Presentation on theme: "ANAESTHESIA FOR INTRAUTERINE FETAL SURGERY PRESENTED BY- Dr. Anupam MODERATOR- Dr. Yashwant."— Presentation transcript:
ANAESTHESIA FOR INTRAUTERINE FETAL SURGERY PRESENTED BY- Dr. Anupam MODERATOR- Dr. Yashwant
Fetal surgery is ……….. Indicated in conditions which interfere with the normal development of the fetus in-utero but Which when corrected will allow the development of the fetus normally. It is contraindicated in conditions that are incompatible with life medical condition in the mother precluding surgery.
3 types of fetal surgery :- EXIT (Ex-Utero Intrapartum Treatment Procedure) Mid gestation Open Surgery Minimally invasive mid gestation procedures FETENDO (Fetal Endoscopic Surgery) FIGS (Fetal Image Guided Surgery)
EXIT ( Ex-utero intrapartum treatment ) :- EXIT ( Ex-utero intrapartum treatment ) :- Also know as OOPS. It is the intervention that occurs at the time of delivery It is primarily used in cases where baby’s airway requires surgical intervention It starts as a routine LSCS but under GA Head of the baby is delivered, but the placenta is in situ The baby gets oxygen from placenta via umbilical cord
Bronchoscopy of the fetal airway Endotracheal intubation attempted If unsuccessful then tracheostomy is done O 2 delivery to lungs confirmed Cord is cut & Baby is delivered
Indications:- Giant cervical neck mass. CHAOS (Congenital High Airway Obstruction Syndrome- tracheal atresia) Removal of balloon after CDH CCAM (Congenital Cystic Adenomatoid Malformation)
Mid gestational open fetal surgery:- Surgery performed between weeks through hysterotomy. Fetus exteriorized for surgery then placed back in uterus to mature. Indications :- CCAM (Congenital Cystic Adenomatoid Malformation of Lung)- Lobectomy SCT (Sacro-coccygeal Teratoma)- Resection MMC (Meningo Myelocoele)- Repair
FIGS (Fetal Image Guided Surgery) :- Ultrasound image guided procedure Least invasive Least risk of amniotic fluid leak Least risk of PT labour
Indications :- Diagnostic :- Chorion Villus Sampling Amniocentesis Cordocentesis Fetal skin Biopsy Therapeutic :- RFA (Radio Frequency Ablation) of anomalous Twins Cord cauterization in Twins Vesical / Pleural Shunts Balloon Dilatation of Aortic Stenosis
FETENDO (Fetal Endoscopic Surgery) :- Fetoscopic access to the Fetus The fetal visualisation is a combination of endoscopic and sonographic on two different screens Less invasive Less risk of amniotic fluid leak Less risk of PT labour
Indications :- CDH (Congenital Diaphragmatic Hernia)- Balloon Occlusion of trachea TTTS (Twin to Twin Transfusion Syndrome)- Laser coagulation of vessels Cord ligation in cases of acardiac Twins Amniotic bands division
ANAESTHESIA FOR FETAL SURGERY
ANAESTHETIC CHALLENGES Those related to any anaesthetic technique in a pregnant female Techniques used to prevent preterm labour Maintenance of maternal hemostasis in face of tocolytic techniques Maintenance of fetal hemostasis Provision of fetal analgesia.
Anaesthetic considerations :- Maternal Fetal Uteroplacental Preoperative assessment Type of anaesthesia Intraoperative management Post operative care complications
Maternal anesthetic considerations:- Risk of aspiration pneumonitis Risk of pulmonary edema Risk of hypoxia Risk of supine hypotension syndrome Risk of massive hemorrhage Myocardial depression, hypotension
Fetal anaesthetic considerations:-
Fetal anaesthetic considerations: Fetal Cardiac Output is sensitive to heart rate changes Fetus has high vagal tone & low barorecepter sensitivity,hence responds to stress with precipitous bradycardia. Fetal circulating volume is low( 110ml/kg), hence little intra-operative bleeding can cause hypovolemia. Inhalational agents depressess fetal circulation as well-direct myocardial depression, vasodilatation, changes in arterio-venous shunting.
Fetus tends to lose heat much easily from the exposed skin resulting in hypothermia Immature coagulation system predispose the fetus to bleeding and difficulty in achieving hemostasis. Maternal anesthesia reduces placental blood flow, this reduces the amount of O 2 delivered to the fetus( hypoxia) Normal Fetal oxygen saturation is 60-70% and the aim is to maintain it above 40% Intra-operative fetal distress is manifested by bradycardia, decreased fetal oxygen saturation and reduced stroke output.
