FOCUS Annual Fall Classic Respiratory Care of the Patient with Traumatic Brain Injury

Transcription

1 FOCUS Annual Fall Classic 2018 Respiratory Care of the Patient with Traumatic Brain Injury Daniel W. Chipman, BS, RRT Assistant Director of Respiratory Care Massachusetts General Hospital Boston, Massachusetts

2 Respiratory Care of the Patient with TBI Overview Glascow Coma Scale (GCS) Abreviated Injury Score (AIS) Primary vs secondary injury Intubation Ventilation and Oxygenation Mechanical Ventilation Monitoring Extubation/tracheostomy

3 TBI in the United States An estimated 2.8 million people sustain a TBI annually. Of them: 50,000 die, 282,000 are hospitalized, and 2.5 million, nearly 90%, are treated and released from an emergency department. TBI is a contributing factor to a third (30%) of all injury-related deaths in the United States. Every day, 153 people in the United States die from injuries that include TBI. Most TBIs that occur each year are mild, commonly called concussions. Direct medical costs and indirect costs of TBI, such as lost productivity, totaled an estimated $60 billion in the United States in From the Centers for Disease Control and Prevention 2017

4 TBI by Age Children aged 0 to 4 years, older adolescents aged 15 to 19 years, and adults aged 65 years and older are most likely to sustain a TBI. In 2012, an estimated 329,290 children (age 19 or younger) were treated in U.S. EDs for sports and recreation-related diagnosis of concussion or TBI. Adults aged 75 years and older have the highest rates of TBI-related hospitalization and death.

5 Causes of TBI in the United States

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7 Glascow Coma Scale (GCS) Eye Opening Response Spontaneous--open with blinking at baseline 4 points To verbal stimuli, command, speech 3 points To pain only (not applied to face) 2 points No response 1 point Verbal Response Oriented 5 points Confused conversation, but able to answer questions 4 points Inappropriate words 3 points Incomprehensible speech 2 points No response 1 point Motor Response Obeys commands for movement 6 points Purposeful movement to painful stimulus 5 points Withdraws in response to pain 4 points Flexion in response to pain (decorticate posturing) 3 points Extension response in response to pain (decerebrate posturing) 2 points No response 1 point

8 Glascow Coma Scale (GCS) Categorization: Coma: No eye opening, no ability to follow commands, no word verbalizations (3-8) Head Injury Classification: Severe Head Injury----GCS score of 8 or less Moderate Head Injury----GCS score of 9 to 12 Mild Head Injury----GCS score of 13 to 15

9 Brain anatomy Cerebral Cortex Frontal lobe Parietal lobe Occipital lobe Temporal lobe Brain Stem Medulla Cerebellum

10 Frontal Lobes: Most anterior, right under the forehead. Functions How we know what we are doing within our environment (Consciousness) How we initiate activity in response to our environment Judgments we make about what occurs in our daily activities Controls our emotional response Controls our expressive language Assigns meaning to the words we choose Involves word associations Memory for habits and motor activities Observed Problems Loss of simple movement of various body parts (Paralysis) Inability to plan a sequence of complex movements needed to complete multi-stepped tasks, such as making coffee (Sequencing) Loss of spontaneity in interacting with others. Loss of flexibility in thinking Persistence of a single thought (Perseveration) Inability to focus on task (Attending) Mood changes (Emotionally Labile) Changes in social behavior. Changes in personality Difficulty with problem solving Inability to express language (Broca's Aphasia)

11 Parietal Lobes: near the back and top of the head. Functions Location for visual attention Location for touch perception Goal directed voluntary movements Manipulation of objects Integration of different senses that allows for understanding a single concept Observed Problems Inability to attend to more than one object at a time Inability to name an object (Anomia) Inability to locate the words for writing (Agraphia) Problems with reading (Alexia) Difficulty with drawing objects Difficulty in distinguishing left from right Difficulty with doing mathematics (Dyscalculia) Lack of awareness of certain body parts and/or surrounding space (Apraxia) that leads to difficulties in self-care. Inability to focus visual attention Difficulties with eye and hand coordination

12 Occipital Lobes: Most posterior, at the back of the head. Functions Vision Observed Problems Defects in vision (Visual Field Cuts) Difficulty with locating objects in environment Difficulty with identifying colors (Color Agnosia) Production of hallucinations Visual illusions - inaccurately seeing objects Word blindness - inability to recognize words Difficulty in recognizing drawn objects Inability to recognize the movement of an object (Movement Agnosia) Difficulties with reading and writing

