Continuous Infusion Of Epinephrine Research Articles

Abstract 211: Epinephrine Does Not Correct Post-ROSC Hypoperfusion Despite Normalizing Blood Pressure A Rat Model Of Severe Pediatric Asphyxial Cardiac Arrest

In children resuscitated from cardiac arrest, systemic hypotension occurs frequently and is associated with worse outcome. The first-line vasoactive treatment for post-arrest hypotension is continuous infusion of epinephrine. Epinephrine dose is titrated to maintain normal blood pressure for age. Epinephrine, however, also leads to vasoconstriction which may impair organ perfusion after resuscitation.We hypothesized that epinephrine infusion during the post-resuscitation period restores systemic blood pressure but not flow to vital organs. Using a model of severe pediatric asphyxial cardiac arrest in developing rats, we simultaneously measured blood pressure (ABP) and flow in carotid (Fc) and femoral (Ff) arteries after resuscitation. We then compared the effects of epinephrine or saline infusions on blood pressure vs flow. One hour after resuscitation from 11.5 minutes of asphyxial arrest, ABP, Fc and Ff were 61.73 ± 2.68; 42.58 ± 3.84; and 19.53 ± 7.00 % of baseline. Epinephrine infusion increased ABP in a dose-dependent manner, reaching 95.13 ± 7.93 % of baseline at 0.5 μg/kg/min. Saline infusion at equivalent volumes increased ABP only marginally to 69.88 ± 2.60 % of baseline. In contrast to its effect on ABP, epinephrine infusion increased Fc only to 49.55 ± 6.49 and Ff to 53.28 ± 7.13 % of baseline. Saline infusion at equivalent volumes, on the other hand, had a more salutary effect than epinephrine on improving blood flow (Fc 64.62 ± 6.64 and Ff 60.25 ± 7.60 % of baseline). Notably, a single 10 cc/kg saline bolus, administered when ABP decreased to ~80% of baseline post-ROSC, increased blood flow and ABP to 100% and 90% of baseline, respectively. These data indicate that epinephrine infusion in the post-arrest period adversely affects arterial blood flow despite normalizing arterial blood pressure. Continued fluid resuscitation with crystalloids potentially has beneficial effect on correcting post-ROSC hypoperfusion. Future studies need to explore the impact of targeting flow rather than blood pressure in the post-arrest period and its association to post-arrest end-organ function in children.

Abstract 15332: Post-Resuscitation Epinephrine Infusion Restores Blood Pressure but Not Blood Flow in a Rat Model of Severe Pediatric Cardiac Arrest

Introduction: In children resuscitated from cardiac arrest (CA), post-arrest hypotension occurs often and worsens outcomes. Continuous infusion of epinephrine (Epi) is the 1st-line treatment for post-arrest hypotension but may worsen organ perfusion due to vasoconstriction. Hypothesis: Epi infusion after resuscitation from pediatric asphyxial CA restores blood pressure but not organ perfusion. Methods: Immature rats (PND18-22, n=34) underwent 11.5 minutes of asphyxial CA followed by resuscitation. Rats with hypotension (mean arterial pressure (MAP)<80% baseline) after resuscitation received infusions of either 0.9% NaCl (NS) or Epinephrine (Epi). MAP, carotid and femoral arterial blood flows (Fc, Ff) and renal oxygen tension (PrO2) were recorded. Results: One hour after resuscitation, MAP, Fc and Ff were 61.73 ± 2.68; 42.58 ± 3.84; and 19.53 ± 7.00 % of baseline, respectively. Epi infusion increased MAP in a dose-dependent manner, reaching 95.13 ± 7.93 % of baseline at 0.5 μg/kg/min. In contrast, Epi infusion up to 0.5 μg/kg/min increased Fc only to 49.55 ± 6.49 and Ff to 53.28 ± 7.13 % of baseline. NS infusion at equivalent volume had a more salutary effect than Epi on improving blood flow (Fc 64.62 ± 6.64 and Ff 60.25 ± 7.60 % of baseline). PrO2 reached 100% of baseline with Epi infusion and inspired O2 fraction (FiO2) = 1. However, at FiO2 = 0.21, Epi failed to restore PrO2 which reached 42% of baseline. Interestingly, a single 10 cc/kg NS bolus increased PrO2 to 100% of baseline at all FiO2 tested. Conclusions: In this rat model of severe pediatric asphyxial CA and resuscitation, post-resuscitation Epi infusion failed to restore carotid and femoral arterial blood flow despite normalizing blood pressure. Furthermore, Epi infusion restored neither renal perfusion nor oxygenation. In contrast, infusion of NS at comparable volumes was more effective than Epi at normalizing carotid and femoral blood flows as well as renal oxygenation. If validated in a large animal model, these results may indicate that Epi infusion after CA resuscitation contributes to organ injury and morbidity in children.

