anaesthesia for cdh

Anaesthesia For Congenital Diaghagramtic Hernia

BY

Professor Dr \ Lobna Abo Elnaser

Ass. Professor Dr \ Nagat Elshmaa

Dr \Amany faheem

Tarek Abdel Hay

Introduction

- Congenital Diaphragmatic Hernia (CDH) is a herniation of abdominal contents into thoracic cavity through congenital defect in diaphragm during intrauterine period due to failure of closure of pleuro-peritoneal canal.

-CDH occurs in 1 in every 2,000 - 5,000 live births world wide

-It is a life threatening condition that needs surgical correction either immediately after birth or after stabilization of the child .

Classification According to the anatomical location of the

defect; Posterior lateral CDH (Bochdalek’s hernia):It is of 2 types:- Right: It is represents about 10% of all cases.- Left: It is represents about 90% of all cases Anterior CDH(Morgagni’s hernia):- It is about 2% of all cases. Para esophageal CDH. Diaphragmatic eventration :It is diffuse thinning of diaphragm that allows abdominal viscera

to protrude upwards through thoracic cavity

Pathophysiology

Lung development in CDH :

No. of bronchial branches is greatly reduced.

Alveolar development severely affected .Pulmonary vasculature in CDH:

Reduction in the total no. of branches Both in

ipsilateral and contra lateral lungs.

Lung hypoplasia or

atelectasis

Mechanical compressionPPHTN

Respiratory distress & inadequate ventilation

Following delivery , bowel fill with air leading to: compression of ipsilateral lung Mediastinal shiftCompression of contralateral lung

Pulmonary vascular

resistance

Pulmonary

artery pressure

Pulmonary vascular

flow

Rt to Lt shunting

Hypoxia , progressiv

e desaturati

on & acidosis Respiratory

failure

Persistent fetal circulation

Clinical PresentationClassic symptoms:- Respiratory distress, Cyanosis & Dyspnea.Physical Exam:- Displaced apex beat to contra-lateral chest side.-Scaphoid abdomen and barrel chest.- Decreased or absent breath sounds on the

ipsilateral chest side.- Bowel sounds in the ipsilateral chest side.Chest X ray:- Loops of bowel in the ipsilateral chest side.- Mediastinal shift to contra-lateral chest side

Clinical Presentation

Associated congenital anomalies : Cardiovascular defects as VSD, PFO or PDA. CNS

defects as myelomeningocele, encephalocele. Genitourinary anomalies. Esophageal atresia . Down syndrome. Anal anomalies.

Approaches For Surgical Repair Of CDH

A- Open surgery:- Laparotomy.- Thoracotomy.B- Minimally-invasive surgery:- Laparoscopic repair.- Thoracoscopic repair.

Anaesthetic concern

1. Specific problems of neonates

2. Specific problems of prematurity

3. Specific problems related to the pathophysiology of CDH

4. Specific problems of the selected surgical procedure

5. Specific problems of laparoscopy

6. Specific problems of open surgery

Anaesthetic concernA- Specific problems of neonates:- Anatomical problems :- as difficult venous access and difficult airway- Physiological problems : as high metabolic rate, limited pulmonary, cardiac and

thermoregulatory reserve and immature renal and hepatic function.

- Pharmacological problems: - as differences in drug response due to multi-system

immaturity when compared to the older child or adult.

Anaesthetic concern

B- Specific problems of prematurity as more liability to:• Perioperative hypoglycemia. • Hypothermia.• Apnea.• Respiratory distress.• Congestive heart failure. • Retinopathy of prematurity.• Intracranial hemorrhage.

Anaesthetic concernC- Specific problems related to the

pathophysiology of CDH Problems related to pulmonary hypoplasia:• Acidosis – Hypoxaemia, Hypercarbia. • Pulmonary hypertension.• Liability to barotraume during MV. Problems related to persistent fetal

circulation (PDA): RT to LT shunt. Problems related to the associated

anomalies. higher mortality because of severe

underdevelopment of the lungs.

