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However, if topicalization is difcult due to the presence of an abscess or an uncooperative patient, an inhalational induction may still be a reasonable approach in the
adult patient. In a review of the literature, only one recent case report had been
found describing an inhalational induction with VL.However, this attempt was
unsuccessful, mandating the need for a surgical airway [36].
A. Dardeer et al.
26.3.3 Direct Laryngoscope (DL) Versus Video Laryngoscope (VL)
The debate of whether VL should be implemented initially in difcult cases or to
give DL a chance is seen on a daily basis among experts. Some argue that a wellpositioned patient with enough time to pre-oxygenate and having adjuncts, like a
gum elastic bougie (GEB) or an intubating malleable stylet, can guarantee the success of the rst attempt for DL, and although VL improves glottis visualization, this
is usually at the expense of prolonged tracheal intubation times and does not necessarily translate into easier intubation. However, VL has denitely earned its place in
modern practice. Avoiding the need to align oral and pharyngeal axes, VLs convert
a difcult view into a relatively easy procedure. Several studies have shown that
VLs improve intubation conditions in morbidly obese patients [37]. Using a screen
to view, the intubation procedure turns it into a task performed and guided by a
team. The team approach may optimize intubation attempts, limit unnecessary
manipulations and trauma, and can help prevent errors such as esophageal intubations. It is also possible to record the intubation process for teaching purposes and
legal documentation [38]. VLs can also be effectively used in awake techniques. It
is useful to highlight that not all VLs are equal. Unfortunately, no single VL technique has shown superiority to others, with each having its pros and cons that should
be weighted upon use. Operator experience must be taken into consideration also,
and one should always use whatever technique he/she masters to ensure the best
outcome. Among the available designs of VLs, hyper-angulated videoscopes carry
some favorable features that translate into higher success rates of intubation. It is
important to understand that there is a learning curve for all VLs, and particularly
for hyper-angulated devices [38]. The hyper-angulation makes it easier to maneuver
around obstacles like a large base of the tongue and will eliminate the need for
excessive force to get a good view. This does not mean it will make the intubation
easier, especially if conducted by an inexperienced operator. Successful intubation
with a hyper-angulated VL mandates a stylet (or another semi-rigid introducer) with
an angulation resembling the angle of the blade [38]. Of the commercially available
designs of hyper-angulated VLs, the D-Blade of C-Mac® VL (KARL STORZ SE &
Co. KG, Tuttlingen, Germany) has unique angulation [39] which exposes the glottis
more clearly than other designs. Combined with its smaller mass, it does not occupy
much of a space in the oral cavity allowing good room for manipulation and maneuvering. However, both GlideScope® and D-Blade® were tested in different clinical
scenarios and different patient populations (patients with a known difcult airway,
patients with cervical spine instability, patients undergoing thoracic surgeries, etc.)
and showed comparable results [40, 41].
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26.3.4 Fiberscopic-Assisted Video-Laryngoscope Intubation
(FAVI) or Combined Technique
Although very handy and powerful tool, the beroptic bronchoscope alone has its
restrictions and limitations. It offers a narrow frontal view of airway structures. This
might be very dangerous while introducing the tube as trauma to the structures not
shown can occur. Trauma to different laryngeal cartilages is a well-documented
complication of difcult and even in uneventful intubation, namely, arytenoids [42–
44]. In cases of epiglottis anomalies where advancing the tube can be opposed by its
abnormal position (e.g., downfolding epiglottis) or morphology, this technique
helps navigate the airway safely [45, 46].
