Malformation of lung in neonates (lobectomy for congenital lobar emphysema and lung cyst).SA Karapurkar, JD Borkar, BJ Birmole
Dept of Anaesthesiology, KEM Hospital, Parel, Bombay, Maharashtra.
Congenital lobar emphysema (CLE) and lung cyst--congenital cystic adenomatoid malformation (CCAM) are rare conditions in the neonatal period. Lobectomy is the only treatment for these conditions. We had 4 neonates, seen over a period of two years, who had congenital lobar emphysema and one neonate who had lung cyst. All babies had undergone lobectomy. Their anaesthetic management is discussed here.
Keywords: Anesthesia, Inhalation, methods,Case Report, Cystic Adenomatoid Malformation of Lung, Congenital, epidemiology,radiography,surgery,Female, Follow-Up Studies, Human, Infant, Newborn, Male, Pneumonectomy, methods,Prognosis, Pulmonary Emphysema, congenital,epidemiology,radiography,surgery,Treatment Outcome,
Congenital lobar emphysema (CLE) and lung cyst-congenital cystic adenomatoid malformation (CCAM) are rare conditions, which are found in the neonatal period. In 1954 Gross and Lewis, published the first case report of CLE. The baby was treated by lobectomy. The etiology of CLE was unknown, in over half of the reported cases. In those cases with a defined etioiogy extrinsic or intrinsic bronchial obstruction most commonly found. Intrinsic obstruction may result from cartilagenous deficiency, bronchial stenosis or redundant bronchial mucosa. Abnormal vessels or lymph nodes are usually responsible for extrinsic compression. Male babies are affected more often than female in the ratio of 2:3.
Congenital lung cyst (CCAM) is also a rare condition, which presents in the neonatal period. It was first described by Stock in 1897. The etiology of this condition is not known. But it is recognized by the absence of bronchotubular glands and cartilage and the presence of tall columnar mucinous epithelium. There is overproduction of luminal bronchiolar structure in the form of cysts of various sizes.
In last 2 years, we had an opportunity to treat 4 babies with CLE and one with lung cyst. All of them underwent lobectomy. The anaesthetic management of these cases is presented in this article.
Five babies presented with repeated attacks of cough and cold, breathlessness, failure to thrive and refusal of feeds [Table - 1]. One baby had cyanosis on admission and another had an episode of cyanosis after birth. Two babies were treated by family physicians with antibiotics and bronchodiiators. One baby underwent a futile bronchoscopy in another hospital, for suspected foreign body or mucous plug in the bronchus.
On examination, all babies were tachypnoeic. They had flaring of alae nasi and intercostal indrawing. One baby had cyanosis. The respiratory rate was around 601min. The pulse rate was around 150-160/min. On examination of the respiratory system, the hemithorax was bulging on the affected side and there was no air entry. Few crepitations were found on the affected side. On examination of the cardiovascular system, the heart sounds were shifted to the opposite side. No gross cardiac anomaly was found.
Following investigations were carried out in these patients: complete blood count, serum electrolytes and chest X-ray (PA and lateral view) were done in all babies. In 4 babies chest X-ray showed tracheal and mediastinal shift to the opposite side. Increased translucency was noted on the affected side [Figure - 1].
The differential diagnosis was CLE, congenital diaphragmatic hernia (CDH), pneumothorax and lung cyst. Chest X-ray of one baby showed hypeducency on the affected side with multiple cystic shadows [Figure - 2]. There was a shift of the trachea and mediastinum to the opposite side. Blood gas studies were not done in any of the babies, as the machine was not working.
