Use of Atropine in Infants and Children
Atropine was first recommended for the treatment of pediatric bradycardia in the 1950s. Although atropine is no longer considered a primary component of the management of pediatric cardiac arrest, it remains an option in the guidelines from the International Liaison Committee on Resuscitation (ILCOR) and its affiliate in the United States, the American Heart Association (AHA), for treatment of bradycardia caused by increased vagal tone, primary atrioventricular (AV) block, or cholinergic drug toxicity. It is also considered a second-line therapy for bradycardia refractory to epinephrine. The 2010 ILCOR and AHA guidelines recommend an atropine dose of 0.02 mg/kg, with a minimum dose of 0.1 mg for all pediatric patients to prevent paradoxical bradycardia. The use of a minimum dose regardless of patient weight or age has come under question over the past decade.
The source most often cited for the 0.1 mg minimum atropine dose is the study by Dauchet and Gravenstein published in a 1971 issue of Clinical Pharmacology and Therapeutics. The authors studied the effects of atropine, given in four divided doses up to a total of 1 mg/70kg in 79 patients undergoing elective surgery. The patients (6 weeks to 79 years) were grouped by age: 6 weeks-2.9 years, 3–6.9 years, 7–12.9 years, 13–19.9 years, 20–39.9 years, 40–59.9 years, and 60–79 years. Atropine was administered as two 1.8 mcg/kg doses, a 3.6 mcg/kg dose, and a 7.1 mcg/kg dose.
The authors noted that after the initial small doses, the heart rate was either normal or lower than normal. It was only after the higher doses that the patients had clear tachycardia. The authors noted that the initial paradoxical bradycardia was not substantially different in infants and young children than in adults when baseline heart rate was taken into account. At the conclusion of the article, the authors suggested a dose of 0.1 mg for newborns (although no newborns were included in the study) and a dose of 0.6 to 0.8 mg in adults; there were no specific guidelines for children or weight-based recommendations provided. Despite the clear limitations of this study, the 0.1 mg dose was adopted as the minimum recommended atropine dose in the belief lower doses were more likely to produce paradoxical bradycardia. In a 2011 article in Pediatrics, Barrington reviewed the data from the Dauchet study and concluded that the assumption that a 0.1 mg minimum dose would prevent paradoxical bradycardia reflected an inaccurate interpretation of the data.
The use of a standard 0.1 mg minimum dose means that patients weighing less than 5 kg are potentially exposed to an excessive dose. Adverse effects from using a standard 0.1 mg atropine dose in neonates have now been reported by several authors. In one recent report, a 1-day-old neonate (3.3 kg) was given 0.1 mg atropine during resuscitation after rapid blood loss during the surgical resection of a sacral teratoma. The patient survived, but failed to exhibit spontaneous movement for more than 24 hours. The medical team, based on the possibility of central anticholinergic syndrome, gave the patient 0.5 mg pyridostigmine and within minutes, the patient had spontaneous purposeful movement. While the authors did not comment on the atropine dose, based on a weight of 1.8 kg (the patient's weight after removal of the 1.5 kg tumor) it was 0.06 mg/kg, well above the recommended weight-based dose.
In addition, several recent studies of preterm and term neonates given weight-based atropine doses of 0.01–0.02 mg/kg have shown no evidence of paradoxical bradycardia. As a result of these reports, the use of weight-based dosing for patients less than 5 kg has become adopted by many pediatric healthcare providers and is noted in several reference texts and clinical guidelines.
Resuscitation
Atropine was first recommended for the treatment of pediatric bradycardia in the 1950s. Although atropine is no longer considered a primary component of the management of pediatric cardiac arrest, it remains an option in the guidelines from the International Liaison Committee on Resuscitation (ILCOR) and its affiliate in the United States, the American Heart Association (AHA), for treatment of bradycardia caused by increased vagal tone, primary atrioventricular (AV) block, or cholinergic drug toxicity. It is also considered a second-line therapy for bradycardia refractory to epinephrine. The 2010 ILCOR and AHA guidelines recommend an atropine dose of 0.02 mg/kg, with a minimum dose of 0.1 mg for all pediatric patients to prevent paradoxical bradycardia. The use of a minimum dose regardless of patient weight or age has come under question over the past decade.
The source most often cited for the 0.1 mg minimum atropine dose is the study by Dauchet and Gravenstein published in a 1971 issue of Clinical Pharmacology and Therapeutics. The authors studied the effects of atropine, given in four divided doses up to a total of 1 mg/70kg in 79 patients undergoing elective surgery. The patients (6 weeks to 79 years) were grouped by age: 6 weeks-2.9 years, 3–6.9 years, 7–12.9 years, 13–19.9 years, 20–39.9 years, 40–59.9 years, and 60–79 years. Atropine was administered as two 1.8 mcg/kg doses, a 3.6 mcg/kg dose, and a 7.1 mcg/kg dose.
The authors noted that after the initial small doses, the heart rate was either normal or lower than normal. It was only after the higher doses that the patients had clear tachycardia. The authors noted that the initial paradoxical bradycardia was not substantially different in infants and young children than in adults when baseline heart rate was taken into account. At the conclusion of the article, the authors suggested a dose of 0.1 mg for newborns (although no newborns were included in the study) and a dose of 0.6 to 0.8 mg in adults; there were no specific guidelines for children or weight-based recommendations provided. Despite the clear limitations of this study, the 0.1 mg dose was adopted as the minimum recommended atropine dose in the belief lower doses were more likely to produce paradoxical bradycardia. In a 2011 article in Pediatrics, Barrington reviewed the data from the Dauchet study and concluded that the assumption that a 0.1 mg minimum dose would prevent paradoxical bradycardia reflected an inaccurate interpretation of the data.
The use of a standard 0.1 mg minimum dose means that patients weighing less than 5 kg are potentially exposed to an excessive dose. Adverse effects from using a standard 0.1 mg atropine dose in neonates have now been reported by several authors. In one recent report, a 1-day-old neonate (3.3 kg) was given 0.1 mg atropine during resuscitation after rapid blood loss during the surgical resection of a sacral teratoma. The patient survived, but failed to exhibit spontaneous movement for more than 24 hours. The medical team, based on the possibility of central anticholinergic syndrome, gave the patient 0.5 mg pyridostigmine and within minutes, the patient had spontaneous purposeful movement. While the authors did not comment on the atropine dose, based on a weight of 1.8 kg (the patient's weight after removal of the 1.5 kg tumor) it was 0.06 mg/kg, well above the recommended weight-based dose.
In addition, several recent studies of preterm and term neonates given weight-based atropine doses of 0.01–0.02 mg/kg have shown no evidence of paradoxical bradycardia. As a result of these reports, the use of weight-based dosing for patients less than 5 kg has become adopted by many pediatric healthcare providers and is noted in several reference texts and clinical guidelines.
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