Uteroplacental considerations:- Maternal hyperventilation is avoided as maternal hypocapnia causes fetal placental vasoconstriction and fetal hypoxia. Maternal BP & myometrial tone correlates with uterine artery blood flow. Maintenance of patent UA & maintenence of maternal BP with in 10% of baseline is critical.
Pre-operative assessment:- Assessment of the mother for fitness for anaesthesia Assessment of the fetus ◦ Detailed USG to r/o other malformations ◦ 3D and 4D examination-Detailed examination of affected organ system ◦ Detailed Fetal Echocardiography, Amniocentesis, Localization of placenta ◦ Fetal MRI Maternal blood cross matched- arrange blood for mother and fetus.
Anaesthesia for open fetal surgery:- Pre-operative preparation- 1. OT warmed 2. Blood arranged 3. Monitors and syringes 4. Prophylaxis for Aspiration 5. Lumber epidural inserted & tested 6. Indomethacin suppository administered 7. Positioning done
The fetus is monitored with Fetal Echocardiography Pulse Oximetry PO 2 from Cord Blood Fetal Hb from Cord Blood
TYPES OF MATERNAL ANAESTHESIA :- Regional Anaesthesia-Lumbar Epidural Deep GA-(Sodium Pentothal + Scoline) + (Isoflurane + Fentanyl+O 2 + Vecuronium) GA with N 2 O- (Sodium Pentothal + Scoline) + (Isoflurane + N 2 O + Vecuronium)
Intraoperative management:- Rapid sequence induction with thiopentone & Sch. Maintenence – Nitrous plus oxygen plus 0.5 MAC (isoflurane, desflurane) Invasive arterial line, secure 2 nd venous catheter, NG tube & Foley's catheter insertion. Fetal status monitored by sterile intraop echocardiography.
Restrict fluids in mother ( post op PE ) Before hysterotomy, nitrous turned off & deepen the patient by increasing inhalational agents to 2 MAC Maintain maternal BP – ephedrine/PE Fetus is given I/M opioids b4 incision. Fetal monitoring with Miniature pulse oximeter & echocardiography done. Blood gas samples help guide therapy during period of fetal distress. Following closure of uterus, anaesthesia converted to regional based technique.( LA,opioids through epidural catheter)
Tocolysis instituted via MgSo4 loading dose followed by infusion. Patient extubated and shifted to recovery. Post-op management:- Tocolysis for at least hours. Adequate maternal pain relief with epidural.
Anaesthesia for EXIT :- No tocolysis One additional OT for possible fetal sugery Desflurane inhalational agent of choice. During hysterotomy, only partial exposure of fetus done. DL / intubation done by surgeon or anaesthesiologist. If baby cant be intubated, tracheostomy done. After assuring adequate fetal oxygenation cord clamped & fetus delivered.
The timing of cord clamping with respect to administration of oxytocin, methergin and carboprost as well as decreasing volatile agents must be coordinated between anaesthesiologist and surgeon. Blood loss is monitored and cross matched blood is administered if needed. If surgery is not required immediately, a neonatology team resuscitates and transports the neonate to NICU.
Fetoscopic surgery:- Epidural anaesthesia:- less effect on fetal hemodynamics & UP circulation & post op uterine activity but lack of uterine relaxation, lack of fetal anesthesia hence, difficulty manipulating the uterus & cord while baby is still moving. Balanced inhalation-opioid anaesthesia:- it eliminates anxiety, nausea, emesis and allows immobile anaestheized fetus, less CV effects than deep inhalational, but provides no uterine relaxation.
Deep inhalational anaesthesia:- provides profound uterine relaxation but affect fetal hemodynamics & UPBF
Maternal complications: - Tocolytic therapy can cause pulmonary edema Subsequent delivery by LSCS Massive hemorrhage Amniotic fluid leak Wound infection Intra uterine infection “Maternal Mirror Syndrome” in cases of fetal Hydrops ( mother mirrors the symptoms that fetus is experiencing) Chorio-amniotic membrane separation
Fetal complications:- Prematurity Intra Uterine Infection Fetal vascular embolic events ◦ Intestinal atresia ◦ Renal agenesis Premature closure of Ductus Arteriosus CNS injuries due to maternal hypoxia or fetal circulatory disturbance Bleeding