Description

Approach to Pediatric Trauma 

Welcome to PICU Doc On Call, A Podcast Dedicated to Current and Aspiring Intensivists.

I'm Pradip Kamat coming to you from Children’s Healthcare of Atlanta/Emory University School of Medicine and I'm Rahul Damania, from Cleveland Clinic Children’s Hospital. We are two Pediatric ICU physicians passionate about all things MED-ED in the PICU. PICU Doc on Call focuses on interesting PICU cases & management in the acute care pediatric setting so let’s get into our episode.

Welcome to our Episode today of a 7 yo M who presents to the PICU after a severe Motor Vehicle Accident.

Here is the case presented by Rahul

A 7-year-old male child is admitted to the PICU after sustaining severe trauma. The patient was brought to the emergency department after a motor vehicle accident that involved an 18-wheeler truck & the family’s car; in this severe accident the 7 yo was noted to be restrained however upon impact was ejected from the vehicle. He was unconscious and had multiple injuries, including a laceration on the head and bruising on the chest. The EMS was activated and the patient presented to the ED for acute stabilization. Upon examination, the patient was found to have a Glasgow Coma Scale score of 8, indicating a serious head injury. He had multiple bruises and abrasions on the chest and arms, and his pulse was rapid and weak. The patient was resuscitated with colloid and blood products, intubated, and transferred to the pediatric intensive care unit for further management.

Notably, a CT scan of the head showed a skull fracture and a subdural hematoma. A chest X-ray showed multiple rib fractures and bilateral pulmonary opacities with no evidence of pneumothorax. The patient was also found to have a grade 2 liver laceration and a splenic injury. Pelvic x-ray and cardiac FAST exam were unrevealing.

To summarize key elements from this case, this patient has:

• A traumatic brain injury
• Pulmonary contusions and is at risk for PARDS
• Liver and spleen injury
• Anemia
• Pertinent negative includes: No pelvic injuries or injuries to great vessels in the chest

Rahul, let's approach the PICU medical management of this case based on a culmination of various guidelines published in the Pediatric Critical Care literature. Namely, let's use this case to dive deep into guidelines for:

Traumatic brain injury (TBI)

****Transfusion and Anemia Expertise Initiative (****TAXI)

pediatric blunt liver and spleen injury management, are also known as the ATOMAC protocol, as well as general PICU management of acute trauma.

As we take the management of this pediatric trauma patient in a systems-based fashion let's first go into the Management of Pediatric Traumatic Brain Injuries, can you start us off with some key management considerations?

• Based on the March 2019 TBI guidelines published in Pediatric Critical Care Medicine in 2019 (PCCM20(3S):p S1-S82, March 2019)
• This patient should have an ICP monitor or even an EVD placed for CSF diversion in consultation with the NS and trauma team. A CPP of at least >50 in our 7 yo patient and ICP < 20 mm Hg has been shown to improve outcomes and reduce mortality.

Just as a quick review, CPP stands for cerebral perfusion pressure, which is the pressure that maintains blood flow to the brain. The formula for CPP is:

CPP = MAP (mean arterial pressure) - ICP (intracranial pressure)

Monitoring does not affect outcomes directly; rather the information from monitoring can be used to direct treatment decisions. Treatment informed by data from monitoring may result in better outcomes than treatment informed solely by data from clinical assessment. In short, it is important to have qualitative and quantitative data to optimize your decision-making.

As we talked about ICP control is so crucial for this patient, Pradip, can you talk to us about some practical points in controlling ICP?

• Appropriate patient position (head midline and elevated 15-30, make certain that cervical collar is not too tight but allows for venous drainage from the skull) is recommended. Control fever, treat hypoxia, and hypercarbia, and avoid hypotension.
• Sedation and analgesia are at the discretion of the treating physician but routine boluses must be avoided to prevent cerebral hypoperfusion. Also, continuous use of propofol for sedation or ICP management is not recommended.

That's a great initial set of practical management tips, head position, temperature control to avoid hyperthermia, and avoidance of hypotension to ensure optimal CPPs. Propofol may have a deleterious effect in some patients as it can reduce the SVR and predispose patients to hypotension, especially when employed in a bolus fashion.

Rahul, what about NMB?

