A 22-year-old previously healthy female was the unrestrained passenger in a highway MVA. Upon impact, a mailbox penetrated the passenger front windshield and struck the patient's face, resulting in severe facial trauma. The patient was intubated in the field for a Glasgow Coma Scale score of 5. She was emergently airlifted to the hospital and, en route, was resuscitated with crystalloid and two units of whole blood.\nThe patient arrived hemodynamically unstable—tachycardic and hypotensive complicated by severe metabolic acidosis (lactate 3.42 mmol/L, reference range: 0.6–2.3 mmol/L). Her right eye was ruptured, and her left pupil was dilated to 5 mm and minimally responsive to light. Three additional units of packed red blood cells (pRBCs) and two units of fresh frozen plasma (FFP) were rapidly administered via a Level 1 rapid infuser in the right 18-gauge antecubital intravenous catheter with stabilization of her hemodynamic status. Trauma series computerized tomography (CT) revealed facial trauma with ruptured right globe, temporal bone fracture, temporomandibular joint-line fractures, and mixed subdural and epidural hematomas with an 8 mm midline shift and effacement of the anterior horn of the right lateral cerebral ventricle. A large amount of air within the right ventricle (RV) extended to the right axillary vein (Figures and ) with air collection under the pulmonary valves () but no immediate RV outflow tract obstruction. The air entrainment was thought to be due to transfusion of products through the Level 1 rapid infuser given that there were no pneumothoraces or air in the superior and inferior vena cava.\nA multispecialty conference was held between the trauma surgery, neurosurgical, cardiac intensive care, and anesthesia teams regarding the optimal treatment plan. The concern was RV air burden may risk embolization and would compound hemodynamic collapse during emergent craniotomy. Aspiration of air via a central line was considered, but the impending risk of brain damage expedited the decision to proceed emergently to the OR for intracranial decompression. While the patient was in the CT scanner, vital signs included bradycardia (50s–60s) and occasional hypertension (systolic blood pressure reaching 150s–160s mm Hg), indicating presence of Cushing's triad. These vital signs along with physical exam findings of left dilated pupil and imaging evidence of an 8 mm cerebral midline shift were consistent with possible critically elevated intracranial pressures. With relatively stable hemodynamics but critical cerebral herniation risk, the decision was made to proceed with emergent craniotomy.\nThe patient arrived to the OR directly from diagnostic radiology, with heart rates between 80 and 90 beats/min and mild hypotension with systolic blood pressures of 90–100 mm Hg without any vasopressor support. She was maintained on inhaled sevoflurane at a minimum alveolar concentration <1.0 with nondepolarizing muscle relaxant. A right radial arterial line was placed. For access, the patient had a previously placed 18-gauge peripheral intravenous and intraosseous catheters. The patient was positioned in pins in the reverse Trendelenburg position. The degree of reverse Trendelenburg position was small (about 10–15 degrees) and was performed to decrease intracranial pressure and for optimum surgical visualization.\nTwenty-five grams (200 mg/kg) of intravenous mannitol was administered. At this point, the patient had approximately 2–2.5 L of estimated blood loss and had received four units of red blood cells (two whole blood, two pRBCs) and four units of FFP. Since intraoperative hemoglobin (9.7 g/dl), coagulation panel, and lactate (normalized to 2.0 mmol/L) were normal, further transfusions were deferred.\nApproximately 28 minutes after incision, end-expiratory CO2 (EtCO2) and mean arterial pressure abruptly fell concomitantly with loss of pulse oximetry waveform. She maintained an organized rhythm but distal pulses could not be palpated. The neurosurgeons were able to palpate intracranial pulsation; therefore, chest compressions were not initiated. Obstructive VAE physiology was assumed, and repeated intravenous epinephrine doses (10 mcg per injection) and 1 L fluid bolus were administered. After the first 30 mcg of epinephrine was administered over approximately 30 seconds, EtCO2 and blood pressure increased and the pulse oximetry waveform returned. An epinephrine infusion was initiated to maintain hemodynamic stability. In aggregate with hemodynamic resuscitation, the patient was immediately placed on 100% inspired oxygen and taken out of reverse Trendelenburg position to a more neutral position.\nThe patient remained hemodynamically stable on the epinephrine infusion and did not have a recurrence of such an event for the rest of the procedure. At the conclusion of the right hemicraniectomy and hematoma evacuation, intraoperative transesophageal echocardiography (TEE) showed hyperdynamic contractility and persistent, though nonobstructive air in the right ventricle. The intracardiac air burden was substantially less compared to the amount visualized on preoperative CT scan. There was no patent foramen ovale or regional wall abnormalities. At this point, the patient had displayed normal and stable vital signs for two hours. Thus, in the presence of hemodynamic stability in a patient without cardiac or other major comorbidities, the decision was made to proceed with the remainder of planned surgery. Furthermore, the ophthalmology and plastic surgery teams indicated that urgent surgical intervention may potentially preserve function of the patient's right eye while decreasing chance of infection.\nOnce the TEE probe was removed, the ophthalmology and plastic surgery teams performed a right eye enucleation, repair of brow and facial lacerations, complex repair of nasal laceration and cartilage, repair of upper and lower eyelid lacerations and reduction and fixation of numerous, complex frontozygomatic fractures, and irrigation and debridement of open wound, which collectively took 90 minutes of additional operating time.\nTotal OR time totaled 569 minutes. Using a goal-directed transfusion threshold of 8.0 g/dL, the patient received a total of two units of pRBCs and two units of FFP intraoperatively. Additionally, a total of 5,000 cc of crystalloid and two grams of intravenous calcium chloride were administered. Estimated blood loss for the procedure was 300 mL with 4000 mL of urine output. The epinephrine infusion was weaned off by the end of the procedure (highest dose 0.1 mcg/kg/min).\nA postoperative head CT revealed expected postoperative changes with complete resolution of midline shift. The patient was then transported to the neurological intensive care unit intubated for ongoing cares. Given her age, lack of preexisting cardiac comorbidities, and resolution of her hemodynamic instability, further cardiac evaluation was deferred. She remained intubated for airway protection but was extubated within 36 hours of admission. The patient exhibited no gross neurological deficits and was able to verbally communicate shortly after extubation. She continues to progress with traumatic brain rehabilitation in the outpatient setting.
