Brain Injuries Summary PDF

**[Brain injuries ]** Cushing's triad - widened pulse pressure (increasing systolic, decreasing diastolic) bradycardia, and irregular respirations. Monro-kellie hypothesis - an increase in one compartment is offset by a change or decrease from another compartment (to reduce pressure caused by bloo...

**[Brain injuries ]** Cushing's triad - widened pulse pressure (increasing systolic, decreasing diastolic) bradycardia, and irregular respirations. Monro-kellie hypothesis - an increase in one compartment is offset by a change or decrease from another compartment (to reduce pressure caused by blood entering the brain CSF is pushed into the spinal cavity) PRIMARY = occur due to trauma impairing nervous cells SECONDARY = result due to complications from initial injury i.e. ischemia FOCAL = specific area of brain DIFFUSE = more than one area of the brain FOCAL Cerebral contusion - occurs due to blunt trauma to local brain tissue that produces capillary bleeding into brain tissue. FOCAL Coup injury - direct contusion of brain at the site of external force. FOCAL contrecoup injury - rebound injury on opposite side of the brain causing another contusion. FOCAL Hemorrhaging - result of vascular injury causing bleeding can occur in any of several compartment's epidural, subdural and subarachnoid spaces or into the brain itself. FOCAL Epidural bleed - bleeding between the dura matter and skull involves arterial blood vessels bleeding occurs rapidly which can cause an increase in intercranial pressure. FOCAL Subdural bleed - bleeding between the dura and subarachnoid space involves Venous blood vessels developing slowly. (acute, subacute, chronic) FOCAL Subarachnoid bleed - bleeding between arachnoid membrane and the pia mater surrounding the brain involves arterial blood vessels. FOCAL Intracerebral bleed - ruptured blood vessels within the brain blood loss is small but causes irritation of the nervous tissue and an increase in intercranial pressure. DIFFUSE Concussion - transient neurogenic dysfunction caused by a mechanical force to the brain. DIFFUSE axonal injury - tearing/disruption of axonal fibers in white matter and brain stem caused by blunt force trauma 3 types. 1. Mild - coma 6-24 hours 2. Moderate - widespread neurological damage prolonged coma 24+ hours 3. Severe axonal disruption in cerebral hemispheres, diencephalon, and brain stem survival rate 50-60% DIFFUSE hypoxic injury -- inadequate BF (no nutrients e.g. glucose) = ischemia = lack of O2 to cerebral vessels = cerebral hypoxia if prolonged causes infarction. **[Medical conditions of the head ]** TIA -- temporary disturbance in focal cerebral BF due to clot = ischemia and hypoxia (reverses before infarction occurs) Stroke -- sudden impairment of cerebral circulation causing acute focal neurological disorder resulting in injury or death of brain tissue. RL1/7t Drain. Paralysis on left side of body Vision problems Ouick, inquisitive behavioural style Memory loss Left Drain Paralysis on right side of body Speech/ language problems Slow, cautious behavioural style Memory loss Ischemic stroke -- - Thrombotic -- thrombus blocks BF in brain (due to chronic atherosclerosis or narrowing of a vessel) - Embolic -- embolism breaks away and flows to brain blocking artery stopping BF. Hemorrhagic stroke -- - Most fatal sudden rupture of cerebral BV either intracerebral or subarachnoid causes swelling/compression of brain tissue = immediate increase in ICP = progresses rapidly to coma and or death. Seizure -- temporary abnormal behavior due to electrical discharge - Status epilepticus -- seizures that do not stop spontaneously or occur in succession without recovery. - Postictal state -- post seizure altered level of consciousness typically lasts max 1h Generalized seizures -- occurs simultaneously in both hemispheres -- - Absence seizure (NON-MOTOR) - non-convulsive causing disturbance in consciousness typically only occur in children characterized as a blank stare, motionless and unresponsive. Usually lasts a few seconds resuming normal activity immediately. - Tonic colonic seizure (MOTOR)  Focal seizure -- - Simple - without impairment of consciousness (only in one hemisphere characterized by chaotic movement or dysfunction