6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
A) SUMMARY 1) Prehospital emesis and/or decontamination is NOT recommended.
6.5.2) PREVENTION OF ABSORPTION
A) SUMMARY 1) Emesis is NOT recommended. a) ONSET: The onset of action may be as soon as one hour. Initial symptoms are vomiting and abdominal pain. If large amounts have been ingested, coma, seizures, or serious dysrhythmias may be occur.
b) Vomiting alone does not necessarily remove the seeds, even if accomplished within 1 hour (Porter & Kruy, 1982). Ingestion of intact seeds rarely, if ever, results in toxicity (Frohne & Pfander, 1984). Instead, the seeds pass through the GI tract without absorption of taxine.
c) In a retrospective survey of 11,197 Taxus species exposures, there were no fatalities. When compared to no therapy, decontamination therapy had no impact on patient outcome (Krenzelok et al, 1998).
B) ACTIVATED CHARCOAL 1) CHARCOAL ADMINISTRATION a) Consider administration of activated charcoal after a potentially toxic ingestion (Chyka et al, 2005). Administer charcoal as an aqueous slurry; most effective when administered within one hour of ingestion.
2) CHARCOAL DOSE a) Use a minimum of 240 milliliters of water per 30 grams charcoal (FDA, 1985). Optimum dose not established; usual dose is 25 to 100 grams in adults and adolescents; 25 to 50 grams in children aged 1 to 12 years (or 0.5 to 1 gram/kilogram body weight) ; and 0.5 to 1 gram/kilogram in infants up to 1 year old (Chyka et al, 2005). 1) Routine use of a cathartic with activated charcoal is NOT recommended as there is no evidence that cathartics reduce drug absorption and cathartics are known to cause adverse effects such as nausea, vomiting, abdominal cramps, electrolyte imbalances and occasionally hypotension (None Listed, 2004).
b) ADVERSE EFFECTS/CONTRAINDICATIONS 1) Complications: emesis, aspiration (Chyka et al, 2005). Aspiration may be complicated by acute respiratory failure, ARDS, bronchiolitis obliterans or chronic lung disease (Golej et al, 2001; Graff et al, 2002; Pollack et al, 1981; Harris & Filandrinos, 1993; Elliot et al, 1989; Rau et al, 1988; Golej et al, 2001; Graff et al, 2002). Refer to the ACTIVATED CHARCOAL/TREATMENT management for further information.
2) Contraindications: unprotected airway (increases risk/severity of aspiration) , nonfunctioning gastrointestinal tract, uncontrolled vomiting, and ingestion of most hydrocarbons (Chyka et al, 2005).
C) GASTRIC LAVAGE 1) Gastric lavage may be of some use in patients with large, deliberate, recent ingestions, but physicians should take into consideration the size of the seeds (1/4 to 1/2 inches) and the length of the needles (1/2 to 1 inch long). Lavage may NOT remove this material effectively unless it has been chewed or otherwise broken. 2) INDICATIONS: Consider gastric lavage with a large-bore orogastric tube (ADULT: 36 to 40 French or 30 English gauge tube {external diameter 12 to 13.3 mm}; CHILD: 24 to 28 French {diameter 7.8 to 9.3 mm}) after a potentially life threatening ingestion if it can be performed soon after ingestion (generally within 60 minutes). a) Consider lavage more than 60 minutes after ingestion of sustained-release formulations and substances known to form bezoars or concretions.
3) PRECAUTIONS: a) SEIZURE CONTROL: Is mandatory prior to gastric lavage.
b) AIRWAY PROTECTION: Place patients in the head down left lateral decubitus position, with suction available. Patients with depressed mental status should be intubated with a cuffed endotracheal tube prior to lavage.
4) LAVAGE FLUID: a) Use small aliquots of liquid. Lavage with 200 to 300 milliliters warm tap water (preferably 38 degrees Celsius) or saline per wash (in older children or adults) and 10 milliliters/kilogram body weight of normal saline in young children(Vale et al, 2004) and repeat until lavage return is clear.
b) The volume of lavage return should approximate amount of fluid given to avoid fluid-electrolyte imbalance.
c) CAUTION: Water should be avoided in young children because of the risk of electrolyte imbalance and water intoxication. Warm fluids avoid the risk of hypothermia in very young children and the elderly.
5) COMPLICATIONS: a) Complications of gastric lavage have included: aspiration pneumonia, hypoxia, hypercapnia, mechanical injury to the throat, esophagus, or stomach, fluid and electrolyte imbalance (Vale, 1997). Combative patients may be at greater risk for complications (Caravati et al, 2001).
b) Gastric lavage can cause significant morbidity; it should NOT be performed routinely in all poisoned patients (Vale, 1997).
6) CONTRAINDICATIONS: a) Loss of airway protective reflexes or decreased level of consciousness if patient is not intubated, following ingestion of corrosive substances, hydrocarbons (high aspiration potential), patients at risk of hemorrhage or gastrointestinal perforation, or trivial or non-toxic ingestion.
6.5.3) TREATMENT
A) SUPPORT 1) Treatment is symptomatic and supportive. GI irritation may occur following mild toxicity; replace fluids as indicated.
