Presentation on theme: "Head Trauma NOTE: Beginning with third edition of this text, material included in this chapter has been based upon recommendations of Brain Trauma Foundation."— Presentation transcript:
0 International Trauma Life Support, 7e Head Trauma10Key Lecture PointsCover the anatomy.Cover the physiology of the brain and explain why hyperventilation is no longer recommended except in cases of herniation syndrome.Emphasize the control of the airway in the patient with an altered level of consciousness. Stress that suction must be available at all times.Stress that a patient with a serious head injury (Glasgow Coma Score of 8 or less) will not tolerate hypoxia or hypotension. In this situation do not allow the blood pressure to get below 100–110 systolic.Mention that prehospital providers tend to inadvertently hyperventilate head-injured patients. Stress that, if possible, capnography should be used to prevent inadvertent hyperventilation.Mention the aspects of the Glasgow Coma Score and that each part should be recorded, not just the total score. This score should always be recorded if there is altered mental status.Stress indications for hyperventilation.
2 Overview Anatomy of head and brain Pathophysiology of traumatic injury Primary and secondary injuryMechanisms of secondary brain injuryAssessment, management, potential problemsManagement of cerebral herniation syndrome
3 Head Trauma Traumatic brain injury (TBI) Major cause of death and disabilityCNS injury in 40% multiple traumaDeath rate twice of non-CNS injury25% of trauma fatalitiesAssume spinal injury with serious injuryPotential for altered mental statusPotential for altered mental status with head injury eliminates possibility of field clearance for spinal injury.
4 Head Anatomy IMAGE: 10-1 Anatomy of the head NOTE: Briefly review key issues of anatomy.Skull is essentially a closed box.Rigid and unyielding bony skull protects brain from injury, but also makes closed space container, so no room for significant swelling.NOTE: Point out bony prominences of interior skull, which can cause damage to brain with movement from trauma.NOTE: Point out foramen magnum at base where brain stem becomes spinal cord. This is only significant opening through which pressure can be released.Fibrous coverings of brain are meninges.Dura mater, arachnoid mater, pia mater listed from outermost to innermost.TEACHING TIP: Students can think “Brain PAD” to remember order of layers. (Brain is “padded” by meninges, starting with Brain and moving out, layers are P – A – D.)Brain tissue is fragile, easily damaged if not protected by meninges. Brain tissue requires a constant supply of blood (oxygen and glucose) to survive.Cerebrospinal fluid (CSF) is nutrient fluid found beneath arachnoid and pia mater layers and bathes brain and spinal cord.Brain “floats” inside CSF and allows for some movement with cushioning to absorb minor forces. However, brain attached at base, which causes more movement at top of brain. Significant force from blunt trauma can cause “third collision” of brain into skull.
5 Brain Injuries Primary Secondary Immediate damage to brain tissue Direct result of injury forceLittle can change injury after it occursSecondaryResult of hypoxia or decreased perfusionPrehospital care can help preventPrimary brain injury is the immediate damage to the brain tissue that is the direct result of the injury force and is essentially fixed at the time of injury.Little can be done to change the injury after it has occurred.Primary brain injury is better managed by prevention with such measures as use of occupant restraint systems in autos, the use of helmets in sports, work, and cycling, firearms education, and so forth.Secondary brain injury is the result of hypoxia or decreased perfusion of brain tissue.Good prehospital care can help prevent the development of secondary brain injury. In response to the primary insult, swelling can cause a decrease in perfusion.As a consequence of other injuries, hypoxia or hypotension may occur and both are damaging to brain tissue.
6 Brain Injuries Coup Contracoup The “3rd collision” Area of original impactContracoupThe “4th collision”Rebounding hitting the opposite sideInjuries may occur to the brain in the area of original impact (“coup”) or on the opposite side (“contracoup”).The interior base of the skull is rough (Figure 10-2), and movement of the brain over this area may cause various degrees of injury to the brain tissue or to blood vessels supporting the brain
7 Brain Anatomy Intracranial volume Brain CSF Blood vessel volume Dilatation with high pCO2Constriction with low pCO2Slight effect on volumeNOTE: Briefly review key issues of anatomy.NOTE: Point out brain stem (respiratory center) at area of foramen magnum.NOTE: Point out optic nerves would come directly from brain to pupils (pupil evaluation).Increased volume of any one of these components has to result in decrease of another component.Vasoconstriction or vasodilation influence intracranial volume.Brain normally adjusts blood flow in response to metabolic needs based on level of carbon dioxide in blood (pCO2).Normal level of pCO2 is around 40 mmHg (also commonly listed as 35 to 45 mmHg).Increased pCO2 (hypoventilation) promotes cerebral vasodilatation, which increases ICP. Lowering pCO2 (hyperventilation) causes vasoconstriction and decreases blood flow.Hyperventilation has only minimal effect on ICP.NOT, as previously thought, that hyperventilation improved cerebral blood flow by causing vasoconstriction and decreasing ICP.
