given alone significantly prevented the temporal reduction in mean arterial pressure, but had no significant effects on medullary perfusion and oxygenation or creatinine clearance. Thus, in experimental septic acute kidney injury, dexmedetomidine reduced norepinephrine requirements, attenuated its adverse effects on the renal medulla, and maintained renal function.