Transcript Obstetric resuscitation - asja
Prepared by Ahmed El-Henawy, MD.
Lecturer of Anesthesia, Ain Shams University Presented by Wael Samir, M.Sc.
Assistant Lecturer of Anesthesia, Ain Shams University
INTRODUCTION
During resuscitation there are two patients, mother & fetus.
The best hope of fetal survival is maternal survival.
Consider the physiologic changes due to pregnancy.
PHYSIOLOGICAL CHANGES
CARDIOVASCULAR SYSTEM
RESPIRATORY SYSTEM
GASTROINTESTINAL SYSTEM
AIRWAY CHANGES
CARDIOVASCULAR SYSTEM
Blood volume (90ml/Kg) - 50% increase in plasma volume - 30% increase in RBC volume COP (40%) - 30% increase in stroke volume - 15% increase in heart rate SVR - Due to vasodilatory effects estrogen , progesterone and prostacyclin.
SUPINE HYPOTENSION SYNDROME
Because of these cardiovascular changes and the tendency for blood flow to be shunted from the uteroplacental circulation under conditions of hypovolemia, patients can bleed extensively before normally recognizable physical signs such as tachycardia and hypotension occur.
SUPINE HYPOTENSION SYNDROME
5 to 8% of pregnant women experience a 30 to 50% drop in blood pressure in the supine position Becomes evident from the 20 th week of pregnancy It can be associated with signs of shock such as pallor, sweating, nausea and vomiting Caused by the near total occlusion of the
IVC GRAVID UTERUS
by the Compression of the aorta does not cause maternal hypotension , instead it cause arterial hypotension leading to inadequate uterine blood flow and fetal asphyxia.
AIRWAY CHANGES
Increased risk of difficult intubation: - Intrinsic and extrinsic deposition of adipose tissue - Large tongue - Edema of upper airway - Limited cervical spine mobility
RESPIRATORY SYSTEM
Increase in MV ( mainly due to larger tidal volumes )
Increase in Oxygen consumption
Decrease in FRC As a result
Closing capacity may exceed FRC with subsequent airway closure, V/Q mismatch, right to left shunt and hypoxemia.
Rapid desaturation during periods of apnea.
Supine, trendlenburg and lithotomy positions are poorly tolerated.
GASTROINTESTINAL SYSTEM
GERD and increased incidence of aspiration: 1.
2.
3.
4.
Upward displacement of the stomach leads to an incompetent LES Progesterone effect , with a decrease in the tone of the LES Increased intragastric pressure Delayed gastric emptying during labour
ETIOLOGY OF CARDIAC ARREST
BEAU-CHOPS B leeding E mbolism A nesthesia related U terine atony C ardiac disease H ypertensive diseases O thers P lacenta previa/abruption S epsis
INITIAL INTERVENTION FOR THE FIRST RESPONDER
Call for HELP
CODE – OB
The team should include:
1.
2.
3.
4.
5.
Usual code blue team Obstetrician Obstetric anesthesiologist Newborn resuscitation team and equipment Surgical nurse with emergency cesarean section tray
INITIAL INTERVENTION FOR THE FIRST RESPONDER
Left uterine displacement ( LUD ) Administration of 100% oxygen Venous access by 2 wide bore venous cannulae
ABOVE THE DIAPHRAGM
.
Search and treat any reversible cause of cardiac arrest - IV Calicum chloride for Mg toxicity - IV fluid bolus for hypovolemia
SPECIAL CONSIDERATIONS
Position
Airway
Circulation
Defibrillation
Emergency Caesarian section
POSITION
Left uterine displacement
Aiming to relieve
aortocaval compression
of the gravid uterus.
-Inferior vena caval occlusion is the norm in the supine position at term and results in >60% reduction in venous return. In order to reduce this pelvic tilt is required. However cardiac compressions becomes progressively more difficult to perform effectively the more the patient is tilted: A tilt of between 15 – 30° is suggested.
Method - One handed technique - Two handed technique - Wedge under the right hip - Human wedge
ONE HANDED TECHNIQUE
TWO HANDED TECHNIQUE
Patient in a 30° left-lateral tilt using a firm wedge
AIRWAY
Apply continuous cricoid pressure during positive pressure ventilation for any unconscious pregnant woman.
Early endotracheal intubation Performed by skilled personnel - ETT with smaller ID - Be prepared for a difficult intubation
CIRCULATION
The incidence of ineffective external chest compressions is higher in pregnant women due to: - Large breasts - Upward displacement of the heart - 15 to 30 degree lateral tilt In order to overcome this problem the operator’s hand should be placed slightly above the middle of the sternum.
After this adjustment if chest compressions are still not effective ( no carotid pulse OR poor capnograph trace ) a thoracotomy and open cardiac massage should be considered.
DEFIBRILLATION
Follow standard ALS guidelines There is no evidence that shocks from a direct current defibrillator have adverse effects on the heart of the fetus.
If fetal or uterine monitors are in place, remove them before delivering shocks.
Adhesive pads are safer and easier to apply than manual paddles
EMERGENCY CESAREAN SECTION
WHY ?
WHEN ?
HOW ?
WHAT GESTATIONAL AGE?
WHY?
Delivery of the baby empties the uterus, relieving both the venous obstruction and the aortic compression.
Delivery also allows access to the infant so that newborn resuscitation can begin.
Allows open cardiac massage as the heart can be reached relatively easy through the diaphragm.
It is important to remember that you will lose both mother & infant if you cannot restore blood flow to the mother’s heart.
WHEN?
CPR leader should consider the need for an ER cesarean section as soon as a pregnant woman develops cardiac arrest.
The best survival rate for infants 24-25 weeks in gestation occurs when the delivery of the infant occurs no more than 5 minutes after the mother’s heart stops beating.
This typically requires that the provider begin the delivery about 4 minutes after cardiac arrest.
HOW ?
A midline ( classical ) incision has been recommended as it is helped by the separation of the recti muscles that occur later in pregnancy.
The delay caused by aseptic precautions may itself be fatal.
A scalpel , pair of forceps and gloves for the operator’s protection maybe all that’s required.
WHAT GESTATIONAL AGE?
Gestational age < 20 weeks: Need not be considered because this size gravid uterus is unlikely to significantly compromise maternal cardiac output.
Gestational age 20 to 23 weeks: Perform to enable successful resuscitation of the mother, not the survival of the delivered infant, which is unlikely at this gestational age.
Gestational age > 24 weeks: Perform to save the life of both the mother & infant.
CONCLUSION
Maternal and fetal survival depend on rapid and skilled resuscitation.
Consider early (< 5 min) Cesarean delivery.
Training in ALS for pregnant woman is essential for maternity unit personnel.
Beware of aspiration and difficult intubation LUD is essential for successful resuscitation