Equipment guidelines: Pearls and pitfalls

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8 Equipment guidelines

Pearls and pitfalls

Chapter Contents

Resuscitation equipment

Normal vital signs

Initial ventilator settings

The paediatric resuscitation room

This section is intended to assist you by providing practical tips that are usually only learnt by experience. For all the disposable and reusable equipment, advice is given based on a combination of evidence, best practice, familiarity and availability of possible alternative options.

Resuscitation equipment

Laryngoscope blade

Traditionally, a straight blade (e.g. Phillips/Miller/Wisconsin) is advised when performing direct laryngoscopy in a child in order to control the large epiglottis. The reality is that either a curved (Macintosh) or a straight blade may be used, depending on the preference of the laryngoscopist. Similarly, the actual size of blade selected is not important as long as the cords are well visualized, dependent both on laryngoscopist comfort and on anatomical factors.

Endotracheal tubes – cuffed vs. uncuffed

A decade ago children were always intubated using uncuffed ETTs but recent research supports the routine use of cuffed ETTs in children over 6 months of age.

Advantages of a cuffed ETT:

• helps to prevent aspiration of gastric contents

• prevents the leakage of ventilation past the ETT leading to gastric insufflation

• the use of the exact size is less important than with an uncuffed tube.

Disadvantages of an uncuffed ETT:

• inability to accurately measure tidal volumes

• more prone to displacement in the trachea

• must fit tightly – recent evidence suggests that pressure-related complications might be higher with uncuffed tubes.

While preparing for the intubation, always have the estimated size ETT as well as tubes with an internal diameter 0.5 mm smaller and 0.5 mm larger than the expected size available. Length-based resuscitation tapes are more accurate than age-based formulas in estimating the ETT size for children up to approximately 35 kg. The size of the nostril or the little finger should never be used.

ETT cuff pressures must be monitored with a cuff pressure manometer as subjective assessment of cuff pressure is totally unreliable. Pressures should be kept less than 20 cm H2O and just enough to ensure that there is no leakage of air during positive pressure ventilation.

ETT depth

Unlike adults, the correct position of the ETT is in the mid-trachea. Although most texts suggest that ETT position should be guided by ensuring that the two transverse cord marker lines on the ETT are positioned at the level of the child’s vocal cords, the position of these lines can be variable, depending on the manufacturer, and is therefore not advised. Formulas for depth of insertion are often promoted but still are probably not the most accurate way of estimating depth. A useful rule of thumb is to convert the ID into a distance in centimetres that the ETT should be passed distal to the vocal cords. This will apply to both the full size and half size ETT: the tip of a size 4 and 4.5 mm ID ETT should be positioned 4 cm distal to the vocal cords. The technique of using palpation of the ETT in the neck to estimate the depth of insertion is unreliable and should not be used. Depth can be maintained consistently via in-line immobilization of the head and appropriate padding behind the torso or head, depending on age. Any flexion, extension or lateral movement of the head can lead to ETT displacement.

Introducer (stylet)

An introducer should be used in all intubations unless a bougie (tracheal tube introducer) is going to be used. Ensure that the tip of the introducer does not protrude past the tip of the ETT as this may cause trauma to the airway. Bend the tip to about (but no more than) 30° to optimize the chances of first-time intubation success. It is worthwhile to lubricate the stylet prior to inserting it into the ETT to aid in its removal postintubation.

Bougie (tracheal tube introducer)

A bougie should be readily available. This is an intubating stylet that is longer than the standard ETT introducer. A suitable water-based lubricant (or lidocaine spray) should be used for ease of insertion and removal of the bougie once intubation is achieved. Although useful as an adjunct for difficult airways (e.g. Cormack Lehane Grade 3A), the device may be used on easier airways in order to practise and maintain the skill for when it is truly required.

Oropharyngeal airway

The Guedel airway and the Berman airway are two versions of this commonly used device. It is a useful airway adjunct to open an airway in unconscious bag–mask ventilated patients. The size can be estimated by measuring from the corner of the mouth to the angle of the mandible. During insertion the tongue should be controlled by a tongue depressor or laryngoscope blade while inserting the airway along the curvature of the pharynx. Do not insert the airway upside-down and rotate it in the mouth as this can cause trauma to the pharynx.

Nasopharyngeal airway

A nasopharyngeal airway is a valuable adjunct in patients who are unconscious or semi-conscious. A well-lubricated airway can be inserted with the bevelled edge aligned with the septum of the nose. This avoids trauma to the turbinates as well as the nasal septal mucosa. Care should also be taken to ensure that it is inserted parallel to the floor of the nasal cavity to avoid trauma to the turbinate mucosa. Do not use if a base of skull fracture is suspected. There is no evidence to suggest the optimum measurement for nasopharyngeal airway size. The distance from the nostril to the ipsilateral tragus is commonly used.

Bag–valve resuscitator

The bag–valve resuscitator must be tested before use. This can be done in the following easy steps:

1. Place a hand underneath the patient-connection end.

2. Squeeze the self-inflating portion of the bag and check that air is expelled.

3. Seal the patient-connection end with the palm of your hand.

4. Squeeze the self-inflating portion of the bag and check that there is no leakage in the rest of the bag.

5. If a pop-off valve is present, perform the abovementioned steps first with the valve open, and secondly with the valve closed.

6. Lastly, the reservoir should be attached to the patient-connection end and held in place while the self-inflating portion of the bag is squeezed repeatedly. This should inflate the reservoir bag completely, and reveal any leaks in the reservoir. This also exposes any fault with the one-way non-return valve of the bag–valve resuscitator: if the reservoir inflates and deflates, this may indicate that the one-way valve is dysfunctional.

The infant bag–valve resuscitator should be used on children less than 10 kg. The paediatric bag–valve resuscitator can be used on patients weighing 10–39 kg. The adult bag can be used on patients weighing more than 40 kg. The adult bag can be used on patients weighing less than 40 kg – during ventilation the bag–valve resuscitator should be compressed only with the force required to obtain adequate chest rise.

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