PBL 2 Week 2 Quiz

1. PBL 2 Week 2 Quiz

2. Skin Revision 1 • List the five layers of the epidermis, the two layers of the dermis and state what the hypodermis comprises: • What is the role of sebum? • What is the name of the antigen presenting cell (APC) found in the skin, and what MHC does it express?

3. Skin Revision 1 • List the five layers of the epidermis, the two layers of the dermis and state what the hypodermis comprises: • Stratum cornium, lucidium, granulosm, spiousum, basale • Papillary and reticular dermis • CT and Adipose • What is the role of sebum? • Keeps skin soft/moisturised, ↓ bacterail growth by ↓ pH, reduces evaporation • What is the name of the antigen presenting cell (APC) found in the skin, and what MHC does it express? • Langerhan cell, MHC class II

4. Skin Revision 2 • List three ‘natural flora’ of the skin • What is the active component in skin which creates vitamin D3 from sunlight? • Describe three ways in which thermoregulation is accomplished via the skin:

5. Skin Revision 2 • List three ‘natural flora’ of the skin • Proprionibacterium acnes, Staphylococcus aureus, Staph. epidermidis • What is the active component in skin which creates vitamin D3 from sunlight? • 7 dehydrocholesterol • Describe three ways in which thermoregulation is accomplished via the skin: • Sweating, insulation via subcutaneous fat and hair, alteration of dermal blood vessels

6. Assessment of Burns 1 • What percentage of burn TBSA equates to a systemic inflammatory response? Which system does this pose the most immediate threat too? • An adult was admitted with burns to their right arm, forearm, thigh and leg, as well as half of their front and back. Approximately what %TBSA does this equate too? • List three factors which would lead you to suspect inhalation burns have been obtained:

7. Assessment of Burns 1 • What percentage of burn TBSA equates to a systemic inflammatory response? Which system does this pose the most immediate threat too? • 20-25%. Respiratory system. • An adult was admitted with burns to their right arm, forearm, thigh and leg, as well as half of their front and back. Approximately what %TBSA does this equate too? • ~45% • List three factors which would lead you to suspect inhalation burns have been obtained: • Burns to face and neck or inside mouth and nose, hoarseness, chest noises, hypoxia, carbonaceous sputum, env. factors: noxious gases/fumes, enclosed space.

8. Assessment of Burns 2 • Describe the appearance of a superficial burn and why it looks like this.Do you get necrosis? • What is one of the distinguishing features of a “2nd Degree”, partial thickness burn? • For a full thickness burn, list the three zones observed and state which of these can be saved and which of these can increase in size.

9. Assessment of Burns 2 • Describe the appearance of a superficial burn and why it looks like this.Do you get necrosis? • Red – endothelial damage  vasodilation and slight oedema. No necrosis. • What is one of the distinguishing features of a “2nd Degree”, partial thickness burn? • Blister – epidermal necrosis, dermal spared, separation of layers. • Blood redness – blood cells stuck out in the dermal layer • For a full thickness burn, list the three zones observed and state which of these can be saved and which of these can increase in size. • Zone of Coagulation (could spread if treatment/management is not sufficient), zone of stasis (can potentially be saved), zone of hyperaemia.

10. Acute Management of Burns 1 • List three guiding principles for first aid of burns: • When should IV line resuscitation be utilised? • What are the factors which determine the severity of a chemical burn? What is the difference between an acid and alkali burn?

11. Acute Management of Burns 1 • List three guiding principles for first aid of burns. Ice? • Cool the burn/ stop the burning process. No ice! • Reduce inflammatory mediator production • Reduce tissue damage progression in first 24hrs. • When should IV line resuscitation be utilised? • Partial thickness burns >15% in adult and 10% kid • What are the factors which determine the severity of a chemical burn? What is the difference between an acid and alkali burn? • pH, length of contact, volume/concentration of active agent, physical form of agent. • Alkalis: protein denaturation and fat saponification no barrier stopping further spread.

12. Acute Management of Burns 2 • For what type of burns should silver sulfadiazine be used? What are the contraindications for its use? • List three of the referral criteria to a special burns unit: • What is the mechanism behind the opioid- sparing powers of paracetamol?

13. Acute Management of Burns 2 • For what type of burns should silver sulfadiazine be used? What are the contraindications for its use? • Small, superficial partial thickness • Term pregnancy or newborn  kernicterus • List three of the referral criteria to a special burns unit: • Burns >10%TBSA for adult and 5% for kids, • deep partial or full thickness burns >5%, • inhalation or circumferential burns, • burn across joint, hand, face, perenium • Sig. associated injury or PMHx. • Sig. chem or electrical burn • What is the mechanism behind the opioid- sparing powers of paracetamol? • Who knows?