Anaesthetic management: All babies were labelled as ASA IV. The babies were wrapped in warm cotton woof gamgees and placed on the heating mattress. Cardioscope was attached to all babies. Ryle's tube was aspirated with a syringe. Anaesthetic management of all the babies remained the same. Before starting anaesthesia, 0.01mg/kg atropine was given intravenously. Each baby was oxygenated with air leak for 2 minutes and then gradually halothane was started. The percentage of halothane was slowly increased upto 2 to 2.5%, keeping a close watch on the heart rate and respiration. Occasional gentle assistance was given. Once the patient reached the deeper plane of anaesthesia, halothane was stopped and 2-3 breaths of 100% oxygen were allowed. After introducing laryngoscope, a proper size endotracheal tube (ET-n was inserted. The baby was connected to anaesthesia machine through Jackson Rees modification of Ayre's 'T-piece'. Anaesthesia was maintained on oxygen (02) a 1 to 1.5% halothane, on spontaneous breathing. After confirming air entry and proper fixation of ETT, the baby was kept in either right or left lateral position depending upon the side to be operated. Precordial stethoscope was fixed on the chest, opposite to the side being operated. Till the chest was opened, the baby was breathing spontaneously, about 4 to 4.5 litres 02 with 1 to 1.55 halothane. Occasional gentle manual assistance was given. After the chest and the pleura were opened, the baby was paralysed with pancuronium 0.06 mg/kg. The respiration was controlled manually. The anaesthesia was maintained with oxygen and nitrous oxide in ratio of 50:50. The maintenance dose of pancuronium was a quarter of the initial dose.
Throughout the procedure, air entry, heart sound, rectal temperature, color, pulse rate and volume and ECG tracing on cardioscope were monitored. Blood loss was also monitored. Blood gases could not be estimated. All parameters were maintained within the normal range throughout the operation.
Fluid and blood replacement: Fluid was given at the rate of 10 ml/kg/hr in the form of paedilyte M. Five mi of 10% dextrose was given intermittently intra-operatively. Though the blood loss was not much, 10 ml/kg blood was transfused in every baby. Calcium gluconate 20 mg/kg was given intravenously at the end of the procedure. Once the rectal temperature rose to 37ºC, the muscle relaxant effect was reversed with atropine 0.02 mg/kg and neostigmine 0.05 mg/kg
Before the extubation, every baby was allowed to breathe air for 10-15 minutes maintaining its expiratory blast, heart sound, colour and reflex activities. Then while giving 100% oxygen blast, the ETT was removed. Again the baby was given oxygen by a face mask and observed for 15-20 minutes and then shifted to paediatric intensive care. Three litres of oxygen was given through oxygen tent and temperature was maintained with a spotlight and a blanket.
One baby had severe wheeze and intercostal indrawing after extubation. Immediately, the trachea was reintubated. The bay was connected to paediatric ventilator. Initially 1 mg/kg pethedine was given intravenously. But as there was no response, 0.06mg/kg pancuronium was given intravenously to paralyze the patient. But the wheeze continued and pediatrician's opinion was sought. They suggested hydrocortisone and aminophylline drip as per body weight for 24 hours. There was no response, though the baby was maintaining colour. There was no response to terbutaline also (0.05 mg/kg subsequently 3 hourly). After 48 hours the ETT got blocked and was removed. As the baby's reflex activities were normal, the baby was not reintubated and was kept under observation for 2 hours. There was no change in the colour, heart rate and reflexes. However, intercostal indrawing continued. Later, oedema was noted in the loins, lower abdomen and dorsum of feet. The urine output was good and the hydration was adequate. The neonatologist who was consulted, noted other anomalies namely hypertelorism, short columella, hooknose, large philtrum, large upper lip with loose skin on dorsum of hands and back of neck. The diagnosis was "cutis laxa" with systemic involvement.
No confirmatory tests and definitive treatment are available for the disorder. Vital parameters of this baby were all satisfactory depsite the wheeze at discharge a few days later.
Histopathological studies of four specimens showed distended alveoli and elongated cystic spaces consistent with CLE. One specimen showed multiple cysts of various sizes consistent with lung cyst.
Follow-up chest X-rays of all the babies showed adequate expansion of the remaining lobe.
[Figure - 3] and [Figure - 4]
Congenital lobar emphysema and lung cyst are rare conditions in the neonatal period. These present as respiratory distress of various degrees. Sometimes, there may not be any symptoms for as long as 5 to 6 months. Normally male babies are affected more often than female.
