2019 56 Maternal Collapse Flashcards
What are the physiological & anatomical changes in pregnancy that affect resuscitation?
- Aortocaval compression, reducing cardiac output from 20/40
- Hypoxia, due to changes in lung function, increased O2 use & diaphragmatic splinting
- Difficult intubation
- Increased risk of aspiration
How should aortocaval compression be relieved for resuscitation?
- Manual displacement to the left
- Left lateral tilt 15-30•
- Spinal board before tilting in major trauma
What should remain the same in the life support algorithm?
ABCDE approach
Defibrillation energy levels
Drugs & doses
Who should decide when to discontinue resuscitation efforts?
Consultant obstetrician
Consultant anaesthetist
With cardiac arrest team consensus
When, where & how should perimortem CS be carried out?
- In women over 20/40
- If no ROSC within 4 mins of correct CPR
- Where collapse has occurred
- Via midline vertical or suprapubic transverse incision
- Scalpel & cord clamps from resus trolley
What is the antidote to magnesium toxicity?
10ml 10% calcium gluconate or
10ml 10% calcium chloride
Slow IV injection
What is the antidote to local anaesthetic toxicity?
Intralipid 20%
NB report to NHS Improvement & Lipid Rescue site
How should anaphylaxis be treated?
1) 1:1000 adrenaline 500 micrograms (0.5ml) IM
2) Repeat after 5 mins if no effect
3) Hydrocortisone 200mg
4) Chlorphenamine 10mg
5) Take mast cell triptase
What are the survival rates for in-hospital maternal cardiac arrest?
50%
How should maternal collapse be reported?
- Clinical incidence form for all collapse
- MBRRACE for all deaths
What is the incidence of cardiac arrest in pregnancy?
1:36,000
How are the 4Hs affected in pregnancy?
Hypovolaemia
Bleeding, spinal, septic or neurogenic
Hypoxia
Breathing, cardiac: cardiomyopathy, MI, aortic dissection, aneurysms
Hypo/hyperkalaemia, hyponatraemia
K no more likely, Na oxytocin use
Hypothermia
No more likely
How are the 4Ts affected in pregnancy?
Thromboembolism
AFE, PE, air embolus, MI
Toxicity
Local anaesthetic, Mg, other
Tension pneumothorax
Following trauma/suicide attempt
Tamponade
Following trauma/suicide attempt
What should be added to the 4Hs & 4Ts?
Eclampsia
Pre-eclampsia
Intracranial haemorrhage
How does the plasma volume change in pregnancy & impact on resus?
⬆️ up to 50%
Dilutional anaemia
Reduced oxygen carrying capacity
How does the heart rate change in pregnancy?
⬆️ 15-30 BPM
How does the cardiac output change in pregnancy?
⬆️ by 40%
Significantly reduced by pressure of gravid uterus on IVC
How much of the cardiac output is directed to the uterus at term?
10%
How does arterial blood pressure change in pregnancy?
⬇️ by 10-15 mmHg
How does the oxygen consumption change in pregnancy?
⬆️ by 20%
How does the residual capacity change in pregnancy?
⬇️ by 25%
What are the GI changes in pregnancy?
⬇️ gastric motility
Relaxed oesophageal sphincter
⬆️ weight
What is the incidence of major obstetric haemorrhage?
6:1000
What are the causes of major obstetric haemorrhage?
- PPH
- Placenta praevia
- Placental abruption
- Uterine rupture
- Ectopic pregnancy
What is the incidence of amniotic fluid embolism?
1.7 per 100,000
How does amniotic fluid embolism present?
During or within 30 mins of birth
Acute hypotension
Respiratory distress
Acute hypoxia
May progress to seizures & cardiac arrest
How does amniotic fluid embolism progress?
- Vascular occlusion
- Pulmonary hypertension
- LV dysfunction or failure
- Coagulopathy
- Massive PPH
What is the major cardiac cause of maternal death?
- Ischaemia
- Sudden arrhythmia with structurally normal heart
What are the cardiac causes of maternal death?
- Ischaemia
- Arrhythmia
- Aortic root dissection
- Congenital & rheumatic heart disease
- Cardiomyopathy
- Coronary artery dissection
- Acute LV failure
- Infective endocarditis
- Pulmonary oedema
What are the most common causative organisms of maternal sepsis?
- Group A Strep
- Group B Strep
- Group D Strep
- Pneumococcus
- E. Coli
What are the signs of local anaesthetic toxicity?
- Feeling inebriated & light-headed
- Sedation
- Circumoral paraesthesia & twitching
- Convulsions
- Cardiovascular collapse
- Arrhythmia: sinus bradycardia, conduction blocks, asystole, VT
How should mast tryptase levels be taken?
3 timed samples:
1. ASAP after resus started
2. 1-2 hours after symptom onset
3. 24 hours later
What proportion of cardiac output can be provided by chest compressions?
30% if not pregnant
10% if pregnant
What proportion of circulating volume can be lost before becoming symptomatic?
Up to 35%
What are the rates for CPR?
2 ventilation breaths 10/min
30 chest compressions 100-120/min
How often should adrenaline be given in resus algorithm?
Every 3-5 mins
What are the shockable rhythms?
VF
Pulseless VT
What are the non-shockable rhythms?
Asystole
PEA
What are the energy values for defibrillation?
200J biphasic
360J monophasic
What drugs are considered in the resus algorithm?
Amiodarone
Atropine
Magnesium