Nearly Fatal Hydroxychloroquine Overdose Successfully Treated with Midazolam, Propofol, Sodium Bicarbonate, Norepinephrine, and Intravenous Lipid Emulsion

Background In the context of the current COVID-19 pandemic, there has been renewed interest in the drug hydroxychloroquine. However, clinicians should be aware of the dangers of hydroxychloroquine intoxication, an insufficiently studied condition. Case Report. We present a case of autointoxication with 20 g hydroxychloroquine in a 35-year-old woman. Cardiac monitoring showed ventricular arrhythmias for which high-dose midazolam and propofol were initiated, resulting in a brief normalization of the cardiac rhythm. Because of the reoccurrence of these arrhythmias, intravenous lipid emulsion was administered with fast cardiac stabilization. Treatment with continuous norepinephrine, potassium chloride/phosphate, and sodium bicarbonate was initiated. On day 6, she was extubated and after 11 days, she was discharged from the hospital without complications. Conclusion Since high-quality scientific evidence is lacking, treatment options are based on experience in chloroquine toxicity. Activated charcoal is advised if the patient presents early. Sedation with diazepam, early ventilation, and continuous epinephrine infusion are considered effective in treating severe intoxication. Caution is advised when substituting potassium. Despite the lack of formal evidence, sodium bicarbonate appears to be useful and safe in case of QRS widening. Intravenous lipid emulsion, with or without hemodialysis, remains controversial but appears to be safe. As a last resort, extracorporeal life support might be considered in case of persisting hemodynamic instability.

Comparison of Continuous Infusion of Epinephrine and Phenylephrine on Hemodynamics During Spinal Anesthesia for Cesarean Delivery: A Randomized Controlled Trial

PurposePhenylephrine is a commonly used vasopressor for the treatment of spinal-induced hypotension in obstetric patients, but it is associated with reflex bradycardia and a corresponding decrease in cardiac output. This study aims to assess the effectiveness of continuous epinephrine versus phenylephrine infusion in the prevention of postspinal maternal hypotension. MethodsEighty-two women undergoing cesarean delivery were randomly divided into the epinephrine group (group E) and the phenylephrine group (group P). The patients received a continuous infusion of phenylephrine 1 μg kg−1 min−1 or epinephrine 0.1 μg kg−1 min−1 synchronously with intrathecal administration. Hemodynamic parameters were recorded, and umbilical cord blood gases were analyzed after delivery. The incidence of maternal hypotension, bradycardia, nausea, and vomiting was recorded. FindingsBlood pressure, heart rate, and cardiac output after spinal anesthesia induction were greater in group E than in group P (P < 0.05). In addition, there was a significant difference in the incidence of bradycardia (5% vs 22.5%, P = 0.02) and mean (SD) umbilical artery pH (7.31 [0.07] vs 7.28 [0.06], P = 0.04) between the groups. ImplicationsWith the dose of 0.1 μg kg−1 min−1, infusion of epinephrine is more effective at maintaining blood pressure close to baseline during spinal anesthesia with a lower decrease in maternal heart rate and cardiac output compared with phenylephrine. Epinephrine may be superior to phenylephrine in terms of the incidence of bradycardia and umbilical artery pH. chictr.org.cn identifier: ChiCTR-IIC-17010960.

Flow irregularities from syringe infusion pumps caused by syringe stiction.

