Case study: Trial to examine quicker diagnostic test for hospital-acquired pneumonia patients

Researchers are investigating whether intensive care patients suffering from hospital-acquired pneumonia could have the correct pathogen identified in just over an hour, thanks to a clinical trial supported by the NIHR.

 

Hospital-acquired pneumonia (HAP) is an infection of one or both lungs, which causes the sufferer to have difficulty breathing. It is usually caused by bacteria and, by definition, occurs 48 hours or more after hospital admission.

 

Ventilator-associated pneumonia (VAP) is a type of HAP that occurs in ventilated patients. Intensive care patients are particularly prone to HAP and VAP, which have a mortality of 30-70% and add 7-9 days to the survivor’s hospital stay. 

 

The INHALE study, led by UCL and UEA, is looking at a new test that  can detect and distinguish between more than 25 types of bacteria and viruses that commonly cause HAP/VAP. Early knowledge of the pathogens responsible could help doctors treat the conditions more quickly and accurately, promoting better outcomes and better ‘antibiotic stewardship’.

 

Vicky Enne, Senior Research Fellow at UCL, explained: “Usually, when it looks as though someone is developing HAP or VAP, standard care is that they have a culture sent off to a lab. While waiting two or three days for the result, their doctors then will prescribe empirical “best guess” antibiotics.

 

“These antibiotics may not, however, be the right antibiotics for the type of bacteria causing the pneumonia. This can mean that the treatment is not effective.  Or – more often – that the patient gets a very broad-spectrum antibiotic which disturbs their gut flora, selecting resistance. This will mean there are fewer options for the treatment of infections in the future.

 

“The new test can identify bacteria and critical antibiotic resistances in just over an hour, which has the potential to make a big difference.”

 

In the trial, which began recruitment in autumn 2019, patients are randomised to either receive standard care or to the new diagnostic test. Researchers are looking at whether patient outcomes are improved by the test and if antibiotic stewardship is improved, with less inappropriate and wasteful use. Linked work, as part of the same NIHR-funded research programme, explores the cost-effectiveness of the test, and what behaviours guide antibiotic prescribing using the test.

 

With the onset of the COVID-19 pandemic in March 2020, the trial was suspended. When it restarted as part of the NIHR's Managed Recovery Programme in August 2020, the decision was made to include COVID-19 patients, as they will be part of ICU caseload for the foreseeable future. Severely ill COVID-19 patients are vulnerable to secondary HAP and VAP due to the prolonged ventilation and intensive-care stays. 

 

Under the Managed Recovery Programme, NIHR is working in partnership with UKRD, the devolved administrations, and other stakeholders. The aim is to ensure that targeted support enables rapid recovery of selected studies, such as INHALE, across a range of conditions. The programme builds on the success of research and learnings during the pandemic.

 

“We’ve now recruited 558 people across 14 sites in all,” adds Vicky, “University College London Hospitals NHS Foundation Trust was the highest recruiter, with 140.”

 

In North Thames, the Royal Free Hospital NHS Foundation Trust and Great Ormond Street Hospital for Children NHS Foundation Trust also took part in INHALE. Provisional results from the trial are expected in March 2022.