The Intensive Care Unit (ICU) is a type of hospital ward designed to care for people with critical and potentially life-threatening illnesses. Patients in the ICU often struggle with a variety of distressing symptoms like pain, anxiety, agitation, or delirium. Managing these struggles is a key part of care in the ICU; if left untreated, they can lead to other illnesses or even death.
Researchers like Dr. Kim Lewis are exploring the success of different management methods and creating guidelines for ICU practitioners based on published studies. Dr. Lewis and other collaborators around the world recently published a new set of guidelines in the journal Critical Care Medicine.
Guidelines for Care in the ICU
It’s very common for patients with critical illnesses to experience unpleasant symptoms. While they’re often predictable side effects of a patient’s illness, the discomfort of intensive care and life support can also play a role in them. In other words, the reason why someone is admitted to the ICU can cause distress—but so can the experience of being in the ICU itself.
The Society of Critical Care Medicine (SCCM) works to mitigate these issues by publishing evidence-based clinical practice guidelines with recommendations to improve patient care and outcomes in the ICU. These PADIS (pain, agitation/sedation, delirium, immobility, and sleep disruption) guidelines also consider factors such as efficacy, feasibility, price, accessibility, and patient acceptance.
Their previous set of PADIS guidelines was published in 2018. Since then, many new studies have been published in relevant areas, leading the SCCM to assemble a panel of international experts, ICU survivors, and methodologists to develop an updated set of guidelines. Dr. Lewis was one of the international experts who worked on this project.
Dr. Lewis’ Background in Medicine and Research
Dr. Lewis is an Adult Critical Care Consultant at St. Joseph’s Healthcare Hamilton (SJHH) and a clinical epidemiologist who conducts research in critical care. In the ICU, she supports people and their loved ones during some of the hardest times of their lives, and she finds significant meaning in this.
Dr. Lewis wanted to make an even bigger difference in the world and help care for more patients than just the ones she saw day-to-day in the ICU. This led her to researching critical care to help shape how healthcare workers all over the world practice medicine in the ICU.
Updates to PADIS Guidelines
Sedation
In 2018, researchers recommended using either propofol or dexmedetomidine to sedate adult ICU patients who are mechanically ventilated when light sedation and/or decreasing delirium are high priorities for care.
Since then, the number of studies investigating sedation methods in the ICU has increased from 3 to 29; this increase in data has resulted in a better understanding of sedatives. The recent guideline update recommends that practitioners use dexmedetomidine rather than propofol for sedation as in most cases it’s more effective in sedating patients.
Delirium
Antipsychotic medications are commonly used both inside and outside the ICU to treat delirium, but there is a lack of clinical understanding of how they affect patients. The 2018 PADIS guidelines made a recommendation against using antipsychotics in this way as at the time, there was no evidence that they had any effect on delirium.
Researchers have since conducted studies showing that antipsychotics are effective in decreasing delirium in patients, and that curiously, despite no other correlations with health markers such as how long patients received mechanical ventilation or how long they stayed in the hospital, these medications were possibly associated with lower patient mortality.
With no clear explanation as to why antipsychotic drugs are correlated with lower patient mortality, the panel updating the PADIS guidelines decided that they couldn’t reasonably advise for or against their use in delirium treatment. More research is needed to better understand the effects of antipsychotic use in the ICU.
Immobility
The 2018 PADIS guidelines recommended conditionally mobilizing ICU patients based on hospital capability and specifications. In the 2025 PADIS guideline update, the panel recommends that ICU patients partake in enhanced mobilization instead – referring to any mobilization activities that are more than standard practice in the ICU.
The researchers recognize that some hospitals have limited resources, so in some cases, enhanced mobilization in the ICU may result in reduced care in other areas. As a result, while they still generally recommend enhanced mobilization for ICU patients, they recognize that this is not a viable solution for every hospital.
Sleep duration
The previous PADIS guidelines did not make a recommendation for or against using melatonin for improved sleep in adult ICU patients due to limited evidence of its efficacy. Although there is still limited research in this area, studies have shown that melatonin has a very low risk of adverse effects, so the authors of the updated PADIS guidelines recommend using it conditionally as it may benefit some patients.
Anxiety in ICU Patients Remains Under-examined
There continues to be a severe lack of research about anxiety in ICU patients, despite how common anxiety is in people receiving critical care. ICU practitioners often use sedatives known as benzodiazepines to treat patients experiencing anxiety, and the recent PADIS guidelines aimed to examine evidence about whether this treatment was effective.
Unfortunately, the researchers only found one study that addressed this question—a study that focused solely on burn victims and had limited evidence. This lack of research is particularly alarming because physicians like Dr. Lewis see patients struggling with anxiety almost every day.
“Imagine being on a ventilator, unable to speak, being woken up throughout the night,” Dr. Lewis explained. “It’s no wonder that we see ICU patients experiencing anxiety on a daily basis, and that many of them are traumatized and continue to face psychological distress even after they’re discharged.”
Without evidence-based recommendations for treating anxiety, practitioners are left to rely on clinical intuition to make treatment decisions, such as which drugs they should administer to patients.
The 2025 updated PADIS guidelines include a call to action for researchers to investigate cases of anxiety and potential treatments in ICU patients. Dr. Lewis hopes that this encouragement will lead to the development of evidence-based guidelines that will improve psychological conditions for people in the ICU.
Next Steps
Dr. Lewis says that this recent update to the PADIS guidelines certainly won’t be the last. These updates are in response to emerging research. As more critical care research gets published, the guidelines will need to be reassessed to provide practitioners with the most accurate information possible.
Dr. Lewis found a great deal of fulfillment in leading this research project and is looking forward to continuing her career in critical care research.
“It’s so exciting and fulfilling to be the first author listed on a paper that can change care for so many people,” she said. “This project involved skilled researchers working in hospitals all over the world—our work has already gone far beyond the St. Joe’s ICU.”