Chapter 32. Airway Management in an Uncooperative Down Syndrome Patient with an Upper GI Bleed

This 33-year-old white female patient with Down syndrome (Figure 32-1) presented to the gastrointestinal (GI) service with a history of vomiting blood. You first encounter her when she is brought to the operating room at 22:00 hours with gross hematemesis and the general surgeon is going to attempt GI endoscopy to determine the site of bleeding and its cause, and attempts to stop it. Failing that, an open laparotomy is planned.

As she is being transferred to the operating room (OR) table, her only IV is inadvertently pulled out. In the past, she has had repeated episodes of aspiration pneumonia felt to be related to grossly carious teeth and is scheduled for a full mouth dental extraction in 2 weeks.

On examination, she is 5 ft 2 in (157.5 cm) tall and weighs 210 lb (96 kg) with a moderate developmental delay. Vital signs are: heart rate (HR) 122 beats per minute (bpm), blood pressure (BP) 100/80 mm Hg, and her oxygen saturation on blow by oxygen is 92% (she is combative and will not permit an oxygen mask to be applied). You suspect that she has aspirated some blood.

She is not cooperative and will not permit an IV to be restarted. She does not answer questions. She lies on her side with her head flexed forward and will not extend her neck when requested nor will she permit you to do so. She will not open her mouth as per your request and it seems that blood is everywhere.

According to the surgeon, her sister has cared for her for the past 20 years (parents are deceased). As far as her sister knows, she is perfectly healthy and has never had an anesthetic before. She is on no medication and has no allergies. Her past cardiac history is unremarkable according to the surgeon. She does not smoke.

Blood work done earlier in the day shows hemoglobin of 10.2 g/dL (102 mmol/L) and is otherwise normal.

She will require a general anesthetic with an endotracheal intubation. In addition, she is grossly uncooperative, is exhibiting some evidence of hypovolemia, has features indicative of a difficult airway, and has probably aspirated some blood.

32.2.1 What Kind of Vital Organ System Reserve Does This Patient Have?

Cardiovascular reserve: The elevated pulse rate and the narrowed pulse pressure suggest an element of hypovolemia. You are hoping that the surgeon is correct and that she has no congenital heart disease (eg, an endocardial cushion defect).

CNS reserve: She is moderately developmentally delayed and anticipated to be combative on emergence. Her response to sedative hypnotic agents and ketamine for sedation is unpredictable.

Respiratory system reserve: She is moderately obese and is expected to have some restrictive lung disease with predictable consequences. In addition, she has probably aspirated blood and has a past history of repeated aspiration pneumonias. Her saturation on blow by oxygen is 92%. It is likely that she has limited oxygen reserves and will rapidly desaturate if she obstructs, or if she is paralyzed. Postoperative mechanical ventilation is a possibility. She is in extreme regurgitation and aspiration risk.

32.3.1 Employing the Mnemonics Suggested in Chapter 1, Does This Patient Have a Difficult Airway?

On MOANS-guided airway evaluation (see Section 1.6.1), you gain no confidence that you will be able to ventilate this patient using bag-mask-ventilation (BMV) when it becomes necessary. If her neck cannot be extended, a mask seal will be difficult. She is obese and the decrease in compliance may hinder BMV.

Employing LEMON (see Section 1.6.2) to assess the difficulty associated with laryngoscopy and intubation reveals that the look of this patient suggests difficulty. When you attempt to evaluate the geometry of her upper airway, you are unable to assess the volume of her mandibular space. This is particularly problematic in a person with Down syndrome (DS) in which the initial impression is that the tongue is relatively large for the volume of the mouth. You also have no idea where her larynx is relative to the base of her tongue. You are unable to evaluate a Mallampatti and get some idea as to airway access. Additionally, she is obese and you are unable to evaluate the degree of neck mobility.

The mnemonic for difficulties in using extraglottic devices (EGDs) is RODS (see Section 1.6.3). Whether there is restricted mouth opening or not is unknown. There does not appear to be any upper airway obstruction and the airway is neither distorted nor disrupted. As mentioned earlier, she is obese and the decreased compliance (stiff) may militate against successful ventilation with an EGD.

Finally, the patient should be assessed for a potentially difficult cricothyrotomy using the mnemonic SHORT (see Section 1.6.4). There is no history of prior anterior neck surgery, hematoma, or other overlying process that masks the anatomy. However, she is obese, and in addition, one is unable to ascertain whether access to the anterior neck is possible. There is no history or evidence of radiation or tumor.

In summary, she has a potentially difficult airway and is not a candidate for a rapid-sequence induction, even though with a stomach potentially full of blood that would ordinarily be the preferred technique.