The current study aimed to evaluate the extent of the slide-stick phenomenon in differently designed infusion syringes at various infusion rates and filling positions. Fluid delivery from three 50-mL infusion syringe brands (BD; Codan; Fresenius) was investigated using a flow sensor at flow rates of 0.5, 1.0, or 5.0mLh-1 , with the syringes filled with either 10, 30, or 50mL of distilled water. Two identical models (A/B) of the same infusion pump model were used. The effect of flow rate variations on the plasma concentration of a continuous epinephrine infusion in a 3kg neonate receiving a continuous infusion of 0.1μgkgmin-1 epinephrine was studied using a pharmacokinetic simulation model. Considerable variations in calculated plasma epinephrine concentration were detected between flow rates of 5 and 0.5 or 1mLh-1 for all syringe types and filling volumes. The median deviation of plasma concentration for the 5mLh-1 flow rate varied depending on assembly from 1.3% (Codan) to 1.8% (Fresenius). This was more pronounced for lower flow rates, where at 1mLh-1 the deviation varied from 3.3% (BD) to 4.8% (Fresenius) and at 0.5mLh-1 from 4.9% (BD) to 5.4% (Fresenius). Differences between filling volumes (within syringe type and flow rate) did not appear to have relevant influence on variations in calculated plasma epinephrine concentration. Infusion set rate rather than syringe brand or filling volume was a major predictor for syringe stiction-related amount of variation in the calculated plasma epinephrine concentration.

Effect of Continuous Epinephrine Infusion on Survival in Critically Ill Patients: A Meta-Analysis of Randomized Trials.

Epinephrine is frequently used as an inotropic and vasopressor agent in critically ill patients requiring hemodynamic support. Data from observational trials suggested that epinephrine use is associated with a worse outcome as compared with other adrenergic and nonadrenergic vasoactive drugs. We performed a systematic review and meta-analysis of randomized controlled trials to investigate the effect of epinephrine administration on outcome of critically ill patients. PubMed, EMBASE, and Cochrane central register were searched by two independent investigators up to March 2019. Inclusion criteria were: administration of epinephrine as IV continuous infusion, patients admitted to an ICU or undergoing major surgery, and randomized controlled trials. Studies on epinephrine administration as bolus (e.g., during cardiopulmonary resuscitation), were excluded. The primary outcome was mortality at the longest follow-up available. Two independent investigators examined and extracted data from eligible trials. A total of 5,249 studies were assessed, with a total of 12 studies (1,227 patients) finally included in the meta-analysis. The majority of the trials were performed in the setting of septic shock, and the most frequent comparator was a combination of norepinephrine plus dobutamine. We found no difference in all-cause mortality at the longest follow-up available (197/579 [34.0%] in the epinephrine group vs 219/648 [33.8%] in the control group; risk ratio = 0.95; 95% CI, 0.82-1.10; p = 0.49; I = 0%). No differences in the need for renal replacement therapy, occurrence rate of myocardial ischemia, occurrence rate of arrhythmias, and length of ICU stay were observed. Current randomized evidence showed that continuous IV administration of epinephrine as inotropic/vasopressor agent is not associated with a worse outcome in critically ill patients.

Performance of modern syringe infusion pump assemblies at low infusion rates in the perioperative setting

BackgroundSyringe infusion pumps are used for the precise continuous administration of intravenous drugs. Their compliance and mechanical deficiencies have been found to cause considerable start-up delays, flow irregularities during vertical displacement, as well extensive delays of occlusion alarms at low infusion rates. The aim of this study was to evaluate the performance of several modern syringe infusion pumps at low infusion rates and the impact on drug concentration. MethodsSeven currently marketed syringe infusion pump assemblies were assessed in an in vitro study during start-up, vertical displacement manoeuvres, and infusion line occlusion at a set flow rate of 1 ml h−1. The measured data were used as input for a pharmacokinetic simulation modelling plasma concentration during a standard neonatal continuous epinephrine infusion. ResultsThe mean time from starting the infusion pump to steady-state flow varied from 89 to 1622 s. The zero-drug delivery time after lowering the pump ranged from 145 to 335 s. In all assemblies tested, occlusion alarm delays and measured flow irregularities during vertical displacement manoeuvres resulted in relevant deviations in plasma epinephrine concentration (>25%) as calculated by the pharmacokinetic simulation model. ConclusionProblems with the performance of syringe infusion pump assemblies can have considerable impact on plasma drug concentration when highly concentrated short-acting cardiovascular drugs are administered at low flow rates. The problems, which affected all assemblies tested, are mainly related to the functional principle of syringe infusion pumps and will only partially be solved by incremental improvements of existing equipment.

