Critically IllNCT07330505
Transducer Levelling Errors in Everyday ICU Practice - A Multicentre Blinded Observational Study
An observational study of Critically Ill and Haemodynamic Instability, run by Vastra Gotaland Region at 2 sites in Sweden.
Trial summary
Invasive pressure monitoring (arterial blood pressure via arterial catheter and central venous pressure via central venous catheter) is fundamental to clinical decision-making in intensive care. Treatment with vasopressors, fluids, and nursing interventions depends on accurate measurements. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Critically Ill, Haemodynamic Instability
- How many people
- 60 participants
- Where
- 2 sitesSweden
- Study dates
- 1 Feb 2026to 1 May 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study population consists of adult (≥18 years) critically ill, mechanically ventilated ICU patients receiving routine invasive arterial blood pressure and central venous pressure monitoring, often under sedation and vasoactive support.
Who may be able to join
- Age ≥18 years
- ICU admission
- Mechanically ventilated
- Arterial catheter for MAP
- Central venous catheter for CVP
- Ongoing vasopressor therapy
Who cannot join
- Severe hemodynamic or respiratory instability
- Contraindications for lateral positioning
- Expected survival <24 hours
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden2 sites, 2 recruiting
- Recruiting
Sahlgrenska University Hospital
Gothenburg
Carl Sjödin, PhD student, +46313421096, carl.sjodin@vgregion.se
- Not yet recruiting
Skaraborgs Sjukhus
Skövde
Fredrika Sundberg, PhD, +46722047984, fredrika.sundberg@vgregion.se
About this study
Invasive pressure monitoring (arterial blood pressure via arterial catheter and central venous pressure via central venous catheter) is fundamental to clinical decision-making in intensive care. Treatment with vasopressors, fluids, and nursing interventions depends on accurate measurements. Because pressure transducers are hydrostatic, even small levelling errors can produce clinically relevant deviations (approximately 1 mmHg per 1.3 cm of vertical misplacement). Such errors may contribute to inappropriate therapy, for example under-recognition of hypotension, unnecessary vasopressor escalation, or missed venous congestion.
This prospective, multicenter, blinded observational study will quantify transducer levelling deviations during routine ICU care and evaluate whether clinically relevant deviations are associated with treatment decisions. Adult mechanically ventilated ICU patients with an arterial catheter, a central venous catheter, and ongoing vasopressor therapy will be included at hospitals in Västra Götalandsregionen, Sweden. Two blinded reference lines/sensors will be placed at predefined physiological zero levels for MAP and CVP and connected in parallel to the patient monitoring system. Continuous deviation (mmHg) between the clinical transducer position and the blinded reference level will be recorded for 8 hours while clinical staff remain unaware of the reference setup. MAP/CVP-related treatment decisions (e.g., vasopressor adjustments, fluid therapy, and nursing interventions) will be recorded with timestamps.
The study will provide real-world data on the magnitude and frequency of invasive pressure transducer misalignment in daily ICU practice and its potential relationship to patient management.
Read the detailed description
This is a prospective, multicenter, blinded observational study evaluating the accuracy of invasive pressure transducer levelling for arterial pressure (mean arterial pressure, MAP) and central venous pressure (CVP) during routine intensive care. Adult mechanically ventilated ICU patients with an indwelling arterial catheter and central venous catheter receiving vasopressor therapy are observed without any protocol-mandated changes to standard clinical care.
To quantify levelling deviations without influencing clinical behavior, a parallel reference measurement setup is connected to the existing monitoring system. Two fluid-filled reference lines are connected in parallel to the pressure dome used for invasive monitoring and secured to the chest wall at the fourth intercostal space at half of the anteroposterior thoracic diameter, one on each side of the chest. This configuration allows continuous estimation of vertical deviation (mmHg) between the clinical transducer position and a predefined physiological reference level. During lateral positioning, deviation is calculated using the midpoint between the two reference lines as the reference. Reference lines are covered with dressings to maintain blinding of clinical staff to the reference levels.
Physiological waveforms and calculated deviations are recorded continuously for an 8-hour monitoring period for each participant. In parallel, treatment actions plausibly influenced by interpretation of MAP or CVP (including vasopressor titration, fluid administration or removal, and nursing interventions related to positioning or transducer handling) are documented with timestamps to allow temporal association analyses. Relevant contextual variables are collected to support interpretation of deviations and clinical responses.