In FOB, the primary operator has full control over the procedure, and the assistant is restricted to providing only limited help. Furthermore, skill and time management place restrictions on the use of the beroptic intubation due to rapid oxygen
desaturation in patients with hemodynamic and respiratory-related comorbidities,
airway masses, or redundant mucosa in some cases of OSA, which increase morbidity and mortality [47]. In an attempt to overcome these challenges, a combined
intubation technique using beroptic bronchoscopic intubation assisted via video
laryngoscope (Fibroscopic Assisted Video-laryngoscopic Intubation; FAVI) for difcult airways was described in 2004 by Doyle [48]. This combination increases the
visualization of the airway and provides a more holistic view of the airway. This
denitely translates into lower morbidity and mortality if conducted properly and
by an experienced operator. The technique is performed by a team: an operator and
an assistant. The VL is introduced by the assistant for a broad inspection of the area
and appropriately identifying key landmarks (epiglottis, arytenoids, false vocal
cords, and true vocal cords), followed by the introduction of the beroptic bronchoscope with a loaded endotracheal tube. The operator then introduces the berscope
and advances it toward the vocal cords. After conrmation of entering the trachea,
the tube is pushed gently through the cords, and with the help of the wider view
provided by VL, trauma to airway structures is avoided [49].
26.3.5 Use ofSupraglottic Airway Devices (SADs)
asIntubating Adjuncts
Despite the great maneuverability of beroptic devices, they can be difcult to
manipulate in an anesthetized patient because the collapse of airway muscles will
close the space required to navigate the scope easily or the redundant mucosa of the
upper airway in OSA patient will jostle the scope. Even with the use of berscopespecic oropharyngeal airways (e.g., Ovassapian plastic oropharyngeal airway), it
might still be difcult, especially in the case of redundant mucosa. In this regard,
SADs can provide a good conduit to berscopes to maintain the patency of the airway, in addition to maintaining oxygenation and ventilation throughout the procedure. This is particularly useful in critical patients and difcult airways, where
procedure time might be stretched due to technical challenges. An endotracheal
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tube may be railroaded over a bronchoscope through the SAD, or an Aintree
Intubating Catheter (Cook Critical Care, Bloomington, IN, USA) may be advanced
over the bronchoscope into the trachea through the SAD, then both the berscope
and SAD are removed leaving the intubating catheter in situ, acting as a “railroading” device for endotracheal tube, or can also be used as a ventilating device buying
more time to the anesthetist.
A. Dardeer et al.
26.3.6 Awake Fiberoptic Intubation (AFOI)
AFOI stands as the best technique for a predicted difcult airway. The safety net
provided by the patient himself being awake and controlling his airway until it is
secured using an endotracheal tube gives the operator a relatively relaxed working condition. Difcult Airway Society (DAS) has recently published a set of
guidelines for awake tracheal intubation in adults, which outlines the best practices to conduct a safe AFOI [50]. It is of paramount importance to provide adequate topical anesthesia to the airway to avoid patient discomfort, coughing, and
physiological responses associated with stimulation of the upper airway. The
practice is now shifted from invasive airway blocks to the “spray-as-you-go”
approach, which gives similar outcomes with fewer risks. The maximum dose of
lidocaine should not exceed 9mg/kg of body weight. Operators should be alert
to the great ability of mucous membranes to absorb large amounts of drugs that
are sprayed on, and it is fairly easy to hit toxicity if the operator is not cautious
enough [50]. Mild to moderate sedation also facilitates the procedure. Among
drugs used for sedation, remifentanil target-controlled infusion (TCI) appears to
provide better conditions for AFOI when compared with propofol TCI in normalweight patients. Dexmedetomidine is another option, providing favorable intubation conditions during AFOI, without respiratory depression and airway
obstruction. However, evidence about the best sedation technique for AFOI in
obese, especially those suffering from OSA, is still lacking. Sedation should ideally be administered by an independent practitioner, and it should not be used as
a substitute for inadequate airway topicalization [50]. Supplemental oxygen
should always be administered during awake tracheal intubation. There should
be no more than three attempts, with one further attempt by a more experienced
operator (3+1 rule) [50].