Study of the Effects of Epinephrine on Cerebral Oxygenation and Metabolism During Cardiac Arrest and Resuscitation by Hyperspectral Near-Infrared Spectroscopy.

Epinephrine is routinely administered to sudden cardiac arrest patients during resuscitation, but the neurologic effects on patients treated with epinephrine are not well understood. This study aims to assess the cerebral oxygenation and metabolism during ventricular fibrillation cardiac arrest, cardiopulmonary resuscitation, and epinephrine administration. To investigate the effects of equal dosages of IV epinephrine administrated following sudden cardiac arrest as a continuous infusion or successive boluses during cardiopulmonary resuscitation, we monitored cerebral oxygenation and metabolism using hyperspectral near-infrared spectroscopy. A randomized laboratory animal study. Nine healthy pigs. None. Our study showed that although continuous epinephrine administration had no significant impact on overall cerebral hemodynamics, epinephrine boluses transiently improved cerebral oxygenation (oxygenated hemoglobin) and metabolism (cytochrome c oxidase) by 15% ± 6.7% and 49% ± 18%, respectively (p < 0.05) compared with the baseline (untreated) ventricular fibrillation. Our results suggest that the effects of epinephrine diminish with successive boluses as the impact of the third bolus on brain oxygen metabolism was 24.6% ± 3.8% less than that of the first two boluses. Epinephrine administration by bolus resulted in transient improvements in cerebral oxygenation and metabolism, whereas continuous epinephrine infusion did not, compared with placebo. Future studies are needed to evaluate and optimize the use of epinephrine in cardiac arrest resuscitation, particularly the dose, timing, and mode of administration.

Abstract 359: Use of Resuscitative Balloon Occlusion of the Aorta in a Swine Model of Prolonged Cardiac Arrest

Introduction: Despite advancements in CPR, survival to hospital discharge remains low for in- and out-of-hospital cardiac arrest (CA). Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is an evolving tool for temporary control of non-compressible truncal hemorrhage. In this investigation, we examined whether REBOA use during non-traumatic CA would produce favorable hemodynamic changes associated with return of spontaneous circulation (ROSC). Hypothesis: We hypothesized that REBOA use during CPR would result in higher coronary perfusion pressure (CPP) and common carotid artery blood flow (C-Flow) in a prolonged model of CA. Methods: Six male swine were anesthetized and instrumented to measure and monitor CPP, and C-Flow. A REBOA catheter (Prytime Medical Devices) was advanced into zone 1 of the aorta through the femoral artery. Ventricular fibrillation was electrically induced and untreated for 8 minutes. CPR was started manually at minute-8, then changed to mechanical CPR at minute-12 for the duration of the experiment. Continuous infusion of epinephrine (0.0024mg/kg/min) was simultaneously started with mechanical CPR. The REBOA balloon was inflated beginning at minute-16 for 3 minutes then deflated for 3 minutes for a total of 6 cycles. At the end of the final cycle (REBOA inflation), CPR was stopped (after 33 minutes of total arrest time) and animals were defibrillated using 200 J biphasic shocks, repeated up to 6 times. Animals achieving ROSC were monitored for an additional 25 minutes. Results: Analysis using repeated measure ANOVA showed significant differences between balloon deflation and inflation periods for CPP (p&lt;0.0001) with mean difference(SD) of 14(2.6) (Range: 17 to 42) mmHg and for C-Flow (p&lt;0.0001) with mean difference(SD) 16(23) (Range: 115 to 269) mL/min across all animals. Three animals achieved ROSC and had significantly higher CPP (48 vs. 24mmHg, p&lt;0.0001) and C-Flow (249 vs. 168mL/min) by t-test (p&lt;0.0001). Post-mortem aortic histology did not reveal any changes produced by balloon inflation. Conclusion: REBOA significantly increased CPP and C-Flow in this swine model of prolonged CA. These increases may have contributed to the ability to achieve ROSC after greater than 30 min of CA.