An 18 year-old female patient was scheduled for a craniotomy and excision of a mid-brain ependymoma in a seated position. Her clinical, biochemical and coagulation parameters were normal. In the operating theatre, standard monitors (electrocardiograph [ECG], non invasive blood pressure, pulse oximeter) were attached. General anesthesia was induced with fentanyl and thiopentone and intubation was facilitated with vecuronium. Anesthesia was maintained with oxygen, air, isoflurane, fentanyl and atracurium with controlled ventilation using a tidal volume of 500 ml and respiratory rate (RR) of 12 breaths/min to achieve normocarbia. Intra-operative monitoring (using a Datex Ohmeda S5) included heart rate, ECG, oxygen saturation by pulse oximetry, RR, end-tidal carbon dioxide (EtCO2), central venous pressure (CVP) (via the basilic vein), invasive blood pressure, airway pressure, volume of intravenous fluids infused, urine output, nasopharyngeal temperature, arterial blood gas (ABG), blood glucose and blood loss. Transesophageal echocardiography was not monitored as this was not available in our institute. There were no hemodynamic changes during moving the patient to a seated position. Baseline ABG analysis and CVP were normal.\nAt the time of opening of the dura, there was a sudden decrease in EtCO2 from 36 to 20 mmHg and then, further, to 15 mmHg. Concurrently there was a small tear in the occipital sinus. A VAE was therefore suspected. The EtCO2 changes observed during the VAE, with corresponding arterial blood gas analyses, are depicted in . There were no associated changes in hemodynamics or oxygenation. The EtCO2 returned to normal within a few minutes, following measures such as administration of 100% oxygen and prevention of further air entrainment through packing of the surgical site with saline-soaked gauze. The tear in the occipital sinus was identified and clipped.\nExcision of the tumor was uneventful, and intra-operative blood loss during the excision was around 500 ml. CVP was maintained at around 11-14 cmH2O. The patient remained hemodynamically stable. During the final stages of dura closure, application of the Valsalva maneuver was requested by the surgeon to check for cerebrospinal fluid leaks and assess the adequacy of hemostasis. Immediately after releasing the sustained positive pressure during the Valsalva maneuver, the EtCO2 again suddenly decreased from 30 to 9 mmHg, followed by a reduction in blood pressure to 62/30 mmHg and ST-T depression by 1 mmHg. Precordial auscultation at the apex of the heart revealed a mill-wheel murmur. The PaCO2 to EtCO2 gradient was 39 mmHg (). A massive VAE was contemplated and the surgeon was cautioned.\nImmediately, 100% oxygen was administered and the incision site was packed with saline-soaked gauze pieces. The patient was then repositioned in a left lateral recumbent position. About 50-60 ml of air was aspirated from the central venous catheter. She was resuscitated with 1 L of intravenous voluven® (6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride injection) and an injection of 6 mg mephenteramine. Blood pressure and EtCO2 returned to normal. The mill-wheel murmur disappeared. Soon afterwards, the rest of the surgical procedure was continued in the lateral position.\nAt the time of wound closure, bleeding was noted from the suture line and the wound was therefore reopened to check for the source of the bleeding. The bleeding from the wound was diffuse, with no identifiable bleeding site. An abnormality in coagulation was suspected. Since blood loss was high and hemostasis could not be obtained surgically, two units of packed red blood cells (PRBCs), four units of fresh frozen plasma (FFPs) and four units of platelet-rich plasma (PRPs) were administered without waiting for the coagulation profile report. Initially, the blood began to clot and the bleeding stopped. The patient was shifted to the neurosurgical intensive care unit for post-operative ventilation and observation. Later, there was continued oozing from the operative site and from the external ventricular drain (EVD). A post-operative computerized tomography scan of the brain showed a hematoma at the operative site, which was evacuated on the first post-operative (PO) day. Surgical findings showed further oozing from the operative site and surrounding cerebellar surfaces. These were corrected with blood and blood products. The patient's blood parameters and coagulation profile, with interventions made in the following PO days are shown in . There was continued oozing at the operative site and also from other intravenous and arterial cannulation sites. She deteriorated neurologically, showing clinical features of raised intracranial pressure and an EVD persistently draining blood. On the fourth PO day, inotropic support was initiated, as the patient developed persistent hypotension along with a decreasing Glasgow Coma Scale value and absent pupillary reaction. Finally, on the fifth PO day, she passed away despite resuscitative measures.