8 Brain Physiology Intracranial pressure (ICP) Pressure of brain and contents in skullCerebral perfusion pressure (CPP)Pressure required to perfuse brainMean arterial pressure (MAP)Pressure maintained in vascular systemNOTE: Focus on concept that brain perfusion requires pressures be within a certain range, not on actual measurements.If ICP is too high, brain will be forced (herniated) out of skull.Brain perfusion requires that pressure within circulatory system be sufficient to allow oxygen transfer into brain tissue (CPP).Pressure maintained in circulatory system calculated by evaluating systolic and diastolic pressures (MAP).SUPPLEMENTAL INSTRUCTOR NOTES:Normal ICP 5–15 mmHg.ICP >15 mmHg is dangerous.ICP >25 mmHg leads to cerebral herniation.CPP >60 mmHg required to perfuse brain.MAP = diastolic BP + 1/3 (systolic BP – diastolic BP)Thereby giving mean (average) pressure (diastolic pressure wave is twice as long as systolic for each cardiac contraction).
9 Brain Physiology Cerebral perfusion CPP = MAP – ICP MAP constant + ICP increase = CPP decreaseMAP decrease + ICP constant = CPP decreaseHypotension not tolerated with ICP increaseMAP decrease + ICP increase = CPP criticalSystolic pressure 110–120 mmHg minimum needed to maintain sufficient CPPNOTE: Focus on concept that brain perfusion requires pressures be within a certain range, not on actual measurements.ICP is increased with severe injury and/or ischemia due to swelling of brain tissue.Cushing's response (reflex)—When ICP increases, systemic blood pressure increases to try to preserve blood flow to brain. The rise in systemic blood pressure triggers a drop in pulse rate as body tries to lower blood pressure.Cerebral perfusion decreases if ICP approaches MAP, which can occur either from increasing ICP or decreasing blood pressure (MAP).Hypotension will have a devastating effect if ICP is high.In order to maintain sufficient CPP (at least 60 mmHg), systolic blood pressure must be least 110 to 120 mmHg in patient with severe head injury.Hypotension with severe TBI (GCS of <9) is rare.Aggressive attempts to significantly increase CPP (above 70 mmHg) with fluids and vasopressors should be avoided due to risk of adult respiratory distress syndrome (ARDS).
10 Increasing ICP Cushing's response Vital Sign Change with Increasing ICPRespirationIncrease, decrease, irregularPulseDecreaseBlood pressureIncrease, widening pulse pressureCushing's responseAs ICP increases, systolic BP increasesAs systolic BP increases, pulse rate decreasesFrequent vital signs measurement is extremely important in head trauma. They can indicate changes in ICP. Reassess frequently.Unusual respiratory patterns may reflect level of brain or brain stem injury.Just before death, patient may develop a rapid, noisy respiratory pattern called central neurogenic hyperventilation. However, it is not as useful an indicator as are other vital signs in monitoring course of head injury.Abnormal respiratory patterns may indicate a chest injury or other problem that could lead to hypoxia if untreated.Cushing's response (reflex)—When ICP increases, systemic blood pressure increases to try to preserve blood flow to brain. The rise in systemic blood pressure triggers a drop in pulse rate as body tries to lower blood pressure.This hypertension is usually associated with a widening of pulse pressure (systolic minus diastolic pressure).Other causes of hypertension include fear and pain.Hypotension due only to head injury is rare. If hypotensive, look for hemorrhage.
11 The Injured Brain Cerebral herniation syndrome Brain forced downward CSF flow obstructed, pressure on brainstemLevel of consciousnessDecreasing, rapid progression to comaAssociated symptomsIpsilateral pupil dilatation, out-downward deviationContralateral paralysis or decerebrate posturingRespiratory arrest, deathSudden rise in ICP may force portions of brain downward, obstructing flow of cerebrospinal fluid and applying great pressure to brain stem.Classic findings on exam are a decreasing level of consciousness (LOC) that rapidly progresses to comadilation of pupiloutward–downward deviation of eye on side of injury,paralysis of arm and leg on side opposite injury, or decerebrate posturing.This syndrome often follows an acute epidural or subdural hemorrhage.Pupil difference and eye deviation due to III nerve and and accessori nuclei compression.
