Airway Management of Pregnant Patient in Cesarean Section

1. Saeid Safari, MD
Laryngeal mask for failed intubation in
emergency Caesarean section

2. Introduction
• We wish to present a case of failed intubation in a pregnant
patient for emergency cesarean section for fetal distress which
was successfully managed by the use of the laryngeal mask

3. What concerns the anesthesiologist when
administering general anesthesia for cesarean
section?

4. Main Concern
• This population is at greater risk for difficult intubation, rapid
oxygen desaturation, and aspiration of gastric contents.
• The goal is to minimize maternal risk and neonatal depression.

5. Discussion

6. Introduction
• A study of anesthesia-related deaths in the United States
between 1979 and 1990 revealed that the case-fatality rate
with general anesthesia was 16.7 times greater than that with
regional anesthesia.
• Most anesthesia-related deaths were due to hypoxemia when
difficulty securing the airway was encountered.

7. • Many cases of failed intubation occur when a “difficult airway” is
not recognized before induction of general anesthesia.
• Airways change during pregnancy and may worsen during labor,
especially in a preeclamptic patient.
• Careful airway evaluation, although imperfect, must be performed
before initiation of general anesthesia.

8. • Physical changes associated with pregnancy, including weight
gain, enlarged breasts, and oropharyngeal edema, can complicate
endotracheal intubation.
• In addition, certain disease states such as preeclampsia may
predispose to failed intubation.

9. • Central to decreasing the risk associated with general anesthesia
is early assessment of the mother's airway.
• It has been reported that airway evaluation can often identify a
parturient with a difficult airway, but it was not performed in
upward of 10% of cases in which maternal mortality occurred.

10. The greatest risks are associated with:
1. a Mallampati class 4 airway,
2. a short neck,
3. protruding maxillary incisors,
4. and mandibular recession.

11. • all patients must have a repeat airway examination performed
before initiation of anesthesia for cesarean section because it has
been demonstrated that labor may be associated with changes in
the maternal airway.

12. 3 key points of anesthesia-related maternal
deaths
1. anesthesia-related deaths from airway factors occurred during
emergence and recovery and not during induction of general
anesthesia;
2. system errors such as deficiencies in postoperative monitoring
and in supervision of junior anesthesiologists contributed to
fatalities; and
3. obesity and African American race were highlighted as risk
factors for anesthesia-related maternal mortality.[203]

13. Management of failed intubation in pregnancy with
reference to the presence or absence of fetal distress.

14. Basic algorithm of the Difficult Airway Society

15. Unanticipated Difficult Intubation
• The most difficult situation is management of unanticipated
airway difficulty in a patient requiring emergency surgery.
• If it is essential to proceed with surgery, a traditional technique
has been to continue with a facemask and oral airway while
maintaining cricoid pressure.
• Continuation of anesthesia with an LMAc is now an established
technique, though not always effective.

16. Unanticipated Difficult Intubation
• The PLMA forms a better seal than the LMAc does and provides
improved protection against aspiration.
• It may be preferred by users who have proven competence with
the device.
• Early conversion to tracheal intubation with devices such as the
AIC is desirable

17. “Cannot Intubate, Cannot Ventilate”

18. “Cannot Intubate, Cannot Ventilate” Situation
• Ventilation with noninvasive techniques fails to maintain
oxygenation and tracheal intubation proves impossible.
• This scenario may develop rapidly but often occurs after repeated
unsuccessful attempts at intubation.

19. “Cannot Intubate, Cannot Ventilate” Situation
• Before resorting to invasive percutaneous airway techniques,
maximum effort must be made to achieve ventilation and
oxygenation with noninvasive techniques, such as optimum mask
ventilation and use of SADs.

20. “Cannot Intubate, Cannot Ventilate” Situation
• Facemask ventilation may require the two-person technique and
the use of an oral or nasal airway.
• It may be necessary to reduce cricoid pressure to achieve
satisfactory ventilation.
• If satisfactory oxygenation cannot be achieved with a facemask,
an SAD should be used instead.

21. Insertion of an LMA in the
“cannot intubate, cannot ventilate” situation
has a significant failure rate.

22. “Cannot Intubate, Cannot Ventilate” Situation
• The risks associated with an invasive rescue technique must be
constantly weighed against the risk of hypoxic brain damage or
death.
• Rapid development of severe hypoxemia, particularly when
associated with bradycardia, is an indication for imminent
insertion of a percutaneous airway that can reliably deliver a large
minute volume with an FIO2 of 1.0.

23. “Cannot Intubate, Cannot Ventilate” Situation
• Many cricothyrotomy techniques have been criticized because
they are not capable of providing effective ventilation.
• If noninvasive techniques do not restore oxygenation,
cricothyrotomy is the percutaneous airway of choice
• It is not possible to define the SpO2 at which cricothyrotomy
should be performed—it depends on the degree of hypoxemia and
how rapidly it is deteriorating.

24. “Cannot Intubate, Cannot Ventilate” Situation
• Cannula cricothyrotomy carries a lower risk of significant
bleeding. It may be considered when dedicated equipment is
immediately available and staff are fully trained in its use.
However, it may fail or cause barotrauma.
• If it cannot be performed rapidly, is ineffective, or causes
complications, surgical cricothyrotomy should be performed
immediately.

25. “Cannot Intubate, Cannot Ventilate” Situation
• Surgical cricothyrotomy with insertion of a cuffed tube is more
invasive but can be performed very rapidly and allows effective
ventilation with low-pressure sources.

26. Final steps
• Emergency invasive airway access is a temporary measure to
restore oxygenation and will be followed by definitive airway
management.
• This may be a formal tracheotomy, but tracheal intubation is
possible in some patients.