14. Long Term Management of Burns 1 • List three professions involved in a burns unit: • What three factors result in venous stasis and ischaemia, post-burn? • What is an eschar? • Why is Acticoat Absorbent used to dress escharotomy wounds?

15. Long Term Management of Burns 1 • List three professions involved in a burns unit: • Nurse, physio, nutritionist, OT, social worker, mental health, orthotics, doctor/surgery. • What three factors result in venous stasis and ischaemia, post-burn? • ↑ blood viscosity, localised oedema and ↓ circulatory blood volume • What is an eschar? • A dry scab/slough formed on the skin from protein denaturization. • Why is Acticoat Absorbent used to dress escharotomy wounds? • Provides antimicrobial protection and absorbency.

16. Long Term Management of Burns 2 • In what way do characteristics of a burn influence infection? • What burn injury may prior alcohol consumption exacerbate? • What is an autogenous graft? What is the difference between a graft and a flap? • List the four factors influencing graft survival:

17. Long Term Management of Burns 2 • In what way do characteristics of a burn influence infection? • The greater the severity and extent of the burn, the greater the frequency of infection • What burn injury may prior alcohol consumption exacerbate? Why? • Pulmonary issues. ????? • What is an autogenous graft? What is the difference between a graft and a flap? • A graft taken from the recipient. • Graft: no vascular pedicle, derives its blood flow from recipient site revascularization. Flap: vascular network intact. • List the four factors influencing graft survival: • Vascularity of recipient bed, level of contact b/n graft and bed, immobilization of graft-bed unit, level of bacteria presence.

18. Wound Healing and Scars 1 • What is the difference b/n resolution and repair? • How does healing by second intention differ from first intention? • What does healing by tertiary intention involve?

19. Wound Healing and Scars 1 • What is the difference b/n resolution and repair? • Resolution: destroyed tissues are capable of regeneration. • Repair: extensive tissue damage where regen. cant occur and collagenous scar tissue is used. • How does healing by second intention differ from first intention? • First: no sig. tissue loss, clean wound, close edges. • Second: sig. tissue loss. Longer epithelialisation, scar formation and contraction • What does healing by tertiary intention involve? • Debridement of the wound and may require skin grafts for full healing. Open wound for several days.

20. Wound Healing and Scars 2 • What are the four stages of wound healing and what occurs in each stage?

21. Wound Healing and Scars 2 • What are the four stages of wound healing and what occurs in each stage? • Haemotoma: vasoconstriction, platelet aggregation, fibrin clot formation. • Inflammation: vasodilation, ↑ vasc. perm. Neutrophils, Mᵠ and lymphocytes release GF to start wound healing • Granulation tissue formation: presence of macrophages and neutrophils, angiogenesis and the depsoition of Type III collagen by fibroblasts following fibrogenesis • Wound contraction/ECM deposition/remodelling: epithiliaization, fibroblasts require oxygenation to perform, whole wound contraction ~ day 10 from fibroblasts. Remodelling sees Type III collagen  Type I, excess broken down, regression of vessels and granulation tissue.

22. Infections 1 • List three issues and costs associated with HAIs: • List three viral causes for HAIs: • Which infection sites are Staph epidermidis commonly responsible for? • What predisposes someone to vancomycin resistant enterococci (VRE)?

23. Infections 1 • List three issues and costs associated with HAIs: • Morbidity and mortality, ↑ hospital stay, cost of therapy, ↓ productivity, insurance claims, additional reservoir for infection • List three viral causes for HAIs: • Norovirus, cytomeglavirus, rotavirus, herpes simplex, respiratory syncytial virus • Which infection sites are Staph epidermidis commonly responsible for? • IV lines, shunts and prosthetics • What predisposes someone to vancomycin resistant enterococci (VRE)? • Use of a broad spectrum antibiotics

24. Infections 2 • The most common cause of hospital acquired diarrhoea is due to… • Provide characteristics of blood collection for an infected patient. • Provide some examples of ways to ‘break’ the infection chain.