12 Herniation Syndrome Aggressive therapy needed Hyperventilation is indicatedVentilate 20 per minute for adultVentilate 25 per minute for childrenVentilate 30 per minute for infantsMaintain ETCO mmHgHyperventilation will decrease the size of the blood vessels in the brain and briefly decrease ICP.In this situation the danger of immediate herniation outweighs the risk of cerebral ischemia that can follow hyperventilation.The cerebral herniation syndrome is the only situation in which hyperventilation is still indicated.You must ventilate every three seconds [20/minute] for adults, every two and one-half seconds [25/minute] for children, and every two seconds [30/minute] for infants.)If you have waveform capnography, attempt to keep the ETCO2 at about mmHg.
15 Head Injuries Skull injuries Suspect fracture Management Linear nondisplacedDepressedCompoundSuspect fractureLarge contusion or darkened swellingManagementDressing, avoid excess pressureIMAGE: 10-3 Types of skull fracturesSkull injuries can be linear nondisplaced fractures, depressed fractures, or compound fractures.Suspect an underlying skull fracture in adults who have a large contusion or darkened swelling of scalp.Very little can be done for skull fractures in field except to avoid placing direct pressure upon an obvious depressed or compound skull fracture.Open skull fractures should have wound dressed, but avoid excess pressure when controlling bleeding.
16 Brain Injuries Concussion No structural injury to brain Level of consciousnessVariable period of unconsciousness or confusionFollowed by return to normal consciousnessRetrograde short-term amnesiaMay repeat questions over and overAssociated symptomsDizziness, headache, nausea and/or ringing in earsA concussion implies no structural injury to brain that can be demonstrated by current imaging techniques. There is a brief disruption of neural function that often results in loss of consciousness, but many people will have a concussion without a loss of consciousness.Classically there is a history of trauma to head with a variable period of unconsciousness or confusion and then a return to normal consciousness.There may be amnesia following injury. This amnesia usually extends to some point before injury (retrograde short-term amnesia), so often patient will not remember events leading to injury.Short-term memory is often affected, and patient may repeat questions over and over as if he has not been paying attention to your answers.Patients may also report dizziness, headache, nausea and/or ringing in ears
17 Brain Injuries Cerebral contusion Bruising of brain tissue Swelling may be rapid and severeLevel of consciousnessProlonged unconsciousness, profound confusion or amnesiaAssociated symptomsFocal neurological signsMay have personality changesCerebral contusion is bruised brain tissue.Presents with a history of prolonged unconsciousness or serious alteration in level of consciousness.Example: profound confusion, persistent amnesia, abnormal behavior.May still be unconscious on arrival.May have focal neurological signs (weakness, speech problems) and appear to have suffered a cerebrovascular accident (stroke).Depending upon location of cerebral contusion, patient may have personality changes such as inappropriately rude behavior or agitation.Brain swelling may be rapid and severe.
18 Brain Injuries Diffuse axonal injury Diffuse injury Generalized edemaNo structural lesionMost common injury from severe blunt head traumaAssociated symptomsUnconsciousNo focal deficitsDiffuse axonal injury: Most common type of injury as a result of severe blunt head trauma. Brain is injured so diffusely that there is generalized edema. Usually, there is no evidence of a structural lesion. In most cases patient presents unconscious, without focal deficits.
19 Brain Injuries Anoxic brain injury Small cerebral artery spasms due to anoxiaNo-reflow phenomenonCannot restore perfusion of cortex after 4–6 minutes of anoxiaIrreversible damage occurs >4–6 minutesHypothermia seems protectiveAnoxic brain injury is injury to brain from lack of oxygen.As we know, if brain is without oxygen for a period greater than 4 to 6 minutes, irreversible damage almost always occurs.Following an anoxic episode, perfusion of cortex is interrupted because of spasm that develops in small cerebral arteries.After 4 to 6 minutes of anoxia, restoring oxygenation and blood pressure will not restore perfusion of cortex (“no-reflow phenomenon”), and there will be continuing anoxic injury to brain cells.Hypothermia seems to protect against this phenomenon, and there have been reported cases of hypothermic patients being resuscitated after almost an hour of anoxia.