2) Monitor for cardiac toxicity (ie, hypotension, dysrhythmias) following a significant overdose. Patients with persistent dysrhythmias, hemodynamic instability, or persistent CNS depression require airway support and should be intubated.
3) Accidental ingestion of yew plants by children rarely results in significant toxicity (Krenzelok et al, 1998). However, adults with deliberate ingestions may develop severe effects and should be brought into the emergency department for decontamination and observation.
4) Ingestion of intact seeds rarely, if ever, results in toxicity (Frohne & Pfander, 1984). Instead, the seeds pass through the GI tract without absorption of taxine.
B) MONITORING OF PATIENT 1) Monitor vital signs.
2) Institute continuous cardiac monitoring and obtain an ECG after a significant overdose.
3) Obtain a basic metabolic panel after a significant overdose.
C) HYPOTENSIVE EPISODE 1) The hypotension produced by Taxus has been resistant to treatment with dopamine or dobutamine (Feldman et al, 1987; Yersin et al, 1987). Other measures may be required if these agents are unsuccessful. 2) SUMMARY a) Infuse 10 to 20 milliliters/kilogram of isotonic fluid and keep the patient supine. If hypotension persists, administer dopamine or norepinephrine. Consider central venous pressure monitoring to guide further fluid therapy.
3) DOPAMINE a) DOSE: Begin at 5 micrograms per kilogram per minute progressing in 5 micrograms per kilogram per minute increments as needed (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). If hypotension persists, dopamine may need to be discontinued and a more potent vasoconstrictor (eg, norepinephrine) should be considered (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
b) CAUTION: If ventricular dysrhythmias occur, decrease rate of administration (Prod Info dopamine hcl, 5% dextrose IV injection, 2004). Extravasation may cause local tissue necrosis, administration through a central venous catheter is preferred (Prod Info dopamine hcl, 5% dextrose IV injection, 2004).
4) NOREPINEPHRINE a) PREPARATION: 4 milligrams (1 amp) added to 1000 milliliters of diluent provides a concentration of 4 micrograms/milliliter of norepinephrine base. Norepinephrine bitartrate should be mixed in dextrose solutions (dextrose 5% in water, dextrose 5% in saline) since dextrose-containing solutions protect against excessive oxidation and subsequent potency loss. Administration in saline alone is not recommended (Prod Info norepinephrine bitartrate injection, 2005). b) DOSE 1) ADULT: Dose range: 0.1 to 0.5 microgram/kilogram/minute (eg, 70 kg adult 7 to 35 mcg/min); titrate to maintain adequate blood pressure (Peberdy et al, 2010).
2) CHILD: Dose range: 0.1 to 2 micrograms/kilogram/minute; titrate to maintain adequate blood pressure (Kleinman et al, 2010).
3) CAUTION: Extravasation may cause local tissue ischemia, administration by central venous catheter is advised (Peberdy et al, 2010).
D) BRADYCARDIA 1) ATROPINE a) ATROPINE was ineffective in reversing bradycardia in presence of complete heart block (Cummins et al, 1990). b) ATROPINE/DOSE 1) ADULT BRADYCARDIA: BOLUS: Give 0.5 milligram IV, repeat every 3 to 5 minutes, if bradycardia persists. Maximum: 3 milligrams (0.04 milligram/kilogram) intravenously is a fully vagolytic dose in most adults. Doses less than 0.5 milligram may cause paradoxical bradycardia in adults (Neumar et al, 2010). 2) PEDIATRIC DOSE: As premedication for emergency intubation in specific situations (eg, giving succinylchoine to facilitate intubation), give 0.02 milligram/kilogram intravenously or intraosseously (0.04 to 0.06 mg/kg via endotracheal tube followed by several positive pressure breaths) repeat once, if needed (de Caen et al, 2015; Kleinman et al, 2010). MAXIMUM SINGLE DOSE: Children: 0.5 milligram; adolescent: 1 mg. a) There is no minimum dose (de Caen et al, 2015).
b) MAXIMUM TOTAL DOSE: Children: 1 milligram; adolescents: 2 milligrams (Kleinman et al, 2010).
2) PACEMAKER a) Transvenous pacing may be necessary following a significant exposure.
b) A pacemaker was unsuccessful in reversing ventricular dysrhythmias caused by the ingestion of yew leaves (Yersin et al, 1987).
c) In another case, a transcutaneous external cardiac pacemaker with pediatric pacing electrodes significantly improved hypotension and bradycardia secondary to complete heart block following a yew ingestion in a 5-year-old girl. Bradycardia resumed after a transvenous pacemaker was placed (Cummins et al, 1990).