of one area of the body) - Complex - last 2-3 minutes with impairment of consciousness/awareness (begins in localized area of brain but may progress to both hemispheres - often arise from the temporal lobe developing to include deeper brain structures often accompanied by automatisms - repetitive, non-purposeful activities) **[Shock ]** - **inadequate oxygen delivery and consumption at a cellular level = inadequate perfusion of tissues = some tissues/organs become hypoxic = death** Trauma triad of death - hypothermia, acidosis, and coagulopathy - catabolic = breaking down molecules into smaller units either (aerobic metabolism breaking down substrates in ATP with oxygen this is carried out in the mitochondria) or (Anaerobic metabolism breaking down substrates into ATP without oxygen) - anabolic -- building molecules from smaller units. Circulatory shock 1. Hypovolemic (bleeding -- internal and or external, dehydration, third space losses -- infection, inflammation, and burns) 2. Cardiogenic (decreased CO despite adequate BV) either intrinsic -- MI, Arrythmias' and valve problems or extrinsic -- tension pneumothorax and cardiac tamponade 3. Obstructive (mechanic obstruction of BF) -- pulmonary embolism, dissecting aortic aneurism, pneumo/hemothorax and tumor. Distributive shock 1. Neurogenic -- where there is increased parasympathetic stimulation and decreased sympathetic stimulation due to a CNS injury, hypoxia or medication 2. Anaphylactic - where an allergen causes a type-I hypersensitivity reaction through an IgE response leading to bronchoconstriction, airway oedema, vasodilation and increased blood vessel permeability 3. Septic shock -characterised by a systemic infection, where mediators are released causing endothelial damage, increased blood vessel permeability and organ dysfunction. Respiratory conditions Acute respiratory failure - failure of respiratory system in one (or both) gas exchange functions (oxygenation of venous blood, CO2 elimination) this can be due to heart failure, lung failure or both Respiratory Failure can be divided into two main types: Hypoxemic respiratory failure: failure of gas exchange function Hypercapnic/hypoxemic respiratory failure: ventilatory failure occu Acute Respiratory Failure Hypoxemic Respiratory Failure Ventilation-perfusion Impaired diffusion Mismatch Hypercapnic/hypoxemic Respiratory Failure - Ventilation-perfusion mismatch - areas of lung are ventilated but not perfused or vice versa results in carbon dioxide retention - Impaired diffusion - gas exchange between alveolar air and pulmonary blood impeded due to \^ distance for diffusion or decreased permeability of respiratory membranes affecting gas exchange Pulmonary embolism - a blood-borne substance lodges in a pulmonary artery branch mechanically obstructing flow (obstructive shock) Respiratory acidosis - occurs in chronic conditions where alveolar ventilation is impaired causing \^ in CO2 - may occur with decreased respiratory drive, lung disease and disorders of the chest wall and respiratory muscles. Asthma - overreaction to various stimuli, leading to recurrent episodes of - wheezing, breathlessness, coughing and chest tightness. - Associated with widespread variable airflow obstruction - Chronic inflammatory component leads to airway remodeling (long term) COPD - chronic obstructive pulmonary disorders - Chromic/recurrent obstruction of pulmonary airways - Obstruction usually progressive and accompanied by inflammatory responses to noxious particles/gases. - Leading cause of morbidity and mortality worldwide (cause by smoking, asthmatic issues and general airway hyper-responsiveness conditions - Bronchiectasis - uncommon form of COPD results in permanently dilated bronchi and bronchioles supporting muscle and elastic tissue destroyed with chronic infection/inflammation. - Emphysema - Emphysema - destruction of tissues and alveoli, causing enlarged airspaces leasing to gas trapping, hyperinflation of lungs and increases total lung capacity - Chronic Bronchitis - increase mucus production, small airway obstruction and chronic productive cough (chronic irritation from smoking and recurrent infections) **Cardiovascular disorders** -- - Becks triad (cardiac tamponade) -- muffled heart