Respiratory illness in the immunocompromised has a wide differential. Consider seeking specialist advice from respiratory medicine/infection specialist. 

Recommended initial investigations are listed below, but sputum has a low sensitivity for diagnosing opportunistic infections.Deep sampling will likely be required, such as induced sputum or bronchoalveolar lavage. Liaise early with physiotherapy/respiratory teams.

Initial investigations

Send prior to discussion with infection specialist. 

Sputum, send four samples:

  • Sputum for culture; TRAK as 'C&S-Respiratory (Routine Bacteriology)'
  • Sputum for atypicals; TRAK as 'Respiratory Sputum (Inc Atypicals)
  • Sputum for TB (and other Mycobacteria); TRAK as 'Mycobacteria TB Ix respiratory'
  • Sputum for mycology; TRAK as 'Mycology FUNG Ix  respiratory'

Viral throat swab:

  • Swab throat and nose at same time with single swab, send in viral transport medium.                                                            TRAK as 'Resp Virus Screen

Blood tests:

  • HIV test
  • CMV IgG (clotted tube) and consider CMV PCR on blood (EDTA tube)
  • Other mycology: consider fungal biomarkers (beta-D Glucan, galactomannan, Aspergillus precipitans).

Pneumocystis pneumonia treatment recommendations

Treatment should be done in conjuction with an infection specialist. Do not treat PCP empirically unless under specialist guidance. 

Assess severity

Mild: PaO2 >11 kPa

Mild-moderate: PaO2 9.4 – 11

Moderate-severe: PaO2 8 – 9.3 kPa

Severe: PaO2 <8 kPa OR SaO2 <91% on air (assuming normal lung function)

Treatment duration

Recommended total duration: 21 days (total duration = IV + oral)

Co-trimoxazole 120mg/kg/day for 3 days in 3 divided doses 

1ml of IV cotrimoxazole contains 96mg of co-trimoxazole.

Co-trimoxazole 90mg/kg/day for 18 days in 3 divided doses

Round to nearest 480mg when switching to oral.

Mild and mild-moderate disease can be treated with the same dose orally

If co-trimoxazole not tolerated:

Clindamycin 600mg every 8 hours orally (if oral route unavailable: 900mg every 8 hours IV)

PLUS

Primaquine 15mg daily orally

Assess need for steroids

Corticosteroid therapy is of benefit in severe or moderate-severe disease if started within 72 hours of starting anti-PCP therapy:

Prednisolone:

Day 1-5: 40mg twice daily

Day 6-10: 40mg daily

Day 11-21: 20mg daily

If oral route unavailable IV Methylprednisolone at 75% of prednisolone dose.