3) DIGOXIN IMMUNE FAB a) Digoxin immune Fab fragments may be useful in patients with severe dysrhythmias.
b) Ten mg of digoxin-specific FAB antibodies were given 9 and 12 hours following the ingestion of Taxus leaves and berries in a 5-year-old girl with bradycardia and hypotension secondary to complete heart block after eating Taxus brevifolia. No immediate improvement was noted; however, heart rate and contractility improved over the next few hours and spontaneous atrial pacing resumed (Cummins et al, 1990).
c) An adult with severe cardiac dysrhythmias was treated with Fab-fragment following the intentional ingestion of Taxus leaves. Her digoxin plasma level rose to greater than 5 ng/mL. The digoxin level gradually declined after 1 week of therapy, and she was discharged for further psychiatric care 12 days later. One month later she died of cardiogenic shock following a repeat ingestion of yew leaves (Willaert et al, 2002).
d) CASE REPORT/FATALITY: A young adult developed hypotension, respiratory distress and a wide complex tachycardia following an intentional ingestion of English Yew (taxus baccata) seeds; the amount and time of the ingestion were unknown. Shortly after admission, the patient went into cardiac arrest and treatment included CPR, sodium bicarbonate, calcium, amiodarone and electrical defibrillation. Digoxin immune fab fragments were added for pulseless activity and a return of spontaneous circulation occurred; however, the effect was temporary and the patient continued to decompensate. Asystole developed that was unresponsive to further therapy and resuscitation efforts were withdrawn (Sun et al, 2015).
E) VENTRICULAR ARRHYTHMIA 1) May be refractory to usual therapy. Unstable rhythms require cardioversion. Treat QRS widening with sodium bicarbonate. 1 to 2 mEq/kg IV is a reasonable starting dose. Monitor arterial blood gases, goal is pH 7.45 to 7.55. Amiodarone or lidocaine may be used for ventricular tachycardia. Patients with persistent dysrhythmias may require extracorporeal membrane oxygenation or cardiopulmonary bypass for support until dysrhythmias and hypotension resolve. 2) VENTRICULAR DYSRHYTHMIAS SUMMARY a) Obtain an ECG, institute continuous cardiac monitoring and administer oxygen. Evaluate for hypoxia, acidosis, and electrolyte disorders (particularly hypokalemia, hypocalcemia, and hypomagnesemia). Lidocaine and amiodarone are generally first line agents for stable monomorphic ventricular tachycardia, particularly in patients with underlying impaired cardiac function. Amiodarone should be used with caution if a substance that prolongs the QT interval and/or causes torsades de pointes is involved in the overdose. Unstable rhythms require immediate cardioversion.
3) LIDOCAINE a) Lidocaine has been used with mixed success (Feldman et al, 1987; Yersin et al, 1987). b) LIDOCAINE/INDICATIONS 1) Ventricular tachycardia or ventricular fibrillation (Prod Info Lidocaine HCl intravenous injection solution, 2006; Neumar et al, 2010; Vanden Hoek et al, 2010).
c) LIDOCAINE/DOSE 1) ADULT: 1 to 1.5 milligrams/kilogram via intravenous push. For refractory VT/VF an additional bolus of 0.5 to 0.75 milligram/kilogram can be given at 5 to 10 minute intervals to a maximum dose of 3 milligrams/kilogram (Neumar et al, 2010). Only bolus therapy is recommended during cardiac arrest. a) Once circulation has been restored begin a maintenance infusion of 1 to 4 milligrams per minute. If dysrhythmias recur during infusion repeat 0.5 milligram/kilogram bolus and increase the infusion rate incrementally (maximal infusion rate is 4 milligrams/minute) (Neumar et al, 2010).
2) CHILD: 1 milligram/kilogram initial bolus IV/IO; followed by a continuous infusion of 20 to 50 micrograms/kilogram/minute (de Caen et al, 2015). d) LIDOCAINE/MAJOR ADVERSE REACTIONS 1) Paresthesias; muscle twitching; confusion; slurred speech; seizures; respiratory depression or arrest; bradycardia; coma. May cause significant AV block or worsen pre-existing block. Prophylactic pacemaker may be required in the face of bifascicular, second degree, or third degree heart block (Prod Info Lidocaine HCl intravenous injection solution, 2006; Neumar et al, 2010).
e) LIDOCAINE/MONITORING PARAMETERS 1) Monitor ECG continuously; plasma concentrations as indicated (Prod Info Lidocaine HCl intravenous injection solution, 2006).
4) AMIODARONE a) AMIODARONE/INDICATIONS 1) Effective for the control of hemodynamically stable monomorphic ventricular tachycardia. Also recommended for pulseless ventricular tachycardia or ventricular fibrillation in cardiac arrest unresponsive to CPR, defibrillation and vasopressor therapy (Link et al, 2015; Neumar et al, 2010). It should be used with caution when the ingestion involves agents known to cause QTc prolongation, such as fluoroquinolones, macrolide antibiotics or azoles, and when ECG reveals QT prolongation suspected to be secondary to overdose (Prod Info Cordarone(R) oral tablets, 2015).
b) AMIODARONE/ADULT DOSE 1) For ventricular fibrillation or pulseless VT unresponsive to CPR, defibrillation, and a vasopressor therapy give an initial dose of 300 mg IV followed by 1 dose of 150 mg IV. For stable ventricular tachycardias: Infuse 150 milligrams over 10 minutes, and repeat if necessary. Follow by a 1 milligram/minute infusion for 6 hours, then a 0.5 milligram/minute. Maximum total dose over 24 hours is 2.2 grams (Neumar et al, 2010).
c) AMIODARONE/PEDIATRIC DOSE 1) Infuse 5 milligrams/kilogram as a bolus for pulseless ventricular tachycardia or ventricular fibrillation; may repeat twice up to 15 mg/kg. Infuse 5 milligrams/kilogram over 20 to 60 minutes for perfusing tachycardias. Maximum single dose is 300 mg. Routine use with other drugs that prolong the QT interval is NOT recommended (Kleinman et al, 2010).
d) ADVERSE EFFECTS 1) Hypotension and bradycardia are the most common adverse effects (Neumar et al, 2010).