sounds, JVD, hypotension Coronary artery disease (CAD) - coronary arteries narrow due to atherosclerosis (fatty fibrous deposits that occlude arteries can be stable or unstable) = decreased BF, supply doesn't meet demand = ischemia/hypoxia -- two types - Ischemic heart disease (IHD) (typically due to atherosclerosis or vasospasm) - Stable angina (fixed coronary obstruction) hearts blood supply is temporarily exceeded by myocardial oxygen demand. Acute coronary syndrome (ACS) - Unstable angina (UA) - formation of thrombus that does not cause complete occlusion and myocardial damage - rapid onset regardless of activity, last longer than 20 minutes, unrelieved - Acute myocardial infarction - death of portion of heart muscle due to ischemia causing hypoxia Heart failure - when heart cannot pump sufficiently to meet body\'s needs. - Occurs due to any functional/structural disorder (systolic disfunction -- contraction decreasing ejection fraction and CO, diastolic dysfunction -- relaxation- decreased pre-load, SV and CO) to the heart causing insufficient cardiac output. - Right sided heart failure (most common cause - left sided heart failure) - blood backlogs into right atrium and peripheral circulation (due to ineffective right ventricular contractility - deoxygenated blood from systemic circulation cannot be moved into pulmonary circulation, increases right ventricular atrial and systemic venous pressures -peripheral oedema develops (accumulating according to gravity) - Left-sided heart failure - left ventricle working ineffectively so cardiac output decreases, and blood backlogs into left atrium and lungs - causes increased venous pressure intervascular fluid shifts into interstitium of lung = pulmonary oedema - LV disfunction commonly caused by hypertension and MI Cardiogenic pulmonary Oedema - accumulation of fluid in alveoli of lungs affecting lung expansion and gas exchange Pericarditis - inflammation of the pericardium (commonly from bacterial infection) Pericardial effusion - accumulation of fluid in the pericardial cavity - usually from inflammation or infection Cardiac tamponade (CT) - compression of heart secondary to flid/blood/pus accumulation in pericardial sac **GI/abdominal disorders --** Gastroesophageal reflux disease (GORD) - short lived heart burn after eating due to transient relaxation of esophageal sphincter causing backflow of gastric contents into esophagus. Pain occurs in the epigastric and retrosternal area and may radiate to throat or shoulder.   Reflux esophagitis - occurs with conditions e.g. GORD causing mucosal injury in the esophagus (inflammation) - barrettes esophagitis - persistent reflux = mucosal damage = epithelial change   Hiatus hernia - protrusion of stomach through esophageal hiatus - Sliding/axial hernia (95%) bell-shaped protrusion of stomach above diaphragm - Paraoesophageal/non-axial hernia - separate portion of stomach enters thorax though widened opening progressive enlargement   Esophageal varices - gradual obstruction of venous BF in liver = portal vein hypertension (obstruction causes collateral circulation to take blood back to vena cava) - commonly due to cirrhosis   Gastritis - inflammation of the gastric mucosa - Acute - mucosal mucosal process = vomiting, pain, severe = hemorrhage/ulceration - common cause bacterial infection, alcohol etc. - Chronic - chronic inflammatory changes from number of causes   Peptic ulcer - caused by excess HCI, pepsin secretion, or weakened mucosal wall - ulcer can erode blood vessel wall = bacterial peritonitis can cause obstruction of GI tract   Gastroenteritis - acute illness manifestation = diarrhea and vomiting - associated with fluid shifts, dehydration, shock and death   IBS - GI disorder with many different types (psychosocial abnormalities, sensory, CNS processing, mortality) and various symptoms e.g. - Abdominal pain - Altered bowel function - Bloating etc.   