Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / @xirurgi_2025 / @xirurgi_2025 - 911 - файл
.pdf
386
https://t.me/medicina_free
https://t.me/medicina_free
387
54.
DIFFICULT AIRWAY:SPECIAL CONSIDERATIONS INPREGNANCY
Rania Elkhateb and Jill M.Mhyre
CLINICALCASE
laryngoscopy. Cephalad displacement of the diaphragm
decreases the functional residual capacity by 20% by the end
A 32- year- old woman is transferred from the labor and delivery triage unit to the obstetric operating room for umbilical
cord prolapse. She has no previous surgical history, allergies, or medical problems, and received limited prenatal
care. She has an estimated body mass index of 42 kg/ m2.
e obstetricians request emergent delivery. Airway examination reveals a Mallampati III view with normal mouth
opening, thyromental distance, and neck mobility. She
receives 15 mL of nonparticulate antacid in preparation for
rapid sequence induction of general anesthesia.
of pregnancy, and can decline by another 25% when chang-
ing from sitting to supine position. Consequently, preoxy-
genation is less eective in establishing an oxygen reserve
prior to the onset of apnea. In addition, maternal oxygen
consumption increases 20% during pregnancy.3 Together
the decrease in oxygen reserve and the increase in oxygen
consumption markedly reduce the duration of apnea before
desaturation develops. Obesity further impedes preoxygen-
ation and accelerates apnea- induced desaturation,4 because
it reduces functional residual capacity, decreases chest wall
compliance, increases airway resistance, and increases in
MECHANISM OFDIFFICULT AIRWAY
INOBSTETRIC PATIENTS
pulmonary vascular resistance.
Expanding circulating blood volume, decreased oncotic
pressure, and vascular congestion promote airway edema in
5
normal pregnancy. Preeclampsia, prolonged oxytocin infuDicult airway has been dened as “the clinical situation
in which a conventionally trained anesthesiologist experiences diculty with facemask ventilation of the upper airway, diculty with tracheal intubation, or both.”1 In most
obstetric anesthetics, rapid sequence induction of general
anesthesia with laryngoscopy is selected to facilitate immediate endotracheal intubation; however, a plan for facemask
ventilation or supraglottic airway ventilation is always necessary. When initial attempts at laryngoscopy and tracheal
intubation do fail, and ventilation is delayed or dicult,
inadequate oxygen delivery to the maternal alveoli can rapidly produce maternal hypoxemia, risking hypoxic injury in
the mother, fetus, or both. Other serious complications of
dicult airway management include aspiration of gastric
contents, airway trauma, pulmonary edema, and undesired
intraoperative awareness.
2
A number of anatomic and physiologic changes of
pregnancy contribute to dicult intubation and airway
management. Pregnancy- related weight gain and breast
enlargement make patient positioning both more dicult
and more important for both optimal preoxygenation and
sions, and volume resuscitation for postpartum hemorrhage
can worsen airway edema.6 Edema combined with mucosal
friability exacerbate the consequences of airway trauma,
which can lead to both bleeding that obscures visualization
and dicult ventilation.
Pregnancy is associated with increased intragastric pressure, incompetent lower esophageal sphincter tone, and,
once labor begins, delayed gastric emptying, each of which
increases the risk of aspiration. Progesterone, pain, fear, and
exogenous oxytocin and opioids all impede gastric emptying. Even in the absence of these factors, the unpredictable
nature of obstetric surgery means that patients frequently
present within hours of having eaten. Rapid sequence
induction with immediate tracheal intubation minimizes
the risk of aspiration of gastric contents and the duration of
apnea between induction of anesthesia and tracheal intubation. However, deploying this technique may instigate a
reluctance to mask ventilate, even as the oxygen saturation
begins to fall. Cricoid pressure may obscure the visualization of the airway, impair ventilation, and/ or add to the difculty of intubation.