5) PROCAINAMIDE a) PROCAINAMIDE/INDICATIONS 1) An alternative drug in the treatment of PVCs or recurrent ventricular tachycardia when lidocaine is contraindicated or not effective. It should be avoided when the ingestion involves agents with quinidine-like effects (e.g. tricyclic antidepressants, phenothiazines, chloroquine, antidysrhythmics) and when the ECG reveals QRS widening or QT prolongation suspected to be secondary to overdose(Neumar et al, 2010; Vanden Hoek,TL,et al).
b) PROCAINAMIDE/ADULT LOADING DOSE 1) 20 to 50 milligrams/minute IV until dysrhythmia is suppressed or toxicity develops from procainamide (hypotension develops or the QRS is widened by 50%), or a total dose of 17 milligrams/kilogram is given (1.2 grams for a 70 kilogram person) (Neumar et al, 2010).
2) ALTERNATIVE DOSING: 100 mg every 5 minutes until dysrhythmia is controlled, or toxicity develops from procainamide (hypotension develops or the QRS is widened by 50%) or 17 mg/kg have been given (Neumar et al, 2010).
3) MAXIMUM DOSE: 17 milligrams/kilogram (Neumar et al, 2010).
c) PROCAINAMIDE/CONTROLLED INFUSION 1) In conscious patients, procainamide should be administered as a controlled infusion (20 milligrams/minute) because of the risk of QT prolongation and its hypotensive effects (Link et al, 2015)
d) PROCAINAMIDE/ADULT MAINTENANCE DOSE 1) 1 to 4 milligrams/minute via an intravenous infusion (Neumar et al, 2010).
e) PROCAINAMIDE/PEDIATRIC LOADING DOSE 1) 15 milligrams/kilogram IV/Intraosseously over 30 to 60 minutes; discontinue if hypotension develops or the QRS widens by 50% (Kleinman et al, 2010).
f) PROCAINAMIDE/PEDIATRIC MAINTENANCE DOSE 1) Initiate at 20 mcg/kg/minute and increase in 10 mcg/kg/minute increments every 15 to 30 minutes until desired effect is achieved; up to 80 mcg/kg/minute (Bouhouch et al, 2008; Ratnasamy et al, 2008; Mandapati et al, 2000; Luedtke et al, 1997; Walsh et al, 1997).
g) PROCAINAMIDE/PEDIATRIC MAXIMUM DOSE 1) 2 grams/day (Bouhouch et al, 2008; Ratnasamy et al, 2008; Mandapati et al, 2000; Luedtke et al, 1997; Walsh et al, 1997).
h) MONITORING PARAMETERS 1) ECG, blood pressure, and blood concentrations (Prod Info procainamide HCl IV, IM injection solution, 2011). Procainamide can produce hypotension and QT prolongation (Link et al, 2015).
i) AVOID 1) Avoid in patients with QT prolongation and CHF (Neumar et al, 2010).
6) WIDE COMPLEX TACHYCARDIA a) SUMMARY: Various treatments have been tried, including procainamide, magnesium, and cardioversion.
b) CASE REPORT: An adult patient experiencing wide QRS complex tachycardia received several treatments including lidocaine, electrical direct current cardioversion, procainamide and magnesium sulfate without improvement. The procainamide was discontinued when its potential to further widen the QRS was recognized. The patient recovered with general supportive care (Nora et al, 1993).
F) SODIUM BICARBONATE 1) CASE REPORT: A young adult male developed cardiac dysrhythmias (ventricular tachycardia; rate 166), hypotension and seizure-like activity after chewing and swallowing 168 yew seeds. Initially, the patient was treated with amiodarone and cardioversion. Six hours later, sodium bicarbonate (50 mEq bolus; followed by an infusion at 37.5 mEq/hr) was given for a recurrence of wide complex tachycardia and hypotension. The QRS narrowed within minutes of the bolus. Of note, the amiodarone drip was inadvertently continued for approximately 4 hours after the sodium bicarbonate drip was started. The bicarbonate drip was continued overnight with no further episodes of dysrhythmias, along with normal vital signs and mental status. The patient was discharged at 56 hours with a normal ECG (Pierog et al, 2009).
2) ANIMAL STUDY: Intravenous hypertonic sodium bicarbonate was found to be ineffective in reversing the widening of the QRS interval in swine poisoned with intravenous taxus. There were no significant differences in cardiac index (cardiac output/kg) or heart rate between the experimental and the control group (Ruha et al, 2002).
G) EXTRACORPOREAL MEMBRANE OXYGENATION 1) SUMMARY: Extracorporeal life support was successfully used to treat severe Taxus baccata poisoning in 3 adults (Baum et al, 2015; Soumagne et al, 2011; Panzeri et al, 2010).
