Maria Cronhjort

Maria Cronhjort

Affiliated to Research | Docent
Visiting address: Entrévägen 2, 18257 Danderyd
Postal address: D1 Kliniska vetenskaper, Danderyds sjukhus, D1 Anestesi och intensivvård, 182 88 Stockholm

About me

  • I work as Research Leader and Consultant of Anaesthesia and Intensive Care at the Department of
    Anaesthesia and Intensive Care at Danderyd Hospital, with focus on intensive
    care. I graduated in 2017 with the thesis Treatment of septic patients-fluid,
    blood and timing of antibiotics. Since 2013, I have worked with Prof Anders
    Perner's research group in Copenhagen and I am a board member of the Collaboration for Intensive Care Research. I did a research visit in 2017
    at Prof Rinaldo Bellomo's hospital in Melbourne, where I studied the
    physiological effects of a fluid bolus. I am the main supervisor for four
    doctoral students (Olof Wall, Jens Christensen, Elisabeth Andersson, Mikael Hallengren) and
    co-supervisor for three doctoral students ( Anna Augustsén, Cristian Duré, Erik Boberg).


  • My research is focused on sepsis treatment
  • the chain of care, early detection and fluid therapy.

    Current projects

    Peripherally administered norepinephrine during surgery
    Norepinephrine is the drug of choice to counteract hypotension in septic shock. It is conventionally administered in a central venous catheter as extravasation might lead to necrosis. Recently it has been recommended to start early peripheral administration of norepinephrine in septic shock to gain time and to avoid unnecessary fluid administration. The safety of peripheral administration of norepinephrine has only been studied in a few, smaller studies. I am the sponsor of an observational study of the safety of peripheral administration of norepinephrine during surgery. We have included 1000 patients at three hospitals in Sweden. The patients who receive peripherally administered norepinephrine during surgery are closely observed for local complications as subcutaneous infusion and hypertension. The aim is to study if peripheral administration of norepinephrine is safe. If the risk for local complications of peripherally administered norepinephrine is low, the results will be immediately applicable to patients undergoing surgery. Norepinephrine will help to avoid hypotension and lead to less fluid overload, two clinical situations that are associated with increased mortality and morbidity. Inclusion of patients was completed in 2022 and the manuscript has been accepted for publication. I am the main supervisor of two doctoral students in the project.

    Sepsis-early detection and treatment
    Sepsis is a common condition with high mortality, accounting for 20% of global deaths. The incidence of sepsis in Sweden is unknown, as only a limited number of septic patients receive the correct diagnosis code. Women receive antibiotics later than men and there might be protective effects from female sex hormones. We have formed a multi-disciplinary research group at Södersjukhuset and developed a script for automatic identification of the septic patients. We will further describe sepsis incidence in Stockholm and analyze associations between time to treatment, gender and mortality. We will also study gender differences in symptoms of sepsis at onset, fulfillment of sepsis bundles and mortality. Our method is independent of correct diagnosis by the treating physician. We have validated the script during 2023 and it has been submitted for publication. I am the main supervisor of one doctoral student and co-supervisor of one doctoral student in this project.

    Restrictive fluid therapy
    Observational studies have indicated an association between fluid overload and mortality. Several RCTs performed in low-income countries have shown lower mortality with restrictive fluid therapy. We have performed the first randomized clinical trial in the setting with access to full intensive care, the CLASSIC-trial, aiming at clarifying this. This was an international randomized clinical trial conducted in European ICUs where 1554 patients in septic shock were given either a restrictive or standard fluid treatment. Primary outcome was 90-day mortality. We also evaluated 1-year mortality and quality of life.
    Within the CLASSIC trial, I lead a sub-study that will explore pathophysiological mechanisms within two areas of clinical concern for patients in septic shock: vascular integrity and cardiac dysfunction. We will compare differences in markers of endothelial and cardiac damage between the restrictive and standard fluid therapy groups. Glycocalyx markers might be able to identify patients at risk for fluid leakage leading to more complications from fluid therapy. This might be a way to individualize fluid therapy in septic patients. I supervise one doctoral student in this project.

