Emergency Thoracotomy for Congenital Lobar Emphysema - Anesthesiology Concerns.

Congenital lobar emphysema (CLE) is a rare malformation of lungs, which presents usually in neonatal period or infancy as acute hypoxia and respiratory distress. It is characterized by the lobar over aeration of the normal lung followed by respiratory distress due to partial obstruction of bronchus by ball-valve effect. We would like to present the case of a 3-month-old female preterm (31 weeks) baby who presented to our neonatal intensive care unit with respiratory distress for 1 day. The baby was diagnosed with left-sided CLE having severe mediastinal shift to the right side and a dextroposition heart. Her venous blood gas showed PaCO2 of 70 mmHg and SpO2 of 70% with 15 L high-flow nasal oxygen. We would like to highlight the anesthesia techniques of airway management and ventilation during the critical period of induction till thoracotomy and exteriorizing the emphysematous lobe. Copyright:

INTRODUCTION

Congenital lobar emphysema (CLE) is a rare congenital disorder of lungs causing acute respiratory distress in infancy. It is characterized by postnatal overdistension of one or more lobes of histologically normal lung. Progressive distension of one or more lobes of lungs due to partial obstruction of bronchus by ball valve effect causes compression of mediastinal structures, atelectasis of normal lungs, and mediastinal shift causing cardiorespiratory collapse in the form of hypotension, hypercarbia, hypoxia, and acidosis. Early diagnosis and emergency thoracotomy could be one of few methods of managing such patients coming to emergency room in acute distress. Anesthetizing such patients is really challenging.

CASE REPORT

A 3-month-old female preterm baby (31 weeks) presented to neonatal intensive care unit (NICU) with sudden respiratory distress and desaturation. She was breathing at 80 breaths per minute, and saturation was 70% on room air with severe intercostal retractions and nasal flaring. She was weighing 3.2 kg and her heart rate was 170/min. Diagnosis was made with chest X-ray, computed tomography scan, and lung ultrasound and was confirmed as CLE of the left upper lobe, compressing the mediastinum to the right side and causing atelectasis of the left lower lobe and right upper lobe [Figures 1 and 2].

Figure 1

Computed tomography thorax showing dextroposition heart

Figure 2

Chest X-ray showing emphysematous left lung

Routine hematological and biochemical investigations were done and echocardiogram showed dextrorotation and pseudo-dextrocardia with no other congenital anomalies and good left ventricular function and no pulmonary artery hypertension.

As intubation and mechanical ventilation would worsen the situation, the baby was maintained on spontaneous breathing on high-flow nasal oxygen (HFNO) with 15 L and was saturating 87% to 90%. The baby was shifted to operation theater with HFNO and was placed under baby warmer and standard monitors such as electrocardiography, noninvasive blood pressure, and pediatric wrist pulse oximeter (SpO2) connected. The surgeon was asked to be ready for thoracotomy before we induced. Our plan was to maintain spontaneous breathing with endotracheal intubation till the thoracotomy and exteriorizing the emphysematous lobes. The baby was having a 22 G intravenous (i.v.) cannula in the right wrist through which we started i.v. balanced salt solution at the rate of 15 ml per hour through a syringe pump. We induced the patient with i.v. ketamine 5 mg and i.v. fentanyl 3 μg with sevoflurane 2% in 100% oxygen.

Contrary to our expectations, the baby stopped breathing and we had to intubate immediately without bag-mask ventilation. We intubated with a 3.0 oral uncuffed tube and pushed it to the right side and started gentle hand ventilation with Jackson-Rees circuit. ETCO2 tracing was noted on the monitor and air entry was confirmed on the right side. Hemodynamics were stable, but the saturation was 60% even with 100% FiO2. The baby was positioned right lateral for surgery and draped. Left thoracotomy was done in 3to4 minutes. Emphysematous left upper lobe exteriorized and the saturation came up to 95% with 100% FiO2.[Figure 3]. The compliance of the reservoir bag improved.

Figure 3

Exteriorized emphysematous lobe

The endotracheal tube was pulled out till it was noticed that the left lower lobe was getting inflated. Inj. Atracurium 1.6 mg was given and positive pressure ventilation was maintained bypressure control volume guarante mode. FiO2 was slowly decreased to 50%. Blood loss was replaced adequately and the surgery went on for 80 min. Emphysematous lobe was removed .Leaktest was done to confirm that there was no airleak from bronchial stump. Intercostal nerve block was given for postop painrelief. The wound was closed with an intercostal drain.

The baby was shifted to NICU on ventilator with good hemodynamics and saturation of more than 93% on FiO2 of 40%.

She was on ventilator for 4 days till her PaCO2 stabilized and her lungs fully expanded. She was extubated and weaned off oxygen using HFNO after extubation. The baby got discharged on day 14 after surgery.

DISCUSSION

CLE is a rare malformation of lung causing sudden respiratory distress in neonates and infants till 6 months of age.[1] Incidence is 1 in 70,000–1 in 90,000 live births.[2] The most commonly affected is the left upper lobe followed by right upper and middle lobes.[3] Multiple lobes are involved occasionally. Anesthetizing these children is challenging as the positive pressure ventilation would worsen the conditions by producing mediastinal shifts and compression of normal lungs and great vessels. We would like to have the emphysematous lobe removed before giving any anesthetic drugs. It is practically not possible without analgesia.

Various methods of induction, intubation, and maintenance of anesthesia are described in the literature.[4] The most critical part is induction and intubation which can produce both cardio- and respiratory dysfunction. Positive pressure ventilation can expand the emphysematous lobe and can increase the intrathoracic pressure leading to cardiovascular compromise. As most of the normal lungs are collapsed in these patients, our ventilation would not be adequate. This inadequate ventilation would lead to hypercarbia, acidosis, and arrhythmia. Our patient had preoperative increased PaCO2 and was tachycardic which showed that the ventilation was inadequate with HFNO. Hence, the only option was immediate thoracotomy and exteriorizing the emphysematous lobe and allowing the normal lungs get adequate ventilation for carbon dioxide elimination. One other technique described in literature was selective endobronchial intubation of healthy lung till thoracotomy and lobectomy.[5],[6] Some have maintained spontaneous ventilation with i.v. ketamine and sevoflurane with caudal epidural analgesia till thoracotomy.[7]

In our patient, we had a plan A of maintaining spontaneous ventilation on endotracheal tube till thoracotomy. When it failed and when ventilation became mandatory, we adapted plan B by selectively intubating the right bronchus providing at least some oxygen to normal lungs. This could give us some time for preparation for emergency thoracotomy which was the only lifesaving procedure. We could have tried caudal epidural analgesia with sevoflurane and i.v. ketamine maintaining spontaneous ventilation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.