The timing of the preoperative evaluation could be influenced by the demographic characteristics, the institutional organization, the patient’s clinical condition, and the surgical procedure. The organizational system used for the clinical evaluation and preoperative risk stratification and clinical planning varies among institutions and type of intervention [15].

Hospitalization of healthy children for a preoperative evaluation the day before surgery should be considered as improper in most minor elective surgical procedures. A day hospital stay does not reduce costs nor does it save time because the patient should be evaluated again on the day of surgery [16].

The ASA-PS can provide suggestions on the timing of preoperative visit [17]. The ASA Task Force on Preanesthesia Evaluation suggested that for low-risk patients undergoing low grading procedures, preanesthesia could be performed the same day of the surgery [18]. The “one-stop anesthesia” modality is a clinical pathway designed for day surgery procedures (Fig. 2.1). This modality reduces the access to the hospital for day surgery interventions with significant social, psychological, and economic advantages. It is also characterized by a high diagnostic accuracy and a high parents’ satisfaction [19–23]. The “one-stop anesthesia” is a modification of the “one-stop surgery” where patients are screened before the procedure by external specialists [24, 25].

The preoperative evaluation of high-risk patients and/or scheduled for major surgery should be performed before the day of surgery [23, 26]. Nurses and the pediatrician have a central role on the screening and preparation of the surgical patient independent of the type of surgery [27–30].

The preoperative risk stratification has organizational consequences including the care settings (in hospital, day of surgery), the postoperative care levels (e.g., PACU, PICU, etc.), and the selection of the institution (hospital vs ambulatory surgery center) [31].

The preoperative assessment should precede any request of laboratory and instrumental tests. The anamnesis usually takes advantage of questionnaires, submitted to parents, in a “face-to-face” procedure, by phone, online, or compiled at home [32, 33] (Appendix A). As an assessment support, it is also possible to use a specific software, which helps to reduce the amount of preoperative tests [34]. The medical history should provide information of all the present and past medical problems. It should include extensive information of medication intake including natural medicines. Any allergic reaction to food, medications, or other substances (e.g., latex) must be addressed.

When looking for information regarding previous anesthesia experiences, it is extremely important to focus the airway management and respiratory or cardiovascular complications. It is also important to consider the postoperative consequences of anesthesia and surgery like nausea and vomiting, pain or unsettled behavior (i.e., emergence delirium) during awakening, and behavioral changes persisting days or weeks after surgery.

The family history should include information of genetically transmitted diseases (malignant hyperthermia, neuromuscular disease, etc.), cases of unexplained deaths, bleeding disorders, passive smoking, or other environmental or social conditions.

The preoperative evaluation can also be an opportunity to observe the parent’s behavior and the relations within the family, with indications of the possible preoperative anxiety level.

A thorough assessment of the airway; the cardiovascular, respiratory, and nervous system; and the state of hydration should be performed before any procedure including anesthesia. The physical examination should take into account the awareness of the motor, cognitive, language, and social development of the child [35].

The physical examination may vary according to the age of the patients. The physical examination of infants should be flexible, in order to take advantage of the periods in which the child is quiet or asleep, to auscultate the lungs or heart in the parents’ arms. Better collaboration results can be achieved with a pacifier, a smile, a comforting speech, and the use of toys or custom distraction.

Toddlers can be active, curious, or, conversely, shy or less cooperative. Much of the neurological and musculoskeletal assessment may be inferred from the child observation when playing and walking into the visit room. The anxiety reduction can be achieved with a demonstration of the instrument use on the parent or on his reassuring object (e.g., his moppet, favorite toy, etc.).

Providing preschool child’s simple explanations of the evaluation phases is always useful. Inviting them to count, explain the colors, talk about a favorite activity, and externalize your approval is all useful strategies during the evaluation.

The school-age children willingly cooperate during the examination. They appreciate the information regarding what you do and why you are doing it.

Teenagers may show concern about their developing body. The choice of performing the physical exam with the parents belongs to the patient.

The body weight and length should be measured and compared with the reference values. During the first 4 years of life, there is a rapid growth rate. The height, with minimal difference between the sexes, increases on average, by 24 cm in the first year of life, by 11 cm in the second year, by 8 cm in the third, and by 7 cm in the fourth. Babies double the birth weight around the 5th months. Their weight triples around the 1st year and quadruples around the 2nd year. From four years old to the beginning of puberty, the growth is more restrained and relatively constant in time. The stature increase is on average 5–6 cm per year in both male and female children. The weight gain per year varies between 1,770 and 2,800 grams [36]. The Pediatric Early Warning Score (PEWS) could be useful in children with abnormal physical examination and/or in emergency situation and may provide additional clinical elements for the evaluation of children undergoing urgent surgical procedures [37].

