Traumatic rupture of the subclavian artery is a rare lesion occurring in patients subjected to violent injury. Ischemia requiring surgical revascularization is also rare among the pediatric population. ^[1] Vascular injuries can result in significant blood loss, limb loss, serious life-long threatening disability, and even death. Injuries can result from blunt or penetrating trauma, and these injuries can be isolated or in the setting of complex multisystem trauma.^[2] Vascular trauma (i.e. arterial and venous) in the pediatric population is uncommon, as it occurs only in 0.6 - 1.4% of all pediatric injuries. ^[3] Penetrating trauma is the most common vascular injury affecting children. Arterial injury in children presents a challenge to the surgeon and the anesthetist; pediatric patients are different from adults as they usually have atherosclerosis-free, spasm-prone, and smaller vessels, with small intravascular volume.^[4] Herein, we report anesthesia challenges faced during the management of a patient with vascular injury.

A 9-year-old male, weighing 20kg, was presented with a stab wound in the left supraclavicular region 12 hours before presentation to our hospital. The patient had a deep stab wound accidentally at home. The patient started bleeding profusely from the injury and was rushed to the nearest hospital. Fluid resuscitation started with crystalloid pressure applied to the wound and the patient was immediately referred to a tertiary care center from where he was further referred to the pediatric tertiary care center. The patient presented there almost 4 hours after the injury. On presentation his left upper limb was cold and there was no radial and brachial pulse palpable. There was a dull percussion note on the left side and on auscultation no air entry. Chest X-ray performed on suspicion of haemothorax showing left side opaque lung field (Fig. 1).

He was maintaining an airway, and a chest tube was inserted, which drained 1100 ml of blood in 2 hours. The patient was further resuscitated with fluid and blood products (5 Packed Cell Volume (PCVs) and 2 Fresh Frozen Plasma (FFPs)). Still, he developed hemorrhagic shock and collapsed for which he was intubated and ventilated but no chest compressions were required. The patient was taken to the Operating room (OR) and wound exploration was done but unsuccessful; the patient was referred to our hospital for vascular and cardiothoracic facilities.

On arrival in our hospital (12 hours from injury), the patient was received intubated and on inotropic support (epinephrine at 0.08mcg/kg/min and dopamine at 10 mcg/kg/min) being given through peripheral IV line; laboratory tests were sent immediately, chest X-ray repeated and the patient was rushed to OR with suspected left subclavian artery injury. The patient was put on an anesthesia machine ventilator, maintaining hemodynamics with inotropic support which was, therefore, continued the same. Midazolam 2mg, ketamine 40mg, and cisatracurium 4mg were given initially, but no inhalational agent started as inotropes were used. The right femoral arterial line was inserted and a sample for preoperative Arterial Blood Gases (ABGs) was drawn. Central Venous Catheter (CVC) insertion was attempted in both femoral but was unsuccessful due to collapsed veins. Draping was completed and surgery started without undue delay of vascular access. After the start of surgery, the endotracheal tube (ETT) was changed under vision to 5.5mmID and fixed at 17cm. 18G cannula secured at the right forearm. Pre-operative ABGs showed pH 7.06, pCO2 56.30mmHg, pO2 157.30mmHg, HCO3 15.7mEq/L, BE -14.9mEq/L and SO2 97.50%. Other laboratory tests reported after the start of surgery showed Hb 11.3g/dl, HCT 33.9%, rest of the laboratory test results were within normal limits except HCO3 13.9mmol/l, PT >180s and INR >18. The patient continued to bleed which was further replaced with 3 PCVs, 6FFPs, and 6 platelets. A cardiopulmonary bypass was arranged and kept on backup, to be used in case of need. Sternotomy was done immediately, the injured site was identified, and the bleeding was secured. Since sternotomy was done, arrangements were made to secure central access by the surgeon directly if necessary. Until then, inotropes were continued by peripheral access. As bleeding was controlled, inotropes started to get tapered and it was decided to establish central access at the end of surgery. Surgical findings revealed a large hematoma in situ, at the injured junction of the left subclavian vein and internal jugular vein and transection of the first part of the subclavian artery distal to the origin of the vertebral artery. Almost 2 liters of blood and clots were evacuated from the left thorax. The repair was done with a PTFE interposition graft. The patient had almost 5 liters of blood intraoperatively. Intraoperative ABGs showed pH 7.29, pCO2 29.20mmHg, pO2 >480mmHg, HCO3 13.8mEq/L, BE -11.1mEq/L and SO2 100%. There were multiple episodes of hemodynamic instability intraoperatively which were managed by adjusting infusion rates of epinephrine and dopamine and boluses of phenylephrine. The patient also received 600mg of calcium gluconate and 150mEq of NaHCO3. The surgery lasted for 5.5 hours. In summary, the patient received 5 PCVs, 2 FFPs, 1-liter colloid, and 1-liter crystalloid pre-operatively, while 3 PCVs, 6 FFPs, 6 Platelets, and 1-liter crystalloid intraoperatively. Urine output was almost 50 ml/hr. (total 300ml) and he had a blood loss of almost 5 liters. Postoperative ABGs showed pH 7.38, pCO2 37.50mmHg, pO2 121.20mmHg, HCO3 21.50mEq/L, BE -3.5mEq/L and SO2 98.7%. Left femoral CVP was inserted postoperatively and the patient was shifted to PICU for further management. His CBC sent from PICU after initial management showed Hb 8.1g/dL, HCT 23.3%, and platelets 116,000 X 106 /L. The patient was extubated after 30 hours and discharged from the hospital after 72 hours of surgery in stable condition with normal cognitive function and no report of ischemia.