387
388
Class I Class II Class III Class IV
https://t.me/medicina_free
In addition, environmental and clinical factors can interfere with optimal preparation and team performance. e
emergent nature of many obstetric surgeries may compel
shortcuts and inadequate preparation prior to anesthetic
induction. As illustrated in the scenario at the beginning of
this chapter, women with limited prenatal care may present
with indications for immediate operative delivery, without
time for a comprehensive anesthetic evaluation or preparation. e increased use of neuraxial anesthesia, as opposed to
general anesthesia in nonemergent obstetric cases, has diminished experience for most providers in dealing with dicult
obstetric airway management.7 Finally, the physical isolation
of many obstetric surgical suites, and the high proportion
of emergent cases that take place at night, mean that highly
skilled assistance is less likely to be available when needed.
PREOPERATIVE ASSESSMENT
FORDIFFICULTAIRWAY
Time for a thorough airway examination may not be possible immediately prior to induction of general anesthesia in parturients, and even if completed, may not result
in the opportunity to change management if insucient
time is available to act on the ndings. As such, a suggested
approach is to evaluate patients, including examination of
the airway, at the time of admission to the labor and delivery unit, and periodically as labor progresses, especially in
women with risk factors for developing airway edema (e.g.,
preeclampsia, prolonged oxytocin infusion, and postpartum hemorrhage).
Risk factors for dicult intubation and dicult ventilation in pregnancy are similar to those in nonobstetric
patients. Individual physical examination ndings do not
RISK OFDIFFICULT AIRWAY INOBSTETRIC
PATIENTS
accurately predict dicult intubation11 so combining multiple evaluation criteria may provide better discrimination
than any single test. Recommended evaluation criteria
such as the Mallampati classication (Figure 54.1), which
Meta- analysis suggests that failed intubation complicates
2.6 (95% CI 2.0 to 3.2) per 1,000 general anesthetics for
obstetric surgery (1 out of every 390), when dened as the
need to abandon endotracheal intubation aer failed direct
laryngoscopy, or aer an alternative intubating technique,
or both.8 In comparison, contemporary reports suggest that
of every 1,000 nonobstetric general anesthetics, approximately 1.5 (95% CI 1.2 to 1.8) cases experience failed intubation,9 and 1.3 (95% CI 1.2 to 1.5) cases experience failed
intubation in the presence of dicult mask ventilation.
screens for visibility of the oropharyngeal structures, and
other predictors are listed in Box54.1.
Pregnancy is a known risk factor for rapid oxygen desaturation. Additional synergistic risk factors include morbid obesity (BMI > 39 kg/ m2), multiple gestation, active
uterine contractions, and inadequate preoxygenation prior
to the anesthetic induction (e.g., diculty maintaining a
tight facemask seal).12 e combination of risk factors for
dicult intubation and either dicult ventilation or rapid
10
oxygen desaturation is particularly ominous.
Regurgitation with pulmonary aspiration can also
ASSESSMENT OFTHE PATIENT
Careful preoperative airway examination should alert the
anesthesiologist about the need to nd an alternative strat-
confound otherwise straightforward airway management.
Gastric contents may be present even when a signicant
amount of time has passed since the last oral intake, but a
history of recent consumption of a large meal would certainly indicate a full stomach.
egy to manage the airway.
Figure54.1 Mallampeti classication. SOURCE:Reprinted with permission from Samsoon GL, Young JR. Difcult tracheal intubation:a retrospective study. Anaesthesia.
1987;42:487– 90.
388 SECTION C. PULMONARY/AIRWAY CRISES
https://t.me/medicina_free
389
timely and periodic airway examination and those patients
BOX 54.1 ESSENTIAL COMPONENTS OFAIRWAY
ASSESSMENT
1. Physical examination for obesity, macromastia
34
with predictors of dicult airway management receive prophylactic interventions to reduce the need for general anesthesia. As discussed above, these interventions may include
early neuraxial labor analgesia, planned neuraxial anesthe-
2. Head and neck examination for facial edema, shortneck
3. Neck exion and atlanto- occipital extension
sia for surgery, or planned awake intubation techniques.
