Pediatrics


Pediatrics, also spelled paediatrics, also known as underage medicine, is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. Within the Commonwealth, pediatrics covers patients until the age of 18, except in India where the pediatric age is 12. The American Academy of Pediatrics recommends people seek pediatric care through the age of 21, but some pediatric subspecialists continue to care for adults up to 26, depending on insurance coverage for young adults who reside with parents. Worldwide age limits of pediatrics have been trending upward year after year. A medical doctor who specializes in this area is known as a pediatrician, or paediatrician. The word pediatrics and its cognates mean "healer of children", derived from the two Greek words: wikt:παῖς and wikt:ἰατρός. Pediatricians work in clinics, research centers, universities, general hospitals and children's hospitals, including those who practice pediatric subspecialties.

History

The earliest mentions of child-specific medical problems appear in the Hippocratic Corpus, published in the fifth century B.C., and the famous Sacred Disease. These publications discussed topics such as childhood epilepsy and premature births. From the first to fourth centuries A.D., Greek philosophers and physicians Celsus, Soranus of Ephesus, Aretaeus, Galen, and Oribasius, also discussed specific illnesses affecting children in their works, such as rashes, epilepsy, and meningitis. Already Hippocrates, Aristotle, Celsus, Soranus, and Galen understood the differences in growing and maturing organisms that necessitated different treatment: Ex toto non sic pueri ut viri curari debent. Some of the oldest traces of pediatrics can be discovered in Ancient India where children's doctors were called kumara bhrtya.
Even though some pediatric works existed during this time, they were scarce and rarely published due to a lack of knowledge in pediatric medicine. Sushruta Samhita, an ayurvedic text composed during the sixth century BCE, contains information about pediatrics. Another ayurvedic text from this period is Kashyapa Samhita. A second century AD manuscript by the Greek physician and gynecologist Soranus of Ephesus dealt with neonatal pediatrics. Byzantine physicians Oribasius, Aëtius of Amida, Alexander Trallianus, and Paulus Aegineta contributed to the field. The Byzantines also built brephotrophia. Islamic Golden Age writers served as a bridge for Greco-Roman and Byzantine medicine and added ideas of their own, especially Haly Abbas, Yahya Serapion, Abulcasis, Avicenna, and Averroes. The Persian philosopher and physician al-Razi, sometimes called the father of pediatrics, published a monograph on pediatrics titled Diseases in Children. Also among the first books about pediatrics was Libellus de aegritudinibus et remediis infantium 1472, by the Italian pediatrician Paolo Bagellardo. In sequence came Bartholomäus Metlinger's Ein Regiment der Jungerkinder 1473, Cornelius Roelans no title Buchlein, or Latin compendium, 1483, and Heinrich von Louffenburg Versehung des Leibs written in 1429, together forming the Pediatric Incunabula, four great medical treatises on children's physiology and pathology.
While more information about childhood diseases became available, there was little evidence that children received the same kind of medical care that adults did. It was during the seventeenth and eighteenth centuries that medical experts started offering specialized care for children. The Swedish physician Nils Rosén von Rosenstein is considered the founder of modern pediatrics as a medical specialty, while his work The diseases of children, and their remedies is considered "the first modern textbook on the subject". However, it was not until the nineteenth century that medical professionals acknowledged pediatrics as a separate field of medicine. The first pediatric-specific publications appeared between the 1790s and the 1920s.

Etymology

The term pediatrics was first introduced in English in 1859 by Abraham Jacobi. In 1860, he became "the first dedicated professor of pediatrics in the world." Jacobi is known as the father of American pediatrics because of his many contributions to the field. He received his medical training in Germany and later practiced in New York City.
The first generally accepted pediatric hospital is the Hôpital des Enfants Malades, which opened in Paris in June 1802 on the site of a previous orphanage. From its beginning, this famous hospital accepted patients up to the age of fifteen years, and it continues to this day as the pediatric division of the Necker-Enfants Malades Hospital, created in 1920 by merging with the nearby Necker Hospital, founded in 1778.
In other European countries, the Charité in Berlin established a separate Pediatric Pavilion in 1830, followed by similar institutions at Saint Petersburg in 1834, and at Vienna and Breslau, both in 1837. In 1852 Britain's first pediatric hospital, the Hospital for Sick Children, Great Ormond Street was founded by Charles West. The first Children's hospital in Scotland opened in 1860 in Edinburgh. In the US, the first similar institutions were the Children's Hospital of Philadelphia, which opened in 1855, and then Boston Children's Hospital. Subspecialties in pediatrics were created at the Harriet Lane Home at Johns Hopkins by Edwards A. Park.