Inflammatory bowel disease - inflammation of bowel and may have systemic manifestations - Crohn\'s - slow progressive recurrent inflammation of sections of GI tract - can effect all layers of the intestinal wall causes fibrosus and narrowing of the lumen - Ulcerative colitis - non-specific continuous inflammatory condition - causes oedema and weakening = ulceration   Diverticular disease - may cause fatal obstruction hemorrhage or infection - Diverticulum (herniating of mucosa though muscle layer of colon wall) - Diverticula - multiple pouches - Diverticulosis - diverticular are present - asymptomatic - Diverticulitis - pouches become inflamed or perforate - **Diverticulitis** occurs when small, bulging pouches (diverticula) that can form in the walls of the colon become inflamed or infected. These pouches are common, particularly in older adults, and their presence without inflammation is known as **diverticulosis**. When these pouches become inflamed, it is referred to as diverticulitis, which can lead to several complications.   Appendicitis - primary obstruction (calcified stone, gallstone etc.) of appendix causing inflammation = continued production of mucus increasing pressure in lumen, occlusion of small BV appendix. Becomes ischemic, bacteria leaks out of dying walls, rupture can cause peritonitis, may develop into sepsis   Bowel/intestinal obstruction - lack of intestinal content movement more common in small intestine (smaller size). Partial or complete blockage due to - Mechanical obstruction - intrinsic/extrinsic - Functional - neurologic impairment   Peritonitis - acute or chronic inflammation of peritoneum - develops secondary to chemical and or bacterial invasion - inflammation spreads fast = inflammatory response (vasodilation, increased capillary permeability)   Hernia - portion of internal organ protrudes through wall of cavity surrounding it - Reduced - manipulated back into place - Incarcerated - Strangulated   Liver failure - can cause organ failure and stops the liver making products such as bile additionally the liver cannot store glucose - anemia can occur due to impaired iron metabolism as. Liver plays a huge role in iron storage and regulation disease affects the livers abilities in iron.  Gall stones - abnormalities in composition of bile, stasis of bile and inflammation of gall bladder which may result in stone formation (made up of cholesterol and bilirubin) - Small stones = indigestion and biliary colic - Larger stone = obstruction - jaundice   Cholecystitis Acute - diffuse inflammation of gallbladder, secondary to outlet obstruction Chronic - repeat acute or chronic irritation of gallbladder with gall stones   Pancreatitis - inflammation of pancreas - Acute - auto digestion of pancreatic tissue by prematurely activated (caused by alcohol abuse and gall stones) pancreatic enzymes - Chronic - persistent inflammation cause irreversible change to pancreas structure and function. Abdominal hemorrhage - caused by trauma, aneurysm etc. symptoms - diarrhea, melena, hematemesis, coffee ground vomit.   Ectopic pregnancy - embryo implanted outside the uterus causing fallopian tube to stretch to accommodate the fetus occurs before 12 week gestation   Acute abdomen pain - sudden, severe abdominal pain **Renal disorders --** Acute renal failure - rapid failure of renal function in both kidneys - Directly reduced blood flow to kidneys or inflammation/necrosis of tubules causing obstruction and back flow (dialysis may be used) - Reduced urine production increased reabsorption of electrolytes UTI - commonly caused by E.coli can adhere in mucosa, women are anatomically vulnerable, infection will ascend if not washed out during urination, immune response insufficient, bladder lining does to provide enough protection - Urethritis - urethra inflamed, red, swollen - Cystitis - bladder wall inflamed, red, swollen (bladder becomes hyper-reactive with reduced capacity) - If infection ascends can cause kidney infection (pyelonephritis) Glomerulonephritis - bilateral inflammation of glomeruli, typically following streptococcal infection - Earlier infection creates antigen-antibody complex that lodges in glomerular capillaries triggers type 3 hypersensitivity (activates complement) causing congestion, decreased BF to kidney, renin secretion, increase BP, acute kidney failure, death   Kidney infection - sudden inflammation caused by bacterial infection involves one or both kidneys extending from the ureter into kidneys - Pus fills kidney pelvis and calyces, kidney medulla is inflamed if infection is severe pus can compress renal artery and vein