Pneumonia Flashcards
Relevance
0.5-1% of adults in UK affected each year
16% of all deaths in children under 5, 808,694 in 2017 (WHO)
USA - most common cause of hosp admission except birth
**Common cause of sepsis and septic chock, causing 50% OF EPISODES
Pregnant women at risk - leading cause of death in maternity settings
Adult literature relevant to MH
Hospital Acquired Pneumonia - relevance
Increases hospital stay by 7-9 days per patient
Second most common hospital acquired infection other than UTI’s - significant mortality association
LD - respiratory conditions are major contributor to death amongst cohort
Chronic health conditions - MH population high, pneumonia risk is significant
Causes
Genetics, underlying medical and lifestyle conditions, determine pneumonia susceptibility
- babies and young children
- people over 65 - poor immune system - less cilia
- people who smoke - fewer cilia
- people with otehr health conditions such as asthma, cystic fibrosis, kidney, liver, HIV, anything which affects immune system - malnourished, post surgery,
Definition / Classification
No definition - too many types
Bacterial, Viral, Fungal - organism
Part of lung affected - lobar, bronchial
Location - Community-acquired or Hospital-acquired pneumonia
Mycoplasma pneumonia - ‘walking pneumonia’
Aspiration pneumonia - esp if laying- acid in lungs
Atypical pneumonia
Most common causes
Streptococcus pneumoniae - especially children
Hameophilus influenzae
Respiratry syncytial virus
Describe
Air sacs fill with puss and may become solid. Inflammation may affect one lung or both (double v single)
Inflammatory process
Purulent respiratory secretions, pyrexia and chest x-ray changes associated with the area of infection
Characteristics - describe
Inflammation and infection in the terminal bronchioles and alveoli, leading to engorgement of the capillaries and subsequently stasis of blood and also causing conslidation
21% oxygen in
Consolidation
Region of normally compressible lung tissue that has filled with liquid(fluid/exudate) instead of air
Shadowing on chest x-ray - can be detected on auscultation
Heavy fluid - pressure on the alveoli - can cause atelectasis (airway collapse)
Consolidation
Region of normally compressible lung tissue that has filled with liqui(fluid/exidate) instead of air
Shadowing on chest x-ray - can be detected on auscultation
Heavy fluid - pressure on the alveoli - can cause atelectasis (airway collapse)
Air journey - respiratory system
Oxygen in 21% in to down trachea, to bification of tracea (charina) - divide into right and left bronchiole tree, travels down via brionchioles, terminal brionchiles, alveoli - capillary interface, into circulation
Prevented at capillary interface
Respiratory Auscultation - what do you find?
Wheezing
Rales (upper airways) - popping crackling
Rhonchi - fluid - assoc. with heart failure and pneumonia - deep sea sounds
Atelectasis
airway collapse due to fluid in alveoli
Diagnosing pneumonia
Clinical symptoms - malaise, lethargy, fever, persistent cough, pleuritic pain
Dyspnoea - difficult / laboured breathing
Cough - sputum yellow green, rusty
Accompanied by pyrexia, chest x-ray changes and leucocytosis - elevated WBC count
Auscultation - rales, rhonchi
Send off lab sample - streptococcus pneumoniae?
Leucocytosis
Elevated WBC count
Dyspnoea
Shortness of breath - difficulty breathing
Classic diagnostic?
Start with chest x-ray
Inflammation
Th2 cells - white cells involved in inflammatory response
Th2 cells are activated by virus, bacteria, fungus
Release of cytokines
Get inflammatory response - symptoms (consolidation)
Helper type Th2 cell is a distinct type of T cell that secretes IL-4,5,9,11,13,17,25 (inflammatory mediators / cytokines)
Other cytokines produced by Th2 cells stimulate eosinophil activation and survival (IL-5) or promote mast cell activation (IL-9)
Inflammatory response:
- VASODILATION, INCREASED PERMEABILITY of blood vessels
- Emigration of phagocytes from the blood into the area of injury
- Tissue repair
- In pneumonia this presents as consolidation
Symptoms
Muscular aches Respiratory system Fever, Low BP Fast HR Nausea vomiting
Can hear it with stethoscope
Lobes of lungs
3 lobes on Right side (superior, middle, inferior)
2 on Left side (superior, lower)
Most common for pneumonia?
