Paediatric trolley equipment

Allman and Wilson (2006) recommended that a paediatric anaesthetic trolley should contain a variety of anaesthetic equipment. The items required are (Subhash 2004, Allman and Wilson 2006, The Royal College of Anaesthetists 2015):

• A Magill forceps.
• Suction equipment.
• Electrocardiograph.
• A bag-valve-mask resuscitator (self-inflating resuscitation bag).
• A bougie and/or intubation stylet.
• Airway management equipment, including capnographic equipment.
• An appropriate breathing circuit.
• A paediatric pulse oximeter.
• Paediatric blood pressure cuffs.
• Paediatric vascular access equipment, including intraosseous needles.
• Burettes and syringe pumps for rapid and accurate fluid and drug delivery.
• Temperature probes.
• An appropriate defibrillator.
• Paediatric laryngoscopes.

Breathing circuits

Definition

A breathing circuit is a construction of components that connect a patient’s airway to an anaesthetic machine.

The circuit transports anaesthetic gases and oxygen to and from the patient (Davey and Ince 2004). One of the main considerations for anaesthetic equipment for the paediatric patient is the removal of as much dead space as possible in the breathing circuit; it should also be lightweight, offering low resistance in spontaneous breathing (Subhash 2004, Allman and Wilson 2006). For this reason a catheter mount should not be used (Allman and Wilson 2006).

Children weighing less than 20kg

Non-rebreathing circuits, such as the Ayre’s T-piece or modified Ayre’s T-piece (Mapleson F classification), are generally used for children weighing under 20kg. This has a double-ended reservoir bag; one end attaches to the circuit, the other is open to the atmosphere and can be occluded if intermittent positive pressure ventilation is required. The bag allows for an indication of respiratory movements (Allman and Wilson 2006, Anaesthesia UK 2014). It produces minimal dead space and resistance to breathing.

The T-piece has an adaptor for oxygen cylinders, which should always be kept in case the patient needs to be transferred to the recovery area with the T-piece. A paediatric breathing filter, to which capnography, an angle piece and a face mask can be connected, should be attached at the patient end. The T-piece is connected to the auxiliary common gas outlet of the anaesthetic machine, and the lever is opened to activate the outlet. Always ensure the common gas outlet is closed once it is no longer in use.

Children weighing more than 20kg

If the patient weighs more than 20kg, usually around seven years of age, a normal circuit may be used with a 0.5L reservoir bag, paediatric filter and angle piece or a paediatric circle circuit that connects directly to the gas and scavenging outlets of the anaesthetic machine, as with an adult circuit. If there are different opinions or the child is on the cusp of another age bracket or size, ask the anaesthetist what they would prefer. If changing circuits between patients, a leak test should be performed in accordance with the manufacturers’ guidelines.

Oropharyngeal airway

Definition

The oropharyngeal or Guedel airway is a curved airway adjunct placed into the mouth to assist with ventilation or keep the airway of a patient open pre or post-extubation.

It is important to use the correct size because failure to do so may cause airway obstruction. This adjunct is usually inverted during insertion, except in the case of infants, because they have a soft palate that may be traumatised easily (Allman and Wilson 2006).

Nasopharyngeal airway

The nasopharyngeal airway is of limited use in the paediatric airway, but may be better tolerated at lighter levels of anaesthesia, compared with an oropharyngeal airway. It may be used during induction and recovery for patients with some congenital airway problems and in children with obstructive sleep apnoea. This adjunct should be lubricated before use. Measurement for the correct size should be taken from the tip of the nostril to the tragus of the ear (Allman and Wilson 2006).

Face masks

Definition

Face masks are of clear plastic with an inflatable rim, shaped like a teardrop, or round in the case of neonates (Allman and Wilson 2006).

The masks allow for observation of breathing (misting of the mask) and regurgitation. Face masks should be clear and fit the child’s face closely; this can sometimes be difficult since the face of a child is relatively flat as compared with that of an adult (Phillips 2007). The size is estimated so that it fits from around the bridge of the nose to the cleft of the chin (Allman and Wilson 2006).

Laryngoscope

There are a variety of shapes and sizes of laryngoscope available and use of a particular one may depend on the anaesthetist’s preference. However, anatomical differences in the paediatric patient may also dictate which to use. Up to the age of about four or five, the epiglottis may be too floppy to allow visualisation of the vocal chords using a curved laryngoscope blade, and so a straight blade should be available (Adewale 2009).

Allman and Wilson (2006) advocated the use of a straight blade, particularly for children under six months old. In the healthcare organisation where the author works, it is standard practice to have both available on the paediatric airway trolley, but the size two Macintosh (curved blade) is most commonly used. Varghese and Kundu (2014) found that both the Miller (straight blade) and the Macintosh provided similar views and ease of intubation in patients aged between one and 24 months.

Complications

Complications may occur during the induction, maintenance or post-operative stages of paediatric anaesthesia. However, all possible eventualities are beyond the scope of this module. If a ‘can’t intubate, can’t ventilate’ situation occurs, the child should be awakened, as in adult anaesthesia (Prasad 2012). One of the most common problems the operating department practitioner or anaesthetic nurse is likely to encounter is laryngospasm. The management pathway for laryngospasm is provided in Figure 5.

Laryngospasm is caused by stimulation of the pharynx, for example, by suctioning or by obstruction from mucus, blood and/or any other material. It is more common in children, especially those aged less than nine years, than in adults (Allman and Wilson 2006). Patients with Down’s syndrome are also more susceptible to laryngospasm (Hatfield and Tronson 2009). The use of inhalation induction, presence of asthma and upper respiratory tract infection also increase the risk.

Figure 5

Laryngeal spasm causes the glottis to close tightly; it is the body’s emergency response to prevent foreign material from entering the lower respiratory tract (Hatfield and Tronson 2009). Often no air at all passes through the tight closure, but occasionally, if partially closed, stridor is heard; tiny amounts of air can pass but are insufficient for normal body functioning. A child will become cyanosed more rapidly than an adult because of their increased metabolic demand for oxygen and low functional residual capacity.

Learning points

1. A breathing circuit is a construction of components that connects a patient’s airway to an anaesthetic machine where the circuit transports anaesthetic gases and oxygen to and from the patient. Non-rebreathing circuits, such as the Ayre’s T-piece or modified Ayre’s T-piece are generally used for children weighing under 20kg.
2. The oropharyngeal or Guedel airway is a curved airway adjunct placed into the mouth to assist with ventilation or keep the airway of a patient open pre or post-extubation.
3. Laryngospasm is caused by stimulation of the pharynx, for example, by suctioning or by obstruction from mucus, blood and/or any other material. It is more common in children, especially those aged less than nine years, than in adults.
4. Laryngeal spasm causes the glottis to close tightly; it is the body’s emergency response to prevent foreign material from entering the lower respiratory tract. Often no air at all passes through the tight closure, but occasionally, if partially closed, stridor is heard; tiny amounts of air can pass but are insufficient for normal body functioning.