Two landmark international studies led by Prof Ignacio Martin-Loeches from the School of Medicine, Trinity College Dublin and St James’s Hospital, Dublin, have been recently published in the journals The Lancet and Nature Medicine, placing Irish critical care research firmly on the global stage.
Prof Martin-Loeches, who this year became the first Academic Professor of Intensive Care Medicine at Trinity College Dublin after being a Clinical Professor for some years, is also a clinician scientist, leading major research programmes that bridge bedside care and advanced science to improve outcomes for critically ill patients.
The Lancet paper, ‘Community Acquired Pneumonia’, reframes community- acquired pneumonia (CAP) as a medical emergency, not a routine infection. CAP is among the world’s leading causes of hospitalisation and death, responsible for around two million deaths every year. In Ireland, it is one of the most common reasons for emergency admission — especially among older adults and those with existing health problems.
“Every winter, our emergency departments are flooded with pneumonia cases,” said lead author Prof Martin- Loeches. “Many patients need high-level monitoring or ventilation, but our hospitals are chronically overcrowded, and ICU capacity is extremely limited. That delay in getting to the right level of care can cost lives.” Ireland has about six ICU beds per 100,000 people, compared with 30 in Germany and 10-to-12 in the UK — among the lowest rates in Europe. This shortage means Irish ICUs often run at full capacity, forcing hospitals to care for some critically ill patients in emergency rooms or general wards.
The Lancet paper calls for faster recognition, better diagnostics, and personalised treatment pathways. It
also highlights that pneumonia survivors remain at risk of heart attacks, strokes, and prolonged fatigue well after discharge.
The Lancet study also addresses the escalating problem of antibiotic overuse in the community. “GPs are under enormous pressure,” said Prof Martin-Loeches. “Patients often come in expecting an antibiotic, especially in winter. But many infections are viral, and antibiotics simply won’t help.
“We have to support, not criticise, our GPs. They’re working under intense time pressure and with limited diagnostic resources. Giving them access to rapid molecular or biomarker- based tests would make a huge difference — it would help them confirm bacterial infections and prescribe confidently while protecting antibiotic effectiveness.”
In the companion Nature Medicine study, Prof Martin-Loeches and an international team uncovered how the immune system breaks down in sepsis and critical illness.
Analysing over 7,000 blood samples from patients with sepsis, Covid-19, trauma, and burns, they identified two key immune failure patterns — myeloid overactivation, and lymphoid suppression.
Their new model, called Hi-DEF, functions like an ‘immune ECG’, showing whether a patient’s immune system is overactive or exhausted.
“For decades, we’ve treated sepsis as one disease,” said Prof Martin-Loeches. “In reality, each patient’s immune system behaves differently. Understanding these patterns helps us choose the right therapy at the right time.”
The study also revealed that certain immune profiles respond better to anti- inflammatory drugs like anakinra, while others may be harmed by steroids — a breakthrough that could guide more precise, safer treatments in the future.
“Having two Irish-led studies published in The Lancet and Nature Medicine is a major milestone for Trinity and for Irish critical care,” said Prof Martin-Loeches.
“But it’s also a reminder of the challenges we face — overcrowded hospitals, limited ICU capacity, and the enormous daily pressure on GPs and emergency staff. Pneumonia and sepsis are time-critical emergencies, and we need to make sure patients in Ireland can access the level of care they deserve.”
