Download Infectious Diseases for Interns

Infectious Diseases
for Interns
19 Oct 2012
Dr Karen Lim
TNH Infectious Diseases Registrar
(with acknowledgements to Dr Raquel Cowan)
Overview
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Diagnosis
Severe sepsis – alarm bells
Management of the sick patient
Presentations of note
What to use?
Check your micro…
Diagnosis
Why worry about fever / sepsis?
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5% of ED presentations
Infection the most common cause of fever of
short duration
Overall mortality of septic shock in Australia
is about 40% emphasising the importance of
early detection
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Gram-positive septicaemia mortality is 10 – 20%
Higher in Gram-negative
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Assessment
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Methodical and thorough
Corroborative Hx from family
Vital signs
Look at all covered/hidden areas
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axilla, groin, perineum, ears, teeth, thyroid, natal cleft,
prostate…
Ask a colleague for confirmation of signs
Repeat the history and examination
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Patients are often unwell/confused/tired in ED and may not
be able to give an accurate history
Signs may evolve e.g. murmurs with endocarditis
What’s in a “septic screen”?
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Bloods: FBE, U+E, CRP, LFT
Blood cultures x 3, 20 minutes apart
CXR
Urine M/C/S
Swabs
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Wound
Respiratory
Other: ABG, lumbar puncture, ascitic tap, CT
scan
Severe sepsis – alarm
bells
Abnormal vital signs
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Tachypnoea (99%) – acidosis (metabolic
38%), impending respiratory failure
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Earliest clinical sign of sepsis regardless of site of
infection
Tachycardia > 120bpm (97%) – often
accompanied by hypotension
Hypotension < 100mmHg in adults
Temperature > 39*C in adults (70%)
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Hypothermia < 36*C (13%)
Brun-Buisson C et al. JAMA 1995: 274(12)
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Other alarm bells
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Patient presents within the first 12 hours
Profound effect on the patient
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Pallor, mottled skin and/or cold peripheries
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Inability to stand or walk
Marker of impending shock
Severe muscle and joint pain
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Early symptom
Anterior thighs
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Other alarm bells
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Rigors
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Altered conscious state or behavioural change
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Focus of infection or sign of severe sepsis
Encephalopathy 35%
Repeated vomiting in the absence of diarrhoea
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Assume bacteraemia until proven otherwise
May be a marker of bacteraemia, abdominal, CNS
pathology
Severe headache
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Can be false localising sign
Brun-Buisson C et al. JAMA 1995: 274(12)
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Beware the fever…
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Recurrent
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Unexplained rash
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Haemorrhagic, petechial, purpuric – bacteraemia
Toxic shock syndrome
Back pain or neck pain
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Things may have progressed
Non-specific to specific phase of illness
Epidural abscess
Focal pain
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Often means focal infection
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Beware the fever…
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Sore throat and/or dysphagia with normal looking
throat
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Jaundice
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Associated with increased risk of death, ICU admit, inc
LOS
Bacteraemia, cholangitis, pyogenic liver abscesses,
malaria
Abdominal pain
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Epiglottitis
Appendicitis
Recent surgery or other medical intervention
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Complication
Infectious Diseases: A clinical approach; edited by Allen Yung et al. 3rd edition 2010
Management of the sick
patient
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Admission
Fluid resuscitation
Early antibiotics
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Broad spectrum if diagnosis is unclear
Appropriately targeted antibiotics if localising
symptoms or signs
Ask for help!!!
Timely antibiotics is the key
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Kumar A et al. Crit Care Med 2006; 34:1589-1596
Effective Abx in
1st hour of
hypotension had
a survival rate of
79.9%
Each hour of
delay was
associated with
average
decrease in
survival of 7.6%
(OR 1.67; 95%
CI, 1.12-2.48)
From: Initiation of Inappropriate Antimicrobial Therapy Results in a Fivefold Reduction of Survival in Human
Septic Shock
CHEST. 2009;136(5):1237-1248. doi:10.1378/chest.09-0087
Survival dropped
fivefold from 52.0% to
10.3% (OR, 9.45; 95%
CI, 7.74 to 11.54; p <
0.0001) with
inappropriate initial
therapy
Impact of antimicrobial appropriateness on survival in major epidemiologic subgroups.