• Neuromuscular blockade may be required if ICP remains elevated despite adequate sedation. Muscle relaxation can also prevent shivering, fighting against the ventilator, and permit hyperventilation if it is required. Intermittent dosing of short-acting agents (eg, vecuronium or rocuronium) is preferred.
• Seizure prophylaxis with levetiracetam or phenytoin to prevent post-traumatic seizures is recommended for the first 7 days. Uncontrolled seizures can increase ICP.
• For ICP management: Any ICP > 20 mmHg for > 5 minutes requires intervention:
• First-tier therapies include: CSF drainage, bolus/infusion of hypertonic saline, sedation-analgesia/NMB
• Second-tier therapies used for refractory intracranial hypertension (20-40% of severe TBI cases) include Hyperventilation, surgery for decompressive craniectomy or to remove mass lesion (a repeat CT scan may be required), hyperventilation, moderate hypothermia (32-34), barbiturate coma, higher levels of osmolar therapy.

I think this is a great time to incorporate an essential physiologic concept, of cerebral metabolic rate of oxygen consumption.

CMRO2 refers to the cerebral metabolic rate of oxygen consumption, which is a measure of the amount of oxygen used by the brain. CMRO2 can be increased during periods of Increased neural activity, Hypercapnia, Hypoxia, increased temperature and increased ICP

It is important to note that these factors can impact the brain's oxygen consumption, and in some cases, an increase in CMRO2 can lead to a decline in brain function if the brain is not able to adequately meet its increased oxygen demand.

• Let's pivot to the next organ system in this patient — our patient had bilateral pulmonary contusions, about this patient meet at-risk PARDS criteria? and what would be your mechanical ventilation strategy?
• The patient has bilateral contusions. One study (Intensive Care Med Nov 2019, 36(7):) reported that Pediatric ARDS in children with pulmonary contusion is independently associated with lower GCS scores. This patient is at risk for PARDS based on the presence of bilateral contusions and initial GCS < 8. The incidence of PARDS in TBI is ~ 9%, and its presence is associated with significantly increased morbidity and mortality. (Nair AB, Cohen MJ, Flori HR. Pediatr Crit Care Med 2020; 21:122–128). There are no clear oxygenation/Ventilation guidelines in TBI-associated PARDS. We should avoid high positive pressures (PIP) and high positive end-expiratory pressures (PEEP) as long as oxygenation remains adequate; otherwise high PIP and PEEP may increase intrathoracic pressure and impede venous drainage. We target a PCO2 35-45 mmHg and avoid hyperventilation to prevent cerebral ischemia due to decreased cerebral blood flow.

To summarize, PARDS in trauma is a heterogenous disease — it is important to pay attention to the cardiopulmonary interactions of increased positive intrathoracic pressure as this can have effects on preload to the heart as well as venous drainage of the cerebral vasculature.

Pradip, What about fluid status?

• Additionally, we should pay close attention to fluid status: Treat hypovolemia with isotonic fluids (eg, normal saline) to achieve normal, rather than excess, volume status. We should avoid the administration of hypotonic fluids (eg, D5W). Although recent evidence from basic science research, observational research, and clinical trials suggests that using balanced crystalloids rather than saline may have beneficial effects on acid–base balance, renal physiology, and patient outcomes, we need to be careful about using balanced fluids in TBI so as to not cause iatrogenic hyponatremia. Although adult studies have reported poor outcomes with fluid overload in pediatric patients, the role of FO in pediatric TBI outcomes is not clear. Drawing from adult studies it is best to be vigilant about fluid balance and avoid fluid overload.

Intensivists should pay close attention to serum electrolytes and glucose while managing Trauma patients: Serum Na should be monitored at least twice daily in TBI patients. If hyponatremia develops despite the use of NS, we should think of SIADH or CSW.

Our patient in our case was noted in the PICU to become progressively hypothermic, Rahul can you highlight the effect of hypothermia in the setting of pediatric trauma?

• Yes, I think it is important for us to review the terrible triad of trauma. The "triad of death" in trauma refers to a combination of three physiological conditions that often occur together and significantly increase the risk of death in trauma patients. The triad of death is a dangerous state, as each component can contribute to the others, exacerbating the risk of death. The triad includes acidosis, hypothermia, and coagulopathy. Early recognition and aggressive management of these conditions are crucial in improving outcomes in trauma...