26.3.7 The Role ofTracheostomy
Despite all the different techniques that can safely secure the airway, it is important to keep Front of Neck Access or Airway (FONA) also ready, as it might
come to the point that FONA would be life-saving. In some selected cases, the
only way to secure the airway properly and safely is a temporary tracheostomy.
This can be done under local anesthesia in an awake patient. Percutaneous
Dilatational Tracheostomy (PDT) has been compared extensively to surgical
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tracheostomy (ST), with a favorable prole characterized by fewer wound infections, lower rates of clinically signicant bleeding, and signicant cost savings
[51]. This procedure, however, is done with endotracheal tube inserted and
entails the bronchoscopic-guided insertion of a needle into the trachea, followed
by insertion of a guidewire into the lumen, and then serial dilation via the
Seldinger technique. Thus, and despite having a favorable safety prole, it cannot replace awake ST in the case of non-intubated patients where placing a tube
is expected to be extremely challenging or nearly impossible. Relative contraindications for PDT include but are not limited to uncorrectable coagulopathy,
inability to extend the neck, cervical spine instability, aberrant neck vasculature,
distortion of the anterior tracheal anatomy, overlying cellulitis or the most important which is unavailability of surgeon who can perform revision/open tracheostomy. Although safe and effective, PDT is not without risk. Of complications
known to be associated with PDT, trachea-innominate artery stulas and posterior tracheal injury tend to be the most feared.
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26.4 Intraoperative Management
Unless indicated by patients’ comorbidities, invasive monitoring beyond the ASA
standard is not recommended for patients with OSA.The level of monitoring should
also be established according to the nature of the scheduled surgical procedure. All
anesthetic induction agents are known to decrease the tone of pharyngeal musculature that acts to maintain airway patency. Choosing one agent over another is based
on the nature and the length of the procedure. It is prudent to use shorter actingagents, avoid large doses of opioids that will continue exerting their action into the
postoperative period, causing excessive sedation and hypoventilation, and avoid use
of neuromuscular blocking agents (NMBA) as long as feasible, or use rocuronium
as it has a specic reversal agent (sugammadex) that will ensure complete recovery
(if used with appropriate dosage and backed by neuromuscular monitoring) [52].
This strategy will allow patients to return quickly to their baseline physiology and
decrease the potential risks.
26.4.1 Mechanical Ventilation
The perfect mechanical ventilation strategy for obese patients undergoing general
anesthesia is a question asked by many clinical studies. In a recent meta-analysis by
Wang etal. [53], it was found that a combination of volume-controlled ventilation,
associated with high positive end expiratory pressure (PEEP) value and lung recruitment maneuvers (collectively known as Protective Lung Ventilation Strategies;
PLVS), is superior to other strategies of reducing the risk of atelectasis and hypoxemia and to improve oxygenation and intraoperative pulmonary compliance. Obese
patients would benet of PLVS that can be effectively applied during general anesthesia [54].
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A. Dardeer et al.
26.4.2 Special, Possibly Life-Threatening, Situations
There is always a risk of bleeding in OSA surgery, which can be serious and lifethreatening. LASER is used for a more precise cut and better hemostasis. This,
however, increases the risk of airway res, in addition to other risks of using LASER
in the operating theatre. Aside from OSA surgery, and generally speaking, there is
always a risk of accidental intraoperative extubation, especially in the head and
neck area. Taking into consideration difculties in managing OSA patients’ airways, such an event might be catastrophic under anesthesia and during surgery, and
it cannot be stressed more how securing the endotracheal tube in position in this
category of patients is of paramount importance and life-saving.