Presentations of note
Meningococcal disease
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85% meningitis, 15-20% septicaemia
Usually present < 24 hrs
May initially have systemic prodrome, before
develop specific symptoms - fever, headache,
anorexia, vomiting, myalgias, pallor
Honeymoon period
Later severe unaccustomed headache and rash
Photophobia and neck stiffness not universal
Rash may be absent or atypical
Endocarditis
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Variable clinical picture - difficult diagnosis to make
in ED
Acute - more common
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Subacute
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Staphylococcal
RF’s - IVDU, haemodialysis, lines, prosthetic valve
Systemically unwell +/- septic or cardiogenic shock
Non-specific: fevers, wt loss, anorexia
Specific: embolic phenomenon, murmur, cardiac failure,
GN
Need blood cultures prior to ABx
Epidural abscess
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Fever and back pain is a spinal infection until
proven otherwise
Severe back pain - think of epidural abscess
IVDU are at higher risk of spinal infections
Assess vital signs and neurology
Blood cultures, ABx and an urgent MRI
Call for help!
Cellulitis and Erysipelas
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Micro
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Streptococcus pyogenes (Group A Strep)
Other beta haemolytic strep
Staph aureus
Risk factors
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Trauma to skin
Skin inflammation
Lymphatic dysfunction
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Venous disease
Surgery
Malignancy
Tinea
Cellulitis
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Differential diagnoses
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DVT
Necrotising fasciitis
Lipodermatosclerosis
Bursitis
Zoster
Gout
Cellulitis - Alarm features
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Progressive systemic toxicity
Rapidly progressive erythema
Severe pain
Hypotension
Immunosuppression
Epidemiology
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Animal contact
Water contact
Travel
Cellulitis - Management
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Inpatient versus outpatient
Inpatient
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Any alarm signs
Immunosuppressed
Diabetic
Ulcers
Ischemia
Unable to walk
Shock
Unable to take oral medications
Cellulitis - Management
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Antibiotics
Gram positive organisms
 Anti-staphylococcal penicillins
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1st generation Cephalosporins
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Cephazolin, Cephalothin, Cephalexin
Allergies
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Flucloxacillin or Dicloxacillin
Clindamycin, Vancomycin, Cotrimoxazole
Other
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Wound care
Elevation
DVT prophylaxis
Diabetic feet
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Polymicrobial
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Staph, Group A Strep, Gram negatives
Need to assess:
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vascular supply
neuropathy
extent of soft tissue destruction
bone involvement
Diabetic feet
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Predictors of OM
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Further assessment
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Probe to bone (very specific)
Ulcer size > 2x2cm
Duration > 2 weeks
Soft tissue involvement: MRI
Osteomyelitis: CT
Beware necrotising fasciitis or gas gangrene
Nosocomial sepsis
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Plastic
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Surgical procedures
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IDC, drain tubes, IV cannulas, CVC, PICC, ports
Procedural complication e.g. leak, perforation, haematoma
Wound infection
Hospital acquired pneumonia
C. difficile colitis
Pressure wounds
Management
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Require broad spectrum antibiotics to cover potentially
resistant pathogens
Issues with elderly infections
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Risk factors
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Chronic and debilitating diseases
Normal physiology of aging
Alteration in immune function
History taking can be difficult
Symptoms and signs tend to be non-specific /
atypical
Several organ systems affected
Blunted clinical features
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Fever
Acute septic arthritis with chronic OA
Common things are common
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Pneumonia
