Year 3 surgery Flashcards
Define severe inflammatory response syndrome?
Cluster of 2 features:
- Temperature <36deg C or >38 deg C
- HR >90BPM
- RR >20
- WBC <4 or >12 x10^9/L
What makes sepsis different from severe inflammatory response syndrome?
All the features of SIRS are found in Sepsis PLUS - culture-documented infection.
What features take sepsis to severe sepsis?
Features of organ dysfunction, hypotension or hypoperfusion
This includes reduced GCS, oliguria or raised lactate
What features take severe sepsis to septic shock?
Features of severe sepsis PLUS ongoing hypotension/ hypoperfusion despite fluid resuscitation
What are the red flags for sepsis?
1- objective measured altered GCS
2- SBP = 90mmHg (or drop of >40 from normal)
3- HR >/= 130bpm
4- RR >/= 25. Min
5- Needs O2 to maintain SpO2 >/= 92% (88% in COPD)
6- Non-blanching rash/ mottled/ ashen/ cyanotic
7- Lactate >/= 2mmol/L
8- Recent chemotherapy
9- Not passed urine in 18 hours (<0.5ml/kg/hr if catheterised)
What are potential sources of infection leading to seps?
Resp Brain Urine Surgical Skin/joint/wound In dwelling device Other
What are risk factors for sepsis?
> 75yrs old
Impaired immunity (e.g. diabetes, steroids, chemo)
Recent trauma/ surgery/ invasive procedure
In dwelling lines/ IVDU/ broken skin
What is the sepsis 6?
Give- fluids, antibiotics, oxygen
Take- urine output, lactate, blood cultures
How is neutropenic sepsis treated?
Broad spectrum antibiotics administered within 1 hour
Take blood cultures prior to giving antibiotics but not delayed treatment of antibiotics
Name 2 bacteria that are commonly found in the upper respiratory tract
Staphylococcus sp
Streptococcus sp (Strep pneumoniae, viridans streptococcus)
Haemophilus sp
Anaerobes
Name 2 bacteria that are commonly found on the skin
Staphylococcus sp
Coryneform bacteria or diptheroids
Propionibacterium sp
Name 2 bacteria that are commonly found in the GIT
Anaerobes
Enterococcus sp
Enterobacteriaceae (Escherichea coli, Klebsiella sp)
Streptococcus sp (Streptococcus anginosus group)
Lactobacillus sp
Candida sp
Name 2 bacteria that are commonly found in the genital tract
Lactobacillus sp Streptococcus sp (Streptococcus agalactiae)
What criterion is used for helping diagnosing infective endocarditis?
Duke’s criteria
What constitutes Duke’s criteria for infective endocarditis?
-2 major + 1 minor/ 1 major + 3 minor/ 5 minor
-Major criteria= 1- Typical micro-organism from 2 or more sets of blood cultures, ideally more than 12 hours apart
2- Positive echocardiogram showing vegetation, abcess, dehiscence of prosthetic valve or new valve regurgitation
-Minor criteria=
1- predisposing heart condition or IVDU
2- Fever >38deg C
3- Vascular phenomena- emboli, my optic aneurysm, haemorrhage, Janeway lesions
4- Immunological phenomena- GN, Osler’s nodes, Roth’s spots, rheumatoid factor
5- Microbiological evidence- positive blood cultures but falls short of major criteria i.e. atypical micro-organism
6- Echo findings- consistent with endocarditis but not a major criteria e.g. thickened valve leaflets, transmural thrombus
What fibres carry sensory information relating to touch?
A-beta fibres
What fibres carry pain and temperature information?
A-delta and C fibres
What is the difference between A-delta and C -fibres?
A-delta - myelinated and quick signals
C - unmyelinated and slow signals
Name 4 inflammatory and chemical signals that cause peripheral sensitisation
Bradykinin
Histamine
Potassium
Hydrogen ions
What is the difference between direct or secondary activation of nerve fibres causing peripheral sensitisation?
Direct is where there is direct damage to the neurones causing hyperalgesia
Secondary is the damage/ change seen in the CNS
What is Peripheral sensitisation?
Injury to area/ cell damage -> flare response of nociceptors -> production of excessive amounts of neuropeptides -> increased sensitivity to heat and touch.
The sensitivity is much more pronounced after the damage and the stimulus may only be of a low intensity
What are 2 common causes of primary hyperalgesia?
Surgery
Trauma
What is central sensitisation?
Sustained activation of receptors in post-synaptic dorsal horn leads to long-term “wind-up” of the receptors (in particular NMDA receptors) and increased sensitivity
Produces secondary areas of hyperalgesia in areas of normal tissue surrounding the injury
What is gate theory?
Non-painful stimuli can override painful stimuli and reduce painful sensation
What is allodynia?
Pain resulting from non-painful stimulus
What is hyperalgesia?
Increased response to a painful stimulus
What is paraesthesia?
Altered sensation including pins and needles sensation, typically related to nerve damage
What is visceral pain?
Pain arising from internal organs
Afferent innervation is predominantly through small unmyelinated fibres
Relatively few afferent fibres compared to somatic sensation and spinal afferents are stimulated bilaterally
Poorly localised dull pain, often felt in the midline
Often associated with autonomic features
What is referred pain?
Convergence of somatic and visceral afferent signals