Pediatric thoracic trauma itself is a unique challenge owing to the peculiar characteristics of anatomy, physiology, metabolism, and therapeutic options in children. ^[5] Penetrating trauma occurs nearly 6-fold less than blunt trauma in children while penetrating thoracic wounds even less. About 35% of such patients require surgical intervention.^[5] In our patient, the injury resulted in hemorrhagic shock. Children develop hypoxemia more rapidly due to diminished FRC which gets deteriorated in case of chest trauma. Therefore, the targets of anesthetic management were to prevent any physiological injury due to shock, minimize hypoxia and hypoxemia, and maintain perfusion.^[5] Hemothorax due to thoracic vascular trauma leads to significant blood loss, hypovolemic shock, lung volume loss, empyema, and possible lung entrapment.^[6] Chest tube placement for hemothorax may lead to further blood loss due to the loss of tamponade effect on the injured vessel. ^[7] This leads to severe hemodynamic alterations and warrants emergent surgical exploration of the wound.

In addition to this, arterial trauma in children also remains a significant challenge. When this occurs within the thoracic cavity, it further aggravates the situation. The such injury usually results in massive blood loss leading to massive transfusion. ^[7] In our case, a massive transfusion had already been done before arrival and had led to known complications which were coagulopathy, hypothermia, and citrate toxicity causing hypocalcemia. Still, during surgery, further transfusion was necessary for maintaining hemodynamic stability and end-organ perfusion along with managing the complications of massive transfusion. Another important objective was the prevention of the lethal triad of coagulopathy, acidosis, and hypothermia. ^[8] Since CVP could not be secured therefore permissive hypotension was tolerated. A balanced blood transfusion strategy of delivering PCV, FFPs, and platelets was employed. Hypothermia and hypocalcemia were also managed by active warming, blood warmer, and giving calcium. With the collaboration of the anesthetic and surgical team, such a difficult case was managed quite successfully and the patient’s life and arm were saved.

In conclusion, In an emergency, waiting for optimization is not always possible. One needs to know the available resources and how to use them for the maximum advantage. Sometimes decisions have to be taken clinically even if they are not recommended. In such cases time is always a key factor, therefore a pragmatic approach towards a life or limb-threatening emergency should always be the priority.