2) CASE REPORT: A 24-year-old woman with a history of Asperger syndrome and depression was admitted with nausea and bradycardia after intentionally ingesting Taxus baccata leaves (yew metabolites were found in serum; a toxicology screen was negative). Although the patient was immediately decontaminated with gastric lavage followed by activated charcoal and 80 mg of digitalis antitoxin, cardiogenic shock occurred within 5 hours of exposure. Following extensive cardiopulmonary resuscitation lasting 225 minutes, the patient was stabilized using veno-arterial extracorporeal membrane oxygenation (ECMO) implantation. The patient was found to have highly impaired biventricular function with minimal cardiac output despite the ongoing use of high dose inotropes and ECMO therapy. An ECG showed ventricular escape beat with a prolonged QRS complex. After 12 hours of aggressive care, the patient's rhythm changed to sinus arrest with atrioventricular junctional escape that was amenable to internal pacing. The various interventions were maintained for another 12 hours and she was successfully weaned from ECMO 70 hours after implantation. No neurologic deficits were observed. Eight days later the patient was successfully transferred out of the ICU. Four weeks after exposure, an ECG showed normal sinus rhythm, no evidence of organ damage and normal laboratory values (Baum et al, 2015).
3) CASE REPORT: Severe bradycardia with hypotension, followed by recurring episodes of ventricular tachycardia occurred in an adult after intentionally ingesting T. baccata leaves. Initial therapy included amiodarone and cardioversion followed by a temporary ventricular demand inhibited pacemaker. An intra-aortic balloon pump (IABP) was added for intractable hypotension. Due to a lack of response, extracorporeal life support (ECLS) was started approximately 6 hours after admission. Within 12 hours, gradual improvement in perfusion and cardiovascular parameters were observed; the ECG showed normal sinus rhythm with a type I A-V block 24 hours after admission. ECLS was stopped 3 days after admission; IABP and epinephrine were discontinued on day 4. The patient recovered completely and was transferred to a psychiatric unit 17 days after exposure (Panzeri et al, 2010).
4) CASE REPORT: Atypical bundle branch block followed by ventricular dysrhythmias and cardiogenic shock with QRS widening occurred about 3 hours after ingesting 10 leaves from a garden yew in a 46-year-old man. A transthoracic echography confirmed severe left ventricular dysfunction. The patient developed recurrent episodes of ventricular fibrillation unresponsive to drug therapy. Extracorporeal life support (ECLS) was then started with rapid improvement (approximately 1 hour) in hemodynamic status, sinus rhythm, and a narrowing QRS. A repeat echography and ECG were normal by the second hospital day. ECLS was weaned after 50 hours and the patient was transferred to a psychiatric unit on day 7 with no cardiac or neurologic deficits (Soumagne et al, 2011).
H) FAT EMULSION 1) SUMMARY a) Limited data. Lipid emulsion therapy along with sodium bicarbonate and supportive care was used successfully to treat significant cardiotoxicity (ie, hypotension) due to Taxus Baccata poisoning in a young adult (Ovakim et al, 2015).
2) CASE REPORT a) CASE REPORT: A 21-year-old woman developed a syncopal episode about 6 hours after ingesting 250 mL of cut Yew leaves in water over a 2 hour period. When the paramedics arrived, the patient was alert with a slightly irregular heart beat and stable blood pressure. Upon arrival to the ED, the patient had severe wide complex tachycardia and a blood pressure of 58/35. Intravenous fluids, norepinephrine and multiple doses of sodium bicarbonate produced only minimal change. A bolus and intravenous infusion of lipid emulsion was added along with several additional doses of sodium bicarbonate. She was transferred to the ICU and remained hemodynamically stable overnight while being maintained on a sodium bicarbonate infusion. By the next day her ECG was normal and she was transferred to psychiatry (Ovakim et al, 2015). b) Intravenous lipid emulsion (ILE) has been effective in reversing severe cardiovascular toxicity from local anesthetic overdose in animal studies and human case reports. Several animal studies and human case reports have also evaluated the use of ILE for patients following exposure to other drugs. Although the results of these studies are mixed, there is increasing evidence that it can rapidly reverse cardiovascular toxicity and improve mental function for a wide variety of lipid soluble drugs. It may be reasonable to consider ILE in patients with severe symptoms who are failing standard resuscitative measures (Lavonas et al, 2015). c) The American College of Medical Toxicology has issued the following guidelines for lipid resuscitation therapy (LRT) in the management of overdose in cases involving a highly lipid soluble xenobiotic where the patient is hemodynamically unstable, unresponsive to standard resuscitation measures (ie, fluid replacement, inotropes and pressors). The decision to use LRT is based on the judgement of the treating physician. When possible, it is recommended these therapies be administered with the consultation of a medical toxicologist (American College of Medical Toxicology, 2016; American College of Medical Toxicology, 2011): 1) Initial intravenous bolus of 1.5 mL/kg 20% lipid emulsion (eg, Intralipid) over 2 to 3 minutes. Asystolic patients or patients with pulseless electrical activity may have a repeat dose, if there is no response to the initial bolus.
