Principles of Surgical Care Flashcards
Definition of shock
Inadequate peripheral tissue perfusion resulting from lack of oxygen and nutrient supply to the cells
4 stages of shock
- initial
- compensatory
- progressive
- refractory
Types of shock
- hypovolaemic
- cardiogenic
- distributive (Septic, anaphylactic, neurogenic)
- obstructive (cardiac tamponade, PE)
Definition of severe sepsis
Acute organ dysfunction secondary to infection
Definition of septic shock
Severe sepsis and hyptension not reversed with fluid resus
Diagnosis of septic shock
Both criteria met:
- evidence of infection
- refractory hypotension
Plus 2 or more:
- tachypnoea
- HR >90
- WCC <4000 or >12000
- T <36 or >38
Pathophysiology of septic shock
- usually endotoxin-producing gram negative bacilli
- Free LPS bind to CD14 on monos, macs and neuts
- cytokine release causes systemic vasodilatation and decreases cardiac contractility
Treatment of septic shock (OVERS)
- oxygen admin and airway support
- volume resus
- early AB admin
- rapid source ID and control
- support of major organ dysfunction
Layers of the skin
- epidermis
- dermis
- subcutaneous fat
What is secondary healing?
- edges of full thickness wound are not approximated
- granulation tissue
- contraction
4 phases of wound healing
- haemostasis
- thromboxane and prostaglandin release
- inflammation
- proliferation
- remodelling
Criteria for diagnosis of surgical site infection
- purulent drainage from surgical incision
- organism isoalted from culture of fluid/tissue
- at least one of:
pain/tenderness, localised swelling, redness, heat - systemic findings
- an abscess or other infection of deep layers of the incision/cavity
Surgical wound classification
Class 1 = clean Class 2 = clean-contam Class 3 = contam Class 4 = dirty-infected Class 5 = unclassified
Definition of an acute wound
Healed in 3 weeks and remodelled in 1 year
Definition of chronic wound
Persists beyond 3 months
Characteristics of the ideal dressing
- removes exudates and toxins
- maintains high humidity
- debrides necrotic tissue
- allows for gaseous exchange
- anti-bacterial
- hypoallergenic
- free from particulate matter
- no trauma with removal
- reasonably priced and easily available
Risk factors for pressure sores
- immobilization
- PVD
- CCF
- advanced age
- malnutrition
- cachexia
- obesity
Variables that influence surgical recovery
- patient factors
- precipitating factors
- surgical strategy
- type of anaesthesia
Common surgical respiratory complications
- atelectasis
- pneumonia
Less common surgical respiratory complications
- aspiration
- ARDS
- pneumothorax
- pleural effusion
- PE
When does periop MI usually happen?
3 days post op
Risk factors for periop MI
Patient factors
- AS
- recent MI
- arrythmia
- heart failure
Op factors
- vascular surgery
- surgery >3 hours
Risk factors for surgical haemorrhage
- coagulopathy
- massive transfusion
Cardiovascular complications in surgery
- periop MI
- haemorrhage
- DVT
Common GI surgery complications
- ileus
- constipation
- wound complication
- intra-abdominal sepsis
Less common GI surgery complications
- stress gastritis
- jaundice
- pancreatitis
- enterocutaneous fistula
Wound complications
- infection
- dehiscence
- sinus
- entercutaneous fistula
Practical clinical post-op problems
- pyrexia
- respiratory distress
- inadequate urine output
- confusion/delirium
Causes of delirium
- drugs/withdrawal
- infection/ischaemia
- metabolic
- trauma of CNS/ temp
- oxygen lack
- psych
What structures are infected in erysipelas?
- upper dermis
- superficial lyphatics
What structures are infected in cellulitis?
- deeper dermis
- subcutaneous fat
Organisms that cause cellulitis
- beta-haemolytic strep
- S. aureus
Predisposing factors for cellulitis and erysipelas
Local
- trauma
- inflammation
- infection
- oedema
Systemic
- HIC
- DM
- CF
Important differentials for cellulitis and erysipelas
- necrotizing infection
- DVT
Supportive treatment of cellulitis and erysipelas
- elevation
- treat underlying cause
- hydrate skin
- compression stockings
Antibiotics for cellulitis
Cloxacillin for 5-10 days
Antibiotics for erysipelas
- penicillin
- cloxacillin
Who gets recurrent cellulitis
- Obese
- lymphoedema
Definition of necrotising skin and tissue infections
Fulminant tissue destruction, systemic signs of toxicity, early organ dysfunction and high mortality
- muscle often spared (good blood supply)
Types of necrotizing infections
Type 1 = polymicrobial
Type 2 = hemolytic strep gangrene
Nectrotizing myositis = clostridium perfringens
Clinical findings in necrotizing infections
Local
- pain out of keeping
- crepitus
- skin anaesthesia
- tissue necrosis
Systemic
- high pyrexia
- organ dysfunction
Lab
- WCC >20000
- metabolic acidosis
- renal failure
Surgical management of necrotizing infections
- aggressive debridement
- re-evaluation in 24 hrs
- skin grafts
Definition of an abscess
Collection of pus within the dermis and deeper skin tissues
Furuncle
Infection of hair follicle
Carbuncle
Coalescence of several inflamed follices
Which abscesses need AB?
- > 5cm
- multiple lesions
- extensive cellulitis
- associated co-morbidities
- immunosuppression
- systemic signs
- lack of response to drainage
