→ Discuss indications of general anesthesia for operative delivery → Explain aspiration risk for general anesthesia in pregnancy and prevention strategy Outline anaesthesia plan of care for induction, maintenance and emergency Describe effect of volatile anaesthetics on uterine blood flow and tone Discuss intraoperative strategies to prevent postoperative nausea and vomiting Discuss other complications of general anaesthesia and clinical management

1. GENERAL ANESTHESIA
&
C-SECTION
PART II
Dasht-e Barchi Project
Kabul - December 2018
Dr. Sandro Zorzi
References:
- Anesthesiology - Longnecker Ed. 2017
- Obstetric Anesthesia Handbook 2010 Fifth Edition S.Datta
- Essential Obstetric and newborn care MSF 2015

2. Learning Objectives:
MODULE 4 GENERAL ANAESTHESIA:
● Discuss indications of general anesthesia for operative delivery
● Explain aspiration risk for general anesthesia in pregnancy and prevention strategy
● → Outline anaesthesia plan of care for induction, maintenance and emergency
● → Describe effect of volatile anaesthetics on uterine blood flow and tone
● Discuss intraoperative strategies to prevent postoperative nausea and vomiting
● Discuss other complications of general anaesthesia and clinical management
● List recovery room disharge criteria following general anaesthesia for C-section

3. BEFORE INDUCTION:
● Check drugs/equipment and if possible conduct a focused history and physical
examination (mallampati, comorbidity, laboratory….).
● A communication system should be in place AND USED between obstetric providers,
anesthesiologists, and other members of the multidisciplinary team → TEAM WORKING!!!
● The patient should be placed supine with left uterine displacement and optimal airway
positioning.
● Following IV lines testing, fluid loading and monitoring (electrocardiography, pulse
oximetry, blood pressure, and capnography) preoxygenation with 100% oxygen should be
performed. In urgent situations, four maximal breaths of 100% oxygen will provide
adequate preoxygenation.
● After the surgical drapes have been applied and the operating personnel are ready at the
bedside, the surgeon should be instructed to delay the initial incision until the anesthesia
provider confirms correct placement of the endotracheal tube and gives verbal
confirmation to proceed with the operation. TIMING IS IMPORTANT!!

4. AIRWAY ASSESSMENT
L-E-M-O-N scoring system:
L – Look. Four criteria are used for the look category: facial trauma, large incisors, beard or moustache,
large tongue.
E – Evaluate. Evaluation is done using the 3-3-2 rule.
1. Inter-incisor distance: patient's mouth is opened adequately to allow the placement of three
fingers between the upper and lower teeth
2. Hyomental distance: three finger breadths are used
3. Thyromental distance: two finger breadths are used
M – Mallampati. This is done with the patient seated with the head in the neutral position and mouth
fully open and the tongue protruded maximally without phonation while the interviewer looks from the
front at the patient's eye level and inspects the pharyngeal structures with a pen torch without the
patient phonating.
O – Obstruction. Patients are evaluated for stridor, foreign bodies, and other forms of sub- and
supraglottic obstructions including tumors, abscesses, inflamed epiglottis, or expanding hematoma.
N – Neck mobility. This is a vital requirement for successful intubation. It is assessed by the patient in
the sitting position to place their chin down onto their chest and then to extend their neck so they are
looking towards the ceiling.

6. CRICOID PRESSURE
● Specifically agree the location of the cricoid cartilage with the assistant before you induce
anaesthesia. Ensure the anaesthetic assistant is comfortable in the role.
● Excessive cricoid force applied by the anaesthetic assistant can lead to failed intubation.
● Anaesthetic assistants regularly check their cricoid force on the theatre scales to maintain it at 20
to 30 N (2 to 3 kg on the scales).
● A pressure of 10 N should be applied prior to loss of consciousness and the assistant must be
instructed to increase the pressure as soon as consciousness is lost.

