Respiratory tract infections(Diagnosis and Management )

Question 1

what is pneumonia

Answer 1

an infection that inflames the air sacs in one or both lungs, potentially causing them to fill with fluid or pus. It can be caused by bacteria, viruses, or fungi.

Question 2

categories or types of pneumonia

Answer 2

community acquired pneumonia(CAP)
hospital acquired pneumonia(HAP)
aspiration pneumonia
ventilator associated pneumonia (VAP)

Question 3

give a summary of what you know about the pathogenesis of pneumonia

Answer 3

in pneumonia, bacterial, fungal or viral pathogens are inhaled or aspired

these pathogens invade the lower respiratory tract(mainly the alveoli), if the defense mechanism in the upper respiratory trract is unable to deal with them.

the immune system responds to the infection by initiating an inflammatory response, filling the alveoli with pus, inflammatory cells..etc

Lungs harden as a result.

note that the opaque are on a chest X ray may indicate pneumonia. because the lungs are normally clear on the chest X ray

Question 4

symptoms of pneumonia

Answer 4

sputum production
breathlessness and wheezing
chest pain
fever
sore throat
signs on a CXR that may indicate pneumonia

Question 5

how do we diagnose pneumonia

Answer 5

patient’s symptoms(i.e typical LTRI symtpoms) with new consolidation on a CXR

assess the patients oxygen saturation

carrying out tests, mainly** CRP**, FBC, U&E and LFTs

microbial tests(sputum and blood cultures & urine legionalla and pneumococcal antigen)

using the severity scores for pneumonia (CRB-65/ CURB-65)

LTRI= lower respiratory tract infection

Question 6

for people presenting with symtpoms of a LTRI but without a clinical diagnosis of pneumonia, what do we do with relation to antibiotic prescribing, if CRP is;
<20mg/L
>=20mg/L
> 100mg/L

Answer 6

do not routinely offer antibiotic therapy
consider delayed antibiotic prescription
offer antibiotic therapy

Question 7

difference between CRB-65 score and CURB-65 score

Answer 7

CRB-65 and CURB-65 are both scoring systems used to assess the severity of community-acquired pneumonia (CAP) and determine the need for hospitalization, but CRB-65 is a simplified version of CURB-65. CRB-65 omits the blood urea nitrogen (BUN) measurement, making it easier to use in settings where laboratory testing is not readily available.

Question 8

the four factors for which a point is awarded (each) in CRB65

Answer 8

confusion
respiratory rate>= 30/min
blood pressure (systolic <90mmHg &/or diastolic<= 60mmHg)
age> 65years

Score 0 = low risk (<1% mortality risk)
Score 1 or 2 = intermediate risk (1 – 10% mortality risk)
Score 3 or 4 = high risk (>10% mortality risk)

Question 9

what do we do if the CRB65 score is 2 or more

what about if the score is 0

Answer 9

consider hospital assessment

make a home based decision

Question 10

what should be done within four hours of confirming a diagnosis of CAP in hospitalised patients

what if sepsis is indicated for this patient

Answer 10

start antibiotic treatment

start antibiotic treament within an hour

Question 11

the important factors for which points are awarded in CURB65

Answer 11

Confusion (AMT 8 or less)
Urea >7mmol/L
Respiratory rate ≥30/min
Blood pressure systolic <90mmHg and/or diastolic ≤ 60mmHg
Age >65years

0 or 1: low risk (less than 3% mortality risk)
2: intermediate risk (3-15% mortality risk)
3 to 5: high risk (more than 15% mortality risk)

Question 12

CAP can be caused by a variety of organisms, but which organism is the most common cause of it in the UK

Answer 12

Streptococcus
pneumoniae

Question 13

how do we proceed if someone has these CURB65 scores;
under 1

2-3

3 or more

Answer 13

Consider home-based care for people with a CURB65 score of 0 or 1
Consider hospital-based care for people with a CURB65 score of 2 or more
Consider intensive care assessment for people with a CURB65 score of 3 or more

Question 14

how do we treat low risk CAP

Answer 14

Offer a 5-day course of a single antibiotic to patients with low-severity community-acquired pneumonia

Question 15

first choice antibiotic for low risk CAP in adults, if no penicillin allergy

Answer 15

amoxicilin 500mg TDS for 5 days

Question 16

if amxocillin is unsuitable or if penicillin allergy, what are the alternatives for moderate severity CAP

Answer 16

doxycycline 200mg on the first day then 100mg once a day for 4 days
or
Clarithromycin 500mg twice a day for 5 days
or
erythromycin 500mg four times a day for 5 days

clarithromycin and doxycycline are to be avoided in pregnancy, so erythromycin is used as the alternative if patient is pregnant or could get pregnant

also note that clarithromycin and erythromycin could be used as first line treatments instead of amoxicillin in moderate CAP

Question 17

first choice antibiotic for high severity CAP if no penicillin allergy

Answer 17

Co-amoxiclav 500/125 mg three times a day orally or 1.2 g three times a day
plus
Clarithromycin 500 mg twice a day orally or intravenouslly for 5 days
or
Erythromycin 500 mg four times a day orally for 5 days

Question 18

for patients with high severity CAP and penicillin allergy which antibiotic is used

Answer 18

Levoflaxacin 500mg twice daily orally or intravenously for 5 days

Question 19

if amxocillin is unsuitable or if penicillin allergy, what are the alternatives for low severity CAP

Answer 19

Doxycycline 200 mg on first day, then 100 mg once a day for 4 days (5-day course in total)
Clarithromycin 500 mg twice a day for 5 days
Erythromycin
(in pregnancy) 500 mg four times a day for 5 days

Question 20

first choice for moderate severity CAP in patients with no penicillin allergy

Answer 20

Amoxicillin 500 mg three times a day for 5 days, PLUS ONE of the following 2 options if atypical pathogens suspected

clarithromycin 500 mg twice a day for 5 days
OR
erythromycin(in pregnancy) 500 mg four times a day for 5 days

Question 21

some predisposing features of HAP

Answer 21

Stroke
Mechanical ventilation
Chronic lung disease
Recent surgery
Immunosuppression
Previous antibiotics
Alcohol dependence & smoking
Diabetes

Predisposing factors are inherent characteristics or variables that increase an individual’s vulnerability or risk for developing a specific condition or illness.

