9.2 Sepsis, Tuberculosis, HIV, and Multidrug-Resistant Organisms
Key Takeaways
- The sepsis one-hour bundle is: measure lactate, obtain blood cultures before antibiotics, give broad-spectrum antibiotics, begin 30 mL/kg crystalloid for hypotension or lactate at least 4 mmol/L, and start vasopressors if the mean arterial pressure stays below 65 mmHg.
- Active pulmonary tuberculosis requires an airborne infection isolation room at negative pressure with 12 or more air changes per hour and a fit-tested N95 respirator; the patient wears a surgical mask, never an N95, when leaving the room.
- Rifampicin turns urine, sweat, and tears orange-red and permanently stains soft contact lenses; isoniazid causes peripheral neuropathy that pyridoxine prevents; ethambutol causes optic neuritis with loss of red-green discrimination.
- In HIV, the CD4 count predicts opportunistic infection risk while the viral load measures treatment response; a CD4 count below 200 cells/mm³ marks the threshold for Pneumocystis prophylaxis.
- Multidrug-resistant organisms are controlled by contact precautions, dedicated equipment, environmental cleaning, and antimicrobial stewardship; Clostridioides difficile additionally requires soap-and-water handwashing and a sporicidal cleaning agent.
9.2 Sepsis, Tuberculosis, HIV, and Multidrug-Resistant Organisms
Infectious disease items test three separate competencies: recognising deterioration early, containing transmission correctly, and managing long antimicrobial regimens with distinctive toxicities. Each has its own set of numbers, and examiners expect you to know them precisely.
The Sepsis Continuum
Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is sepsis with persisting hypotension requiring vasopressors to maintain a mean arterial pressure of at least 65 mmHg, together with a lactate above 2 mmol/L despite adequate fluid resuscitation.
Early recognition relies on pattern rather than a single value. Bedside triggers include new confusion, respiratory rate of 22 or more, systolic blood pressure of 100 mmHg or less, temperature above 38 °C or below 36 °C, heart rate above 90, reduced urine output, and mottled or poorly perfused skin. In older adults, new confusion alone may be the only presenting sign, and a neutropenic or immunosuppressed patient may be afebrile and normotensive until they collapse.
The one-hour bundle is the deliverable, and the order within it matters:
- Measure lactate, and remeasure if the initial value is above 2 mmol/L.
- Obtain blood cultures before administering antibiotics.
- Administer broad-spectrum antibiotics.
- Begin rapid crystalloid at 30 mL/kg for hypotension or a lactate of 4 mmol/L or more.
- Start vasopressors — noradrenaline (norepinephrine) first line — if the patient remains hypotensive during or after fluid resuscitation, targeting a MAP of at least 65 mmHg.
Lactate is a marker of anaerobic metabolism and tissue hypoperfusion; a rising lactate despite resuscitation signals ongoing shock. Nursing monitoring centres on hourly urine output as a real-time perfusion gauge, continuous vital signs, mental status, capillary refill, and vigilance for the disseminated intravascular coagulation that complicates severe sepsis.
Tuberculosis
Screening and diagnosis. The tuberculin skin test is read at 48 to 72 hours by measuring the induration, not the erythema. Induration of 5 mm or more is positive in HIV infection, recent close contacts, and the immunosuppressed; 10 mm or more in healthcare workers, recent migrants from high-incidence countries, and people with diabetes or chronic kidney disease; 15 mm or more in people with no risk factors. A previously BCG-vaccinated patient may test positive on skin testing, which is why an interferon-gamma release assay is often preferred in migrant populations common across Qatar's workforce. A positive test indicates infection, not active disease: chest radiography and sputum for acid-fast bacilli distinguish latent from active tuberculosis.
Isolation. Active pulmonary or laryngeal tuberculosis requires an airborne infection isolation room — negative pressure relative to the corridor, at least 12 air changes per hour in new construction, exhausted outside or through HEPA filtration, with the door kept closed. Staff wear a fit-tested N95 respirator or higher, donned before entering. When the patient must leave the room for an essential procedure, the patient wears a surgical mask, not an N95, because a surgical mask contains their exhaled droplet nuclei while allowing them to breathe comfortably.