Right bronchus - as higher, more vertical, bigger
Cell walls - humans?
NO - bacteria, plants
Humans have cell membranes
Virus’ don’t have cell walls
Laboratory sample
streptococcus comes back green
Clinical presentation - ‘way in’ logical thinking
‘Advanced investigations’
Systemic - high fever, chills
Temperature 36.0-37,5
AIRWAY:
Respiratory rate depth and pattern - 12-20 breaths per minute normal depth
Oxygen - not delivered, cells respire anaerobically, make lactic acid, pH starts to fall, chemoreceptor, medulla olongata, phrenic nerve, increased resp
Cyanosis - lungs full of fluid - can’t get oxygen from respiratory to circulatory system
Pulse and BP
Pyrexia mega principle
Pyrexia in pneumonia
Pyrexia inhibits bacterial growth, mobilises immune defences, damage membranes of body and bacteria cells
Any human cell that’s damaged releases PYROGENS
More damage, more pyrogens
Pyrogens travel to HYPOTHALAMUS, act directly or via prostoglandins, change the set point of thypothalamus, body then perceived to be too cold, activate nervous system, start to shiver which brings your temperature up
Examples of pyrogen
IL-1 - acts directly on hypothalamus (pyrogen and cyctokine)
Tumour Necrosis Factor - the principle cytokine that mediates acute inflammation
TNF - acts directly on hypothalamus AND stimulates other white cells to release IL-6, IL-8 (more cytokines)
More cytokines, more neutrophils
TNF Tumour Necrosis Factor stimulates production of?
Interleukin 6 = proinflammatory cytokine, stimulates liver to produce acute phase proteins, STIMULATES THE PRODUCTION OF NEUTROPHILS
Interleukin 8 = PRODUCED BY MACROPHAGES IN THE ALVEOLI AND ATTRACTS NEUTROPHILS TO THE SITE OF INFLAMMATION
What are the products of cellular aerobic respiration?
Carbon dioxide, heat, ATP, water
What causes increase in heat?
Increase muscle use
heart beating faster
liver working hard fighting infection -
IL-1 and TNF on hypothalamus
TNF - IL1 &
Aerobic resp - metabolic rate goes up
Excessive high temperatures:
Swell mitochondria
Change cell permeability
Temperature leads to….
Sweating
Leads to dehydration - lost a lot? circulatory volume is reduce, BP can fall
Why does HR go up if BP falls?
If BP falls (e.g. due to sweating)
Baroreceptors in neck - measure BP
Connected to Medulla Oblongata
Connected to heart via vagus nerve
Break taken off vagus nerve, HR speeds up
BUT - also stress - adrenaline
Why sputum green?
neutrophils have ‘respiratory burst’ - they produce free radicals
enzymes in the white cells, made of iron, cause change in colour
Live neutrophils stain yellow - eosinophils
Iron enzymes + sputum = green
Raised white blood cell count?
Leukocytosis
neutrophils - tend to rise with bacterial infections
lymphocytes - viral infection
monocytes - chronic cancer
eosinophiles - parasitic infections
basophils - anaphalyxis
End point - impact on funtioning
Lungs - oxygen in co2 out
requires - large surface area, thin membrane for gaseous exchange, good blood supply, concentration gradient, adaptable
consolidation impedes process
o2 cant move down bronchiole tree into circulatory system
…becoming…HYPOXIC
(asthma, pneumonia - can both cause)
reduction of available oxygen systemically for cells, tissues and organs
less oxygen in arteriole blood
Tissue Hypoxia
Starved of oxygen for 4 minutes - brain, kidney, heart
Tissue becomes necrotic
Clot - anything downstream is starved of oxygen
Alveoli filled with fluid =
Oxygen can’t reach the bloodstream
Normal pH of blood
Normal lactate
Normal carbon dioxide
Normal oxygen
blood: 7.35 - 7.45
lactate: 0.5 - 1
carbon dioxide: 4-6.5 kilapascals
oxygen: 11-14 killapascals
low oxygen - hypoxia
Types of hypoxia
5 x types
Anaemic hypoxia - decreased haemoglobin
Hypoxic hypoxia - asthma, choke and pneumonia
Ischaemic hypoxia - arteriolar obstruction or vasoconstriction
Oxygen affinity hypoxia - e.g carbon monoxide poisoning
Stagnant hypoxia - very low blood pressure
Types of hypoxia
5 x types
Anaemic hypoxia - decreased haemoglobin
Hypoxic hypoxia - asthma, choke and pneumonia
Ischaemic hypoxia - arteriolar obstruction or vasoconstriction
Oxygen affinity hypoxia - e.g carbon monoxide poisoning
Stagnant hypoxia - very low blood pressure
What happens if deprived of oxygen?