7. AIRWAY POSITIONING

8. ...BEFORE THE INDUCTION...
→ PREVISION OF DIFFICULT INTUBATION HIGH?
CAN WE DO SPINAL ANESTHESIA? IF NO ALWAYS:
- Equipment, facilities, and support personnel available/check in OT
- Resources/treatment of potential complications like failed intubation and oxygenation are planned before induction
LARINGEAL MASK MUST BE READY TO USE!!
- For C-section ask always to check the FHB if possible (especially if indication is fetal distress). The surgeons have to prepare the patient
to do the incision after the intubation (ideally induction/delivery < 3-10 minutes). So only after the surgical drapes have been applied
and the operating personnel are ready at the bedside, the surgeon should be instructed to delay the initial incision until the anesthesia
provider confirms correct placement of the endotracheal tube and gives the verbal confirmation to start.
- Preoxygenation with 100% oxygen should be performed to delay the onset of hypoxemia stemming from the parturient’s decreased
functional residual capacity and increased oxygen consumption. Additional insufflation of 2 – 5 litres of Oxygen via nasal cannulae or
catheter improves pre-oxygenation and oxygen reserve. In urgent situations, four maximal (ie,approaching vital capacity) breaths of
100% oxygen will provide adequate preoxygenation.
- During induction and intubation all the team help/attend the anesthesist and is ready to help if necessary

9. RAPID SEQUENCE INDUCTION
1. Premedication: PONV, antibiotic. Ephedrine or phenyleprhine, 30 u.i. oxytocin prepared
2. Monitoring of blood pressure, pulse, ECG, O 2 saturation,capnography, temperature,
check if functional 2 IV line
3. Left uterine displacement and airway optimal positioning
4. Preoxygenation with 100% oxygen and alert the team about the beginning of the
procedure
5. Induction with thiopental (4-5mg/kg) or ketamine (1-1,5mg/kg,drug of choice if
hemorragic patient) and succinylcholine (1-1,5mg/kg) while maintaining cricoid
pressure
6. After intubation cuff endotracheal tube and check correct positioning and ventilation
before connect to ventilator [ glostavent: 6ml/kg, RR 10-12, flow 2l O2/2l Air ] and give
the confirmation to start to the surgeon

10. MAINTENANCE
1. Fifty percent O2 with a small amount of isoflurane (up to 0,5-0.75%), unless
contraindicated, use IV drugs for maintenance.
2. Avoidance of hypo/hyperventilation: end-tidal carbon dioxide around 32 mmHg.
3. Muscle relaxants: nondepolarizing muscle relaxants (vecuronium 0,04/0,06 mg/kg) with
the use of a neuromuscular blockade monitor if possible
4. Desufflation of the stomach by a gastric tube after induction and intubation
5. Minimization of the induction-delivery interval
6. Minimization of the uterine incision-delivery interval: talk with the surgeon!!
7. Use of narcotics/postoperative pain killers/others in the mother after delivery of the
baby
8. Always remind to be ready and ask to the surgeon if need more uterotonics
(misoprostol, methylergomethrin, oxytocin)
9. Extubation performed when the mother is wide awake and after antagonization of the
neuromuscolar block

11. KEY POINTS :
1. Check equipment/drugs and plan in case of anesthesia complications
2. Before the induction re-evaluate the patient and check IV line/monitoring
3. Always remind to calibrate the anesthesia on the antropometric values of weight and
height.
4. TEAM WORKING AND TIMING!!
5. In special conditions like pre-eclampsia/eclampsia BE CAREFUL about fluid overload for
the high risk of pulmonary edema
6. Every patient need a different anesthesia care moduled on vital signs, urine output and
comorbidity but all need the surgical WHO checklist!!!
7. Always remind that hypotermia, acidosis, coagulopathy must be prevented
8. If hemorragic patient remind to have already thought about transfusion or if necessary
activeted the massive transfusion protocol
9. In case of atony remind that halogenated gas like isoflorane must be stopped, they can
give. Concentrations should be reduced to <1-1.5 MAC(ISOFLORANE MAX 0,75%), the
threshold above which relaxation of uterine tone cannot be attenuated with oxytocin.

13. TEST
1) After what point are all pregnant women considered to have full stomachs?
a) After the first trimester
b) Before the thid trimester
c) After the third trimester
d) After the second trimester
e) Before the labor
2) Anemia in pregnancy is defined as hemoglobin level below:
a) < 11 gr/dl
b) < 8 gr/dl
c) < 12 gr/dl
d) >7 - < 10 gr/dl, < 7 gr/dl is defined as severe anemia
e) < 8 gr/dl
3) What is the Body Mass Index (BMI):
a) The BMI is defined as the body mass divided by the square of the body wheight, and is universally expressed in units of kg/m2
b) The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/cm2
c) The BMI is defined as the body massdivided by the square root of the body wheight, and is universally expressed in units of kg/m2
d) The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2
e) The BMI is defined as the body mass divided by the square root of the body height, and is universally expressed in units of kg/cm2