obstructing urine outflow to ureter - Bilateral obstruction can cause renal failure - Recurrent infection causes scar formation (loss of tubule function, hydronephrosis)   Kidney stones (renal calculi) - due to large amounts of relatively insoluble salts in filtrate of insufficient fluid - Stones (very large or small once formed continue to accumulate into a large stone) can form in any part of the urinary tract but typically in the kidneys - majority of stones and composed of calcium salts. - Stones obstruct urine flow can result in infection if stasis of urine occurs - if in kidney or ureter can cause hydronephrosis (atrophy of renal tissue secondary to back pressure of urine behind obstructing stone) Chronic renal failure - gradual irreversible destruction of kidneys represents loss of functioning kidney nephrons with progressive deterioration of - glomerular filtration, tubular resorptive capacity (reabsorbing electrolytes), endocrine functions of the kidney. - Gradual loss of nephrons asymptomatic till advanced **Endocrine and environmental disorders --** Hypopituitarism - deficient secretion of hormones from the pituitary gland (can be partial of total secretion failure) absence/decrease in the secretion of one or more pituitary hormones leads to loss of function in a particular gland or organ it controls - acquired typically occurs later in life. - Complex syndrome involving metabolic disfunction, sexual immaturity and growth retardation. Goitre - enlargement of the thyroid gland caused by hypo/hyperthyroidism. - May compress the esophagus causing swallowing difficulty and pressure on trachea. - Simple - thyroid hormone secretion insufficient for metabolic needs causing enlargement of the gland to compensate. - Endemic - effects regional groups in which soil and food iodine levels are low (iodine is trapped by thyroid gland and used to synthesize T3 and T4)   Hyperthyroidism (overactive thyroid due to increased secretion of T3 and T4) - stimulates protein, lipid and carbohydrate metabolism - Graves' disease - most common form autoimmune disorder increasing T4 - clinical manifestations - hyper-metabolism, toxic goitre, exophthalmos - Thyroid storm - extreme life threatening graves' disease causing hyperthermia, tachycardia, HF, delirium/coma   Hypothyroidism - hypothalamic, pituitary or thyroid insufficiency/resistance to thyroid hormone. Severe forms are - - Chronic autoimmune thyroiditis - antibodies destroy thyroid gland tissue - Myxedema - severe adult hypothyroidism - myxedema coma - acute hypothyroidism causing hypotension, hypoglycemia, hypothermia and loss of consciousness - clinical manifestations non-pitting oedema - Cretinism - untreated congenital hypothyroidism thyroid gland non-functional/absent Addison\'s disease - insufficient adrenocortical secretions e.g. cortisol and aldosterone primary cause is autoimmune destruction of more than 90% of adrenal glands or impaired pituitary secretion of adrenocorticotropin. Gestational diabetes - glucose intolerance during pregnancy in woman not previously diagnosed with diabetes. - Pregnancy causes chronic increase in BG (beta cell cannot compensate) insulin resistance, hyperglycemia, increased supply of glucose to fetus.   Diabetes insipidus - deficient ADH secretion or renal resistance to ADH 3 forms - - Neurogenic - deficiency of ADH. - Nephrogenic - resistance of renal tubules to ADH - Psychotogenic - caused by polydipsia washed out ADH more quickly then can be replaced decreased ADH = altered intracellular and extracellular fluid control causing increased renal excretion in urine, less water absorption in distal segments of renal tubules, exponential increase in urine output low urine osmolality, increasing thirst and severe dehydration. **Burns**  - Thermal burn (most common)   - Chemical burn - typically occurs on face, eyes, arms, and legs though contact, ingestion (may cause internal burns and inhalation   - Electrical burns (uncommon) - current passes though body via transthoracic (hand-to-hand - higher mortality as current travels straight though the heart) or head-to foot may cause extensive damage via electro thermal burn and or physiological change. (current has travels though path of least resistance typically blood vessels, nerves and muscles to more resistance e.g. bones and skin current also will have an entry (depressed and leathery) and exist point (extensive and explosive) - only indicators of an electrical burn due to majority of the damage being internal (including cardiac arrythmias, skeletal muscle injury, hemodynamic instability)- if patient does not immediately die it is unlikely they wil Burn classification. 