Epinephrine induced cardiomyopathy in a child with anaphylaxis

Transient cardiomyopathy is an uncommon occurrence in patients with anaphylaxis. Catecholamine induced direct toxicity is one of the proposed mechanisms. We report a case of cardiomyopathy in a child with anaphylaxis who was treated with multiple doses of epinephrine as well as a continuous infusion of epinephrine. A twenty one month old girl with egg allergy presented to our hospital with anaphylaxis, after multiple doses of epinephrine injections, developed cardiorespiratory dysfunction and required endotracheal intubation and mechanical ventilation. Work up showed depressed cardiac function, which improved with milrinone and furosemide infusions. Conclusion: Epinephrine is the treatment of choice for anaphylaxis however caution should be exercised when administering multiple doses of epinephrine. Myocardial function needs to be assessed in children with persistent hypotension after anaphylaxis and catecholamine-induced cardiomyopathy should be considered in children with anaphylaxis when severe myocardial dysfunction is present.

Severe Hypotension, Hypoxia, and Subcutaneous Erythema Induced by Indigo Carmine Administration during Open Prostatectomy.

Indigo carmine (also known as 5,5′-indigodisulfonic acid sodium salt or indigotine) is a blue dye that is administered intravenously to examine the urinary tract and usually is biologically safe and inert. Indigo carmine rarely may cause adverse reactions. We treated a 66-year-old man who had general anesthesia and radical retropubic prostatectomy for prostate cancer. He had a previous history of allergy to bee sting with nausea, vomiting, and dizziness. Within 1 minute after injection of indigo carmine for evaluation of the ureters, the patient developed hypotension to 40 mmHg, severe hypoxia (the value of SpO2 (peripheral capillary oxygen saturation) was 75% on 40% inspired oxygen concentration), poor air movement and bilateral diffuse wheezing on auscultation, and marked subcutaneous erythema at the upper extremities. After treatment with 100% oxygen, epinephrine (total, 1.5 mg), hydrocortisone (100 mg), diphenhydramine (50 mg), albuterol nebulizer (0.083%), and continuous infusion of epinephrine (0.15 μg/kg/min), the vital signs became stable, and he recovered completely. In summary, indigo carmine rarely may cause life-threatening anaphylactic or anaphylactoid reaction that may necessitate rapid treatment to stabilize cardiovascular, hemodynamic, and pulmonary function.

Anaphylaxis

BackgroundAnaphylaxis is the quintessential critical illness in emergency medicine. Symptoms are rapid in onset and death can occur within minutes. Approximately 1500 patients die annually in the United States from this deadly disorder. It is imperative, therefore, that emergency care providers be able to diagnose and appropriately treat patients with anaphylaxis. Any delays in recognition or initiation of therapy can result in unnecessary increases in patient morbidity and mortality. DiscussionRecent literature, including updated international anaphylaxis guidelines, has improved our understanding and management of this critical illness. Anaphylaxis is a multisystem disorder that can manifest signs and symptoms related to the cutaneous, respiratory, cardiovascular, and gastrointestinal systems. Epinephrine remains the drug of choice and should initially be administered intramuscularly, into the anterolateral thigh, as soon as the diagnosis is suspected. For patients unresponsive to repeated intramuscular injections, a continuous infusion of epinephrine should be started. Antihistamines and corticosteroids are second-line medications and should never be given in lieu of, or prior to, epinephrine. Aggressive fluid resuscitation should also be used to treat the intravascular volume depletion characteristic of anaphylaxis. Patient observation and disposition should be individualized, as there is no well-defined period of observation after resolution of signs and symptoms. ConclusionsFor patients with anaphylaxis, rapid and appropriate administration of epinephrine is critical for survival. Additional therapy, such as supplemental oxygen, intravenous fluids, antihistamines, and corticosteroids should not delay the administration of epinephrine.

