RESUSCITATION IN PREGNANCY DURING AND AFTER

The overall incidence of cardiac arrest during late pregnancy is  estimated to be one in 30000,  however survival rate following such an event is extremely low. Most deaths are due to acute medical conditions associated with pregnancy rather than due to causes from pregnancy itself. Resusctation in pregnancy is different as we have two potential patients, the mother and the fetus. The best hope of fetal survival is maternal survival. Factors peculiar to pregnancy such as the anatomical, physiological and pathological changes make resuscitation difficult  in late pregnancy. The major considerations are :

Respiratory

• Increased  alveolar ventilaton and oxygen consumption
• Increased oxygen demand
• Reduced chest compliance
• Reduced functional residual capacity
• Increased risk of  aspiration
• Laryngeal edema
• Airway obstruction due to edema and soft tissue hypertrophy

Gastrointestinal

• Incompetent gastroesophageal (cardiac) sphincter
• Increased intragastric pressure
• Increased risk of regurgitation
• Increased acidity of gastric contents

Cardiovascular

• Physiological anemia
• Supine hypotension syndrome 

Anatomical

• Obesity, turning the patient to one side is difficult and requires assistance
• Hypertrophied breasts  cause difficulty in laryngoscopy  and prevents effective chest compression or defibrillation

Basic life support

•  Remove dentures or foreign body from airway
•  Suction and artificial airway,  if available
•  Ventilation by mouth to mouth or using an ambu bag. Remember to apply cricoid  pressure
• Turn the patient to get  lateral displacement of uterus and thereby preventing venacaval obstruction by the gravid uterus. A left lateral displacement is made by tilting the body to 30 degrees which can be  achieved with a cardiff wedge kept beneath the right buttock or a rolled towel  or pillow if wedge is not available. The other techniques to provide tilt are by manual displacement of uerus or by tilting onto the back of an upturned chair. A human wedge is the one where the patient is turned onto a rescuers knees to provide a stable position for BLS.
• Chest compressions at the rate of 30:2, consider the cephalad movement of the diaphragm, and so the hands should be kept at a higher level during compression

ACLS

• Early inyubation is recommended
• Airway is "difficult"
• Tracheal intubation difficult due to  anatomical changes like short neck, edematous soft tissues,  large tongue, and large breasts
• So isertion of laryngoscope is difficult hence,  short handle may be used  for the scope,  removing the blade and re attach after insertion into the oral cavity, or using a curved blade like Mc Coy, or polio blade etc are advised
• LMA classic or FAST TRACH  are advised  for emergency airway access if intubation fails.  Release cricoid pressure during insertion and re apply after insertion of LMA eventhough cricoid pressure  is not very effective with LMA insitu.
• Defibrillation  when needed should be done according to standard ACLS defibrillation doses. Remove all fetal or maternal monitors while giving shock. DC shocks are found to be not harmful to the fetus
• Immediate iv access and fluid resuscitation in case of hemorrage
• Consider low tidal volumes, enough to make a visible chest rise
• Consider early caesarean section  when standard rsuscitative measures fail to restore maternal circulation and shoul be done in less than 5 minutes.(even after mother's heart stops) caesarean section helps to relieve aortocaval compression and incrase venous return, thereby improve cardiac output.It also increases thoracic compliance
• Vaso pressors are also used as per standard ACLS protocols eventhough fetal blood flow is reduced

Differential diagnoses to be considered during or immediately after resuscitation

• Immediate abdominal ultrasound for concealed hemorrage
• Excess magnesium sulphate(may be iatrogenic). Administer calcium gluconate      1 gram or one ampoule.  Empirical therapy also is life saving.
• Acute coronary syndromes to be considered in elder patients.  Fibrinolytics  are  contra indicated hence percutaneous coronary intervention is the treatment of choice for STEMI
• Pre eclampsia, or eclampsia,  consider treatment of hypertension or emergency caesarean section
• Aortic dissection, a rare possibility
• Life threatening pulmonary embolism or stroke  here fibrinolytics must be administered as prognosis was found to be good ,in spite of risk, in  massive embolus
• Amniotic fluid embolism  consider  immediate CABG
• Trauma and drug overdose

Ref;   1) Circulation. 2005;112:IV-150 – IV-153. AHA guidelines for CPCR
         2) The abc of resuscitation,   BMJ