20 Brain Injuries Intracranial hemorrhage Epidural Subdural Intracerebral Between skull and duraSubduralBetween dura and arachnoidIntracerebralDirectly into brain tissueSubarachnoidBetween the arachnoid and pia materIMAGE: Cross-section of cranial meninges attached to brain.NOTE: Overview of next slides.
21 Intracranial Hemorrhage Acute epidural hematomaArterial bleedTemporal fracture commonOnset: minutes to hoursLevel of consciousnessInitial loss of consciousness“Lucid interval” followsAssociated symptomsIpsilateral dilated fixed pupil, signs of increasing ICP, unconsciousness, contralateral paralysis, deathIMAGE: Figure 10-4: Epidural hematoma.Acute epidural hematoma is most often due to a tear in middle meningeal artery that runs along inside of skull in temporal region.Temporal bone (temple) quite thin and easily fractured.Arterial bleeding, so rise in ICP can occur rapidly, and death may occur quickly.History of head trauma with initial loss of consciousness often followed by a period during which patient is conscious and coherent (“lucid interval”).Symptoms:After a few minutes to several hours, develops signs of increasing ICP (vomiting, headache, altered mental status), lapses into unconsciousness, and develops body paralysis on side opposite of head injury.Often a dilated and fixed (no response to bright light) pupil on side of head injury.EMS may be called to evaluate after initial loss of consciousness while in lucid interval. Be suspicious of possibility of a developing epidural hematoma.
22 Intracranial Hemorrhage Acute subdural hematomaVenous bleedOnset: hours to daysLevel of consciousnessFluctuationsAssociated symptomsHeadacheFocal neurologic signsHigh-riskAlcoholics, elderly, taking anticoagulantsIMAGE: Figure 10-5: Subdural hematoma.Acute subdural hematoma is result of bleeding between dura and arachnoid and is associated with injury to underlying brain tissue.Because bleeding is venous, intracranial pressure increases more slowly, and diagnosis often is not apparent until hours or days after injury.Signs and symptoms include headache, fluctuations in level of consciousness, and focal neurologic signs (e.g., weakness of one extremity or one side of body, altered deep tendon reflexes, and slurred speech).Due to underlying brain tissue injury, prognosis is often poor.Mortality is very high (60%–90%) in patients who are comatose when found.Always suspect a subdural hematoma in an alcoholic with any degree of altered mental status following a fall.Elderly patients and those taking anticoagulants are also at high risk for this injury.
23 Intracranial Hemorrhage Intracerebral hemorrhageArterial or venousSurgery is often not helpfulLevel of consciousnessAlterations commonAssociated symptomsVaries with region and degreePattern similar to strokeHeadache and vomitingIMAGE: Figure 10-6: Intracerebral hemorrhage.Intracerebral hemorrhage is bleeding within brain tissue.Traumatic intracerebral hemorrhage may result from blunt or penetrating injuries of head. Unfortunately, surgery is often not helpful.Signs and symptoms depend upon regions involved and degree of injury.They occur in patterns similar to those that accompany a stroke; spontaneous hemorrhages of this type may be seen in patients with severe hypertension.Alteration in level of consciousness is commonly seen, though awake patients may complain of headache and vomiting.
24 Brain Injuries Subarachnoid hemorrhage Blood in subarachnoid space Intravascular fluid “leaks” into brainFluid “leak” causes more edemaAssociated symptomsSevere headacheVomitingComaCerebral herniation syndrome possibleIMAGE: Cross-section of cranial meninges attached to brain.Blood can enter subarachnoid space as a result either of trauma or a spontaneous hemorrhage. Subarachnoid blood causes irritation that results in intravascular fluid “leaking” into brain and causing more edema.Severe headache, vomiting and coma from irritation are common.These patients may have so much brain swelling that they develop cerebral herniation syndrome.