Despite meticulous preoperative evaluation and plan-
ning, unexpected airway diculty may arise during any
4. Mandibular space– thyromental distance
5. Mouth opening and ability to advance the mandible
(upper bitetest)
obstetric surgery. Timely and appropriate management is
essential to avoid maternal or fetal harm, so the anesthesiologist must be prepared in every case with a preformulated
airway management plan that will ensure the team is able to
6. Dentition— protruding maxillary incisors, missingteeth
7. Oropharyngeal structures— Mallampati classication
preserve oxygenation, regardless of the specic airway management techniques or diculties encountered.
13
e airway algorithm should be simple, with logical progression through management techniques, and ideally will be
practiced in simulated scenarios. Anumber of airway man-
Usually obstetric airway examination ndings are either
reassuring or equivocal. Occasionally, the airway examination is suciently worrisome that communication with the
patient and the obstetrician is appropriate to devise a delivery plan that minimizes the likelihood of requiring rapid
sequence induction of general anesthesia. Risks, benets,
and alternatives for a variety of delivery scenarios should be
explored, with decisions documented in the medical record.
Rarely, the airway examination is so ominous that it excludes
standard rapid sequence induction of general anesthesia as
a safe option, and alternative airway management strategies
must be identied; careful multidisciplinary patient- centered
delivery and anesthetic planning is important in thesecases.
In cases of emergency obstetric surgery, a minimal airway examination includes an impression of obesity, palpation of submandibular space, inspection of the oropharynx
and teeth, and the administration of a nonparticulate antacid, all completed rapidly just before applying facemask
oxygen. e purpose if this rapid airway examination is to
identify a patient with suciently ominous airway ndings
to mandate a delay in the anesthetic induction in order to
avoid airway management entirely (by establishing neuraxial anesthesia), or to bring advanced airway equipment and
to recruit additional experienced personnel to the bedside.
agement algorithms have been published
As a general rule, most begin with rapid sequence induction
of general anesthesia followed by immediate intubation. is
approach minimizes the duration of apnea and an unprotected airway, and thereby achieves three objectives:(1)oxygenation, (2)ventilation, and (3)protection from aspiration
of gastric contents. However, when immediate intubation
attempts fail, oxygenation must be prioritized above all other
objectives. is oen entails rescue ventilation with 100%
oxygen using a facemask or supraglottic airway.
To ensure prompt implementation of the airway management algorithm in the event of an airway emergency,
essential airway equipment should be veried as immediately available and functioning prior to the induction of any
obstetric anesthetic. Routine equipment verication should
be completed at least daily, aer each use, and again, immediately before inducing any anesthetic, whether regional or
general anesthesia. Examples of equipment needed for basic
and complex airway management are listed in Boxes 54.2
and 54.3.
16
In preparation for rapid sequence induction of general
anesthesia, eective preoxygenation is crucial. Acceptable
preoxygenation can be provided by 3– 5 minutes of tidal
volume breathing or eight deep breaths using 100% oxy-
13– 15
(Figure 54.2).
gen.17 irty- degree head elevation with the head extended
in a sning position improves the functional residual
PROPHYLAXIS TOLIMIT THERISK
OFDIFFICULT AIRWAY AND PREPARATION
TOOPTIMIZE MANAGEMENT
capacity18 and laryngeal visualization. e ideal position
aligns the external auditory meatus with the sternal notch.
(Figure 54.3) Meanwhile, a wedge under the right hip, with
or without 15 degree le table tilt, displaces the uterus
e foundation of dicult airway management in obstetrics is a preventive approach in which all parturients receive
laterally leward to relieve aortocaval compression and to
increase venous return to the rightheart.
DIFFICULTAIRWAY 389
390
https://t.me/medicina_free
Unanticipated Difficult Intubation in Obstetrics
Ventilated with
secure airway
Succeed
• Call for HELP
• Mask Ventilation
No additional muscle relaxant
Adjust patient position
Adjust cricoid pressure
Alternative
Technique for
Intubation
Max 2 attempts or SpO
Failed
Mask Ventilation
Or
Laryngeal Mask Ventilation
2
<90
Failed
Failed
Can not Ventilate
Can Ventilate
Proceed with CS Surgical Airway
Figure54.2 Algorithm for unanticipated difcult airway.