2) Follow with an intravenous infusion of 0.25 mL/kg/min of 20% lipid emulsion (eg, Intralipid). Evaluate the patient's response after 3 minutes at this infusion rate. The infusion rate may be decreased to 0.025 mL/kg/min (ie, 1/10 the initial rate) in patients with a significant response. This recommendation has been proposed because of possible adverse effects from very high cumulative rates of lipid infusion. Monitor blood pressure, heart rate, and other hemodynamic parameters every 15 minutes during the infusion.
3) If there is an initial response to the bolus followed by the re-emergence of hemodynamic instability during the lowest-dose infusion, the infusion rate may be increased back to 0.25 mL/kg/min or, in severe cases, the bolus could be repeated. A maximum dose of 10 mL/kg has been recommended by some sources.
4) Where possible, LRT should be terminated after 1 hour or less, if the patient's clinical status permits. In cases where the patient's stability is dependent on continued lipid infusion, longer treatment may be appropriate.
I) SEIZURE 1) SUMMARY a) Attempt initial control with a benzodiazepine (eg, diazepam, lorazepam). If seizures persist or recur, administer phenobarbital or propofol.
b) Monitor for respiratory depression, hypotension, and dysrhythmias. Endotracheal intubation should be performed in patients with persistent seizures.
c) Evaluate for hypoxia, electrolyte disturbances, and hypoglycemia (or, if immediate bedside glucose testing is not available, treat with intravenous dextrose).
2) DIAZEPAM a) ADULT DOSE: Initially 5 to 10 mg IV, OR 0.15 mg/kg IV up to 10 mg per dose up to a rate of 5 mg/minute; may be repeated every 5 to 20 minutes as needed (Brophy et al, 2012; Prod Info diazepam IM, IV injection, 2008; Manno, 2003).
b) PEDIATRIC DOSE: 0.1 to 0.5 mg/kg IV over 2 to 5 minutes; up to a maximum of 10 mg/dose. May repeat dose every 5 to 10 minutes as needed (Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008).
c) Monitor for hypotension, respiratory depression, and the need for endotracheal intubation. Consider a second agent if seizures persist or recur after repeated doses of diazepam .
3) NO INTRAVENOUS ACCESS a) DIAZEPAM may be given rectally or intramuscularly (Manno, 2003). RECTAL DOSE: CHILD: Greater than 12 years: 0.2 mg/kg; 6 to 11 years: 0.3 mg/kg; 2 to 5 years: 0.5 mg/kg (Brophy et al, 2012).
b) MIDAZOLAM has been used intramuscularly and intranasally, particularly in children when intravenous access has not been established. ADULT DOSE: 0.2 mg/kg IM, up to a maximum dose of 10 mg (Brophy et al, 2012). PEDIATRIC DOSE: INTRAMUSCULAR: 0.2 mg/kg IM, up to a maximum dose of 7 mg (Chamberlain et al, 1997) OR 10 mg IM (weight greater than 40 kg); 5 mg IM (weight 13 to 40 kg); INTRANASAL: 0.2 to 0.5 mg/kg up to a maximum of 10 mg/dose (Loddenkemper & Goodkin, 2011; Brophy et al, 2012). BUCCAL midazolam, 10 mg, has been used in adolescents and older children (5-years-old or more) to control seizures when intravenous access was not established (Scott et al, 1999).
4) LORAZEPAM a) MAXIMUM RATE: The rate of intravenous administration of lorazepam should not exceed 2 mg/min (Brophy et al, 2012; Prod Info lorazepam IM, IV injection, 2008).
b) ADULT DOSE: 2 to 4 mg IV initially; repeat every 5 to 10 minutes as needed, if seizures persist (Manno, 2003; Brophy et al, 2012).
c) PEDIATRIC DOSE: 0.05 to 0.1 mg/kg IV over 2 to 5 minutes, up to a maximum of 4 mg/dose; may repeat in 5 to 15 minutes as needed, if seizures continue (Brophy et al, 2012; Loddenkemper & Goodkin, 2011; Hegenbarth & American Academy of Pediatrics Committee on Drugs, 2008; Sreenath et al, 2009; Chin et al, 2008).
5) PHENOBARBITAL a) ADULT LOADING DOSE: 20 mg/kg IV at an infusion rate of 50 to 100 mg/minute IV. An additional 5 to 10 mg/kg dose may be given 10 minutes after loading infusion if seizures persist or recur (Brophy et al, 2012).
b) Patients receiving high doses will require endotracheal intubation and may require vasopressor support (Brophy et al, 2012).
c) PEDIATRIC LOADING DOSE: 20 mg/kg may be given as single or divided application (2 mg/kg/minute in children weighing less than 40 kg up to 100 mg/min in children weighing greater than 40 kg). A plasma concentration of about 20 mg/L will be achieved by this dose (Loddenkemper & Goodkin, 2011).
d) REPEAT PEDIATRIC DOSE: Repeat doses of 5 to 20 mg/kg may be given every 15 to 20 minutes if seizures persist, with cardiorespiratory monitoring (Loddenkemper & Goodkin, 2011).
e) MONITOR: For hypotension, respiratory depression, and the need for endotracheal intubation (Loddenkemper & Goodkin, 2011; Manno, 2003).
f) SERUM CONCENTRATION MONITORING: Monitor serum concentrations over the next 12 to 24 hours. Therapeutic serum concentrations of phenobarbital range from 10 to 40 mcg/mL, although the optimal plasma concentration for some individuals may vary outside this range (Hvidberg & Dam, 1976; Choonara & Rane, 1990; AMA Department of Drugs, 1992).