26.4.3 Transoral Robotic Surgery (TORS) andLASER
forEpiglottoplasty
Numerous studies have shown that transoral robotic surgery (TORS) for oropharyngeal cancers is safe and yields satisfactory functional and oncological outcomes. It
is increasingly considered a standard surgical approach with eligible patients. It is
increasingly being used and described in the context of laryngeal cancer surgery as
an alternative to open approaches, which may yield inconsistent functional results
and signicant rates of postoperative complications. It may also be an alternative to
denitive radiotherapy, which entails signicant early and late toxicities. TORS has
been explored as an alternative to endoscopic LASER surgery in patients with difcult exposure, even though there is still a lack of evidence about which procedure
provides better visualization of the vocal cords [55, 56]. However, several studies
have tested TORS in cases of the enlarged base of tongue and epiglottis as a cause
of OSA with promising outcomes that invite more research [57, 58]. In the case of
LASER surgery, airway re should be prevented and monitored closely during the
surgery, and the anesthesia team should be ready for management at any time.
During TORS surgery, the endotracheal tube should be resistant to compression
from the robotic arms, thus requiring a wire-reinforced tube. These tubes resist
compression well, but if compressed above their resistance threshold, they will
buckle and then remain compressed [59].
26.5 Safe Extubation
The critical moments in airway management are intubation, time during the transfer, and extubation, with extubation ranking high in terms of risk of signicant
morbidity and mortality to the patients. Difcult Airway Society (DAS) developed
guidelines [60] to standardize the process of tracheal extubation, minimizing
patients’ risk, in a stepwise approach. It starts with risk stratication of patients as
high or low risk of complication during extubation.
High-risk patients include patients with:
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• Severe cardiopulmonary disease.
• Congenital or acquired airway pathology.
• Morbid obesity.
• OSA.
• Severe gastroesophageal reux.
• Patients who needed multiple attempts at intubation.
Contributing surgical factors include:
• Recurrent laryngeal nerve damage (10.6% in malignant thyroids).
• Hematoma (0.1–1.1% post-laryngeal/thyroid surgery).
• Edema and distortion of anatomy after head and neck surgery.
• Posterior fossa surgery.
• Inter-maxillary xation.
• Drainage of the deep neck and dental abscesses.
Morbidly obese and OSA patients are regarded as high-risk, and a set of specic
recommendations are suggested focused on awake tracheal extubation, managing
logistics and equipment, the importance of skilled assistance, and choosing the
location of extubation (operating room vs. ICU). The DAS guidelines also underline
the importance of extubation over airway exchange catheters in patients for whom
tracheal re-intubation is likely to be difcult. There are two schools of extubation:
“Deep” and “Fully Awake.” When it comes to patients with OSA, deep extubation
is not an option, as the risk of airway collapse and obstruction, up to developing
negative pressure pulmonary edema, is signicant, and this becomes more essential
if it is an airway surgery. The rationale behind extubating in a fully awake state is to
ensure that all protective airway reexes are back, and the patient can take deep
breathes which will prevent atelectasis and reduce the rate of postoperative pulmonary complications. This will also enable the anesthetist to apply CPAP with full
cooperation from the patient’s side. Some anesthetists practice deep extubation to
avoid the pressor response associated with fully awake ones, and this might be true
in patients with ischemic heart disease, but the risk of airway collapse might outweigh the risk of having a sympathetic surge and straining the cardiovascular system. However, fully awake extubation does not and should not mean a struggling
patient. Patient comfort should be maintained throughout the process. To achieve
this, there is number of prerequisites that must be met (pre-extubation criteria):
• Arterial blood gases: Homeostasis and acid-base balance should be restored if
they were disturbed for any reason intraoperatively. A large proportion of OSA
patients tolerates high levels of CO2, so “normal” CO2 might not be a good target.
The patient’s baseline should be checked, and the aim is to return back to it.
• Adequate reversal of muscle blockade and conrming it with neuromuscular
monitoring.
• Ensure that no residual sedatives are in circulation. Last doses of opioids should
be distanced from extubation time, and opioid infusion and “context-sensitive
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A. Dardeer et al.
half-life” should be taken into consideration. If an inhalational agent is to be
used, there’s no conclusive evidence of the superiority of desurane to other
agents, despite having faster wash-in and wash-out times. The results of the stud-
ies conducted comparing desurane to sevourane failed to demonstrate a con-
sistent prole, and if carefully titrated to effect with the help of bispectral index
(BIS), sevourane can give a favorable quick recovery much similar to desu-
rane [61–67].