Emergency
Clinical Judgment
No Emergency
Awaken Patient
Secure airway
e benet of cricoid pressure is controversial due to
lack of scientic evidence to support or abandon its use;
yet it is oen applied.
19,20
Cricoid pressure may obscure the
laryngoscopic view if applied incorrectly, and may induce
anxiety and/ or vomiting if applied before the patient is fully
anesthetized. Cricoid pressure does not increase the risk of
dicult mask ventilation or intubation if it is applied by
a trained clinician.21 If the glottic view is impaired, or if a
supraglottic airway is inserted, the cricoid pressure can be
adjusted or released. Pressure of no more than 10 N forces
has been recommended as a guideline by the Dicult
Airway Society when the patient is conscious; the pressure
390 SECTION C. PULMONARY/AIRWAY CRISES
https://t.me/medicina_free
391
to facilitate dicult direct laryngoscopy and intubation,
BOX 54.2 EQUIPMENT NEEDED FORINDUCTION
OFOBSTETRIC ANESTHESIA
• Facemask and oral airways
15
including a bougie, McCoy blade, or a lighted or beroptic
stylet. Many anesthesiologists now use videolaryngoscopy23
for either the primary intubation attempt or to rescue failed
direct laryngoscopy.
• Gauze and a tongueblade
• 2 working laryngoscope handles
e number of laryngoscopy attempts to achieve endotracheal intubation has been also debated, but a Canadian
airway focus group in 1998 recommended only two
• Macintosh blades:sizes 3and4
• 6.5 styletted endotracheal tube with an empty
10- mL syringe connected to the pilot balloon
attempts, unless there has not been any airway trauma and
it is believed that success can be achieved with another
attempt, in which case a third attempt is justied.
24,25
Multiple attempts increase the risk of airway edema and
• Backup endotracheal tubes in a range ofsizes
• Gum elasticbougie
trauma leading to a “can’t intubate, can’t ventilate” scenario. Once attempts have failed or the oxygen saturation
cannot be maintained above 92% at any stage, then intuba-
• Primary extraglottic airway appropriate for a 70- to 100- kg
person may include one or more of the following devices
• Supraglottic airways with an esophageal drain and/ or
intubating capability preferred (e.g., LMA Supreme, igel,
LMA FasTrach)
• Suction adequate to remove secretions
tion becomes secondary to the primary goal of maintaining adequate maternal and fetal oxygenation. In the event
of failed intubation, additional help should be immediately
requested.
Facemask ventilation is oen the initial technique
used to maintain adequate oxygenation following failed
intubation attempts. Two- handed mask ventilation with
an oral airway can be achieved by a single provider by
setting the ventilator to deliver pressure- control ventila-
can then be increased to 30 N when the patient has lost
consciousness.
22
Direct laryngoscopy has been traditionally considered
the gold standard technique for obstetric airway management. Macromastia can impede laryngoscopic blade insertion; strategies and equipment to facilitate successful blade
insertion include a ramped patient position that elevates
the thorax, a short laryngoscopic handle, and a polio
Macintosh blade. In the event of a Cormack Lehane grade
3 or 4 view, a variety of adjunctive equipment may be used
tion.26 Nevertheless, a second person with advanced airway management skills is essential at this stage to prepare
equipment; manage anesthesia, hemodynamics, and the
rest of the operative team; and to prevent xation errors.
Alternatively, or subsequently to facemask ventilation, a
properly sited supraglottic airway may be used to ventilate,
oxygenate, and if necessary serve as a guide for endotracheal
intubation.
27,28
At each stage of the algorithm, the second
person should be preparing equipment for the next step.
For example, if facemask ventilation fails, then while the
supraglottic airway is inserted, the second clinician should
23
BOX 54.3 CONTENT OFPORTABLE STORAGE UNIT
FORDIFFICULT AIRWAY MANAGEMENT
1
prepare for a possible surgical airway.