Drug therapy (RIPE). Directly observed therapy is the standard where adherence is uncertain, because incomplete treatment is what creates resistance.
| Drug | Signature adverse effect | Nursing teaching |
|---|---|---|
| Rifampicin | Orange-red discoloration of urine, sweat, tears; hepatotoxicity | Harmless discoloration but permanently stains soft contact lenses; reduces oral contraceptive efficacy — advise an additional method |
| Isoniazid | Peripheral neuropathy; hepatotoxicity | Give pyridoxine (vitamin B6) to prevent neuropathy; avoid alcohol; report jaundice or dark urine |
| Pyrazinamide | Hyperuricaemia, arthralgia; hepatotoxicity | Encourage fluids; report joint pain |
| Ethambutol | Optic neuritis | Baseline and periodic visual acuity and red-green colour discrimination; report any visual change immediately |
A patient is generally considered non-infectious after clinical improvement on effective therapy with the required number of consecutive negative sputum smears, per local protocol — not simply after a fixed number of days.
HIV Infection
The two numbers. The CD4 T-lymphocyte count predicts susceptibility to opportunistic infection; the viral load measures how well antiretroviral therapy is suppressing replication. Treatment success looks like a rising CD4 count and an undetectable viral load.
| CD4 count | Clinical significance |
|---|---|
| > 500 cells/mm³ | Normal range; usual infections |
| 200–499 cells/mm³ | Increasing risk: candidiasis, herpes zoster, tuberculosis |
| < 200 cells/mm³ | AIDS-defining threshold; start Pneumocystis jirovecii prophylaxis |
| < 100 cells/mm³ | Toxoplasmosis risk |
| < 50 cells/mm³ | Mycobacterium avium complex and cytomegalovirus risk |
Nursing priorities: adherence support, because intermittent antiretroviral therapy breeds resistance; monitoring for the metabolic, renal, hepatic, and haematological toxicities of therapy; nutritional support; and careful confidentiality. Standard precautions apply to all patients and are sufficient for routine HIV care; no additional isolation is required unless a co-infection such as tuberculosis demands it.
Occupational exposure is a recurring exam scenario. After a needlestick: wash the site with soap and water immediately (do not squeeze or use caustic agents or bleach), irrigate mucous membranes and eyes with water or saline, report to occupational health immediately, and begin post-exposure prophylaxis as soon as possible, ideally within hours, following source-patient testing. Hepatitis B immunoglobulin and vaccination are considered separately depending on immune status.
Multidrug-Resistant Organisms
| Organism | Precautions | Distinctive point |
|---|---|---|
| MRSA | Contact | Decolonisation protocols may be used pre-operatively |
| VRE | Contact | Environmental persistence is high; dedicate equipment |
| ESBL and CRE Gram-negatives | Contact | Very limited treatment options; strict stewardship |
| Clostridioides difficile | Contact + private room | Soap-and-water handwashing — alcohol does not kill spores; sporicidal (chlorine-based) cleaning |
| Candida auris | Contact | Persists on surfaces; requires specific disinfectants |
Antimicrobial stewardship is a nursing responsibility, not only a pharmacy one: ensure cultures are taken before the first dose, prompt review for de-escalation from broad to narrow spectrum once sensitivities return, question unnecessarily prolonged courses, and champion intravenous-to-oral switch when the patient is stable.
Regionally Relevant Exposures
Practising in Qatar means keeping two additional exposures in mind. MERS-CoV is endemic in the Arabian Peninsula and is associated with dromedary camel contact and the consumption of raw camel milk; suspected cases require airborne plus contact precautions with eye protection, and prompt notification to public health authorities. Imported infections are common in a highly mobile expatriate population: malaria, dengue, typhoid, and viral hepatitis should be considered in any febrile traveller, which makes a careful travel history part of the standard febrile assessment rather than an optional extra. Notifiable disease reporting to the Ministry of Public Health is a legal obligation and forms part of the nurse's role in the chain of surveillance.
A patient on a medical ward has a temperature of 38.9 °C, a heart rate of 118, a respiratory rate of 26, a blood pressure of 88/50 mmHg, and new confusion. The initial lactate is 4.6 mmol/L. Which set of actions correctly reflects the sepsis one-hour bundle?
A patient with sputum-positive pulmonary tuberculosis in an airborne infection isolation room requires transfer to the radiology department for a chest radiograph. Which action by the nurse is correct?
A patient starting four-drug tuberculosis therapy asks the nurse why an additional vitamin has been prescribed alongside the isoniazid, and reports that their urine has turned orange since starting treatment. How should the nurse respond?