• Performing a “cuff-leak test” might be advised.
• Nasopharyngeal airway might be a good option, as it is better tolerated by
patients.
• Upper airway examination by berscope or video-scope to assess suitability for
extubation: in some cases, especially with longstanding pathology or in airway
surgeries, edema can render extubation risky. Therefore, a berscopic examina-
tion would identify potential risks and help decrease associated morbidity and
mortality, and decrease the rate of reintubations, that would be an emergency
ill-planned intubation should the airway become obstructed later due to edema,
secretions, bleeding, or other causes.
• Patient at a head-up position, or head-up and lateral position for recovery: in
sedated children examined by MRI, the area of the upper airway (the oropharynx,
nasopharynx, and larynx) increased in the lateral position compared to the supine
position, which translates into less chance of obstruction if extubation was per-
formed in this position [68, 69]. However, this technique has not been studied in
adults, although some experts would argue for a comparable outcome if applied
to the adult population, given that in paralyzed adults under GA in lateral posi-
tion, the same effect on the total cross-section is observed, as a note by Isono
etal. [70]. The mechanism of this phenomenon is unknown but thought to be due
to gravitational effects [68]. Since anesthesia induction and intubation are gener-
ally performed in the supine position, the supine position is familiar and com-
fortable for anesthetists, but lateral position technique should be considered in
selected patients, nonetheless. One of the reasons anesthetists may refrain from
recovery and extubation in lateral position is the inability to re-intubate easily,
despite the evidence pointing to the contrary [71, 72]. This is, of course, a skill
that needs training and is not orthodox in anesthesia training worldwide [73].
In case of expected difcult extubation, a number of strategies can be implemented to reduce the risk of failed extubation or losing the airway, in addition to
fullling the pre-extubation aforementioned checklist:
• Use of steroids to decrease airway edema.
• Staged extubation over the wire (Fig.26.5).
• Use of Tritube® (Ventinova Medical B.V., Eindhoven, The Netherlands) as the
airway management technique and keep it inside the airway during recovery; it
is a small-caliber tube (4.4mm outer diameter) and would be tolerated by the
patient allowing smooth recovery and backup ventilation should the weaning and
extubation protract or fails (Fig.26.6).
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• Airway exchange catheters (Fig.26.7).
• Bailey maneuver (exchange to SAD).
• Abandon extubation altogether and delay it for 24h, To be performed in the ICU
after some time and after airway rest.
• Tracheostomy, as a temporary measure, should always be an option on the table,
and some patients would have no other safe alternative.
Fig. 26.5 Staged extubation set with wire
Fig. 26.6 Tritube
Aintree Catheter
Fig. 26.7 Airway exchange catheter
Endotracheal Tube
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26.6 Postoperative Care Management
26.6.1 Postoperative Analgesia
Managing postoperative analgesia for patients with OSA is a challenging task for
any anesthetist, as a ne balance between patient comfort and potential side effects
of opioids (hypoventilation and apnea) should be maintained. That is why the use of
strong opioids (e.g., morphine, buprenorphine, and oxycodone) should be avoided
altogether or reduced, regardless of the method of administration. This is an area
where implementing the concept of multimodal analgesia makes great difference,
by combining regional techniques (if applicable), Non-Steroidal Anti-Inammatory
Drugs (NSAIDs), an analgesic dose of ketamine, and paracetamol at pre-established
times rather than as needed “pro re neta,” (PRN) schedule, to reduce the needed
doses of systemic opioids. Using weak opioids, like tramadol, as rescue treatment is
also advised. Continuous wound infusion of local anesthetic can be used with comparable analgesic effects [74, 75].