25 Head Trauma Assessment ITLS Primary SurveyEvery trauma patient initially evaluated in the same sequenceIMAGE 10-7 Primary Survey with Rapid Trauma Survey
26 Head Trauma Assessment ITLS Primary SurveyLimit patient agitation, strainingContributes to elevated ICPAirwayVomiting common within first hourEndotracheal intubationPreoxygenationNasotracheal or RSI or sedation facilitatedInitial Assessment in head-trauma patient is to determine quickly if patient is brain injured and, if so, if patient's condition is deteriorating.All observations must be recorded because later treatment is often dictated by detection of deterioration of clinical stability.Determining exact type of TBI or hemorrhage cannot be done in field. It is more important presence of brain injury be recognized and supportive measures be provided during transport.TBI patients may be difficult to manage because they are often uncooperative and may be under influence of alcohol or drugs.Remember to check blood glucose in all altered mental status.Limit patient agitation, when possible:Avoid excessive movement or jostling of patient.Limit lights and noise to the necessary.Evaluate if extra rescue personnel not directly involved in patient care in a closed environment are necessary.Consider sedation.IV lidocaine is no longer recommended. Topical lidocaine is acceptable.. Before beginning intubation, ventilate (do not hyperventilate) with high-flow oxygen.Do not allow the head-injured patient to become hypoxic.Note the patient's basic neurological status prior to RSI or sedation, because the medications given can prevent a complete neurological assessment in the hospital.
27 Head Trauma Assessment Rapid Trauma SurveyHeadLacerationsDepressed or open skull fracturesStability of skullSigns of basilar skull fractureBegin with the scalp and quickly, but carefully, examine for obvious injuries such as lacerations or depressed or open skull fractures.The size of a laceration is often misjudged because of the difficulty in assessment through hair matted with blood.Feel the scalp gently for obvious unstable areas of the skull. If none are present, you may safely apply a pressure dressing or hold direct pressure upon a bandage to stop scalp bleeding.Signs of basilar skull fracture on next slide
28 Basilar Skull Fracture Battle's signRaccoon eyesIMAGE10-8a Battle's SignIMAGE10-8b Raccoon EyesBasilar skull fracture indicated by any of following:Bleeding from ear or noseClear or serosanguineous fluid running from nose or earSwelling and/or discoloration behind ear (Battle's sign)Swelling and discoloration around both eyes (raccoon eyes)Battle's sign can occur from immediately following injury to within 1–2 hours postinjury.Raccoon eyes are a sign of anterior basilar skull fracture.Through thin cribriform plate in upper nasal cavity and allow spinal fluid and/or blood to leak out.Raccoon eyes with or without drainage from nose are an absolute contraindication to inserting a nasogastric tube or nasotracheal intubation.Photo courtesy of David Effron, MD, FACEPPhoto courtesy of David Effron, MD, FACEP
29 Pupils 3rd cranial nerve Bilateral dilated, unreactive probable brain stem injuryUnilateral dilated, reactive may be ICPOther causesHypothermiaDrugsAnoxiaOcular traumaIMAGE 10-9 Examination of pupilsThe pupils are controlled in part by the third cranial nerve. This nerve takes a long course through the skull and is easily compressed by brain swelling, and thus may be affected by increasing ICP.Following a head injury, if both pupils are dilated and do not react to light, the patient probably has a brain stem injury and the prognosis is grim.A unilaterally dilated pupil that remains reactive to light may be the earliest sign of increasing ICP.Other causes of dilated pupils that may or may not react to light include hypothermia, lightning strike, anoxia, optic nerve injury, drug effect (e.g., atropine), or direct trauma to the eye.NOTE: Testing for a blink response (corneal reflex) by touching the cornea with the edge of a gauze pad or cotton swab, or by applying overly noxious stimuli to a patient to test for response to pain, are techniques that are unreliable and do not contribute to prehospital assessment.
31 Glasgow Coma Scale Suspect severe brain injury < GCS 9 IMAGE: Table 10-2: Glasgow Coma Scale.In TBI patient, a Glasgow Coma Scale score of 8 or less is considered evidence of a severe brain injury.GCS score that is determined in field serves as baseline for patient; be sure to record it. Record score for each part of GCS, not just total score.Perform a finger-stick glucose on all patients with altered mental status.