Data quality is ensured through predefined measurement procedures, continuous digital waveform acquisition, synchronization of reference and clinical signals, and post hoc review of signal integrity. Periods affected by technical artifacts or signal loss are flagged according to predefined criteria. Data segments that are missing, uninterpretable, or invalid due to technical failure are treated as missing and excluded from analyses, without imputation.
The study is designed to quantify the magnitude and frequency of invasive pressure transducer misalignment during routine ICU care and to explore whether clinically relevant deviations are associated with contemporaneous treatment decisions, with the aim of informing patient safety and quality improvement initiatives.
- Conditions
- Critically Ill, Haemodynamic Instability
- Keywords
- Invasive arterial blood pressure monitoring, Central venous pressure monitoring, Pressure transducer leveling, Pressure transducer positioning, Intensive care unit, Critically ill, Patient safety, Mean arterial pressure, Right atrial pressure
- Medical subject headings
- Critical Illness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Invasive Pressure Monitoring Cohort | Mechanically ventilated adult ICU patients undergoing routine invasive arterial blood pressure and central venous pressure monitoring. Pressure transducer positioning and associated pressure deviations are observed using blinded reference sensors without altering clinical care. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean deviation in transducer position for MAP and CVP
Continuous deviation (mmHg) between the clinical transducer position and the blinded reference zero point. Continuous (mmHg).
Measured: During the 8-hour continuous monitoring period following initiation of blinded reference monitoring
Secondary outcomes (4)
Frequency of clinically relevant deviations
Proportion of monitoring time (%) with deviation >2 mmHg (CVP) or >5 mmHg (MAP). Percentage of total monitoring time.
Measured: During the same 8-hour continuous monitoring period following initiation of blinded reference monitoring
Association between deviations and treatment decisions
Relationship between deviation size and treatment decisions (vasopressor adjustments, fluid therapy, nursing interventions). Binary outcome (decision yes/no), regression analysis.
Measured: During the 8-hour continuous monitoring period, with treatment decisions assessed within 5 minutes following detection of a deviation
Differences in deviation magnitude and frequency across hospitals and ICU specialties.
Differences in deviation magnitude and frequency across hospitals and ICU specialties. Continuous (mmHg), categorical (% above threshold).
Measured: During the 8-hour continuous monitoring period following initiation of blinded reference monitoring
Hemodynamic context of deviations
Association between deviation magnitude and concurrent patient status (SOFA, MAP, CVP, CO, SVR, temperature). Continuous and categorical variables.
Measured: At baseline and during the subsequent 8-hour continuous monitoring period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jan 2026
- Study start1 Feb 2026
- Primary completion1 Mar 2027 (estimated)
- Study completion1 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Critically IllStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vastra Gotaland Region
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Carl Sjödin, Vastra Gotaland Region
- Investigators
- Lotta Johansson, PhD, Principal investigator, Sahlgrenska University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07330505
- Sponsor's protocol ID
- 2024-06578-01
- Status last verified
- Jul 2026
- First submitted
- 18 Dec 2025
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the results will be shared on reasonable request. Shared data will be limited to variables necessary to reproduce the primary analyses and will not include any direct identifiers.
Publications
1. Cecconi, M., et al., Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine. Intensive Care Med, 2014. 40(12): p. 1795-815. 2. Vincent, J.L., Critical care - where have we been and where are we going? New England Journal of Medicine, 2013. 369(19): p. 1839-1841. 3. Vincent, J.L. and D. De Backer, Circulatory shock. New England Journal of Medicine, 2013. 369(18): p. 1726-1734. 4. Giusti, G.D., Critical care nurses' perspectives on cardiac monitoring: barriers and training needs. BMC Nursing, 2024. 23: p. 742. 5. Alastalo, T.T., Critical care nurses' observational skills in detecting early patient deterioration. Intensive and Critical Care Nursing, 2017. 43: p. 97-103. 6. Magder, S., Right Atrial Pressure in the Critically Ill: How to Measure, What Is the Value, What Are the Limitations? Chest, 2017. 151(4): p. 908-916. 7. Sjödin, C., S. Sondergaard, and L. Johansson, Variability in alignment of central venous pressure transducer to physiologic reference point in the intensive care unit-A descriptive and correlational study. Aust Crit Care, 2019. 32(3): p. 213-217. 8. Figg, K.K. and E.C. Nemergut, Error in central venous pressure measurement. Anesth Analg, 2009. 108(4): p. 1209-11. 9. Oh, C., et al., Errors in pressure measurements due to changes in pressure transducer levels during adult cardiac surgery: a prospective observational study. BMC Anesthesiol, 2023. 23(1): p. 8. 10. Jacobs, K., et al., Accuracy of intra-arterial line transducer levelling practice in a general intensive care unit. Aust Crit Care, 2024. 37(1): p. 51-57.