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Urinary tract infection
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Bacteruria in 20% men > 70 yrs, 50% in women > 75 yrs
Look at leukocytes, erythrocytes, squamous cells
Soft tissue infection
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Be wary of diagnosing in the absence of symptoms
Pressure ulcers
Intra-abdominal infections
Bacterial meningitis
Post-operative fever
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Immediate peri-operative period
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Pre-existing infection
Intra-operative manipulation of purulent material
Febrile blood transfusion reactions
Drug reactions
Rare endocrine causes
Fever within 48 – 72 hours
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Usually self limited and not associated with infection in a
majority of patients
Cytokines and tissue damage during the procedure
The surgeon’s five
1) Urinary tract infection
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Usually enteric gram-negatives
Often related to IDC insertion or operation
Staph aureus usually indicates bloodstream infection
Remove catheter and commence empiric antibiotics
2) Surgical site infection
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1 – 5% develop wound infection, higher if pre-existing
infection at site of operation
Careful examination – superficial / deep
The surgeon’s five
3) Pneumonia
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Tachypnoea and fever
Usually aspiration
Don’t forget adequate pain management
CXR
Chest physiotherapy
4) Intravenous cannula and bloodstream infection
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Check IVCs + document everyday
Remove IVC if no longer necessary or at first signs of phlebitis/pain
Change IVCs every 72 hours (or within 24 hours if inserted during an
emergency)
5) Venous thrombosis (DVT / PE)
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Carefully examine legs
O2 sats, blood gases often worse than CXR suggest
CTPA or VQ scan
What to use?
What to use?
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Identify likely source
Consult Guidance, Therapeutic Guidelines or
friendly ID team
Don’t forget renal-adjustment (Table 2.31
intranet version)
Bacteraemia
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You won’t detect bacteraemia unless you do BC’s!
No need to wait for fever!
Ask the lab for morphology
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GPC, GNB etc
Clusters or chains for GPC
Repeat BC
ID and sensitivities take time!
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BC flags +
Gram stain
Plated
ID
Sensitivities
Revision II
Antibiotics for registrars
Basic microbiology
review
Basic microbiology
review
Gram +
GPC
Gram GPB
GNC
Neisseria
GNB
Staphylococcus
Listeria
Streptococcus
Clostridium*
- E. coli
Enterococcus
Bacillus
- Klebsiella
Corynebacterium
- Salmonella
GNCB
Coliforms
- ESCHAPPM
Haemophilus
Pseudomonas
Peptostreptococcus*
Bordetella
(Acinetobacter)
Propionibacterium*
(Acinetobacter)
Bacteroides*
* Anaerobes
(AnO2)
Bacteraemia
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GPC in BC
 Staphylococci
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S aureus (MSSA and MRSA)
S epidermidis and coagulase negative staph
Streptococci
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S pneumoniae
S pyogenes
Others: viridans, milleri etc
Enterococci
Initial ABx choice? Morphology?
 Vancomycin - severely unwell or risk of MRSA
 Anti-staphylococcal penicillins - Flucloxacillin
 1st generation Cephalosporins
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Others: Clindamycin, Cotrimoxazole, Tazocin, Cefepime, Meropenem
Bacteraemia
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GNB
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E coli, Klebsiella, Proteus mirabilis
Haemophilus
Pseudomonas
Salmonella, Typhoid, Campylobacter, Shigella
ESCAPPM:
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Enterobacter, Serratia, Citrobacter, Acinetobacter, Providencia,
Proteus vulgaris, Morganella
ESBLs (extended spectrum B-lactamases)
ABx options
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Ceftriaxone, Ceftazidime, Tazocin, Ciprofloxacin, Meropenem
Anti-pseudomonal: Timentin/Tazocin, Ceftazadime, Meropenem,
Ciprofloxacin
ESBLs: Carbapenem
ESCAPPM: Meropenem, Ceftazadime, Ciprofloxacin, Cotrimoxazole
Bacteraemia
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GNC
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GPB - Vancomycin
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Neisseria meningitidis and gonorrhoea
Bacillus
Corynebacterium
Clostridia
Anaerobes
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Oral - Penicillin
Bowel - Metronidazole
What to use?