13 Temporal Lobes: Side of head above ears. Functions Hearing ability Memory acquisition Some visual perceptions Categorization of objects Observed Problems Difficulty in recognizing faces (Prosopagnosia) Difficulty in understanding spoken words (Wernicke's Aphasia) Disturbance with selective attention to what we see and hear Difficulty with identification of, and verbalization about objects Short-term memory loss. Interference with long-term memory Increased or decreased interest in sexual behavior Inability to catagorize objects (Categorization) Right lobe damage can cause persistent talking Increased aggressive behavior

14 BRAIN STEM: Deep in Brain, leads to spinal cord. Functions Breathing Heart Rate Swallowing Reflexes to seeing and hearing (Startle Response) Controls sweating, blood pressure, digestion, temperature (Autonomic Nervous System) Affects level of alertness Ability to sleep Sense of balance (Vestibular Function) Observed Problems Decreased vital capacity in breathing, important for speech Swallowing food and water (Dysphagia) Difficulty with organization/perception of the environment Problems with balance and movement Dizziness and nausea (Vertigo) Sleeping difficulties (Insomnia, sleep apnea)

15 CEREBELLUM: Located at the base of the skull. Functions Coordination of voluntary movement Balance and equilibrium Some memory for reflex motor acts Observed Problems Loss of ability to coordinate fine movements Loss of ability to walk Inability to reach out and grab objects Tremors. Dizziness (Vertigo) Slurred Speech (Scanning Speech) Inability to make rapid movements

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17 Intracranial Pressure (ICP) Normal = 5 to 15 mmhg ICP monitoring is recommended in most comatose patients with severe head injury ICP should be treated when above 20mmHg, but maintenance of CPP is probably more important Increased ICP may be caused by: tracheal intubation Coughing ETT suctioning Patient/ventilator asynchrony

18 Monroe-Kellie Doctrine intracranial (constant) = v.brain + v.csf + v.blood + v.mass lesion Monro A. Observations on the structure and function of the nervous system. Edinburgh, Creech & Johnson 1823 p.5 Kellie G. An account of the appearances observed in the dissection of two of the three individuals presumed to have perished in the storm of the 3rd, and whose bodie were discovered in the vicinity of Leith on the morning of the 4th November 1821 with some reflections on the pathology of the brain. Trans Med Chir Sci, Edinburgh 1824;1:84-169

19 Indications for ICP Monitoring trauma.org 5:1 2000

20 Cerebral Perfusion Pressure (CPP) Difference between the Mean Arterial Pressure (MAP) and the Intracranial Pressure (ICP) Pressure gradient driving cerebral blood flow and oxygen and metabolite delivery CPP is reduced after TBI and must be restored CPP = MAP - ICP

21 CPP Critical threshold: 70 to 80 mmhg 35% reduction in mortality Mortality increases 20% for each 10 mmhg loss of CPP May be restored by: Decreasing ICP (< 20 mmhg) Increasing MAP therapeutic level avoid hypotension (MAP < 90 mmhg)

22 Oxygen Monitoring Jugular bulb venous oxygen monitoring PbtO2 monitoring

23 Jugular Bulb Venous Oxygen Oonitoring Indication of cerebral oxygenation (O2 delivery) and cerebral metabolism (O2 consumption) Normal range 55 to 71% Monitors global oxygenation Sustained SjvO2 < 50 mmhg indicates cerebral ischemia Randall M. Schell and Daniel J. Cole Anesth Analg 2000;90:559 66

24 PbtO2 Monitoring Monitors focal oxygenation (site of injury) Normal range 35 to 50 mmhg < 15 mmhg indicates ischemia Associated with reduced morbidity and mortality PbtO2 monitoring combined with ICP/CPP based treatment associated with best outcomes Nangunoori, et al Neuro Crit Care 2011

25 Invasive Multimodal Monitoring Rationale: 1) Detect scalp-negative seizures, edema, vasospasm impacting cerebral oxygen delivery/consumption 2) Diagnose reversible causes of coma and neurologic injury by understanding the relationships between multiple physiologic factors and their trend over time (e.g., vasospasm obscured by coma, ICP elevation related to agitation vs. spontaneously occurring; ICP elevation with normal vs. abnormal CPP; brain tissue hypoxia related to sedation holds, brain tissue hypoxia or ICP elevation related to epileptiform activity). 3) Tailor neurocritical care management to patient-specific factors including parameters impacting perfusion (supply) and metabolism (demand): BP, CPP, edema, seizure/iic activity, hypovolemia, sedatives, temperature 4) Evaluate response to treatment (CPP optimization, hyperosmolar therapy, spasmolysis, AED trials)