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Transducer Levelling Errors in Everyday ICU Practice - A Multicentre Blinded Observational Study
- ClinicalTrials.gov ID
- NCT07330505
- Acronym / sponsor ID
- 2024-06578-01
- Conditions
- Critically Ill, Haemodynamic Instability
- Keywords
- Invasive arterial blood pressure monitoring, Central venous pressure monitoring, Pressure transducer leveling, Pressure transducer positioning, Intensive care unit, Critically ill, Patient safety, Mean arterial pressure
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Vastra Gotaland RegionOther government
- Study start
- 1 Feb 2026 (actual)
- Primary completion
- 1 Mar 2027 (estimated)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 9 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Invasive pressure monitoring (arterial blood pressure via arterial catheter and central venous pressure via central venous catheter) is fundamental to clinical decision-making in intensive care. Treatment with vasopressors, fluids, and nursing interventions depends on accurate measurements. Because pressure transducers are hydrostatic, even small levelling errors can produce clinically relevant deviations (approximately 1 mmHg per 1.3 cm of vertical misplacement). Such errors may contribute to inappropriate therapy, for example under-recognition of hypotension, unnecessary vasopressor escalation, or missed venous congestion.
This prospective, multicenter, blinded observational study will quantify transducer levelling deviations during routine ICU care and evaluate whether clinically relevant deviations are associated with treatment decisions. Adult mechanically ventilated ICU patients with an arterial catheter, a central venous catheter, and ongoing vasopressor therapy will be included at hospitals in Västra Götalandsregionen, Sweden. Two blinded reference lines/sensors will be placed at predefined physiological zero levels for MAP and CVP and connected in parallel to the patient monitoring system. Continuous deviation (mmHg) between the clinical transducer position and the blinded reference level will be recorded for 8 hours while clinical staff remain unaware of the reference setup. MAP/CVP-related treatment decisions (e.g., vasopressor adjustments, fluid therapy, and nursing interventions) will be recorded with timestamps.
The study will provide real-world data on the magnitude and frequency of invasive pressure transducer misalignment in daily ICU practice and its potential relationship to patient management.
Detailed description
This is a prospective, multicenter, blinded observational study evaluating the accuracy of invasive pressure transducer levelling for arterial pressure (mean arterial pressure, MAP) and central venous pressure (CVP) during routine intensive care. Adult mechanically ventilated ICU patients with an indwelling arterial catheter and central venous catheter receiving vasopressor therapy are observed without any protocol-mandated changes to standard clinical care.
To quantify levelling deviations without influencing clinical behavior, a parallel reference measurement setup is connected to the existing monitoring system. Two fluid-filled reference lines are connected in parallel to the pressure dome used for invasive monitoring and secured to the chest wall at the fourth intercostal space at half of the anteroposterior thoracic diameter, one on each side of the chest. This configuration allows continuous estimation of vertical deviation (mmHg) between the clinical transducer position and a predefined physiological reference level. During lateral positioning, deviation is calculated using the midpoint between the two reference lines as the reference. Reference lines are covered with dressings to maintain blinding of clinical staff to the reference levels.
Physiological waveforms and calculated deviations are recorded continuously for an 8-hour monitoring period for each participant. In parallel, treatment actions plausibly influenced by interpretation of MAP or CVP (including vasopressor titration, fluid administration or removal, and nursing interventions related to positioning or transducer handling) are documented with timestamps to allow temporal association analyses. Relevant contextual variables are collected to support interpretation of deviations and clinical responses.
