EMERGENCY OBSTETRICS : ANAESTHESIA CONSIDERATION

Dr swati singh

•INTRODUCTION

•TYPES OF OBS EMERGENCIES

•EFFECT OF PREG. ON ANAESTHESIA

•ANAESTHETIC MX OF EMERGENCY

OBS

•COMPLICATION OF ANAESTHESIA

•TIPS FOR EoA

•SUMMARY

INTRODUCTION

An unforeseen, rapidly evolving event requiring immediate management.

Anaesthesia is an essential component of comprehensive EmOC, which includes c s and repair of ruptured uterus.

There is high morbidity & mortality due to Emo but this can significantly reduced by multidisciplinary care

INTRODUCTION

Obstetric emergency is often said to be the unique situation b/c anaesthetist has to deal with 2 patients under the same anaesthetic.

The health of the baby has to beconsidered as well as that of the mother.

Causes of pregnancy-related mortality,

Types of Obstetric EMERGENCIES

Uterine rupture Eclampsia/Pre Eclampsia Obs Haemorrhage Obstructed labour Inversion of the uterus

Physiological Changes-CVSAlmost all the changes seen are due to

high levels of progesterone and include:

Total Blood Volume & CO heart rate 500ml/min blood flow to uterus venous return from legs AORTOCAVAL COMPRESSION

(mechanical)

Impact of CVS changes

Patients with pre-existing cardiac disease may decompensate either during labor or immediately post delivery.

Approx 400 – 600ml blood loss occurs at delivery

Supine hypotensive syndrome

Aortocaval Compression

Physiological Changes - Resp

oxygen consumption due to increased metabolic rate

minute ventilation (due to increased tidal volume)

arterial pCO2 FRC causing a decrease in

oxygen reserves

Impact of Resp. changes

Uptake of inhalational agents is faster

FRC and oxygen consumption increase the risk of hyoxia with apnea

Physiological Changes- Airway

Venous engorgement of airway mucosa

Edema of airway mucosa

Trauma to upper airway with suctioning, intubation

Increased incidence of difficult/failed intubation x10

Require smaller ETT

Physiological Changes-CNS

Decrease in MAC by 25 – 40%Decreased inhalation anesthetic agent requirements

Decreased dose of Local Anesthetic requirement for regional techniques

More rapid onset of neural blockade Increased risk of local anesthetic toxicity

Physiological Changes - GIT

Increased gastric fluid volume and acidity

Decreased competency of lower esophageal sphincter

All parturients are a “full stomach”

Recipe for disaster i.e.ASPIRATION

Classification of Caesarean sections according to urgency

Category 1 Requiring immediate delivery - A threat to maternal or foetal life

Category 2 Requiring urgent delivery – Maternal or foetal compromise that is not immediately life-threatening.

Category 3 Requiring early delivery – But no maternal or foetal compromise.

Category 4 Elective delivery – At a time suited to the woman and maternity staff.

Anesthesia for EmOC

A distinction must be made between a true emergency requiring immediate delivery and one in which some delay is possible.

To determine whether fetus, mother, or both are in immediate jeopardy requiring GA or there is time to safely administer regional anesthesia.

Regional anesthesia is contraindicated in severely hypovolemic or hypotensive patients.

Anesthesia for EmO

Preparation Preventing complications Choice of Anesthetic technique Effects on the fetus

Preparation to Prevent complications

Premeds: antacid (sodium citrate)

Pre Oxygenation with 100% oxygen for 3–5 min

IV access and fluid bolus within 30 minutes of operating

left lateral tilt to prevent hypotension

Routine Monitors: BP, pulse oximeter

Anesthetic techniques

Local infiltration by surgeon Regional anesthesia: spinal, epidural,

cse General anesthesia

The choice of anesthesia for cs is determined by multiple factors, indication for operation, its urgency, patient and obstetrician preferences, and the skills of the anesthetist.

Inhalation Medications Entonox: 50:50 mixture of oxygen and

nitrous oxide Low dose Isoflurane, Halothene, in

oxygen

Advantages: on demand delivery, relatively safe

Disadvantages: variable efficacy, nausea, drowsiness, neonatal depression

Regional techniques Epidural, spinal, combined spinal-epidural

Advantages: – excellent pain control, – less drug transfer to fetus – improved uterine blood flow

Disadvantages: – invasive technique, – (hypotension, headache, itching,

nausea, urinary retention, nerve damage, infection

Amide Na+-channel blockers

LignocaineBupivacaine Macaine Ropivacaine NaropinL-Bupivacaine Chirocaine

- with/without opiates/epinephrine

Parenteral Medications Narcotics: Ketamine, meperidine,

morphine fentanyl

STP, propofol, etomidate etc.

Advantages: relatively good analgesia, good inducing agent

Disadvantages: nausea, vomiting, sedation, neonatal depression (max. 2 hours after meperidine dose), short duration of action

Local Infiltration

Rarely performed

Patient usually in extremis

Surgery must be done via midline incision, gentle retraction, no exteriorization of the uterus

Usually done to supplement a regional technique if local anesthetic toxicity not a concern

General Anesthesia

Em C/S and laparotomy when there is inadequate/absent regional analgesia and delay will cause undue risk to the fetus / mother

In case of haemorrhage Rapid sequence induction of GA is mandatory

Sellick maneuver or cricoid pressure This occludes the oesophagus, thus obstructing the path of regurgitation.

Factors that causes morbidity & mortality in GA

emergency situations

inadequate time for a thorough airway evaluation

unpredicted airway edema

inadequate assessment of proper endotracheal tube position

inadequate skill

Complications ofAnesthesia

– Failed intubation

– Failed ventilation causing death or neurological injury

– Awareness

– Aspiration pneumonia

Tips

COVER ABCD A SWIFT CHECK QSHC 2005 Vol 14

qhc.bmjjournals.com

COVER ABCD

C1 circulation C2 colour O1 oxygen O2 oxygen analyser V1 ventilation V2 vaporizer E1 endotracheal

tube E2 elimination R1 review monitors R2 review

equipment

A airwayB breathingC circulationD drugs

A SWIFT

A air embolism, anaphylaxis, air in pleura, awareness

S surgeon, situation, sepsis W water intoxication I infarct, insufflations F fat syndrome, full bladder T trauma, tourniquet down

CHECK

C catheter/ IV cannula H hyperthermia/ hypothermia H hypoglycaemia E embolus E endocrine C check patient and history K K + K keep the patient asleep

SUMMARY

Role of anesthetist during Obs Emergency

Attending primarily to the mother, and by doing so, assuring the best possible outcome for the baby and the mother

Thank You