1207

Introduction: Pulmonary hemorrhage is a condition with high morbidity that can occur as a result of multiple causes; including pulmonary vasculitis, drug toxicity, aspiration of blood, thrombocytopenia, stem-cell transplant, or sepsis. In many cases no definitive cause is identified. Here, we present an unusual pediatric case of severe pulmonary hemorrhage and respiratory failure with group A streptococcus (GAS) septicemia requiring extracorporeal membrane oxygenation (ECMO). To date, there are few case reports that describe pulmonary hemorrhage in the setting of GAS sepsis. In most published reports, patients presented with a typical prodrome of fever and sore throat that was followed by pulmonary hemorrhage and death. To our knowledge, this is the only report of a patient with pulmonary hemorrhage associated with GAS sepsis that progressed to severe hypoxemic respiratory failure requiring veno-arterial ECMO. A 5-year old boy with a history of mild-persistent asthma presented to a local emergency department with acute onset of inspiratory stridor that rapidly progressed to respiratory failure. History was not concerning for infectious symptoms, foreign body ingestion, or an anaphylactic reaction. Direct laryngoscopy revealed significant airway and vocal cord edema. Initial chest x-ray was unremarkable. The child was stable on minimal ventilatory and oxygen support, and transferred to a tertiary care facility. Nasopharyngeal PCR identified parainfluenza. Dexamethasone was administered for laryngotracheobronchitis and he was observed on positive pressure ventilation overnight. 12 hours later, he developed an episode of acute hypoxemia associated with pulmonary hemorrhage requiring high frequency oscillatory ventilation. Chest x-ray demonstrated bilateral infiltrates. He developed new leukopenia and neutropenia (white blood cell 2200, absolute neutrophil count 830) presumably due to sepsis and he was started on vancomycin and ceftriaxone. Clotting times, fibrinogen, and platelet counts were not consistent with disseminated intravascular coagulopathy. There was no laboratory evidence of autoimmune disease and vasculitis. The following day, he developed hypotension with cardiovascular dysfunction requiring a continuous infusion of epinephrine. Blood and endotracheal cultures grew GAS, and clindamycin was added for anti-toxin effects. His oxygenation continued to deteriorate (oxygenation index mid 40's, PaO2/FiO2 ratio of <75) despite a mean airway pressure of 28 cm water pressure, and he was cannulated for veno-arterial ECMO. On ECMO his lungs were recruited with airway positive release ventilation (APRV). There was no further pulmonary hemorrhage and his pulmonary compliance and native gas exchange eventually improved. He was decannulated after 9 days on ECMO and extubated 6 days later. The patient's lack of prodrome and initially negative blood culture on admission suggest that his GAS infection occurred as a superinfection of a primary viral process. V-A ECMO was successfully implemented in this case of GAS sepsis/pneumonitis with pulmonary hemorrhage and cardiorespiratory failure to provide oxygenation and hemodynamic support.

Case Report II

Case Report II

Arrhythmias in Children

Arrhythmias in children can be classified according to their effect on central pulse: Fast pulse rate - tachyarrhythmia; Slow pulse rate - bradyarrhythmia; and Absent pulse is pulseless arrest (cardiac arrest). Tachyarrythmia may be narrow complex tachycardia (QRS duration ≤ 0.08 s): sinus tachycardia (ST), supraventricular tachycardia (SVT), atrial flutter or Wide-complex tachycardia (QRS duration >0.08 s): ventricular tachycardia (VT), SVT with aberrant intraventricular conduction. The choice of therapy depends on the patient's degree of hemodynamic instability. Attempt vagal stimulation, if patient is stable and if it does not unduly delay chemical or electrical cardioversion. Bradyarrhythmias include: sinus bradycardia, sinus node arrest with atrial, junctional and idioventricular escape rhythms and AV block. The emergency treatment of bradycardia depends on its hemodynamic consequences. If heart rate is <60 beats per minute with poor perfusion despite effective ventilation with oxygen, it may be treated with chest compressions, epinephrine through IV or endotracheal tube. If bradycardia persists or responds only transiently, consider a continuous infusion of epinephrine or isoproterenol and plan for emergency transcutaneous pacing. If bradycardia is due to vagal stimulation or primary A-V block, giving atropine may be beneficial.

