TBI Flashcards
Causes of TBI
Blunt impact
Penetrating injury
Blast Wave
Accelerating-Decelerating Force
Secondary Damages
Neuronal health and tissue loss
BBB breakdown and edema
Upregulation of inflammatory mediators
Gliosis and cell infiltration
These are more likely to occur if patient is not taken to the hospital ASAP
Primary Brain Injury
Initial biochemical process that occur at the impact of injury
Secondary Brain Injury
Delayed brain insult that occurs in minutes, hours, days after primary injury
TBI goals
Stabilize and Attenuate secondary injury
Restore nerve or neuronal injury
To treat hypotension and hypoxia
When is GCS performed?
Within 48 hours of injury
CGS Scores
Higher Scores= better Severe 3-8 Moderate 4-12 Mild 13-14 Normal 15
Physical Exam
Imaging
Labs
Neuro signs and symptoms
Skull fractures, lacerations, CSF, otorrhea or rhinorrea
CT head scan
Arterial blood gas, urine drug screening, Blood alcohol concentration, electrolytes
Seizures, paresthesia, moderate to severe headaches, dizziness, post traumatic amnesia
Therapeutic goals
Optimize Cerebral Perfusion Pressure (CPP)
Treat increased ICP
CPP Formula
CPP= Mean Arterial Pressure (MAP)- Intracranial Pressure (ICP)
MAP Formula
[SBP + (2 x DBP)]/3
ICP should be less than?
CPP should range
20 mmHg
50-70mmHg
For hypotension and CPP <50 mmHg tx with?
IV fluids and possible vasopressors
For hypotension and CPP <50 mmHg tx with?
IV fluids and possible vasopressors
CPP goals should not exceed ______ with fluids or vasopressors
70 mmhg
Patients not receiving vasopressors with CPP> 70mmhg after resuscitation do not require ______
HTN meds to lower CPP target range, unless BP is dangerously high or causing sequelae
Patients not receiving vasopressors with CPP> 70mmhg after resuscitation do not require ______
HTN meds to lower CPP target range, unless BP is dangerously high or causing sequelae
Post resuscitation fluid goal is
euvolemia
Hemodynamic Management tx
Isotonic fluids are used. Normal saline is preferred since balanced solutions are relatively hypotonic and may worsen cerebral edema
BP guidelines for hemodynamic management
SBP >/=100 mmHg in pts 50-69
SBP >/=110 mmHg in pts 15-49 or >70 yo
Increase in MAP may lead to
Elevated ICP due to increased cerebral blood volume and hyperaemia
Decrease in MAP may be associated with
hypoperfusion and ischemia
Hemodynamic management goal
Optimisation of CBF
1st line for post traumatic seizures for first 7 days following injury
Phenytoin, but some prefer levetiracetam
Venous thromboembolism prophylaxis tx
Chemoprophylaxis w/ either unfractionated heparin 5000 units tid or enoxaparin 40 mg/day 24 hours following admission in TBI pts with stability comfirmed on repeat imaging
Coagulopathy may result from existing patient medications such as
warfarin and antiplatelet agents
How can pts taking warfarin be managed?
Prothrombin complex concentrate (PCC) and Vit K
Glucose management tx
Hyper and hypoglycaemia are associated with worsened neurologic conditions
Target: 140-180 mg/dl
When is intensive insulin therapy not recommended?
To target a glucose level b/w 80-110 mg/dl because outcomes are not great
Temperature management tx
Fever should be avoided
Normothermia should be attempted with the use of antipyretic medications surface-cooling devices, or end-vascular temperature management catheters
How does fever worsen ICP?
It increases metabolic demand, blood flow and blood volume
What best describes the most appropriate use of therapeutic hyperventilation for ICP control in the management of TBI patients?
Used briefly to a PCO2 goal of 30 to 35 mm Hg (4.0-4.7 kPa) but only beyond the first 24 hours after a TBI
Hypotension is associated w/ propofol and what should be used to help maintain CPP goals ?
Fluids and vasopressors
What is generally the sedative of choice for controlling ICP in TBI patients?
Propofol
Pharmacotherapy- Intracranial HTN targeting ICP 1st line
IV sedation and analgesia
Empiric use of opioids + sedatives for pain control
Sedative of choice (propofol) , rapid onset short duration
Midazolam may be used in place of propofol (but greater ADRs) , preferred Benzoic due to short half life and easier titration
Pharmacotherapy Hyperosmolar agents, used to mobilise water from brain to vasculature and from cranial space via osmotic gradient
1st line: mannitol 3% and hypertonic saline (3%-23.4% NaCl)
Dose: 0.25g/kg IV over 30 minutes may repeat 6-8 hrs
AE: diuresis, AKI, rebound increase in ICP
Do not administer if serum osmolarity>320 mOsm/L
Hypertonic Saline helps w/ hypovolemic pts.
Do not use is serum Na exceeds 155 mEq/L
2nd line for ICP control (used in pts CI to 1st line or refractory to 1st line)
Barbiturates
Phenobarbital initial loading dose 25mg/kg infused IV over 4 hours
Tapered off during 24-72 hrs after adequate ICP control achieved and maintained from 24-48 hrs
Other Miscellaneous Pharmacotherapy
Loop diuretics - Potential 2nd line for fluid overload pts, not to be used in hypovolemic TBI pts
Neuromuscular blocking agents- used for additional ICP control where sedation control dose is maximised due to hypotension or propofol limitations for example, Conivaptan (arginine vasopressin antagonist) shown to decrease ICP
Hypotension- treated with IV fluids and crystalloids such as hypertonic saline , Ringers Lactate, Dextrose 5%
vasopressors
nicardipine-in persons with HTN
Non Pharm
Head positioning - raise head of bed -decreases ICP and increases CPP
Hyperventilation -decreases ICP
CSF drainage - 1st line in pts with ventriculostomy
Seizure risk factors
CGS less than 10
Intracelebral hematoma
Depressed skull fracture
Phenytoin serum levels
10-20 mcg/ml
VTE prophylaxis
CT scan to rule out intracranial bleeding
Consider anticoagulation risk of intracranial bleeding
Pnuematic compression devices can be used until drug therapy can be used
Recommended drug therapiES- LMWH OR LOW DOSE UNFRACTIONATED heparin
Enoxaparin superior to low dose unfractionated heparin
