W14 50 therapy of systemic infection

Question 1

What is Antimicrobial stewardship?

Answer 1

‘An organisational or healthcare-system wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness.

Question 2

When should you prescribe antibiotics and when not?

Answer 2

Usually don’t unless there are signs of spreading infection, systemic infection, or for an immunocompromised patient if there are signs of necrotising disease. Choice of metronidazole or amoxicillin. If not systemic, don’t prescribe.

Question 3

What considerations should you make when prescribing an antibiotic?

Answer 3

Guidance, local resistance patterns? Previous microbiology results?
Is patient allergic to any drugs?
Are they on drugs that might interact?
Could the pt be pregnant?
Any renal or liver impairment?
What route and duration of therapy?
Warn the patient of specific side-effects or cautions - eg avoid alcohol with metronidozole
When should the pt be reviewed?
What are the signs of things failing to improve? What should the patient do?

Question 4

What is systemic infection?

Answer 4

A causal infecting agent is actively or passively invading host anatomy to disseminate through several systems.

Question 5

What’s the difference between spreading infection and systemic involvement?

Answer 5

Spreading infection eg cellulitis, lymph node involvement
Systemic involvement eg generalised symptoms and signs like fever, tachycardia etc

Question 6

When might systemic infection occur?

Answer 6

When there is a persistent infection/swelling despite local treatment. Eg acute necrotising ulcerative gingivitis (ANUG), sinusitis etc

Question 7

What are the portals for infection to the body?

Answer 7

Penetrating mucosae - mouth and airways, lacunae joints, sinuses, gut and viscera etc, broken skin
Directly into the blood - bites bullets or cuts, surgical site, IV drug abuse, hospital cannulation

Question 8

How can the oral cavity be a source of systemic infection?

Answer 8

Local sepsis and periodontal disease
Surgery or injury
Mucositis and mucosal resistance

Question 9

What is nosocomial infection?

Answer 9

Infections acquired from hospital, not present at admission
Localised or systemic
Evident after 48hrs: procedure related, ventilators are bad, surgery and implants, central venous cannulation, immunosuppression

Question 10

What is bacteraemia?

Answer 10

Presence of viable bacterial organisms within the blood
May be asymptomatic. Transient presence of non-replicating bacteria.
Generally self-limiting but can propagate and threaten life
Bodies natural response system will destroy the bacteria

Question 11

What is septicaemia?

Answer 11

Within the blood.
Proliferating and fulminant. Generally symptomatic.
Usually relative immune compromise.
Generally life or limb threatening.

Question 12

What is meningococcal septicaemia?

Answer 12

Red patches over skin

Question 13

What are the signs of early systemic infection?

Answer 13

Malaise (tiredness)
Myalgia (muscle aches)
Arthralgia (joint aches and pains)
Low grade fever

Question 14

What are the signs of systemic infection at the portal of entry?

Answer 14

Inflammation, pus, swelling, oedema

Question 15

What can systemic infection progress to?

Answer 15

Sepsis

Question 16

What is sepsis?

Answer 16

A life threatening organ dysfunction caused by a dysregulated host response to infection

Question 17

What does the systemic inflammatory response syndrome (SIRS) recommend for a sequential organ failure assessment qSOFA?

Answer 17

Alteration in mental status (GCS =<13)
Systolic blood pressure =<100mmHg
Respiratory rate >=22 per minute

Question 18

What is a septic shock?

Answer 18

A subset of sepsis in which underlying circulatory, cellular and metabolic abnormalities are associated with a greater risk of mortality than sepsis alone.

Question 19

What are some more serious systemic effects of sepsis?

Answer 19

Low blood pressure
Metabolic and cellular abnormalities
Cerebral effects - sleepy, confused, agitated, aggressive
Disseminated intravascular coagulation
Embolism
Multiple organ damage

Question 20

What are the symptoms of sepsis - SEPSIS?

Answer 20

S shivering, fever or very cold
E extreme pain or general discomfort
P pale or discoloured skin
S sleepy, difficult to rouse, confused
I ‘I feel like I might die’
S short of breath

Question 21

What is the composition of an embolism?

Answer 21

Pus and thrombus

Question 22

What organs are usually affected by embolism?

Answer 22

End arterial organs, brain, liver, spleen, kidney
Major limbs or appendages, fingers, skin
Omentum
Eyes

Question 23

Who is susceptible to sepsis?

Answer 23

Infants and immunosuppressed
Primary or secondary malnourished
Cancer patients with or without treatment
Diabetics
Hospitalised
Elderly

Question 24

How does something propagate to systemic infection?

Answer 24

Infective dose
Site = vascular or avascular (synovial cf meninges cf pancreatic abscess)
Duration of contact/local drainage
Immune system competence (inflammatory response, cellular and humoral immunity)

Question 25

How do you diagnose the cause of an infection? Recognition

Answer 25

Culture - take a sample to determine bacteria, viral or fungal
Blood - 60ml volume with sterile technique, high temperature is immaterial
Infected portal or space
Minimise blind treatment unless critically unwell

Question 26

What surgerical therapies can be done at portal of entry or nodes of infection?

Answer 26

Excision and drainage
Thromboectomy
Removal of infected source
Removal on infected prosthesis, line etc
Use antibiotics in conjunction with and not as an alternative to, local measures (won’t work if pus is presented in clots)

Question 27

Which pathogens cause systemic infection?

Answer 27

Bacteria - common systemic infection with specific Antimicrobial therapies
Viral - uncommon systemic infection generally non-specific therapies
Yeasts and fungi - very uncommon systemic infection specific but often ineffective therapies
Protozoans eg malaria - exceedingly common globally, specific therapy

Question 28

What are the general principles of treating patients with systemic infection?

Answer 28

ABCDE approach (resus) - airway compromise? Significant trismus, floor-of-mouth swelling or difficulty breathing, transfer to hospital as an emergency
SEPSIS = an emergency situation requiring immediate care (phone 999, apply oxygen, legs elevated)
Regular antipyretic can be helpful
Anti-infective treatment (see next)

Question 29

What are the principles of anti-infective therapy?

Answer 29

Ideal = targeted therapy with specific agent OR appropriate combination
Monitored response - clinical, microbiological, inflammatory biomarkers
Intravenous dosing - if evidence of sepsis, systemic compromise. Patients unable to swallow.
Drug penetration of all affected systems
Within therapeutic window
Minimised adverse effects
Appropriate treatment and monitoring interval

Question 30

Why might antibiotic drug combinations be used?

Answer 30

May allow lower doses to be used
Used to achieve ‘total kill’ or avoid development of resistance

Question 31

Why are antibiotic drug combinations not used?

Answer 31

Might increase risk of adverse reactions

Question 32

What are the different combination effects of combining antibiotics?

Answer 32

Additive
Synergistic (eg penicillin and aminoglycoside)
Antagonistic (eg penicillin and tetracycline)

Question 33

What drug-drug interactions of antibiotics are there that could be encountered in dental practice?

Answer 33

Most antibacterial will affect INR control in patients on warfarin (increased risk of bleeding or reduced thromboprophylaxis)
Macrolides (clarithromycin) increase plasma concentration of carbamezepine (risk of toxicity)
Metronidazole when given with alcohol will cause a disulfiram-like reaction

Question 34

Where do you get guidance on the antibiotics?

Answer 34

SDCEP