32.3.2 What Other Airway Concerns Do You Have in Patients with DS?

An increased incidence of subglottic stenosis in DS patients is well known.1-4 This has been attributed, at least in part, to the increased incidence of regurgitation and aspiration in these patients during infancy and early childhood.1 Therefore, these patients may require an endotracheal tube that is one to two sizes smaller than the standard size appropriate for the patient's age. In addition, the DS patient is predisposed to obstructive sleep apnea due to a relatively narrow nasopharynx and large tongue.5,6

C-spine subluxation is also seen in these patients and may be of concern in airway management.7 Presently there is no consensus of opinion with respect to the need for preoperative radiological evaluation of the cervical spine for subluxation for patients with DS.

32.3.3 What Are the Airway Management Options?

This patient gives every indication that the management of her airway will be difficult. However, the more pressing problem is deciding how to pharmacologically manage her behavior without compromising her ability to maintain ventilation and oxygenation, to permit either an IV start and/or to gain control of the airway in a controlled fashion that minimizes the risk of aspiration.

Ideally, one would like to identify a preferable airway technique (Plan A), and two alternative methods (Plans B and C). However, with the limited airway evaluation, the most appropriate method chosen must have the least chance of producing apnea, aspiration, or a requirement for rapid action. In addition, the presence of copious amounts of blood in the airway is likely to render indirect visualization techniques (endoscopes, video laryngoscopes, optical stylets) to be of limited use. This really leaves one primary option for consideration: sedation and awake intubation employing a laryngoscope.

Plans B and C will likely include an EGD and the surgeon should be prepared to perform an immediate surgical airway if asked (a double set-up). One would be wise to consider the immediate availability of a lightwand (eg, Trachlight™) if the airway practitioner is sufficiently skilled in its use (see Chapter 11).

32.4.1 What Are the Pros and Cons of the Awake/Sedated Method?

Clearly the sedation and awake intubation approach is not without hazards. The use of sedative hypnotic agents in large oral or intramuscular dosages may provoke paradoxical excitement, or worse, lead to hypoventilation or apnea.

Ketamine is an attractive option. Seven mg·kg−1 (ideal body weight)8-11 can be given orally with the expectation that the patient will be dissociated within 20 minutes, at least to the point that an IV can be placed. If the degree of cooperation is not sufficient after this dose, half the original dose can be repeated at 20 minutes.

Clearly this is not an option in this case. Four mg·kg−1 of ideal body weight IM produces reliable sedation and dissociation in approximately 5 minutes.11-15

The margin of safety with ketamine is greater than other sedative hypnotics, such as midazolam, as it preserves ventilatory function, muscle tone, and airway protective reflexes. The disadvantages of ketamine include the risk of laryngospasm, increase in secretions, emergence reactions, and postprocedure nausea and vomiting

32.4.2 How Exactly Would You Manage the Airway of This Patient?

To prepare for airway management the neck of the patient is prepared in as sterile a fashion as the circumstances will allow and the surgeon and OR team are prepared to perform a surgical airway (double set-up). Ketamine 4 mg·kg−1 is then drawn up and ready to administer IM. Propofol 200 mg and succinylcholine 140 mg are also drawn up. Additionally, an assistant is prepared to place an IV on command if possible. A central line access kit is immediately available.

The following airway devices are immediately available for use:

• Styletted endotracheal tubes (ETTs) of various sizes (5, 6, and 7 mm ID)
• Two suctions with rigid suction handles
• LMA-Fastrach™ (Intubating LMA)
• Trachlight loaded onto a 7 mm ID ETT cut at 26 cm
• Video laryngoscope at the ready
• Flexible bronchoscope at the ready
• Topical local anesthetic spray (eg, 4% lidocaine in a syringe attached to a Mucosal Atomization Device [MAD])

The patient is then placed in the left lateral position on the OR table. An antisialogogue is not administered because it must be administered intramuscularly (see later). A pulse oximeter is applied when the patient permits, as is supplemental oxygen.

When all is ready, the ketamine is administered IM. Sufficient sedation/dissociation is typically achieved within 5 minutes. To permit an IV placement, gradual initiation of Sellick maneuver and an awake look is initiated. If the awake look indicates that orotracheal intubation is likely to be successful, then rapid-sequence intubation (RSI) may be performed, or if the patient is intubated immediately following the awake look, propofol can be administered rapidly after the airway is secured and confirmed. The dose of propofol administered must take into consideration the likelihood of hypovolemia.

Failure to visualize the airway adequately to intubate, or assure that intubation is possible if RSI is employed, in the face of ongoing acceptable oxygen saturations may lead one to resort to Plan B. In the event adequate oxygen saturation cannot be maintained, a surgical airway is immediately performed.

