Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03757442 |
| Other study ID # |
W217038300-2018-77 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
February 1, 2019 |
| Est. completion date |
January 1, 2020 |
Study information
| Verified date |
October 2019 |
| Source |
Hvidovre University Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Introduction Perioperative haemodynamic instability is associated with postoperative
morbidity and mortality. Macrocirculatory parameters, such as the conventionally obtained
mean arterial blood pressure and cardiac output, may be uncoupled from the microcirculation
during sepsis and severe blood loss and may not necessarily be optimal resuscitation
parameters. The peripheral perfusion index (PPI) is derived from the pulse oximetry signal
and reflects perfusion. Reduced peripheral perfusion is associated with morbidity in
critically ill patients and in patients following acute surgery. We hypothesize that patients
with low intraoperative PPI demonstrate high frequency of postoperative complications and
mortality regardless of blood pressure.
Methods and analysis We plan to conduct a prospective observational cohort study in patients
undergoing acute non-cardiac surgery (November 1st, 2017 to October 31st, 2018) at two
University Hospitals. Data will be collected prospectively from patient records including
patient demographics, comorbidity and intraoperative hemodynamic values, with PPI as the
primary exposure variable, and postoperative complications and mortality within 30 and 90
days as outcome variables. We primarily assess association between PPI and outcome in
multivariate regression models. Secondly, the predictive value of PPI for outcome, using area
under the receiver operating characteristics curve is assessed.
Ethics and dissemination Data will be reported according to The Strengthening the Reporting
of Observational Studies in Epidemiology (STROBE). Results will be published in a peer
reviewed journal. The study is approved by the regional research ethics committee, storage
and management of data has been approved by the Regional Data Protection Agency, and access
to medical records is approved by the hospital board of directors at the involved hospitals
and departments.
Description:
Background Perioperative haemodynamic instability is associated with postoperative morbidity
and mortality. Patients undergoing acute major abdominal or hip fracture surgery have high
complication rates and account for a major part of overall postoperative mortality in
developed countries. These patients are often frail, with multiple comorbidities making them
vulnerable to anaesthesia and surgery. Despite the benefit of a multidisciplinary effort to
improve perioperative care, such patients demonstrate a high risk of complications and death.
Conventional perioperative haemodynamic monitoring is often based only on heart rate (HR) and
mean blood pressure (MAP). Although perioperative hypotension is associated with
complications in major surgery, blood pressure is often an inadequate marker of perioperative
organ perfusion, consequently leading to little precision in administration of fluid and
vasoactive medication. Minimally-invasive haemodynamic monitoring of cardiac output (CO), and
goal directed therapy based on stroke volume optimization, has been associated with improved
outcome in major elective surgery, but high quality evidence for the advantage of such
monitoring in emergency surgery is sparse.
Macrocirculatory parameters such as MAP and CO may be uncoupled from the microcirculation
during sepsis and severe blood loss due to sympathetic or medically induced vasoconstriction,
and as such, these parameters are not necessarily optimal for resuscitation.
Assuming that blood flow is directed from peripheral tissue to vital organs during
progressive stages of circulatory impairment and shock, a non-invasive method to detect
impaired peripheral perfusion could be a relevant endpoint.
The peripheral perfusion index (PPI) has the advantage that is derived from the photoelectric
plethysmographic pulse oximetry signal most likely obtained in all patients for evaluation of
arterial oxygen saturation (SAT) already in the emergency room and continued during and after
surgery as in wards and in the ICU. The PPI reflects the ratio between the pulsatile and
non-pulsatile component of the arterial waveform as assessed by light traversing the tissue
addressed, most often the finger, and it decreases in response to hypoperfusion.Thus, PPI
reflects changes in peripheral perfusion and blood volume and reduced peripheral perfusion is
associated with morbidity following acute surgery, in critically ill patients, and patients
presenting septic shock. However, it remains uncertain which threshold for PPI should trigger
intervention in patients undergoing acute surgery reflecting that evaluation is made only in
relatively small populations of mixed medical and surgical patients.
Hypothesis We hypothesize that PPI reflects impaired peripheral circulation and that patients
with low intraoperative PPI, independent of MAP, have higher risk of postoperative
complications and mortality than patients with normal or high PPI.
Objectives The main objective of this study is to evaluate the association between
intraoperative PPI and outcome defined as severe postoperative complications and 30- and
90-days mortality. Secondly, we assess the predictive value of intraoperative PPI in relation
to outcome and evaluate whether PPI has better prediction of adverse outcome than the
commonly used MAP thresholds and try to establish intervention thresholds for PPI that in
acute non-cardiac surgical patients.
