The ICU: Where Lethal Pathogens Lurk - Part 2

Read part one here.

Superfungi and Viruses Wafting About the ICU

Antibiotic-resistant bacteria are hardly the only pathogens posing a grave danger in the ICU. Critical-care patients are also at high risk for resistant fungal infections such as aspergillosis, often spread when spores are launched airborne during hospital construction.

Among ICU patients, the incidence of infectious aspergillosis is an estimated 7%, with a mortality rate in the hospital of 46% and an average cost per patient of $76,235.

Thanks to medical advances, ICU patients are living longer, American researchers observed, but “these patients are at the same time more susceptible to aspergillosis.”

ICU patients are also highly vulnerable to viruses.

As another American team observed, medical and neonatal ICUs are at increased risk for nosocomial outbreaks of influenza, “which are characterized by abrupt onset and rapid spread.”

While improving vaccination rates could help prevent the spread of influenza in the ICU and elsewhere, vaccination can only do so much.

Among influenza patients admitted to an ICU during an 11-week outbreak in the Netherlands, 40% of the patients died, and among those, one-fourth were vaccinated. The researchers estimated vaccine effectiveness at 42% to 53%.

Norovirus is also of concern among critical-care patients. After a newborn in a Texas NICU developed norovirus, other infants showed symptoms within 24 hours. Within 12 days, the virus had struck 28 babies and 12 hospital workers, a reminder that healthcare staff, too, are at risk when infectious microbes waft about the hospital.

Hand Hygiene and Surface Cleaning Fall Short in the ICU

The cornerstones of prevention have always been hand hygiene and surface cleaning. Yet these strategies rely on the skill and attentiveness of human beings, and humans are fallible.

Cleaning crews can only accomplish so much in the time they have, and crews may not possess the training, supplies, or financial incentives to do the best possible job, loads of research shows.

Similarly, even the most dedicated healthcare workers engage in automatic, unconscious behaviours that inadvertently allow for the spread of pathogens.

You might think hand-hygiene compliance would be particularly high in the ICU, given the vulnerabilities of the patients. But a groundbreaking Swiss study found otherwise. In this trial, doctors and nurses wore head-mounted cameras during morning rounds at an intensive care unit, allowing for more accurate monitoring than the typical in-person observation.

The results were troubling: Hand-hygiene compliance ranged from 1% to 5%.

The researchers found healthcare workers’ hands deposit – and likely transmit – potentially harmful microorganisms every 4 seconds onto patients and surfaces.

“People often are unaware of what exactly their hands do while they are focused on the main task goal,” the researchers observed.

Furthermore, doctors and nurses sustained hand rubbing for a median of 11 seconds, far short of the recommended 20 to 30 seconds.

Studies conducted via observation rather than video camera also show hand hygiene to be inadequate in the ICU.

An Irish review of 61 such studies found that compliance among ICU nursing staff was 43.1% and among physicians, just 32.6% — both “notably lower than international targets.”

Destroying Airborne Pathogens in the ICU

The data are clear: hand hygiene and surface cleaning, no matter how well-executed, will not suffice to slow, let alone halt, the massive infection crisis facing intensive care units.

Pathogens must also be removed directly from the air before they can settle on surfaces, contaminate healthcare workers’ hands, or be inhaled by patients.

Airborne transmission of infection is especially common in the ICU, for a number of reasons. Airflow in the ICU is rarely constant, due to the uneven placement of vents and the way beds are partitioned. Movement of staff, visitors, access doors, and privacy curtains also can influence air currents, dispersing harmful microbes throughout the unit.

As an American and Greek team concluded, “Infection control measures [in the ICU] should include airborne, droplet and contact precautions.”

The most effective precaution for airborne transmission in the ICU is the installation of ultra-low energy plasma technology by Novaerus. The technology is safe for 24-hour use around the most vulnerable patients and is proven to destroy the very pathogens that most commonly cause infection in the ICU.

For example, testing shows Novaerus units reduce MRSA by 99.99% over four hours and C. difficile by 99.9% after 40 minutes.

Air dis-infection will go a long way toward protecting ICU patients and staff while contributing to the global fight against superbugs.