32.4.3 How Exactly Was the Airway of This Patient Managed?

After adequate sedation was achieved with IM ketamine, an awake look was performed in the left lateral decubitus position using a #3 Macintosh laryngoscope. About 50% of the glottis was visualized and tracheal intubation was achieved using a #7.0 ETT. After confirmation of the proper tracheal tube placement using end-tidal CO2, the patient underwent volume resuscitation and sedation was carefully titrated using IV propofol. GI endoscopy revealed a bleeding duodenal ulcer. Hemostasis was achieved. The patient was transferred to the ICU intubated and ventilated for further evaluation of her presumed aspiration and ventilatory management.

32.5.1 Should an Antisialogogue Be Given When Ketamine Is Employed?

As a general comment, antisialogogues are typically used whenever topical anesthesia of the oro- and hypopharynx is to be attempted because it minimizes the dilution of local anesthetic agent by saliva and improves the degree of topical anesthesia achieved. In this particular case, it was omitted because it would have required an IM injection.

Ketamine does stimulate tracheobronchial and salivary secretions, and this effect of the drug can potentially cause laryngospasm.12 An antisialogogue, such as glycopyrrolate or atropine, is often given IM 15 to 20 minutes prior to the administration of ketamine to reduce these secretions. Glycopyrrolate is preferred because it produces less intense tachycardia. Unlike other tertiary-substituted antimuscarinics (scopolamine and atropine), glycopyrrolate is a polar quaternary-substituted ammonium compound, which does not cross the blood–brain barrier and therefore avoids the risk of producing confusion and sedation.

32.5.2 How Common Is Laryngospasm with Ketamine?

Laryngospasm is associated with all of the sedative hypnotics to some extent, including ketamine. The incidence of laryngospasm with ketamine is about 1% (ranging between 0.017% and 1.4% in various studies, including studies with data from over 11,000 patients).13-16 It manifests as transient stridor. It is likely related to ketamine-induced sensitization of laryngeal reflexes, and in some cases is thought to be related to excessive upper respiratory secretions.12 Thus, the recommendation has been made that an antisialogogue be coadministered with ketamine. Risk factors for laryngospasm include respiratory infection (fivefold increase) and age (three times greater risk in infants aged 1-3 months than the average).17 One study of nearly 1200 pediatric patients with laryngospasm reported the incidence of complications as hypoxia 3.2%, aspiration 1.1%, and cardiac arrest 0.5%.15

32.5.3 How Common Are Emergence Reactions with Ketamine?

Emergence delirium is the most common side effect of ketamine.18 This response is thought to be caused by the drug's depression of CNS visual/auditory relay nuclei causing altered perception and interpretation of visual and auditory stimuli.19 The occurrence of emergence reactions is associated with age (adults > children), gender (females > males), anxiety level, and psychological state prior to the procedure.18,20,21 The incidence varies but may be as high as 10% to 30% in adults with a much lower occurrence in children. Severe agitation occurs in 1.6% and mild agitation in 17.6% of pediatric patients.19 Emergence reactions are less common in older children (12.1% in those more than 5 years vs 22.5% in children under 5 years of age).20

Small doses of midazolam have been used to treat severe emergence reactions. However, the prophylactic coadministration of benzodiazepines is not recommended since they have no proven benefit, delay ketamine metabolism thereby prolonging recovery, may actually increase the incidence of recovery agitation in specific patient populations, and increase the risk of respiratory depression.17,22-29

32.5.4 Should These Patients Be Recovered in a Dark and Quiet Environment to Prevent Emergence Reactions?

Whether or not a quiet, secluded environment which limits stimuli during the post-recovery period decreases the incidence of emergence reactions is debatable.12 Some suggest that pre-procedure discussions with the patient (adult or child) have a greater impact on reducing the incidence of recovery agitation.12,23 However, the prevailing impression is that less stimulation is advantageous.

32.5.5 How Often Do Patients Given Ketamine Vomit Post-Procedure?

Vomiting occurs in 6.7% of patients, which often persists into the recovery phase, and is also age related, being more common in younger children (12.5% incidence in children under 5 years vs 3.5% in those more than 5 years of age).20 There have been no documented reports of clinically significant aspiration with ketamine when used in patients without contraindications.26

This case study serves as a prototype for the uncooperative, difficult airway with a full stomach, has incipient hemodynamic instability, and is an emergency. Time to plan an approach is limited and hindered by the fact that the patient has no venous access. In an emergency, one does not have the luxury of time, and rigid adherence to the difficult and failed algorithms is advised.

Patient control is achieved with IM ketamine thereby allowing successful IV access. The difficult airway algorithm (Chapter 2) was employed to guide actions directed to managing the airway in this patient. At each step, the imperative is to ensure that adequate gas exchange occurs and one does not burn bridges.