Infection control & patient safety: practice questions with explanations

1Standard precautions and the chain of infection

Infection spreads along a chain: an infectious agent, a reservoir, a portal of exit, a mode of transmission, a portal of entry and a susceptible host. Breaking any link stops the spread. Hands are the most common mode of transmission in hospitals, so hand hygiene is the single most important measure.

Standard precautions apply to every patient, every time:

• Hand hygiene at the WHO five moments. Alcohol rub takes about 20–30 seconds; soap and water about 40–60 seconds and is needed for visibly dirty hands, C. difficile and norovirus.
• PPE chosen for the expected exposure: gloves for blood and body fluids, a gown and eye protection if splashes are likely.
• Safe sharps: no recapping, a sharps container at the point of use, replaced at the fill line.
• Respiratory hygiene, safe injection practice (one needle, one syringe, one time) and clean equipment between patients.

Gloves never replace hand hygiene: clean your hands before putting gloves on and after taking them off.

2Transmission-based precautions

For known or suspected infections, extra precautions are added to standard precautions. Typical examples (follow local policy for details and duration):

• Contact (gown and gloves, dedicated equipment): MRSA, VRE, C. difficile (sporicidal cleaning, soap and water), norovirus, scabies, lice, RSV, many wound infections.
• Droplet (surgical mask within close range, single room or cohorting): influenza, pertussis, Neisseria meningitidis (until 24 hours of effective antibiotics), mumps.
• Airborne (fit-tested N95 respirator, negative-pressure room with the door closed): tuberculosis, measles, varicella and disseminated zoster (airborne plus contact).

During transport, the patient on droplet or airborne precautions wears a surgical mask, and the receiving department is warned. Staff caring for measles or varicella should be immune.

A protective environment is the reverse: positive pressure and filtered air for severely immunocompromised patients, with no fresh flowers or plants.

PPE is put on in this order: gown, mask or respirator, eye protection, gloves. It comes off with gloves first, then eye protection, gown and mask or respirator last; a respirator is removed outside the room. Clean your hands at the end and whenever they become contaminated.

3Sterile technique

Sterile technique keeps all microorganisms away from a sterile site. A few rules cover most questions:

• Sterile touches only sterile. If in doubt, it is not sterile.
• The outer 2.5 cm (1 inch) of a sterile field is non-sterile.
• Keep sterile items above the waist and in sight; never turn your back on a sterile field or reach across it.
• Open the flap furthest away from you first and the nearest flap last.
• Moisture soaking through a drape (strike-through) contaminates the field.
• When putting on sterile gloves, the bare hand touches only the inside of the first glove; the gloved fingers go under the cuff of the second.
• A contaminated item, such as a catheter tip that touches the thigh, is replaced, never wiped.

4Falls, restraints and the environment

Falls. Use a fall risk tool such as the Morse Fall Scale (higher score, higher risk). Combine measures.

Use a low bed with the brakes locked, the call light and walking aid within reach, scheduled toileting, nonslip footwear, a night light and a review of sedating medicines. Four raised side rails can act as a restraint and cause worse falls.

Restraints are a last resort, used only to prevent immediate harm, never for convenience. Try alternatives first.

Restraints need a time-limited order according to policy (no “as needed” orders), a quick-release knot tied to the bed frame (not the side rail), a two-finger fit, and frequent checks of circulation, skin, fluids and toileting.

Fire. RACE: Rescue, Alarm, Contain (close doors), Extinguish or Evacuate. To use an extinguisher, PASS: Pull, Aim at the base, Squeeze, Sweep. Move patients horizontally behind fire doors first, and do not use elevators. Oxygen makes fires burn faster, so there are no flames near it.

Radiation and hazardous drugs. Time, distance and shielding limit radiation exposure; pregnant staff are not assigned to patients with radioactive implants. Chemotherapy spills are handled with a spill kit and PPE.

5Medication safety

Check the rights of medication administration before every dose: right patient, drug, dose, route and time, right documentation, and also right reason, right response and the patient’s right to refuse.

• Identify the patient with two identifiers, such as full name and date of birth, never the room number.
• High-alert medications (insulin, anticoagulants, opioids, concentrated electrolytes, chemotherapy) cause the most harm when errors happen. Use independent double checks and smart pump limits.
• Avoid error-prone writing: no “U” for units, no trailing zero (5 mg, not 5.0 mg) and always a leading zero (0.5 mg, not .5 mg).
• Tall Man lettering (hydrOXYzine, hydrALAZINE) helps tell look-alike names apart. Read back verbal orders.
• Prepare medicines for one patient at a time, never share insulin pens, and use oral syringes for oral liquids.
• Reconcile medications at every transition of care.

A just culture encourages reporting of errors and near misses so that systems can be fixed, while reckless behavior is still addressed. If an error reaches a patient, assess the patient first, then inform the prescriber and report it.

6A worked example

Think about infection control and patient safety together.

7Common mistakes

• Giving an N95 to the patient for transport; the patient wears a surgical mask, the staff wear respirators.
• Using alcohol rub after C. difficile or norovirus instead of soap and water.
• Taking off a respirator inside the room of a patient on airborne precautions.
• Wiping a contaminated sterile item instead of replacing it.
• Tying a restraint to the side rail or using restraints for staff convenience.
• Overriding a barcode or smart pump alert without finding out why it appeared.

In exam questions, look for the option that protects the most people from the most likely harm, and do it first.