26.6.2 Patient Position inBed
As it is important during anesthesia induction, a 25–30° head-up position during the
patient’s stay in the post-anesthesia care unit (PACU) and in the ward increases
upper airway stability [76]. This should be clearly mentioned in the postoperative
nursing instructions. Again, as it was advised during extubation, lateral position
with head-up can be used for postoperative nursing as it would decrease the chance
of obstruction.
26.6.3 Oxygenation, Lung Recruitment, andCPAP
Supplementary oxygen in the postoperative period should be provided until the
patient can maintain preoperative saturation on room air (i.e., return to baseline
without external help). Along with providing extra oxygen, patients should be
instructed to do “breathing exercise” or incentive spirometry, which recruits collapsed alveoli, decreasing the rate of atelectasis [77]. Signicant atelectasis can
cause ventilation/perfusion mismatch and consequent hypoxemia. Unresolved or
neglected collapse can lead to pneumonia [78]. Moreover, CPAP application preand post-operatively can signicantly reduce the rate of respiratory complications,
especially if the patient was using CPAP at home [77]. In such patients, CPAP
should be instituted in the same settings as their home settings. However, CPAP
may not be useful in opioid-induced airway collapse, and prevention (by reducing
the use of opioids) is always advised. It is worth mentioning that the team should be
open to all possibilities, including the need to invasively ventilate a patient should
he fail to respond to such non-invasive measures.
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26.6.4 Ward Versus Intensive Care Unit (ICU)?
Patients disposition either to their normal beds, high dependency unit (HDU)
(level I care), or ICU (level II care) is a multifactorial decision. Patients with
OSA usually need adequate monitoring (SpO2, ECG, heart rate, blood pressure,
and transcutaneous CO2 if available) and surveillance during the first 24h postoperatively, but the level of this monitoring can be a ward nurse in simple cases
with mild to moderate OSA, up to ICU with one-to-one care in cases with
severe OSA and OSA-related complications. It is, of course, a preoperative
decision, but it can also be revisited in the PACU, as the preoperative estimations may be under- or overdoing it. In most cases, patients who have complications in the immediate postoperative period (i.e., in PACU) will have
recurring adverse events and should therefore be monitored in a higher level of
care [79]. The American Society of Anesthesiology recommends a median of
3 h longer postoperative monitoring in patients with OSA after ambulatory
surgery and 7h of post-operative monitoring after the last episode of airway
obstruction or hypoxemia while breathing room air in an unstimulated environment prior to discharge [80]. The organizational factors and readiness to handle
such patients should also be taken into account. For more details, you can visit
the algorithm of the Italian Society of Anesthesia, Analgesia, Resuscitation,
and Intensive Care (SIAARTI)/Italian Association of Sleep Medicine (AIMS)
Recommendations [81].
26.6.5 Criteria forDischarge Home
The literature is insufcient to offer guidance regarding the appropriate time for
discharge of OSA patients at increased perioperative risk from the surgical
facility to an unmonitored setting (i.e., home). Patients at increased perioperative risk from OSA should not be discharged from the hospital until they are no
longer at risk of postoperative respiratory depression, which can be established
by observing patients if they are able to maintain adequate oxygen saturation
level on room air, in an unstimulated environment, preferably while asleep [82].
Prior to discharge, patients with known OSA on Continuous Positive Airway
Pressure/Bilevel Positive Airway Pressure (CPAP/BiPAP) therapy and their
caregivers should be educated to use their CPAP/BiPAP therapy whenever
sleeping. If the patient has a history of non- compliance, education should be
provided regarding the risks of untreated OSA, and barriers that resulted in noncompliance should be identied and addressed [83]. Before discharge, an OSA
treatment plan should be in place for timely follow- up care. This plan should
inform the patient of the next steps for effective treatment and compliance with
CPAP/BiPAP therapy [83].
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