Anaesthetic concern

D- Specific problems of the selected surgical procedure:

1- One lung ventilation.2- Lateral decubitus position.3-Vagal response to tracheal manipulation.4- Systemic hypotension caused by kinking of major

blood vessels, specially those of the liver.5- Contra-lateral pneumothorax.6- Increase intra-abdominal pressure.

Anaesthetic concern

E- Specific problems of laparoscopy : Increase intra-abdominal pressure: gastric

regurgitation and aspiration .

Stretching of peritoneum: bradycardia and bronchospasm.

Intraperitoneal CO2: local irritation , hypercarbia & embolism.

Trocar insertion which may lead to visceral injury.

Anaesthetic concern

F- Specific problems of open surgery as:

• Inability to difficult closure of the abdomen.

• Abdominal compartmental syndrome.

• Blood loss.

Anaesthetic ManagementPreoperative management:I- Preoperative assessment of general condition:History:- Gestational age and birth weight.- Onset of symptoms (dyspenea) after birth or delayed.Physical examination-Skin colour: Cyanosis -Abdomen: Scaphoid shape-Dehydration

Anaesthetic Management

Chest:- Barrel shape.- Decrease breath sound in ipsilateral side.- Bowel sounds in ipsilateral sideHeart: - Tachycardia- Shift of the cardiac apex to other side.- Murmurs if cardiac defect is associated.Signs of the other associated anomaliesas Down syndrome (microcephaly, big tongue, upward

slanting eyes, single crease in the palm of the hand ).

Anaesthetic ManagementInvestigations:- CBC.- ABG.- Serum electrolytes levels.- Blood glucose level.- Blood type and cross-match.- Chest X ray, CT & MRI: o Loops of bowel in the chest, Mediastinal shift.o Site of Defect in the diaphragm.o Compressed fetal lung.-Cardiac Echo: To exclude CHD & estimate PA pressure.


II- Preoperative assessment of prognosis:- Bilateral hypoplasia is associated with high

mortality rate(80%).- Unilateral hypoplasia – the patient may survive with

aggressive treatment.Alveolar - arterial PO2 gradient is more than

500mmHg is predictive of unsurvival.Alveolar - arterial PO2 gradient is 400-500mmHg

is predictive to uncertain prognosis.Alveolar - arterial PO2 gradient is less than 400

mmHg is predictive of survival


III- Diagnosis the site of shunt in persistent fetal circulation

- It is performed by:1- The difference between Pre and post ductal

PaO2:- If shunting occurs via ductus arteriosus: preductal

PaO2 is more than postductal by 20mmHg.- If shunting occurs via foramen ovale: preductal

PaO2 is less that predected for 20% shunting .2- Cardiac catheterization.3- Pulmonary angiography.


IV-Preoperative care:-Decompress stomach by insertion of NGT.

-Correction of dehydration by optimum doses of crystalloids (10 - 15ml/kg/hr boluses).

- Correction of shock in severe cases by fluid and inotropes as dopamine/dobutamine .

- Correction of hypoglycemia (if blood glucose level is less than 45 mg/dL)& proper nutrition


-Correction of hypoxia, hypercarbia and respiratory acidosis by :

• ETT intubation and mechanical ventilation with low inflating pressures to avoid pulmonary barotrauma.

• HFO reduces PA pressures and resistance resulting in better oxygenation.

• Extracorporeal membrane oxygenation (ECMO).

Anaesthetic Management-Reversal of persistent pulmonary hypertension (PPH) to

avoid right to left shunting through the patent foramen ovale and/or ductus arteriosus by:

- Correction of metabolic acidosis.

- Inhaled Nitric oxide (via nasal or face mask): It is effective in Persistant pulmonary HTN.

- Prevention of pain: Fentanyl infusion 3-10 mcg/kg/hr.