Differences between adult and pediatric medicine

The body size differences are paralleled by maturation changes. The smaller body of an infant or neonate is substantially different physiologically from that of an adult. Congenital defects, genetic variance, and developmental issues are of greater concern to pediatricians than they often are to adult physicians. A common adage is that children are not simply "little adults". The clinician must take into account the immature physiology of the infant or child when considering symptoms, prescribing medications, and diagnosing illnesses.
Pediatric physiology directly impacts the pharmacokinetic properties of drugs that enter the body. The absorption, distribution, metabolism, and elimination of medications differ between developing children and grown adults. Despite completed studies and reviews, continual research is needed to better understand how these factors should affect the decisions of healthcare providers when prescribing and administering medications to the pediatric population.

Absorption

Many drug absorption differences between pediatric and adult populations revolve around the stomach. Neonates and young infants have increased stomach pH due to decreased acid secretion, thereby creating a more basic environment for drugs that are taken by mouth. Acid is essential to degrading certain oral drugs before systemic absorption. Therefore, the absorption of these drugs in children is greater than in adults due to decreased breakdown and increased preservation in a less acidic gastric space.
Children also have an extended rate of gastric emptying, which slows the rate of drug absorption.
Drug absorption also depends on specific enzymes that come in contact with the oral drug as it travels through the body. The Supply of these enzymes increases as children continue to develop their gastrointestinal tract. Pediatric patients have underdeveloped proteins, which leads to decreased metabolism and increased serum concentrations of specific drugs. However, prodrugs experience the opposite effect because enzymes are necessary to allow their active form to enter systemic circulation.

Distribution

The percentage of total body water and extracellular fluid volume both decrease as children grow and develop with time. Pediatric patients thus have a larger volume of distribution than adults, which directly affects the dosing of hydrophilic drugs such as beta-lactam antibiotics like ampicillin. Thus, these drugs are administered at greater weight-based doses or with adjusted dosing intervals in children to account for this key difference in body composition.
Infants and neonates also have fewer plasma proteins. Thus, highly protein-bound drugs have fewer opportunities for protein binding, leading to increased distribution.

Metabolism

Drug metabolism primarily occurs via enzymes in the liver and can vary according to which specific enzymes are affected in a specific stage of development. Phase I and Phase II enzymes have different rates of maturation and development, depending on their specific mechanism of action. Enzyme capacity, clearance, and half-life are all factors that contribute to metabolism differences between children and adults. Drug metabolism can even differ within the pediatric population, separating neonates and infants from young children.

Elimination

Drug elimination is primarily facilitated via the liver and kidneys. In infants and young children, the larger relative size of their kidneys leads to increased renal clearance of medications that are eliminated through urine. In preterm neonates and infants, their kidneys are slower to mature and thus are unable to clear as much drug as fully developed kidneys. This can cause unwanted drug build-up, which is why it is important to consider lower doses and greater dosing intervals for this population. Diseases that negatively affect kidney function can also have the same effect and thus warrant similar considerations.

Pediatric autonomy in healthcare

A major difference between the practice of pediatric and adult medicine is that children, in most jurisdictions and with certain exceptions, cannot make decisions for themselves. The issues of guardianship, privacy, legal responsibility, and informed consent must always be considered in every pediatric procedure. Pediatricians often have to treat the parents and sometimes, the family, rather than just the child. Adolescents are in their own legal class, having rights to their own health care decisions in certain circumstances. The concept of legal consent combined with the non-legal consent of the child when considering treatment options, especially in the face of conditions with poor prognosis or complicated and painful procedures/surgeries, means the pediatrician must take into account the desires of many people, in addition to those of the patient.