This 33-year-old white female patient with Down syndrome (DS) (Figure 35–1) presented to the gastrointestinal (GI) service with a history of vomiting blood. You first encounter her when she is brought to the operating room (OR) 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 attempt to stop it. Failing that, an open laparotomy is planned.

As she is being transferred to the OR table, her only intravenous (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) (BMI 38.4) with 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 a hemoglobin of 10.2 g/dL (102 mmol·L⁻¹) and is otherwise normal.

She will require a general anesthetic with 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.

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 (e.g., an endocardial cushion defect).

CNS reserve: She is moderately developmentally delayed and anticipated to be uncooperative and combative on induction and 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 becomes apneic. Postoperative mechanical ventilation is a possibility. She is an extreme regurgitation and aspiration risk.

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

On MOANS-guided airway evaluation (see section “Difficult BMV: MOANS” in Chapter 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 and CRANE (see sections “Difficult DL Intubation: LEMON” and “Difficult VL Intubation: CRANE” in Chapter 1) to assess the difficulty associated with direct and indirect (video) 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 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 Mallampati score and get some idea as to airway access. Additionally, she is obese and you are unable to evaluate the degree of neck mobility. You call for the video-laryngoscope to be available.

The mnemonic for difficulties in using extraglottic devices (EGDs) is RODS (see section “Difficult Use of an EGD: RODS” in Chapter 1). 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 “Difficult Cricothyrotomy: SHORT” in Chapter 1). 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.

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 (ETT) 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.

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 how to pharmacologically manage her behavior without compromising her ability to maintain ventilation and oxygenation and permit either an IV placement 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 direct laryngoscopy.

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 setup). One would be wise to consider the immediate availability of a lightwand if the airway practitioner is sufficiently skilled in its use (see Chapter 12).

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 post-procedure nausea and vomiting.

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 setup). 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:

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  Styleted ETTs of various sizes (5, 6, and 7-mm ID)

  
  
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  Two suctions with rigid suction handles

  
  
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  LMA-Fastrach™ (intubating LMA)

  
  
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  Lightwand loaded onto a 7-mm ID ETT cut at 26 cm

  
  
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  Macintosh laryngoscope with a #3 blade at the ready

  
  
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  Video-laryngoscope with both direct and indirect laryngoscopy capability (e.g., CMAC, Karl Storz Endoscopy-America, Inc.) at the ready

  
  
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  Flexible bronchoscope at the ready

  
  
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  Topical local anesthetic spray (e.g., 4% lidocaine in a syringe attached to a mucosal atomization device [MAD])