Anaphylaxis to dyes during the perioperative period: Reports of 14 clinical cases

Vital dyes are widely used for lymphatic mapping and sentinel lymph node biopsy in patients with malignant tumors, and reports of anaphylactic reactions are becoming more frequent. Our aims were to describe specific clinical features of hypersensitivity reactions to Patent Blue (Guerbet, Roissy, France), results of the allergy workup, and their consequences for patient management. We report a series of 14 clinical cases of dye-induced anaphylaxis recorded between 2004 and 2006 in 4 member centers of a network of French allergoanesthesia outpatient clinics. Reactions appeared to be relatively severe (6/14 grade III reactions). An average 30 +/- 6-minute delay was observed between dye injection and symptom onset. In 9 (65%) patients reactions were sustained for several hours, requiring prolonged continuous epinephrine infusion and transfer to an intensive care unit. Prick test results were positive in 8 patients. In 5 patients prick test results were negative, whereas intradermal test results were positive. Anesthesiologists and allergologists must be aware of this specific risk and of the clinical characteristics of these reactions, which are usually delayed and long lasting.

From the Laboratory to the Bedside

From the Laboratory to the Bedside

The use of a continuous infusion of epinephrine for anaphylactic shock during labor

Background Anaphylaxis is a potentially life threatening, acute, and severe systemic reaction that occurs after the reexposure to a specific antigen. This immunoglobulin E-mediated process is the result of the action of basophils and mast cell mediators, causing severe brochospasm, laringospasm, angioedema, urticaria, and cardiovascular collapse. Case We present a case of anaphylactic shock during labor secondary to administration of ampicillin for group B streptococcus prophylaxis. Generalized itching and hives were soon followed by severe maternal hypotension and tachycardia and prolonged fetal bradycardia. These symptoms responded partially to the administration of fluids and parenteral epinephrine. A continuous infusion of epinephrine was required for persistent maternal symptoms. The infusion did not result in further fetal compromise. The patient delivered a healthy fetus 4 hours after the start of the epinephrine infusion. Conclusion This case supports the use of parenteral (intravenous) epinephrine for the treatment of anaphylactic reactions during pregnancy.

The Use of a Continuous Infusion of Epinephrine for Anaphylactic Shock During Labor

The Use of a Continuous Infusion of Epinephrine for Anaphylactic Shock During Labor

Epinephrine treatment of hypotension in very low birthweight infants.

The aim of this study was to examine the influence of a continuous infusion of epinephrine (adrenaline) on mean arterial blood pressure (MABP), heart rate, urine output and base deficit in very low birthweight infants (VLBWI) with systemic hypotension. In VLBWI who received an infusion of epinephrine for at least 12 h the mean urine output, administered fluid volume, base deficit and administered buffer 12 h before and 12 h during the infusion were recorded. If the infusion was shorter, but given for at least 2 h, the mean heart rate and MABP 2 h before and 2 h during the infusion were recorded. Thirty-one infants with a gestational age of 26 (23-30) wk [median (minimum-maximum)] and birthweight 690 (390-1310) g were included in this retrospective chart review. The patients received an infusion of epinephrine at a postnatal age of 3 (1-21) d. The doses ranged between 0.05 and 2.6 microg kg(-1) per minute within the first 24 h of administration. Three of 31 infants received epinephrine on 2 different occasions. The MABP [+7 (-1 to 13) mmHg, p=0.000001] and the heart rate [+10 (-10 to 42) bpm, p=0.000036] increased significantly (n = 34), whereas total volume administration and urine output remained the same between the 2 periods (Wilcoxon matched pairs test). The base deficit increased significantly [-3 (-10.2 to 2.6), p = 0.0014, n = 19] without a change in the administration of buffer. The infusion of epinephrine increased the MABP and the heart rate without decreasing urine output in VLBWI with hypotension not responding to a dopamine infusion up to 15 microg kg(-1) per minute. A potential adverse effect was an increase in metabolic acidosis.