1. Superficial partial thickness - outer layers of epidermis - involves erythema, blanching on pressure, mild swelling, tender, sometimes blistering, skin maintains protective barrier 2. Partial thickness (destruction of epidermis and upper layers of dermis protective barrier lost - fluid filled vesicles which prevent loss of body water and protect superficial dermal cells promoting healing) and deep partial thickness (destruction of the epidermis and a larger percentage of the dermis - pain sensors remain intact causing severe pain, tactile sensation absent and or greatly diminished, vesicles are flat and dry potential loss of some sensation) - epidermis and various degrees of dermis 3. Full thickness - epidermis, dermis and subcutaneous tissue may involve muscle and bone - effects every body system/organ - dry waxy skin, thrombosed vessels can be seen under burned skin indicating involvement of underlying vasculature, no pain although superficial and partial burns - nerves destroyed, oedema extensive in burn area and surrounding tissue 3 zones of burns 1. Zone of coagulation (point of maximum damage - tissue death) - devitalized, necrotic, white, no circulation 2. Zone of stasis (decreased tissue perfusion)- sluggish circulation may convert to full thickness mottled red 3. Zone of hyperemia (tissue perfusion increased) - outer rim, good blood flow red Respiratory system dysfunction - respiratory injury resulting from inhalation of smoke or chemical products of combustion significant morbidity an mortality - clinical manifestations (facial injury, singed nasal hairs, soot in proximal airways, carbonaceous sputum production and changes in voice) - can lead to swelling and airway obstruction Parklands formular - used to estimate volume of replacement fluid required for first 24 hours - **TBSA BURNED (%) x WEIGHT (KG) x 4(mL)** **Rule of 9s a tool to calculate percentage burned in the field** Rule of Nines **[Spinal trauma ]** Acute spinal cord injury - injury to spinal cord typically resulting from fracture or dislocation of vertebrae which compresses, stretches or tears the spinal cord most occur in areas that provide more mobility than support (C1-C7 or T12-L2). Can be complete, partial (left or right side of the cord, anterior or posterior part of cord, or middle of the cord) and compression injuries    C1-C7 - most common hyperflexion injury and or hyperextension injury to the neck, and a compression fracture this part of the spine controls vital functions e.g. breathing - dislocation of any vertebra may crush or compress the spinal cord compromising the blood supply.   - Tetraplegia - impairment or loss of motor and or sensory function with damage to neural structures in cervical spinal cord - Paraplegia - impairment or loss of motor and or sensory function in thoracic, lumbar or sacral segments of the spinal cord Central cord syndrome (more likely to affect the arms than legs) - injury predominantly in central grey or white matter of the cord  Anterior cord syndrome - usually due to anterior spinal artery infarction spontaneous occurs may be secondary to trauma Brown-Sequard syndrome - one sided spinal cord damage typically due to traumatic injury     Autonomic dysreflexia - patients who had spinal shock now resolved with return of autonomic reflexes C1-T6 injuries at risk - sensory stimulus occurs = massive sympathetic response uncontrolled by the brain - triggered by noxious stimuli to body below level of original injury Immediate resolution required due to significant increase in risk of stroke, HF, unconsciousness, retinal hemorrhage, pulmonary oedema, MI etc.   Torticollis - external deformation - neck twisted to one side with chin protruding to opposite side due to contracture of the sternocleidomastoid muscle associated with muscle spasms causing lateral flexion of cervical spine musculature