CANNOT INTUBATE BUTCAN VENTILATE
• Rigid laryngoscope blades of alternate design and
size from those routinely used; this may include a rigid
beroptic laryngoscope
• Videolaryngoscope
• Tracheal tubeguides
• Flexible beroptic intubation equipment
• Equipment suitable for emergency invasive airwayaccess
• An exhaled carbon dioxide detector
DIFFICULTAIRWAY 391
If there is no immediate urgency then the patient should be
awakened, aer which an alternative approach can be undertaken, such as regional anesthesia or awake intubation.
However, that is a rare situation in obstetric anesthesia.
In the majority of cases, immediate surgery is essential to
preserve the life or health of the mother or fetus or both;
and such procedures can be completed under facemask29
or supraglottic airway ventilation.30 e decision to complete surgery with an unsecured airway depends on the acuity, the ease of ventilation, and the likelihood of signicant
regurgitation and subsequent aspiration. Surgeons should
392
https://t.me/medicina_free
Figure 54.3 Proper patient position illustrated on the right.
be advised to employ a delivery technique that will minimize fundal pressure and expedite procedure completion.
deflated may be helpful. For individuals with high risk
of difficult reintubation, a more conservative approach
may include glottic examination using video laryngos-
CANNOT INTUBATE, CANNOT VENTILATE
If ventilation should fail at any point during the intubation process, then immediate action should be taken to
establish a means to deliver oxygen. Awakening a hypoxic
and apneic patient is rarely an option, but minimal assisted
copy prior to extubation,33 extubation over a stylet or
Cook catheter, or postoperative intubation for 24 hours
or more. All patients who demonstrate a difficult airway
should receive a letter from the anesthesiologist detailing the issue(s) and making recommendations for future
airway management.
ventilation to preserve oxygenation may result in return of
spontaneous ventilation, which should be supported, and
serious consideration should be given to awakening the
KEYPOINTS
patient. If ventilation remains impossible, replacement of a
supraglottic airway device can be attempted while a surgical airway is secured.31 e anesthesiologist should at all
times avoid the temptation to keep repeating certain steps
or airway management techniques that have failed and
instead should move to the next step in the airway algorithm withoutdelay.
Proper preoperative assessment and history taking
detect potential risk factors.
Correct patient positioning and preoxygenation are
essential to provide optimal conditions for intubation.
No more than two intubation attempts are allowed
unless a third one is justied.
TRAINING AND PREPARATION
Expert dicult airway management requires not only
technical prociency but also nontechnical skills in crisis
resource management, team- work, leadership, and decisionmaking. e use of simulation provides opportunity to
build skills in dicult airway management without compromising patient safety, with demonstrated improvements
in technical and nontechnical skills that last up to 1year.
32
Ventilation and oxygenation always takes priority over
repeated attempts at intubation.
A good, well- rehearsed algorithm that is easy to follow
is mandatory for dicult airway management.
Adequate documentation of the dicult airway
in the patient record prevents serious airway
crisis insubsequent anesthesia by taking adequate
preparation.
FOLLOW- UP
Following difficult intubation, patients may have airway
edema that increases risk of failed ventilation at the time
of extubation. Before removal of the endotracheal tube,
confirmation of a leak around it after the cuff has been
392 SECTION C. PULMONARY/AIRWAY CRISES
Poor maternal and neonatal outcome can be avoidedby:
• Proper communication between the patient, anesthetist,
and obstetrician.
• Portable dicult airway cart available in the obstetric
suite with the algorithm card attachedtoit.
https://t.me/medicina_free
393
• Proper education and training; each anesthetist must
be familiar and expert in using at least one of the
equipment options available for dicult airway.
CASE- BASED LEARNING DISCUSSION
1. Describe the essential steps for preoperative assessment
under emergent circumstances. How do the results of
each assessment step change anesthetic management?