6) OTHER AGENTS a) If seizures persist after phenobarbital, propofol or pentobarbital infusion, or neuromuscular paralysis with general anesthesia (isoflurane) and continuous EEG monitoring should be considered (Manno, 2003). Other anticonvulsants can be considered (eg, valproate sodium, levetiracetam, lacosamide, topiramate) if seizures persist or recur; however, there is very little data regarding their use in toxin induced seizures, controlled trials are not available to define the optimal dosage ranges for these agents in status epilepticus (Brophy et al, 2012): 1) VALPROATE SODIUM: ADULT DOSE: An initial dose of 20 to 40 mg/kg IV, at a rate of 3 to 6 mg/kg/minute; may give an additional dose of 20 mg/kg 10 minutes after loading infusion. PEDIATRIC DOSE: 1.5 to 3 mg/kg/minute (Brophy et al, 2012).
2) LEVETIRACETAM: ADULT DOSE: 1000 to 3000 mg IV, at a rate of 2 to 5 mg/kg/min IV. PEDIATRIC DOSE: 20 to 60 mg/kg IV (Brophy et al, 2012; Loddenkemper & Goodkin, 2011).
3) LACOSAMIDE: ADULT DOSE: 200 to 400 mg IV; 200 mg IV over 15 minutes (Brophy et al, 2012). PEDIATRIC DOSE: In one study, median starting doses of 1.3 mg/kg/day and maintenance doses of 4.7 mg/kg/day were used in children 8 years and older (Loddenkemper & Goodkin, 2011).
4) TOPIRAMATE: ADULT DOSE: 200 to 400 mg nasogastric/orally OR 300 to 1600 mg/day orally divided in 2 to 4 times daily (Brophy et al, 2012).
J) ANAPHYLAXIS 1) SUMMARY a) Mild to moderate allergic reactions may be treated with antihistamines with or without inhaled beta adrenergic agonists, corticosteroids or epinephrine. Treatment of severe anaphylaxis also includes oxygen supplementation, aggressive airway management, epinephrine, ECG monitoring, and IV fluids.
2) BRONCHOSPASM a) ALBUTEROL 1) ADULT: 2.5 to 5 milligrams in 2 to 4.5 milliliters of normal saline delivered per nebulizer every 20 minutes up to 3 doses. If incomplete response administer 2.5 to 10 mg every 1 to 4 hours as needed, or 10 to 15 mg/hr by continuous nebulization as needed (National Heart,Lung,and Blood Institute, 2007). CHILD: 0.15 milligram/kilogram (minimum 2.5 milligrams) per nebulizer every 20 minutes up to 3 doses. If incomplete response administer 0.15 to 0.3 mg/kg (up to 10 mg) every 1 to 4 hours as needed, or 0.5 mg/kg/hr by continuous nebulization (National Heart,Lung,and Blood Institute, 2007).
3) CORTICOSTEROIDS a) Consider systemic corticosteroids in patients with significant bronchospasm.
b) PREDNISONE: ADULT: 40 to 80 milligrams/day. CHILD: 1 to 2 milligrams/kilogram/day (maximum 60 mg) in 1 to 2 divided doses divided twice daily (National Heart,Lung,and Blood Institute, 2007).
4) MILD CASES a) DIPHENHYDRAMINE 1) SUMMARY: Oral diphenhydramine, as well as other H1 antihistamines can be used as indicated (Lieberman et al, 2010).
2) ADULT: 50 milligrams orally, or 10 to 50 mg intravenously at a rate not to exceed 25 mg/min or may be given by deep intramuscular injection. A total of 100 mg may be administered if needed. Maximum daily dosage is 400 mg (Prod Info diphenhydramine HCl intravenous injection solution, intramuscular injection solution, 2013).
3) CHILD: 5 mg/kg/24 hours or 150 mg/m(2)/24 hours. Divided into 4 doses, administered intravenously at a rate not exceeding 25 mg/min or by deep intramuscular injection. Maximum daily dosage is 300 mg (Prod Info diphenhydramine HCl intravenous injection solution, intramuscular injection solution, 2013).
5) MODERATE CASES a) EPINEPHRINE: INJECTABLE SOLUTION: It should be administered early in patients by IM injection. Using a 1:1000 (1 mg/mL) solution of epinephrine. Initial Dose: 0.01 mg/kg intramuscularly with a maximum dose of 0.5 mg in adults and 0.3 mg in children. The dose may be repeated every 5 to 15 minutes, if no clinical improvement. Most patients respond to 1 or 2 doses (Nowak & Macias, 2014).