26 Invasive Multimodal Monitoring Inclusion Criteria: 1. Traumatic brain injury 2. GCS 8 on admission or after neurologic decline 3. Admission to Lunder 6 Neuro-ICU from ED or after OR management. 4. Age > 18 years Exclusion Criteria: 1. Contraindication to placement of intracranial monitor (severe coagulopathy, CMO status)

27 Invasive Multimodal Monitoring Ideally placed on the side at risk for secondary tissue injury Injures or contused Viable non-infarcted Side of the dominant injury If significant hematoma is present on side of dominant injury: Placed on contra-lateral side

28 Invasive Multimodal Monitoring

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35 TBI Primary injury Occurs at the scene and is usually the control of the patient care team Secondary injury Anything that occurs to augment the primary injury Prevention of secondary is the aim of the management

36 Management of Severe TBI Establish monitoring parameters for treatment Enhance cerebral oxygen delivery Optimize CPP Optimize management of increased ICP

37 5 Key Principles for ICU Management of Head Injury Normotension Normoxia Normocapnea Normothermia Normoglycemia

38 Assessment and Plan Secure airway Maintain neck in neutral position Obtain serial CT scans Consider placement of ICP monitor/ventriculostomy and PbtO2 Place arterial and CVP lines

39 Emergency Department Airway Intubate GCS 3-8 unable to protect airway SaO2 100%, PaCO mmhg MAP > 90 mmhg Large bore IVs, labs NG/Foley Mannitol 1 g/kg for posturing or unequal/non-reactive pupils

40 Mannitol and TBI Short term use increases serum osmolarity and draws fluid from the brain Long term it may cross the blood brain barrier and increase swelling.

41 No difference between the 2 medications could be found with respect to the extent of reduction of ICP or duration of action

42 Mannitol therapy for raised ICP may have a beneficial effect on mortality when compared to pentobarbital treatment, but may have a detrimental effect on mortality when compared to hypertonic saline. ICP-directed treatment shows a small beneficial effect compared to treatment directed by neurological signs and physiological indicators. There are insufficient data on the effectiveness of pre-hospital administration of mannitol

43 Prepare for ICP/LICOX Insertion Arterial and central lines Administer fluids to keep CVP 5 10 mmhg Albumin/NS Blood products Reverse DIC FFP, Cryo, platelets for abnormal coags Maintain MAP > 90 mmhg or CPP > 70 mmhg Neosynephrine, Dopamine Titrate PaCO2 to keep PbtO2 > 20 mmhg Consider craniotomty for unresponsive ICP Goals: SaO2 100% PaCO mmhg MAP > 90 mmhg PbtO2 > 20 mmhg ICP < 20 mmhg

44 ICU Phase l: Initial 24 hours Maintain Goals If PbtO2 < 15: FIO2 100% (up to hours, then decrease to 30 to 50%) Priorities: to decrease FIO2 Titrate PaCO2 to keep PbtO2 > 20 mmhg Give volume: CVP 5 10 mmhg Fluids until euvolemic, vasopressors to raise MAP Determine optimal CPP for patient (70 mmhg) Consider early Propofol ug/kg/min ICP < 20 Maintain normothermia and appropriate antibiotic coverage Goals: SaO2 100% PaCO mmhg MAP to keep CPP > 70mmHg PbtO2 > 20 mmhg ICP < 20 mmhg

45 ICU Phase ll: > 24 Hours After Admission Maintain FIO2 to keep PaO2 > 80 Titrate PaCO2 to balance ICP < 20 mmhg and PbtO2 > 20 mmhg Determine optimal CPP for patient CVP 5-10 using fluids Vasopressors to increase MAP when euvolemic Sedate continuous Propofol or Versed Pain control continuous morphine or fentanyl Temp o C, using cooling measures Mannitol g/kg bolus if ICP >15 Keep serum osmo < 320 Fluid replacement to maintain euvolemia Consider neurosurgery for refractory ICP Consider pentobar drip if unable to control ICP Goals: PbtO2 > 20 mmhg ICP < 20 mmhg

46 If PbtO2 < 20 mmhg Increase FIO2 to 100% for 15 minutes Drain CSF if > 20 mmhg Increase PaCO2: decrease RR, balance with ICP Optimize CPP: check CVP and MAP Mannitol (if ICP > 20 mmhg) Maintain adequate sedation and anesthesia Consider cooling for temp > 37 o C. Start or increase propofol Consider barbiturate therapy if refractory to other interventions Consider paralytic if unable to maintain PaCO2 and PaO2