2. Following rapid sequence induction of general
anesthesia, direct laryngoscopy revealed a Cormack
Lehane Grade 3B view, and endotracheal intubation
was not possible before the oxygen saturation declined
below 90%. What should be the next course of action
and why? What steps will optimize success during the
second intubation attempt?
3. Despite optimal attempts at direct laryngoscopy and
videolaryngoscopy, endotracheal intubation is not
successful, but mask ventilation is feasible. e cord
prolapse persists, and the obstetrician is adamant
with the plan to proceed with delivery. Under what
circumstances might you awaken the patient or proceed
with delivery, and how should the airway be managed if
the team decides to proceed?
4. e infant is delivered under facemask ventilation, but
following delivery the uterus is atonic, the surgeons
diagnose a lateral extension of their incision into the
broad ligament, and blood loss rapidly accumulates.
What is the best airway management strategy at this
point? At what point is endotracheal intubation
indicated, and how is it best accomplished?
5. What is your recommendation for future airway
management for this patient?
REFERENCES
1. Apfelbaum JL, Hagberg CA, Caplan RA, etal. Practice guidelines
for management of the dicult airway: an updated report by the
American Society of Anesthesiologists Task Force on Management
of the Dicult Airway. Anesthesiology. 2013;118:251– 70.
2. Cook TM, Woodall N, Frerk C. Major complications of airway
management in the UK: results of the Fourth National Audit
Project of the Royal College of Anaesthetists and the Dicult
Airway Society. Part1:anaesthesia. British Journal of Anaesthesia.
2011;106:617– 31.
3. McAuley SE, Jensen D, McGrath MJ, Wolfe LA. Eects of human
pregnancy and aerobic conditioning on alveolar gas exchange during exercise. Canadian Journal of Physiology and Pharmacology.
2005;83:625– 33.
4. Jense HG, Dubin SA, Silverstein PI, O’Leary- Escolas U. Eect of
obesity on safe duration of apnea in anesthetized humans. Anesthesia
& Analgesia. 1991;72:89– 93.
5. Adams JP, Murphy PG. Obesity in anaesthesia and intensive care.
British Journal of Anaesthesia. 2000;85:91– 108.
6. Brock- Utne JG, Downing JW, Seedat F. Laryngeal oedema associated with pre- eclamptic toxaemia. Anaesthesia. 1977;32:556– 8.
7. Lipman S, Carvalho B, Brock- Utne J. e demise of general anesthesia in obstetrics revisited:prescription for a cure. International
Journal of Obstetric Anesthesia. 2005;14:2– 4.
8. Kinsella SM, Winton AL, Mushambi MC. Failed tracheal intubation during obstetric general anaesthesia: a literature review.
International Journal of Obstetric Anesthesia. 2015;24(4):356– 74.
9. Lundstrom LH, Moller AM, Rosenstock C, Astrup G, Wetterslev
J. High body mass index is a weak predictor for dicult and
failed tracheal intubation: a cohort study of 91,332 consecutive
patients scheduled for direct laryngoscopy registered in the Danish
Anesthesia Database. Anesthesiology. 2009;110:266– 74.
10. Kheterpal S, Healy D, Aziz MF, etal. Incidence, predictors, and outcome of dicult mask ventilation combined with dicult laryngoscopy:a report from the multicenter perioperative outcomes group.
Anesthesiology. 2013;119:1360– 9.
11. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting dicult intubation in apparently normal patients: a meta- analysis of bedside
screening test performance. Anesthesiology. 2005;103:429– 37.
12. McClelland SH, Bogod DG, Hardman JG. Pre- oxygenation and
apnoea in pregnancy:changes during labour and with obstetric morbidity in a computational simulation. Anaesthesia. 2009;64:371– 7.
13. Combes X, Le Roux B, Suen P, etal. Unanticipated dicult airway
in anesthetized patients:prospective validation of a management
algorithm. Anesthesiology. 2004;100:1146– 50.