Data quality is ensured through predefined measurement procedures, continuous digital waveform acquisition, synchronization of reference and clinical signals, and post hoc review of signal integrity. Periods affected by technical artifacts or signal loss are flagged according to predefined criteria. Data segments that are missing, uninterpretable, or invalid due to technical failure are treated as missing and excluded from analyses, without imputation.
The study is designed to quantify the magnitude and frequency of invasive pressure transducer misalignment during routine ICU care and to explore whether clinically relevant deviations are associated with contemporaneous treatment decisions, with the aim of informing patient safety and quality improvement initiatives.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Invasive Pressure Monitoring Cohort | – | –Mechanically ventilated adult ICU patients undergoing routine invasive arterial blood pressure and central venous pressure monitoring. Pressure transducer positioning and associated pressure deviations are observed using blinded reference sensors without altering clinical care. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population consists of adult (≥18 years) critically ill, mechanically ventilated ICU patients receiving routine invasive arterial blood pressure and central venous pressure monitoring, often under sedation and vasoactive support.
Key inclusion criteria (6 listed)
- Age ≥18 years
- ICU admission
- Mechanically ventilated
- Arterial catheter for MAP
- Central venous catheter for CVP
Key exclusion criteria (3 listed)
- Severe hemodynamic or respiratory instability
- Contraindications for lateral positioning
- Expected survival <24 hours
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Mean deviation in transducer position for MAP and CVP
Time frame: During the 8-hour continuous monitoring period following initiation of blinded reference monitoring
Continuous deviation (mmHg) between the clinical transducer position and the blinded reference zero point. Continuous (mmHg).
4 secondary outcomes
Frequency of clinically relevant deviations
Time frame: During the same 8-hour continuous monitoring period following initiation of blinded reference monitoring
Association between deviations and treatment decisions
Time frame: During the 8-hour continuous monitoring period, with treatment decisions assessed within 5 minutes following detection of a deviation
Differences in deviation magnitude and frequency across hospitals and ICU specialties.
Time frame: During the 8-hour continuous monitoring period following initiation of blinded reference monitoring
Hemodynamic context of deviations
Time frame: At baseline and during the subsequent 8-hour continuous monitoring period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Background1. Cecconi, M., et al., Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine. Intensive Care Med, 2014. 40(12): p. 1795-815. 2. Vincent, J.L., Critical care - where have we been and where are we going? New England Journal of Medicine, 2013. 369(19): p. 1839-1841. 3. Vincent, J.L. and D. De Backer, Circulatory shock. New England Journal of Medicine, 2013. 369(18): p. 1726-1734. 4. Giusti, G.D., Critical care nurses' perspectives on cardiac monitoring: barriers and training needs. BMC Nursing, 2024. 23: p. 742. 5. Alastalo, T.T., Critical care nurses' observational skills in detecting early patient deterioration. Intensive and Critical Care Nursing, 2017. 43: p. 97-103. 6. Magder, S., Right Atrial Pressure in the Critically Ill: How to Measure, What Is the Value, What Are the Limitations? Chest, 2017. 151(4): p. 908-916. 7. Sjödin, C., S. Sondergaard, and L. Johansson, Variability in alignment of central venous pressure transducer to physiologic reference point in the intensive care unit-A descriptive and correlational study. Aust Crit Care, 2019. 32(3): p. 213-217. 8. Figg, K.K. and E.C. Nemergut, Error in central venous pressure measurement. Anesth Analg, 2009. 108(4): p. 1209-11. 9. Oh, C., et al., Errors in pressure measurements due to changes in pressure transducer levels during adult cardiac surgery: a prospective observational study. BMC Anesthesiol, 2023. 23(1): p. 8. 10. Jacobs, K., et al., Accuracy of intra-arterial line transducer levelling practice in a general intensive care unit. Aust Crit Care, 2024. 37(1): p. 51-57.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the results will be shared on reasonable request. Shared data will be limited to variables necessary to reproduce the primary analyses and will not include any direct identifiers.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Lotta Johansson, PhD principal investigator
Sahlgrenska University Hospital
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Critically Ill and Haemodynamic Instability, run by Vastra Gotaland Region at 2 sites in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Carl Sjödin, PhD student (+46313421096, carl.sjodin@vgregion.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean deviation in transducer position for MAP and CVP (time frame: During the 8-hour continuous monitoring period following initiation of blinded reference monitoring). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07330505, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2026.