25. Infections 2 • The most common cause of hospital acquired diarrhoea is due to… • Clostridium difficle • Provide characteristics of blood collection for an infected patient. • Take two samples, 30 mins apart from separate sites. One anaerobic and one aerobic culture. Be wary of contamination • Provide some examples of ways to ‘break’ the infection chain. • WASH YOUR HANDS!!! Face masks and other PPE, cleaning, disinfection, sterile equipment

26. Sepsis 1 • What is the criteria for SIRS? • What two elements does the normal physiological response to inflammation consist of? • Basically explain the pathophysiology behind SIRS

27. Sepsis 1 • What is the criteria for SIRS? • Two or more of: • Temp >38 or <36 • RR >20bpm (tachypnoea), Hyperventilation PaCO2 <32mmHg • HR >90bpm • Abnormal WCC (>12,000, <4,000) or 10% immature neutrophils • What two elements does the normal physiological response to inflammation consist of? • Acute proinflam. state from innate immunity system recognition of toll receptor ligands, and anti-inflam. phase that modulates this. • Basically explain the pathophysiology behind SIRS • Cytokines released proinflam compounds, which in turn cause endothelial damage and initiate in and extrinsic coagulation. Microthrombi, ischaemia, microcirulatory damage.

28. Sepsis 2 • The most commonly recognised initiator of SIRS is….which is released by…. • What variations of circulation can exist with septic shock? How does this affect the patients clinical features? • What other CF classically present with septic shock? • What actions are required for septic shock treatment?

29. Sepsis 2 • The most commonly recognised initiator of SIRS is….which is released by…. • Endotoxinlipopolysaccharide (LPS), Gram -ve • What variations of circulation can exist with septic shock? How does this affect the patients clinical features? • Hyperdynamic (normal/↑ CO with ↓ PR) – flushed and warm • Hypodynamic (↓CO with ↑PR) – pale and cool, peripheral cyanosis. • What other CF classically present with septic shock? • Abrupt onset of chills, nausea, fever, tachypnea, vomiting, ↓ mental status, hypotension and tachycardia • What actions are required for septic shock treatment? • Remove the cause of infection, maintain perfusion measures (IV fluids, CVS meds) and supportive treatment for complications.

30. Antibiotic Choice 1 • What is the first question to ask when considering AB selection? • What factors influence antimicrobial choice? • When should prophylactic AB therapy be used?

31. Antibiotic Choice 1 • What is the first question to ask when considering AB selection? • Is an antimicrobial essential for treatment? • What factors influence antimicrobial choice? • Side effects, therapeutic drug monitoring, risk of superinfection, adverse drug events/ hypersensitivity, spectrums of act. of microbes • When should prophylactic AB therapy be used? • In situations proven to show benefit or when consequences of infection would prove disastrous

32. Antibiotic Choice 2 • What is empirical therapy and what should its use be based on? • Is pathogen or sensitivity directed therapy more accurate? Why? • What elements of the AB dictate duration of therapy?

33. Antibiotic Choice 2 • What is empirical therapy and what should its use be based on? • Use of ABs before the aetiology of infection is known. Local epidemiology, potential pathogens and their potential resistance • Is pathogen or sensitivity directed therapy more accurate? Why? • Sensitivity. Don’t need to consider potential resistance, ABs pt. has previously used… • What elements of the AB dictate duration of therapy? • Whether the AB’s killing power is concentration dependant or time dependant. Side effects. Toxicity. Pharmodynamics

34. Fluid Balance 1 • What ‘shocks’ make up burn shock and how soon after the burn should IV fluid resus occur to avoid it? • Briefly describe burn shock pathophysiology. • Explain why cardiac function is impaired in burn shock.

35. Fluid Balance 1 • What ‘shocks’ make up burn shock and how soon after the burn should IV fluid resus occur to avoid it? • Hypovolemic and distributive shock. Initiated within 2hrs. Delay ↑ mortality rate. • Briefly describe burn shock pathophysiology. • Microvasculature is damaged. Fluid and protein leak into interstitium. Change in osmotic pressure pulls fluid out of vessels. • Explain why cardiac function is impaired in burn shock. • ↑afterload(catecholamines, vasopressin, angiotensin II, neuropeptide Y released after burn injury) • ↓preload (drop in plasma volume) • Myocardial impairment (gut-derived inflam factors.)

36. Fluid Balance 2 • What is contained within Hartmann’s solution and why is it preferred for burns pt.s? • A 27 year old female weighing 80kg is brought in suffering surface burns to 45% of her body. How much fluid should she receive in the first 8 hours? • What level of urine output are we aiming to maintain?

37. Fluid Balance 2 • What is contained within Hartmann’s solution and why is it preferred for burns pt.s? • Na+, K+, Ca++, Cl-, lactate and fluid. Of the crystalloid family, it most resembles body fluids; also increased death rate with colloids and concerns with plasma. • A 27 year old female weighing 80kg is brought in suffering surface burns to 45% of her body. How much fluid should she receive in the first 8 hours? • 4 x 80 x 45 = 14,400 ml/24 hr,  7,200ml in 8hrs. • What level of urine output are we aiming to maintain with her? • 0.5ml/kg/hr,  40ml/hr