32 Vital Signs Extremely important Obtain & record often IMAGE 10-3 Comparison of Vital Signs in Shock and Head InjuryVital signs are extremely important in following the course of a patient with head trauma. Most important, they can indicate changes in ICP (see next slide).Observe and record vital signs at the end of the ITLS Primary Survey, during the detailed exam, and each time you perform the ITLS Ongoing Exam.Increasing intracranial pressure causes the respiratory rate to increase, decrease, and/or to become irregular.Unusual respiratory patterns may reflect the level of brain or brain stem injury.Just before death, the patient may develop a rapid, noisy respiratory pattern called central neurogenic hyperventilation.Because respiration is affected by so many factors (e.g., fear, emotional disorders , chest injuries, spinal-cord injuries, diabetes), it is not as useful an indicator as are the other vital signs in monitoring the course of head injury. Abnormal respiratory patterns may indicate a chest injury or other problem that could lead to hypoxia if untreated. Extremely importantObtain & record often
33 The Injured Brain Hypotension Fluid administration for TBI GCS <9 Single instance increases mortalityAdult (systolic <90 mmHg) 150%Child (systolic < age appropriate) worseFluid administration for TBI GCS <9Titrate to 110–120 mmHg systolic with or without penetrating hemorrhage to maintain CPPNOTE: GCS <9 is same as GCS of 8 or less.NOTE: Cerebral perfusion pressure (CPP).Usually pediatric patients have a better recovery from TBI.Hypoxia and hypotension appear to eliminate any neuroprotective mechanism normally afforded by age. If child with a serious brain injury is allowed to become hypoxic or hypotensive, chance of recovery is even worse than in an adult with same injury.
34 Secondary Survey & Ongoing Exam Do not delay scene time if load-and-goOngoing ExamRecordLevel of consciousnessPupil size & reactionGCSWeakness or paralysisRecord the level of consciousness, the pupil size and reaction to light, the Glasgow Coma Scale score, and the development (or improvement) of focal weakness or paralysis.This, along with the vital signs, provides enough information to monitor the condition of the head-injured patient.Decisions on the management of the head-trauma patient are based on the changes in all the parameters of the physical and neurological examination.You are establishing the baseline from which later judgments must be made. Record your observations.
35 Management Hypoxia Assist ventilation Perfusion decrease causes cerebral ischemiaHyperventilation increases hypoxia significantly more than it decreases ICPAssist ventilationHigh-flow oxygenOne breath every 6–8 secondsSpO2 >95%Maintain ETCO2 at 35 mmHgEndotracheal intubationSignificant decrease in cerebral perfusion from vasoconstriction, which results in cerebral hypoxia.The injured brain does not tolerate hypoxia.Thus, both hyperventilation and hypoventilation can cause cerebral ischemia and increased mortality in TBI patient.Maintaining good ventilation (not hyperventilation) at a rate of about one breath every 6 to 8 seconds (8 to 10 per minute) with high-flow oxygen is very important.Prophylactic hyperventilation for head injury is no longer recommended.Endotracheal intubation is still recommended for adults if the airway cannot be maintained or if you cannot maintain adequate oxygenation with supplemental oxygen.There is no reason to routinely intubate patients who are maintaining their airway and have normal oxygen saturation.Brain Trauma Foundation guidelines recommend capnography, pulse oximetry, and blood pressure monitoring as critical monitoring procedures for all intubated TBI patients (Level III).There is no evidence to support out-of-hospital endotracheal intubation over bag-mask ventilation of pediatric patients with TBI (Level II).
36 Management Spinal Motion Restriction Consider sedation if aggitated or combativeRecord baseline observations vital signsContinuously monitorIV access avoid hypotentionHyperventilate if cerebral herniationRestrict motion of the neck in a rigid collar and a padded head motion-restriction device.Agitated and combative patients fighting against restraints or ventilations can raise their ICP, as well as place themselves at risk for further cervical-spine injury.Consider sedation in this situation, though be aware that sedation will complicate the neurological evaluation of your patient.Record baseline observations and vital signsContinuously monitor. Record every five minutes.Insert two large-bore IV catheters. Fluid resuscitation (crystalloid) in patients with TBI should be administered to avoid hypotension and/or limit hypotension to the shortest duration possible.Hyperventilation is recommended for use in treating the patient with signs of cerebral herniation after correcting hypotension and/or hypoxia.
37 Hyperventilation Rates Age GroupNormal RateHyperventilationAdult8–10 per minute20 per minuteChildren15 per minute25 per minuteInfants30 per minuteCapnographyMaintain ETCO mmHgNOTE: Assisted ventilation should be with high-flow oxygen.NOTE: Further research is needed on the utility of hypertonic saline solution over crystalloids for treatment of hypotension in TBI patients.NOTE: Routine use of steroids for TBI has not shown improved outcomes.
38 Summary Knowledge of central nervous system Key actions Essential for assessment and managementKey actionsRapid assessment, airway management, prevent hypotension, frequent Ongoing ExamsSerious head injury has spinal injury until proven otherwiseAltered mental status common