How is the operating room prepared for this newborn?

How is the operating room prepared for this newborn?

Before any pediatric patient is brought to the operating room, appropriately sized equipment must be prepared for both anesthesia and surgery. Mnemonics may be used to aid in making sure that all critical equipment is available. This has added importance when preparing for a neonate, infant, or child because they will require equipment that is not normally stocked in the operating room, except in a pediatric hospital. A useful mnemonic is MADIMS, which stands for Machine, Airway, Drugs, Intravenous, Monitors, and Suction.

Machine

Preparing the machine includes following the standard US Food and Drug Administration (FDA) Anesthesia Apparatus Checkout Recommendations, 1993. It is necessary to choose a breathing circuit, either a Mapleson D or a pediatric circle system. The pediatric circle system differs from the adult in that it has hoses that are of lower volume and compliance, which may allow for more constant tidal volumes. Also, heated humidified circuits are available, which can conserve heat and decrease evaporative losses. Some older anesthesia machines have separate pediatric bellows, which may increase the accuracy of delivering very small tidal volumes. Also, the ability to add air to the gas mixture should be assured. This may be necessary for the premature infant, when nitrous oxide cannot be used, in order to avoid high arterial oxygen partial pressures and limit the risk of retinopathy of prematurity.

Airway

Airway equipment is available in all sizes and styles and the anesthesiologist should use the equipment with which he or she is most familiar. The key is to have the appropri-ate sizes available. This includes masks, oral airways, laryn-geal mask airways, endotracheal tubes (ETT), and laryngoscope blades. The best way to be prepared is to have the size that you think you will need and also one size above and below that size. Oral airways are available from size 000 (very small premature neonates) to 9 (large adult). Nasal airways are rarely used in young children due to the risk of adenoidal hemorrhage and the small lumen of the nares. A straight laryngoscope blade (Miller 0 for preterm infants, Miller 0–1 for full-term infants) is often used in neonates and infants.

Uncuffed ETTs have historically been used in infants and children under age 7 years, but a new trend is developing for the use of cuffed tubes in younger age groups. There are many factors to consider when making this decision. In a young child, the narrowest portion of the airway is at the cricoid ring. An ETT should be selected that is neither too small to adequately ventilate the patient nor too large to cause damage to the subglottic area. An important factor, whether the ETT is cuffed or uncuffed, is to have an appro-priate air leak, which is <30 cm H₂O in most cases. A general rule for choosing uncuffed tubes in children ages 2 years and above is: [Age + 16]/4.

If a cuffed ETT is chosen, it should be a half-size smaller. Most full-term neonates will have an appropriate leak with a 3.0 uncuffed ETT, and by a few months of age a 3.5 uncuffed ETT can be used (Table 65.1). After placing the correct size ETT, it is critical to secure it well since even the slightest movement of the ETT in a neonate could result in a mainstem intubation or extubation. If a cuffed ETT is used, the cuff should be inflated only if the air leak is less than that needed to provide adequate positive pres-sure ventilation. A leak at <30 cm H₂O should be present. During the course of the case, the air leak should be checked since the use of nitrous oxide as part of the anesthetic may increase the volume in the cuff. If lung compliance changes during surgery, it may be necessary to add air to the cuff to increase the air leak pressure and improve ventilation.

Drugs

Drugs refer to both the anesthetic and non-anesthetic medications that should be drawn up and immediately available during the anesthetic. These include induction agents, muscle relaxants, and opioids, as well as emergency medications such as atropine and epinephrine. The appro-priate dose of these drugs should be determined in advance, based on the weight of the patient, and drawn up in an appropriately sized syringe.

Intravenous

Intravenous fluid and supplies for placing an intravenous line should be available in the operating room. A buretrol should be a part of the set and no more than 10 mL/kg of fluid should be in the buretrol at any time to prevent fluid overload if it accidentally ran in quickly. All air bubbles should be removed from the intravenous tubing because there is a high incidence of patent foramen ovale in neonates.

Monitors

Monitors should include all those set forth by the American Society of Anesthesiologists (ASA) in their Standards for Basic Intraoperative Monitoring, last amended in October 1998. All other monitors will be based on the clinical condition of the patient and the type of surgery planned.

Suction

Suction should be immediately available and within easy reach of the anesthesiologist. A Yankauer is the best for large volumes because of its large holes, but in small infants it may be necessary to use smaller suction catheters.

Methods for maintaining normothermia in the neonate should also be made available. This is best accomplished with a forced-air warming blanket and warming of the operating room.