14. Balki M, Cooke ME, Dunington S, Salman A, Goldszmidt E.
Unanticipated dicult airway in obstetric patients: development
of a new algorithm for formative assessment in high- delity simulation. Anesthesiology. 2012;117:883– 97.
15. Mhyre JM, Healy D. e unanticipated dicult intubation in
obstetrics. Anesthesia & Analgesia. 2011;112:648– 52.
16. Joy L. Hawkins MDC, Denver, Colorado: Practice guidelines
for obstetric anesthesia: an updated report by the American
Society of Anesthesiologists Task Force on Obstetric Anesthesia.
Anesthesiology. 2007;106:843– 63.
17. Tanoubi I, Drolet P, Donati F. Optimizing preoxygenation in adults.
Canadian Journal of Anaesthesia. 2009;56:449– 66.
18. Hignett R, Fernando R, McGlennan A, etal. A randomized crossover study to determine the eect of a 30 degrees head- up versus a
supine position on the functional residual capacity of term parturients. Anesthesia & Analgesia. 2011;113:1098– 102.
19. Stewart JC, Bhananker S, Ramaiah R. Rapid- sequence intubation
and cricoid pressure. International Journal of Critical Illness and
Injury Science. 2014;4:42– 9.
20. Bhatia N, Bhagat H, Sen I. Cricoid pressure: Where do we
stand? Journal of Anaesthesiology and Clinical Pharmacology.
2014;30:3– 6.
21. Turgeon AF, Nicole PC, Trepanier CA, Marcoux S, Lessard MR.
Cricoid pressure does not increase the rate of failed intubation by
direct laryngoscopy in adults. Anesthesiology. 2005;102:315– 9.
22. Henderson JJ, Popat MT, Latto IP, Pearce AC. Dicult Airway
Society guidelines for management of the unanticipated dicult
intubation. Anaesthesia. 2004;59:675– 94.
23. Law JA, Broemling N, Cooper RM, etal. e dicult airway with
recommendations for management:part1. Dicult tracheal intubation encountered in an unconscious/ induced patient. Canadian
Journal of Anaesthesia. 2013;60:1089– 118.
24. Law JA, Broemling N, Cooper RM, etal. e dicult airway with
recommendations for management:part2. e anticipated dicult
airway. Canadian Journal of Anaesthesia. 2013;60:1119– 38.
DIFFICULTAIRWAY 393
394
https://t.me/medicina_free
25. Crosby ET, Cooper RM, Douglas MJ, etal. e unanticipated dicult airway with recommendations for management. Can J Anaesth.
1998;45:757– 76.
26. Munnur U, de Boisblanc B, Suresh MS. Airway problems in pregnancy. Critical Care Medicine. 2005;33:S259– 68.
27. Gruenbaum SE, Gruenbaum BF, Tsaregorodtsev S, Dubilet M,
Melamed I, Zlotnik A. Novel use of an exchange catheter to facilitate intubation with an Aintree catheter in a tall patient with a
predicted dicult airway: a case report. Journal of Medical Case
Reports. 2012;6:108.
28. Suresh MS. Intubating laryngeal mask airway (ILMA):a life saving
rescue device following failed tracheal intubation during cesarean
section (CS). Anesthesiology. 2004;100:75,A135.
29. Hawthorne L, Wilson R, Lyons G, Dresner M. Failed intubation
revisited: 17- yr experience in a teaching maternity unit. British
Journal of Anaesthesia. 1996;76:680– 4.
30. Minville V, N’Guyen L, Coustet B, Fourcade O, Samii K. Dicult
airway in obstetric using Ilma- Fastrach. Anesthesia & Analgesia.
2004;99:1873.
31. Heard AM, Green RJ, Eakins P. e formulation and introduction
of a “can’t intubate, can’t ventilate” algorithm into clinical practice.
Anaesthesia. 2009;64:601– 8.
32. Boet S, Borges BC, Naik VN, etal. Complex procedural skills are
retained for a minimum of 1 yr aer a single high- delity simulation
training session. British Journal of Anaesthesia. 2011;107:533– 9.