Site of infection
Microorganisms
Therapeutic choices
Unknown source
Concern GNB, GPC
If in shock, MRSA
colonised, vascular
catheter
Febrile neutropaenia
Severe communityacquired pneumonia
Hospital-acquired
pneumonia
Intra-abdominal
Flucloxacillin
Ceftriaxone
Add in Vancomycin
GNB (esp Pseudomonas), GPC
Strep pneumoniae, H. influenzae,
Legionella, Mycoplasma
As above, E.coli, Pseudomonas,
Klebsiella, Acinetobacter
Enteric GNB, anaerobes
Tazocin +/- Vancomycin
Ceftriaxone, Azithromycin
Urinary tract infection
Skin / soft tissue
GNB, Enterococcus
Staph aureus, Strep pyogenes
CNS
N. meningitidis, Strep pneumoniae,
Haemophilus influenzae type B,
Listeria monocytogenes
Ceftriaxone or if unresponsive
Tazocin
Ceftriaxone, Ampicillin,
Metronidazole or Tazocin
Ceftriaxone
Flucloxacillin
Diabetic ulcer: Tazocin
Clindamycin for toxin
Cetriaxone (2g bd)
Benzylpenicillin 2.4g 4/24
?Moxifloxacin
Gentamicin
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Effective against Gram negative bacteria
Generally not used in The Northern Hospital
Irreversible ototoxicity, even after one dose
Reversible nephrotoxicity
Used under ID approval in rare cases
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http://www.wobblers.com/
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Check your micro…
Check the bug, check the
sensitivities
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Healthscope Microbiology
Can certainly come and bite you on the backside
Generally will know
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Gram stain within 24 hours
Organism within 24 – 48 hours
Sensitivities within 48 – 72 hours
Make adjustments to your treatment accordingly
There are usually hidden sensitivities
Extended spectrum betalactamases (ESBLs)
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Enterobacteriacae (eg. E.coli, Klebsiella etc) produce betalactamases that confer resistance to Penicillins
ESBLs also confer resistance to first, second and third
generation Cephalosporins (e.g. Cephazolin, Ceftriaxone)
Plasmid mediated
Increasing incidence
 India RR 146
 Middle East RR 18
 Africa RR 7.7
 Asia (not India) RR 3.4
Think about it if the context is relevant
Treat with Carbapenem (e.g. Meropenem)
Methicillin-resistant Staph
aureus
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Increasing problem in the healthcare system
Consider for those from
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Institutions, nursing homes
Extended hospital stays
Indigenous population, Islander population
Recurrent boil-like infections
Pseudomonas
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Gram-negative
Infections anywhere
Beware colonisation
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COPD, bronchiectasis
Skin
In serious infections do not use ciprofloxacin
alone
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Tazocin, Ceftazadime, Cefepime, Meropenem
Ciprofloxaxin is our only oral option
Antimicrobial Stewardship
at Northern Health 2012
Prescriber flow chart
Getting started
Access Guidance DS through ‘Shortcuts’ from
any networked hospital computer
Guidance DS Main Menu
Logging On
Log on using your general Northern Hospital
Username and Password
Getting Approval
Click on the drug name you want to
prescribe
Getting Approval
Enter patient UR number
Getting Approval
Confirm patient details
Getting Approval
Getting Approval
Confirm Approval
Confirm drug name and correct indication
Approval number
To be written on patient drug chart
Remember…
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History, history, history
Pain is your friend
Take notice of physical, laboratory and
imaging studies
Beware the fever and…
When in doubt… look at the therapeutic
guidelines … or ask
Other tidbits of advice…
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When in doubt, ask…
Multitask
Know what you are asking for and why
Respect the nurses
Inform the patients and their families
If concerned, call a MET call