6) SEVERE CASES a) EPINEPHRINE 1) INTRAVENOUS BOLUS: ADULT: 1 mg intravenously as a 1:10,000 (0.1 mg/mL) solution; CHILD: 0.01 mL/kg intravenously to a maximum single dose of 1 mg given as a 1:10,000 (0.1 mg/mL) solution. It can be repeated every 3 to 5 minutes as needed. The dose can also be given by the intraosseous route if IV access cannot be established (Lieberman et al, 2015). ALTERNATIVE ROUTE: ENDOTRACHEAL ADMINISTRATION: If IV/IO access is unavailable. DOSE: ADULT: Administer 2 to 2.5 mg of 1:1000 (1 mg/mL) solution diluted in 5 to 10 mL of sterile water via endotracheal tube. CHILD: DOSE: 0.1 mg/kg to a maximum of 2.5 mg administered as a 1:1000 (1 mg/mL) solution diluted in 5 to 10 mL of sterile water via endotracheal tube (Lieberman et al, 2015).
2) INTRAVENOUS INFUSION: Intravenous administration may be considered in patients poorly responsive to IM or SubQ epinephrine. An epinephrine infusion may be prepared by adding 1 mg (1 mL of 1:1000 (1 mg/mL) solution) to 250 mL D5W, yielding a concentration of 4 mcg/mL, and infuse this solution IV at a rate of 1 mcg/min to 10 mcg/min (maximum rate). CHILD: A dosage of 0.01 mg/kg (0.1 mL/kg of a 1:10,000 (0.1 mg/mL) solution up to 10 mcg/min (maximum dose 0.3 mg) is recommended for children (Lieberman et al, 2010). Careful titration of a continuous infusion of IV epinephrine, based on the severity of the reaction, along with a crystalloid infusion can be considered in the treatment of anaphylactic shock. It appears to be a reasonable alternative to IV boluses, if the patient is not in cardiac arrest (Vanden Hoek,TL,et al).
7) AIRWAY MANAGEMENT a) OXYGEN: 5 to 10 liters/minute via high flow mask.
b) INTUBATION: Perform early if any stridor or signs of airway obstruction.
c) CRICOTHYROTOMY: Use if unable to intubate with complete airway obstruction (Vanden Hoek,TL,et al).
d) BRONCHODILATORS are recommended for mild to severe bronchospasm.
e) ALBUTEROL: ADULT: 2.5 to 5 milligrams in 2 to 4.5 milliliters of normal saline delivered per nebulizer every 20 minutes up to 3 doses. If incomplete response administer 2.5 to 10 mg every 1 to 4 hours as needed, or 10 to 15 mg/hr by continuous nebulization as needed (National Heart,Lung,and Blood Institute, 2007).
f) ALBUTEROL: CHILD: 0.15 milligram/kilogram (minimum 2.5 milligrams) per nebulizer every 20 minutes up to 3 doses. If incomplete response administer 0.15 to 0.3 milligram/kilogram (maximum 10 milligrams) every 1 to 4 hours as needed OR administer 0.5 mg/kg/hr by continuous nebulization (National Heart,Lung,and Blood Institute, 2007).
8) MONITORING a) CARDIAC MONITOR: All complicated cases.
b) IV ACCESS: Routine in all complicated cases.
9) HYPOTENSION a) If hypotensive give 500 to 2000 milliliters crystalloid initially (20 milliliters/kilogram in children) and titrate to desired effect (stabilization of vital signs, mentation, urine output); adults may require up to 6 to 10 L/24 hours. Central venous or pulmonary artery pressure monitoring is recommended in patients with persistent hypotension. 1) VASOPRESSORS: Should be used in refractory cases unresponsive to repeated doses of epinephrine and after vigorous intravenous crystalloid rehydration (Lieberman et al, 2010).
2) DOPAMINE: Initial Dose: 2 to 20 micrograms/kilogram/minute intravenously; titrate to maintain systolic blood pressure greater than 90 mm Hg (Lieberman et al, 2010).
10) H1 and H2 ANTIHISTAMINES a) SUMMARY: Antihistamines are second-line therapy and are used as supportive therapy and should not be used in place of epinephrine (Lieberman et al, 2010). 1) DIPHENHYDRAMINE: ADULT: 25 to 50 milligrams via a slow intravenous infusion or IM. PEDIATRIC: 1 milligram/kilogram via slow intravenous infusion or IM up to 50 mg in children (Lieberman et al, 2010).
b) RANITIDINE: ADULT: 1 mg/kg parenterally; CHILD: 12.5 to 50 mg parenterally. If the intravenous route is used, ranitidine should be infused over 10 to 15 minutes or diluted in 5% dextrose to a volume of 20 mL and injected over 5 minutes (Lieberman et al, 2010). c) Oral diphenhydramine, as well as other H1 antihistamines, can also be used as indicated (Lieberman et al, 2010). 11) DYSRHYTHMIAS a) Dysrhythmias and cardiac dysfunction may occur primarily or iatrogenically as a result of pharmacologic treatment (epinephrine) (Vanden Hoek,TL,et al). Monitor and correct serum electrolytes, oxygenation and tissue perfusion. Treat with antiarrhythmic agents as indicated.
12) OTHER THERAPIES a) There have been a few reports of patients with anaphylaxis, with or without cardiac arrest, that have responded to vasopressin therapy that did not respond to standard therapy. Although there are no randomized controlled trials, other alternative vasoactive therapies (ie, vasopressin, norepinephrine, methoxamine, and metaraminol) may be considered in patients in cardiac arrest secondary to anaphylaxis that do not respond to epinephrine (Vanden Hoek,TL,et al).
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