CLE is usually unilateral affecting the left upper lobe followed by the right middle and right upper lobes,,,. Involvement of more than one lobe is rare. Similarly involvement of lower lobe is also extremely rare,. The current theory, which suggests inadequate cartilaginous support of the bronchus was first proposed by Gross and Lewis and is most favoured. Polyalveolar lobe (an estimated three to five fold increase in number of alveoli for the whole lobe), is described by Hislop and Reid, in one of the recently described pathological entities that can give rise to CLE,. Macroscopically the specimen of CLE looks yellowish spongy and does not deflate on compression,.
The features of congenital lung cyst are - absence of bronchial cartilage, absence of bronchial tubular glands, presence of tall columnar mucinous epithelium and overproduction of luminal bronchiolar stricture, in the form of cysts of various sizes,. To the naked eye, the affected lobe looks dark, red, solid and bulky with surface bosses corresponding to larger cysts. Surgery is the only treatment.
Severity of symptoms in both the conditions vary depending upon the compression of the normal lung tissue. Myers described three clinical groups: 1. CLE in infancy; 2. symptomatic CEL in older chirdren and asymptomatic CLE (discovered accidentally) . All our babies presented within 6 months of life and had symptoms from birth. Association of CLE with congenital heart disease (CHD) is known in 10-12% patients while CCAM is associated in Prune Belly, pectus excavation, hydranencephaly,.
Once suspected the diagnosis of CLE and lung cysts can be confirmed by chest X-rays,,. In CLE, there is lobar hyperinflation, shift of trachea and mediastinum and ocintralateral or ipsilateral atelectasis. The compressed ipsilateral lobe can be seen on x-ray, as a small, triangular density along the lower cardiac border. The presence of bronchovascular markings in the hyperinflated lobe helps to differentiate CLE from pneumothorax.
Chest X-ray in a case of CCAM will show a sharply defined mass of soft tissue density with scattered radiolucent areas. When an aerated multiple mass occupies the left lower lobe, the appearance may be virtually indistinguishable from CDH. The important feature is, abdominal gas pattern will be normal in CCAM and not in CDH.
Both these conditions usually follow a progressive course. If not recognized and treated, they may be fatal. The accepted treatment in both the conditions is surgical lobectomy of the affected lobe. Operative mortality rate is 3 to 7% whereas with conservative therapies it is 50 to 75%.
Monitoring of the vital parameters, during neonatal surgery is a must. During thoracotomy, the baby is at great risk. On induction of anaesthesia if positive pressure ventilation is applied before opening of the chest, it may cause rapid inflation of emphysematous lobe or cyst with sudden mediastinal shift and cardiac arrest. Therefore, induction of anaesthesia should provide adequate spontaneous ventilation with minimal airway pressure. Occasional gentle assistance is necessary. Once the chest is opened and the affected lobe is delivered, the patient can be paralyzed and the lungs ventilated by controlled ventilation.
Hyperinflation of the emphysematous lobe or cyst can be prevented by avoiding the use of nitrous oxide (N2O) before the delivery of the affected lobe, as (N2O diffuses faster in a closed cavity and expands the cavity, leading to further compression of normal lung and more mediastinal shift in our patients, nitrous oxide was started only after the affected lobe was delivered outside the chest. Since all babies were less than 6 months old, no sedation or local infiltration was used intra-operatively,.
Due to lack of facilities, we could not monitor blood gases and pulse oximetry intra-operatively.
Except for one, none of the babies required ventilatory support in the post-operative period. The post-operative period was uneventful. Post-operative chest x-ray showed good lung expansion in all babies.
One baby had associated 'cutis laxa' which was diagnosed 48 hours later. In this condition, apart from loose skin on the dorsurn of the hands, back of the neck there are acute respiratory disorder, pulmonary obstructive disease, diverticulum of gut, craniofacial deformities. Because of this disorder, the respiration was getting obstructed and did not respond to any line of treatment.
We thank Dean, Seth GS Medical College and King Edward Memorial Hospital and Paediatric Surgery Department, to permit us to publish this article.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4][Table - 1]