47 If PbtO2 > 20 mmhg and ICP > 20 mmhg Drain CSF Decrease PaCO2 to decrease ICP Optimize CPP: fluids and vasopressors to maintain CPP Mannitol (0.25 to 1 gm/kg IV) Consider paralytics or pentobarbitol for ICP control Start/titrate Propofol/barbiturates for ICP control Consider craniectomy

48 Phase lll: weaning Normalize PaCO2 Discontinue paralytics/pentobarbitol Wean Propofol Normalize CPP/CVP Discontinue ICP/CSF drain Decrease analgesia/sedation

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51 CO2 and Cerebral Blood Flow Potent vasoactive effect Hyperventilation causes cerebral vasoconstriction Decreases cerebral blood flow Decreases ICP Ischemia

52 PEEP and TBI PEEP increases intrathoracic pressure Decreased venous drainage Increased cerebral blood volume and ICP Maintain PEEP 5 to 8 cm H2O

53 Protective Lung strategies and TBI High Vt associated with acute lung injury in patients with severe TBI Low tidal volume Moderate PEEP

54 Mechanical Ventilation and TBI Maintain target oxygenation SaO2 > 95% and PaO2 > 80 mmhg Maintain target ventilation mmhg Minimize airway pressures MAP and PEEP Promotes cerebral venous drainage For multi-trauma patients you may have to make some compromise to protective lung strategies

55 TBI and ARDS 10 to 30% patients with TBI develop ARDS Etiology -Aspiration -Pulmonary contusion -Transfusion related acute lung injury (TRALI) -Neurogenic pulmonary edema -High tidal volume and high respiratory rate -Pneumonia -Massive blood transfusion -Sepsis Increased ICU LOS and ventilator days

56 TBI and ARDS Balanced Approach TBI: Adequate oxygenation Preserving cerebral venous drainage (low levels of PEEP) Mild hypocapnia (slightly higher Vt) ARDS Low Vt High PEEP Permissive hypercapnia

57 Lunder 6 NSICU Ventilator Settings Protocol Assist/ Control Ventilation Tidal Volume 4 to 8 ml/kg PBW Inspiratory Time <1.0 sec Driving Pressure <15 cmh 2 0 Plateau Pressure <28 cmh 2 O PEEP 5 to 15 cmh 2 O Set Rate 10 to 30/min F I O 2 to maintain SpO2 93% to 100%

58 Lunder 6 NSICU Ventilator Settings Protocol Pressure Support Ventilation may be initiated if: Team consensus to initiate Intact ventilatory drive, sustained spontaneous breathing FIO2 < 0.6 Pressure support level 5 to 15 cmh 2 O to establish a tidal volume of 6 to 10 ml/kg PBW PEEP 5 to 15 cmh 2 O F I O 2 set to keep SpO 2 93 to 100%

59 Lunder 6 NSICU Ventilator Settings Protocol Assess for Spontaneous Breathing Trial (SBT) daily Perform SBT if: patient breathing spontaneously, FIO2 < 0.5, PEEP < 10 cm H 2 O, patient hemodynamically stable, not requiring continuous infusion of pressors or sedatives SBT: Leave patient attached to the ventilator PEEP < 5 cm H 2 O and pressure support < 5 cmh 2 O Maintain spontaneous breathing 30 to 60 min Discontinue SBT if: a. SpO 2 < 90% b. V T < 4 ml/kg PBW c. Respiratory Rate > 35/min d. Develops respiratory distress defined as 2 or more of the following: i. HR > 120% of baseline ii. BP > 150% of baseline or Systolic > 180 mmhg and Diastolic > 90 mm Hg iii. Marked accessory muscle use iv. Abdominal Paradox v. Diaphoresis vi. Marked dyspnea

60 Endotracheal Tube Suctioning and ICP ETT suctioning increases ICP Especially on the 4 th pass of the suction catheter May be alleviated with lidocaine (ETT or IV) Preoxygenate Increase sedation Must be brief and atraumatic

61 Ventilator Discontinuance and Extubation SBT to assess ability to maintain ventilation Assessment of ability to protect airway prior to extubation Tracheostomy for patients unable to protect their airway

62 Summary TBI is a common injury associated with significant morbidity and mortality requiring prompt intervention. Efforts must be directed at reducing the incidence of secondary injury. Proper monitoring of CPP and cerebral O2 delivery is essential to improving outcomes.