    Future research plans

    Collaboration for Intensive Care Research
    I am a board member of Collaboration for Intensive Care Research (CRIC). CRIC performs pragmatic randomized trials on therapies where there is equipoise, for example transfusion levels, amount of resuscitation fluids, prophylaxis for gastrointestinal stress ulceration. We are planning a platform for intensive care research, INCEPT. The platform will use adaptive trial design and Bayesian statistics. Establishing a platform will give us the opportunity to respond quickly in case of a new pandemic. On this platform, the first two trials will investigate dosing of thromboprophylaxis and the use of albumin in critically ill patients.

    Dosing of thromboprophylaxis
    Despite the use of thromboprophylaxis, the event rate of venous thrombo-embolism remains substantial with a prevalence of 4-10% among critically ill patients. There is important practise variation in dosing of thromboprophylaxis. We will randomize patients to three different treatment arms based on international current practice: low-dose, intermediate dose and weight-based dose of low molecular weight heparins. I will supervise a post-doc who will be the national coordinator for this trial. We are also planning a sub-study on antiFXa levels with different dosing strategies.

    We have performed a sub-study to the CLASSIC trial, which showed important practice variation regarding the use of albumin in critically ill patients. We are planning to randomize patients to restrictive or liberal use of albumin during their stay in the Intensive Care Unit.
    Patient’s perspective on colorectal surgery
    Colo Rectal Cancer, CRC, is the third most common cancer in Sweden. High age and co-morbidities at diagnosis must be considered in choosing aggressive treatment with radiation, chemotherapy and surgery. We want to know if we choose patients correctly for surgery. We will study patients with CRC >
  • 80 years old who do or don’t choose to undergo surgery. We will perform both a qualitative study and a quantitative study of patients’ perspectives and health-related quality of life. I am the main supervisor of a doctoral student who will perform this project in collaboration with consultant colorectal surgeon Deborah Saraste.

    Thrombomodulin to detect necrotizing soft tissue injury (NSTI)
    Rapid diagnosis of NSTI is critical for the outcome of patients but is challenging. Exploratory surgery is required for accurate diagnosis. Since the suspicion of NSTI requires immediate surgical exploration, currently several patients with suspected but without NSTI have emergency surgery that proves unnecessary. In this project we will, in collaboration with Prof Anna Norrby-Teglund and Dr Laura Palma Medina, explore thrombomodulin for improved early diagnosis, as it has been recently identified as a robust potential biomarker for necrosis in the later phase of the disease. We will perform an observational study of thrombomodulin levels in patients with suspected NSTI in the emergency wards at Danderyd Hospital, Södersjukhuset and Karolinska University Hospital.

    Restrictive fluid therapy
    I am preparing for a pilot trial of early peripherally administered norepinephrine to patients in septic shock in the emergency ward. The trial will be performed at Danderyd Hospital and Södersjukhuset.

    Post Intensive Care Syndrome
    More than half of ICU survivors suffer from new-onset physical, cognitive, and psychological problems in the first year after ICU. This is called Post Intensive Care Syndrome (PICS). The department of intensive care at Danderyd Hospital participates in a regional observational study that validates a screening tool to PICS. We will lead a sub-study to evaluate gender differences in frailty and 90-day mortality.

    Cardiac dysfunction in critically ill patients
    Cardiac involvement is common among critically ill patients, but the long-term importance of this is unknown. We will participate in a national observational study where we will perform echocardiography on patients with multi organ failure in the Intensive Care Unit, NCT05860504. We will study the association between cardiac involvement and mortality. We will lead a sub study on different echocardiographic measurements of right ventricular heart failure.

    Patient and public involvement
    Together with Associate Prof Anna Schandl at Södersjukhuset we have formed a group with former ICU patients and relatives from Danderyd Hospital and Södersjukhuset. This group will inform future studies regarding patient important outcomes and facilitate the implementation of research results.


All other publications


  • Affiliated to Research, Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, 2024-2027
  • Affiliated to Research, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, 2023-2025

Degrees and Education

  • Docent, Karolinska Institutet, 2022
  • Degree Of Doctor Of Philosophy, Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, 2017
  • University Medical Degree, Karolinska Institutet, 1995

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