Question 22

what are the diagnostic criteria for HAP

Answer 22

• Purulent sputum
• New/progressive infiltrates on CxR which is
  otherwise unexplained
• Increased O2 requirement
• Temp >38.4⁰C or <36⁰C
• Leucocytosis (>10000 leucocytes/mm3) or
  leucopenia (<4000/mm3)

Question 23

treatment for HAP

Answer 23

Offer antibiotic therapy as soon as possible after
diagnosis, and certainly within 4 hours (or 1 hour if
features of sepsis)

✓ Choose antibiotic therapy in accordance with local
hospital policy (which should take into account
knowledge of local microbial pathogens) and clinical
circumstances for patients with hospital-acquired
pneumonia

✓ Consider a 5-day course of antibiotic therapy for
patients with hospital-acquired pneumonia, review at 5
days and stop if clinically stable

Question 24

first line antibiotic for non-severe HAP and those not at higher risk of developing antibiotic resistance

Answer 24

Co-amoxiclav 500/125 mg three times a day for 5 days then review

Question 25

Alternative oral antibiotics for non-severe symptoms of HAP or signs and not at higher risk of resistance, if penicillin allergy or if co-amoxiclav unsuitable.

Answer 25

Doxycycline 200 mg on first day, then 100 mg once a day for 4 days (5-day course) then review or Cefalexin (caution in penicillin allergy) 500 mg twice or three times a day (can be increased to 1 to 1.5 g three or four times a day) for 5 days then review or Co-trimoxazole 960 mg twice a day for 5 days then review or Levofloxacin (only if switching from intravenous levofloxacin with specialist advice) 500 mg once or twice a day for 5 days

Question 26

First-choice intravenous antibiotics for HAP if severe symptoms or signs (for example, of sepsis) or at higher risk of resistance.

Answer 26

**Piperacillin with tazobactam 4.5 g three times a day (increased to 4.5 g four times a day if severe infection)** **Ceftazidime 2 g three times a day **Ceftriaxone 2 g once a day**** Cefuroxime 750 mg three times a day (increased to 750 mg four times a day or 1.5 g three or four times a day if severe infection) Meropenem 0.5 to 1 g three times a day Ceftazidime with avibactam 2/0.5 g three times a day **Levofloxacin (only if other first-choice antibiotics are unsuitable) 500 mg once or twice a day (use higher dosage if severe infection)**

Question 27

name some antibiotics that can be added to treat HAP if MSRA infection is suspected or confirmed ## Footnote note these are intravenously given , as a dual therapy with the oral antibiotics that are normally given

Answer 27

vancomycin teicoplanin linezoid(if vancomycin cannot be used, specialist advice only)

Question 28

describe aspiration pneumonia

Answer 28

Pulmonary consequences resulting from the abnormal entry of fluid, exogenous substances or endogenous secretions into the lower airway

Question 29

risk factors of aspiration pneumonia

Answer 29

Excess alcohol use Hypnotic drugs General Anaesthetic Coma Poor gag reflex in people who are not alert (unconscious or semi-conscious) after a stroke or brain injury Problems with swallowing e.g. neurological deficits Mechanical disruption of glottis closure e.g. tracheostomy, intubation, NG tube

Question 30

causative organisms of aspiration pneumonia

Answer 30

| Gram-negative enteric bacilli, like; * Enterobacteriaceae * E. coli * Kl

Question 31

symptoms of aspiration pneumonia

Answer 31

cyanosis Chest pain Coughing up foul-smelling, greenish or blood-stained sputum Fatigue Pyrexia Shortness of breath Wheezing Excessive sweating Problems swallowing Infiltrates on CxR ## Footnote Cyanosis is where your skin or lips turn blue or grey

Question 32

treatment for aspiration pneumonia

Answer 32

antibiotics for 7-10days suctions to clear fluids and particulate matter appropriate hydration

Question 33

what do we not give in the treatment or prevention of pneumonia if covid-19 virus is indicated, or if another virus or a fungus is believed to be the cause of the pneumonia

Answer 33

we do not offer antibiotics

Question 34

what do we do if someone has suspected or confirmed secondary bacteria pneumonia?

Answer 34

Start antibiotic treatment as soon as possible

Question 35

what does the pneumococcal vaccine do

Answer 35

protects against infection with Streptococcus pneumoniae (pneumococcus ## Footnote Prevenar 13®, is the 13-valent PCV (pneumococcal polysaccharide conjugate) vaccine (adsorbed) used in the childhood immunisation schedule 2 doses: 1. 3 months of age 2. 1 year of age, on or after the child's first birthday

Question 36

the current vaccine recommended for those at high risk of pneumococcal infection

Answer 36

the 23-valent PPV (pneumococcal polysaccharide vaccine ## Footnote high risk individuals include; * age over 65 years or in at-risk groups aged 2 years or over * asplenia or splenic dysfunction * chronic respiratory disease, chronic heart disease; chronic renal disease; chronic liver disease; chronic neurological conditions * diabetes mellitus requiring insulin or oral hypoglycaemic drugs * immune deficiency because of disease (e.g. HIV infection) or treatment * presence of cochlear implant * conditions where leakage of CSF may occur