- Avoid hypothermia, hypoxia, histamine release

- Avoid increase intrathoracic pressure >30cmH2O


V-Pre-medication:

- Sedatives are not needed.- Anticholinergics:- Atropine: 0.02 mg/kg IM, PO.- Antibiotics . Intra-operative management :

Induction& intubation (if not previously intubated):

Preoxygenation.

Awake endotracheal intubation with non cuffed ETT.

Inhalational induction (Halothane or sevoflurane + 100% O2)

In thoracotomy or thoracoscopy: one lung ventilation if possible


VI-Surgical Position:

- Supine position in laparoscopy or laparotomy.

-Lateral position in thoracoscopy or thoracotomy.VII-Monitoring:

- Standard monitoring (ECG,-Invasive BP, SpO2, temperature & ETCO2)

- Precordial stethoscope.

- ABG from preductal artery

- Airway pressure.

- CVP: To monitor intravascular volume.

- Foley catheter: To monitor urine output and to monitor IAP.


VIII-Maintenance:

- O2/air + Halothane or sevoflurane + fentanyl+ muscle relaxant

- Controlled ventilation (Peak Inspiratory Pressure (PIP) < 30 cm H2O).

- Fluids.

Intraoperative Events

1. Hypothermia

2. Intraoperative acute pulmonary hypertension

3. Hypotension

4. Contra-lateral pneumothorax

5. Increaed Intra-abdominal pressure


hypothermia:lead to:- Cerebral and cardiac depression.- Increased oxygen demand.- Acidosis.- Hypoxia.- Intracardiac shunt reversal.Measures to avoid hypothermia:- Heating blanket.- Increase room temp.- Plastic wrap.- Fluid warmer.


Intraoperative acute pulmonary hypertension:

Diagnosis:

- Increase in Rt - Lt shunt i.e. increased gap between SpO2 of right hand and left foot.

- ECG : RT side strain (ST depression and T-wave inversion in in V1-4).

- ECHO


Treatment:

Avoid factors that increase PVR which in turn lead to Rt→Lt shunting as: Hypoxia, Acidosis, Hypothermia & Pain.

Analgesic: fentanyl (1-3ug/kg/h).

- Hyperventilation to improve oxygenation and reduce PCO2.

- Restriction of fluid.

Pharmacologic therapy (Vasodilators):

- Nitric Oxide (NO) this specifically dilates the pulmonary blood vessels and it is given through endotracheal tube.

Intraoperative Events hypotension:Causes:- Venous return impairment.- Hypovolemia.- Increaed IAPManagement:- Fluids /or inotropic support. contra-lateral pneumothorax:Diagnosis:- A sudden fall in lung compliance.- A drop in blood pressure.- A drop in O2 Saturation.TT:- Immediate placement of a chest tube. Increaed Intra-abdominal pressureStaged closure of abdominal wall

Recovery

- Some babies with small defects can breathe spontaneously immediately after surgery. But The majority require prolonged post operative ventilation due to the increased intra-abdominal pressure with compromised respiratory function.

Criteria of extubation:- Fully awake.- With regular spontaneous breathing.- With vigorous movements of all limbs.- Well saturated.- With stable hemodynamics.

Postoperative care

In Neonatal Intensive Care Unit (NICU) Close monitoring of vital signs.

The baby position: Semi-upright position. Patient warming. Providing analgesia. Control of hypoglycemia. Control of intravascular volume status.

Correction of rebound or persistent pulmonary hypertension (PPHN) that may develop after the postoperative Honeymoon Period (period of rapid improvement that followed by rapid deterioration).

Postoperative care

Nasal or face mask O2 administration:

FiO2 is adjusted to maintain PaO2 more than 150mmHg and the infant is slowly weaned from O2 over 48-72 hours to avoid the honyemoon phenomenon.

MV: CMV or HFOV It is indicated if nasal or face mask O2 administration is not enough to deliver adequate oxygen to the patient.

The goal is maintaining hypocarbia and a pH greater than 7.5

ECMO for oxygenation of markedly hypoxic baby in ICU if MV is not enough to deliver adequate oxygen to the patient.

Thank you

anaesthesia for cdh

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