BASIC LIFE SUPPORT (BLS) strategies are applicable with little modification, but in addition, minimisation of aortocaval compression (ACC) (Chapter 28) using manoeuvres such as a Human Wedge (1), Cardiff Resuscitation Wedge (2), or simply a rolled up towel or pillow under the right abdominal flank should be carried out (Figure 28.2).
ADVANCED LIFE SUPPORT (ALS) strategies (3) are also applicable with little modification, except that urgent consideration should be given to the possibility of delivery by caesarean section (CS) while CPR continues unabated (Chapter 12).
Additional points of note are:
AIRWAY
The application of early cricoid pressure by a skilled operator may be appropriate and facilitate mouth-to-mouth ventilation or the use of a resuscitator device. Inappropriate cricoid pressure can obstruct the airway or stimulate vomiting. Early securement of the airway with a cuffed tracheal tube is ideal and in the absence of this, airway difficulties can supervene at any time and convert an effective resuscitation into an unmanageable situation. Problematic airways occur frequently in obstetrics.
Management plan:
A. Have in your mental foreground a planned, controlled approach to the possibility of "failed intubation".
B. Be mindful of where you are and be prepared:
1. to modify the cricoid pressure;
2. to use different laryngoscope blades (Chapter 38);
3. to cease attempts at tracheal intubation and ventilate;
4. to use the laryngeal mask;
5. to seek a surgical airway (crico-thyrotomy).
C. Remember that:
1. physiological goitre of pregnancy may complicate attempts at a "surgical airway';
2. gastric decompression using an oral rather than a nasal approach is preferable because the risk of epistaxis during instrumentation of the unprepared nose is great.
BREATHING
Low arterial PC02 may further compromise uteroplacental flow.
Venous embolic events may be responsible for a large alveolar dead space.
The pattern of IPPV may contribute to a complex interplay of multiple pathological factors, such as can occur in cardiopulmonary arrest after major regional block in a parturient. Aortocaval compression, "high epidural" with reduced cardiac and vascular sympathetic tone, and high intrathoracic pressures from IPPV or coughing can all contribute towards reducing venous return during resuscitation.
CIRCULATION
Intraabdominal complications of CPR are more likely in late pregnancy. When performing cardiac massage, these can be minimised by carefully placing the hands over the sternum above the xiphoid.
Monitoring of the massage by arterial palpation may be made more difficult by ACC (Figure 28.1) and by the low systemic vascular resistance (SVR) which can render the pulse impalpable.
When, and if, CS is performed the newborn will need immediate advanced life support.
After delivery of the infant, the distal aorta can be occluded so as to control bleeding and improve cardiac afterload and perfusion (although reperfusion injury may occur).
Once the uteroplacental circulation is closed, the SVR will increase and responsiveness to beta agonists may be less blunted.
SUBSEQUENT MANAGEMENT
Establish the diagnosis because this will alter further management.
Some life-threatening conditions require different treatment in the non-pregnant and pregnant states (eg. pulmonary embolectomy, rather than thrombolysis, is preferable after massive obstetric pulmonary embolism).
If resuscitation is rapidly successful (before CS has been performed) the fetus requires careful monitoring until delivery.
Crisis management, team debriefing and bereavement issues may also need to be addressed.
2. Rees GAD, Willis BA. Resuscitation in late pregnancy Anaesthesia 1988 43:347-349.
3. American Heart Association 'Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care' JAMA, OCT 28, 1992 268:16; 2171-2302, (see p 2249)