33. Mort TC, Braett BH. Conventional versus video laryngoscopy for
tracheal tube exchange:glottic visualization, success rates, complications, and rescue alternatives in the high- risk dicult airway patient.
Anesthesia & Analgesia. 2015;121:440– 8.
34. Vasdev GM, Harrison BA, Keegan MT, Burkle CM. Management
of the dicult and failed airway in obstetric anesthesia. Journal of
Anesthesia. 2008;22:38– 48.
394 SECTION C. PULMONARY/AIRWAY CRISES
https://t.me/medicina_free
395
55.
ASTHMA AND PREGNANCY
Grant C.Lynde
CLINICALCASE
prevalence of the disease, changing trends in both how
asthma is dened and diagnosed, or increased recognition
A 26- year- old G2P1001 at 34 weeks with a history of
asthma presents to labor and delivery with severe shortness
of breath. She describes having a recent cold and has been
using her albuterol inhaler with increasing frequency in the
past week. She denies a history of hospitalization or emergency department visits for her asthma. e patient’s respiratory rate is 24, and her room air saturation is 93% with
of the need to treat patients who present with asthma- like
symptoms. Asthma can result in low birth weight, preterm
delivery, and worsening asthma in the mother. Women who
have an acute exacerbation of asthma during pregnancy are
at signicantly higher risk of poor outcome.2 Other comor-
bidities, such as sleep apnea and morbid obesity, also appear
to occur with greater frequency in asthmatic patients.
6– 8
audible wheezing. Following treatment with 2.5 mg/ hr
nebulized albuterol administered continuously for 1 hour,
the patient’s respiratory rate decreased to 16, her room air
saturation rose to 97%, and her subjective symptoms were
reduced. e patient was discharged from the emergency
department with a prescription for prednisone, 40 mg for
5days followed by a 5- day taper, inhaled budesonide (180
mcg, 2 pus twice a day), a peak expiratory ow meter, and
instructions to check and record her levels daily, and an
appointment to visit her OB/ GYN later thatweek.
MECHANISM
Asthma is an obstructive lung disease characterized by bron-
chial hyperresponsiveness, bronchoconstriction, and airway
edema. e inammatory process can result in remodeling
of airways and can also result in chronic changes in airway
structure. While the exact mechanism by which asthma
develops is not fully understood, it is believed that patient-
specic factors interplay with environmental factors,
resulting in an inadequate activation of immune control
PATHOPHYSIOLOGY OFDISEASESTATE
e progression of asthma during pregnancy is highly variable. us, a thorough understanding of the epidemoiology, mechanism of disease, key factors in diagnosis, and
proper steps of treatment are essential for optimal care of
the mother andfetus.
BACKGROUND
mechanism involving T helper cells type 2.9 e “hygiene
hypothesis” proposes that reduced exposure to infectious
disease, improved sanitation, and increased use of antibiot-
ics has resulted in an imbalance of T helper cells type 1 and
2, resulting in the increase in asthma incidence seen since
9,10
1960.
Indoor allergen exposures, including dust mites,
mold, household pets, and German cockroaches, demonstrate a high correlation with the development of asthma
symptoms.
11– 14
Asthma appears to have a genetic component, accounting for both the inheritable nature of the disease as well as the various disease phenotypes that exist.
10
Improvement in symptoms can be seen in 18%– 34% of
patients, while worsening of symptoms can be seen in 20%–
42% of patients.
1– 3
Asthma is one of the most common and
one of the most serious coexisting diseases during pregnancy.
While older estimates of asthma’s prevalence were approximately 1% in pregnancy, more recent studies have suggested the prevalence in the United States is closer to 7%.
4,5
Reasons for this discrepancy may be related to increasing
DIAGNOSIS
e average age of adult- onset asthma in women is approximately 34years, however patients may develop the disease
during early childhood.15 As a result, most parturients with
asthma will be diagnosed prior to pregnancy. Typical symptoms of asthma include wheezing , chest tightness, cough, and
395
Соседние файлы в папке @xirurgi_2025