Preoperative test and radiological studies should not be requested on a routine basis [16]. The indications for these investigations should be documented and based on the information derived from the medical history and physical exam and/or justified by the proposed surgical procedure.

The American Academy of Pediatrics stated, “preoperative tests should be ordered only when they can provide added value, i.e., when there is a reasonable certainty that they will reveal, or better define the clinical conditions that are relevant to the planned anesthesia and/or may affect the anesthesia or surgical outcome” [38]. Specific tests could be requested for diagnostic purposes (e.g., a cardiac ultrasound for exclusion of unknown congenital heart disease), for therapeutic purposes (e.g., allergy tests to exclude cross allergy conditions), and when it is appropriate to have baseline value (i.e., concentration of Hb in a potentially bleeding operation) [39].The usefulness of routine preoperative laboratory tests for one-day surgery in healthy children was confirmed from some Italian authors since several years [40].

Several national societies produced guidelines and recommendations for the preoperative tests. The National Institute for Health and Clinical Excellence (NICE – UK) suggested to avoid request routine test for patients younger than 16 years ASA1 scheduled for elective surgery grade 1 and 2 [41]. For the Italian Society of Pediatric and Neonatal Anesthesia and Intensive Care (SARNePI), the “systematic prescription of complementary tests in children should be abandoned, and replaced by a selective and rational prescription, based on the patient history and clinical examination” [16]. Those recommendations are based on non-randomized cohort studies with concurrent or historical controls, retrospective case-control studies or case series without control groups. A previous blood test (within 6 months) should only be repeated in case of significant changes on the previous clinical conditions.

There is no justification for the routine examination of hemoglobin and hematocrit before minor surgery, and it should be restricted to potentially bleeding surgical cases [42]. The incidence of anemia in children is rare and occurs more easily in infants younger than 1 year. Moreover, the presence of a certain level of anemia does not affect the decision to proceed with surgery [43, 44].

The determination of blood glucose cannot predict the blood glucose concentration at the time of induction. Numerous studies have actually shown a minimum risk of hypoglycemia in children even after prolonged fasting.

The measurement of plasma electrolytes is not justified in asymptomatic children and should be required only in the presence of vomiting, diarrhea, use of diuretics, or other conditions associated with acid-base modifications [45].

There is consensus on the uselessness of nonselective coagulation screening. This test should be restricted to patients with history of coagulopathy and/or as a baseline measure for procedures with high risk of significant bleeding. The routine request of coagulation tests before ENT surgery or central blocks remains one of the most controversial topics of the perioperative care. Most studies show low sensitivity, specificity, and predictive value of partial thromboplastin activated time, prothrombin time, and thrombin time [46–50]. Moreover, false-positive aPTT prolongation is commonly associated to nonspecific antiphospholipid antibodies often present in children with ENT infections or after vaccination [48, 49]. Standardized questionnaires have shown better sensitivity and negative predictive values than aPTT as coagulation screening before surgery. However, it is difficult to find hemorrhagic signs in small children. The impossibility of obtaining a family history of one or both parents’ may compromise the reliability of the questionnaire [51].

Routine request of a preoperative ECG is not recommended in healthy children [52]. The SARNePI recommended the request of a preoperative ECG eventually associated to a cardiac ultrasound in case of pathologic/uncertain heart murmur, suspicion of congenital heart disease, obstructive sleep apnea, severe scoliosis, bronchopulmonary dysplasia (BPD), neuromuscular disease, and in neonates/infants under 6 months of life [16]. The ECG in newborns and infants can detect conduction abnormalities, such as long QT syndrome (LQTS) and the Wolff-Parkinson-White one (WPW) [53]. Investigating maternal factors and fetal factors associated to sudden infant death (smoking, alcohol, intrauterine hypoxia, prone position while asleep, and passive smoke) should be also part of the standard preoperative evaluation. Some congenital heart diseases have asymptomatic evolution during the first weeks after birth [54]. A recent study reveals that up to 30 % of babies and infants with congenital heart disease were discharged from the hospital without diagnosis [55]. Routine physical exam looking for a congenital heart disease between the sixth and eighth week of life is highly recommended.