Switch from aerobic to anaerobic respiration
in 21%, out 16.5% oxygen - I use 25% of oxygen breathed in
binds to haemoglobin - oxyhaemoglobin,
Oxygen journey
Respiration
Nasophayryx, orapharynx, lyn trachea bhronchos bhroncioles diffuses axcross thin membrane to bloodstream binds to haemoglobin forms oxyhaemoglobin, then pumped to tissues
when red cells arrive in capillary bed, xygen diffuses through capillary wall, through interstitial space that surrounds cell, through membrane and into the cytoplasm
oxygen is combined with glucose
- Glycolysis
- Krebs cycle
- Electron transport phosphorylation - make 36 ATP’s
Unable to get oxygen? what happens?
Switch to Anaerobic respiration
Glycolysis - Glucose -> 2 x ATP & Pyruvic Acid
-> Lactic Acid & Lactate
lactate levels start to climb, ph starts to fall
Become more acidic - 7.35 -> 6.8= death
Consequences of anaerobic respiration?
Reduced ATP, disrupted sodium potassium pump
Decrease in pH
Increase in lactate
Compromised cell membrane and cell organelle activity
Cell membrane disruption pathway 1
ATP dependent sodium potassium pump relies on ionic gradient
Sodium accumulates in cell, oedema
Calcium accumulates
Potassium leaks out of cell (always leaks from acidotic cells)
Leads to fluid and electrolyte imbalance
Oedema and alectroltye imbalance disrupt the function of key cell organelles leading to irreverible damage and death
Cell membrane disruption pathway 2
Lysosome - An organelle involved in breaking down proteins & carbohydrates
Thick organelle cell wall full of digestive enzymes
Due to lack of ATP, cell membrane eaten away by enzymes inside lysosome
Once cell walls become permeable, lysosomal enzymes self digest resulting in cell death
2 x major reasons for cell death
- water movement, ph imbalance, electrolyte disturbance
- Lysosomal enzyme activation
caused by lack of oxygen, ph imbalance and failure of sodium potassium pump
ACID
Assessment of pneumonia
Resuscitation council recommend…
Assess area for safety, think about an early call for help, PPE, privacy and dignity
Try to illicit response
A - If responding, airway open. Look listen and feel B - look listen and feel C - D - consciousness, blood glucose E -
Airway
Chest and abdominal movements, accessory muscle use, presence o
Green (iron) or yellow (wbc live) sputum
Cyanosis - purple/blue, grey assoc. with sat <85% changes between 3-5 g / decilitre
Breathing
Look Listen Feel
Respiratory distress Fast respiratory rate* Using accessory muscles* Speech interrupted due to strained breathing Rales, rhonchi with stethoscope Hypoxia
Circulation
Temperature up -> dehydration
Dehydration can cause low BP, increased HR
BP falls - baroreceptors in neck, medulla oblongata, vagus nerve, heat beats faster
Delayed capillary refill, over 2 sec
Perfusion to kidney low, urine output reduced
Perfusion to stomach low, feel sick or vomit
Disability
Altered level of consciousness due to lack of oxygen to brain - hypoxic confusion A C V P U
Blood sugar - elevated due to stress response
Exposure
Maintain privacy and dignity
Minimise heat loss
Check for rashes fractures and breathing
hot to the touch expected in pneumonia
Baseline observations need to be considered
Asthma, pneumonia - ABCDE
Outside of ABCDE…
Pneumonia - changes in chest x-ray, white cell count
Assessment tools for pneumonia
British Thoracic society - CURB 65
C - new mental confusion due to hypoxia U - urea due to dehydration R - fast respiratory rate B - blood pressure systolic <90, diastolic <60 65 - 65 years or older?
Critique - 12-20 is norm (RCUK)
BTS - above 30 is a worry
RCUK - say 25 is a worry
