Purpose

The purpose of this study is to determine whether a decision support system can improve the adherence to thresholds for low blood pressure by anesthesia providers, which in turn prevents their patients from having organ injury.

Condition

Eligibility

Eligible Ages
Between 60 Years and 100 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 60 years and older - Inpatients - Scheduled for a non-cardiac surgical procedure under general or central neuraxial anesthesia

Exclusion Criteria

  • Pre-existing end-stage renal disease: operationalized as a preoperative need for dialysis - The following surgical procedures: renal surgery, cardiac surgery, organ transplantation, ophthalmic surgery, endoscopic gastrointestinal procedures, and (interventional) radiologic procedures. - small non-invasive or minimally-invasive procedures will also be excluded, operationalized as excluding procedures with a surgical time of less than twenty minutes.

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Sequential Assignment
Intervention Model Description
It is an interrupted time-series of a decision support package intervention that aims to study the the effect of the decision support package on patient outcome. The effects of the individual decision support components of the package on healthcare provider behavior will be studied in a nested cluster-randomized trial: in the first month the attending anesthesiologists will be randomized to near-realtime notifications or feedback emails; in the second month in-room providers will be randomized to near-realtime notifications or feedback emails. Starting month four all providers will receive both near-realtime notifications and feedback emails.
Primary Purpose
Prevention
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Hypotension decision support
The intervention period. Several decision support elements are implemented to notify anesthesia providers: attending anesthesiologists and in-room anesthesia providers of intraoperative hypotension (threshold of a mean arterial pressure below 60 mmHg). Two types of decision support will be implemented: near real-time decision support and feedback emails. Near real-time decision support elements will notify the anesthesia providers of a blood pressure drop below the threshold and display the associated increased risk of acute kidney injury. The notification is presented through the pager system for attending anesthesiologists and through the anesthesia information management system for the in-room anesthesia provider. All providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension that is associated with an increased risk of organ injury due to organ ischemia.
  • Procedure: Attending real-time decision support
    Near real-time decision support elements will notify the attending anesthesiologists of a blood pressure drop below the threshold for intraoperative hypotension (mean arterial pressure below 60 mmHg). The notification is presented through the pager system. The page will also display the associated increased risk of organ injury due to organ ischemia.
  • Procedure: In-room real-time decision support
    Near real-time decision support elements will notify the in-room anesthesia provider of a blood pressure drop below the threshold for intraoperative hypotension (mean arterial pressure below 60 mmHg). The notification is presented through the anesthesia information management system. The decision support system will display the associated increased risk of organ injury due to organ ischemia.
  • Procedure: Attending feedback emails
    Attending anesthesiologists will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension (mean arterial pressure below 60 mmHg or lower for a particular duration) that is associated with an increased risk of organ injury due to organ ischemia.
  • Procedure: In-room provider feedback emails
    In-room anesthesia providers will be notified through email within 24 hours after the end of an anesthetic case, when the patient had an episode of intraoperative hypotension (mean arterial pressure below 60 mmHg or lower for a particular duration) that is associated with an increased risk of organ injury due to organ ischemia.
  • Device: Anesthesia Information Management System (AIMS)
    The anesthesia electronic record keeping system
  • Device: Perioperative Data Warehouse (PDW)
    The data warehouse that is used to gather perioperative data and create user reports. In this instance the PDW will be used to send the postoperative feedback emails.
  • Procedure: General anesthesia
    Any anesthetic drugs that are used to induce general anesthesia above the level of sedation.
  • Device: Pager system
    The mobile pager system through which alerts can be sent
  • Procedure: Central neuraxial anesthesia
    Regional anesthesia effectuated through the placement of local anesthetics around the nerves of the central nervous system, e.g. spinal anesthesia and epidural anesthesia.
    Other names:
    • Regional anesthesia
    • Spinal anesthesia
    • Intrathecal anesthesia
    • Subarachnoid anesthesia
    • Epidural anesthesia
    • Central neuraxial blockade
  • Procedure: Non-cardiac surgery
    Any surgical intervention that is not aimed at surgical correction of the heart
  • Drug: Propofol
    Anesthetic drug used to maintain general anesthesia
  • Drug: Sevoflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Desflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Isoflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Ephedrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Phenylephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Norepinephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Epinephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Dobutamine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Dopamine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Isoproterenol
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Milrinone
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Atropine
    Cardiovascular drugs used to treat intraoperative hypotension
  • Drug: Glycopyrrolate
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Vasopressin
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Terlipressin
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Sodium Chloride 0.9%
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Ringer's lactate
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Hydroxyethyl starch solutions
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Fresh Frozen Plasma
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Packed Red Blood Cells
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Albumin solutions
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Plasma-Lyte
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Lidocaine
    Local anesthetic used for central neuraxial anesthesia.
    Other names:
    • Lignocaine
  • Drug: Bupivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Levobupivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Ropivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Mepivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Tetracaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Prilocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Procaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Chloroprocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Benzocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Articaine
    Local anesthetic used for central neuraxial anesthesia.
Active Comparator
Usual care group
The 'before' period - or historic control group - during which no decision support for intraoperative hypotension was being used, also known as 'usual care'. This is the three year period prior to the intervention period (the 'Intraoperative hypotension decision support' arm).
  • Procedure: General anesthesia
    Any anesthetic drugs that are used to induce general anesthesia above the level of sedation.
  • Procedure: Central neuraxial anesthesia
    Regional anesthesia effectuated through the placement of local anesthetics around the nerves of the central nervous system, e.g. spinal anesthesia and epidural anesthesia.
    Other names:
    • Regional anesthesia
    • Spinal anesthesia
    • Intrathecal anesthesia
    • Subarachnoid anesthesia
    • Epidural anesthesia
    • Central neuraxial blockade
  • Procedure: Non-cardiac surgery
    Any surgical intervention that is not aimed at surgical correction of the heart
  • Drug: Propofol
    Anesthetic drug used to maintain general anesthesia
  • Drug: Sevoflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Desflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Isoflurane
    Anesthetic drug used to maintain general anesthesia
  • Drug: Ephedrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Phenylephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Norepinephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Epinephrine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Dobutamine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Dopamine
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Isoproterenol
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Milrinone
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Atropine
    Cardiovascular drugs used to treat intraoperative hypotension
  • Drug: Glycopyrrolate
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Vasopressin
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Terlipressin
    Cardiovascular drug used to treat intraoperative hypotension
  • Drug: Sodium Chloride 0.9%
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Ringer's lactate
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Hydroxyethyl starch solutions
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Fresh Frozen Plasma
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Packed Red Blood Cells
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Albumin solutions
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Plasma-Lyte
    Intravenous fluid used to treat intraoperative hypotension
  • Drug: Lidocaine
    Local anesthetic used for central neuraxial anesthesia.
    Other names:
    • Lignocaine
  • Drug: Bupivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Levobupivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Ropivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Mepivacaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Tetracaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Prilocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Procaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Chloroprocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Benzocaine
    Local anesthetic used for central neuraxial anesthesia.
  • Drug: Articaine
    Local anesthetic used for central neuraxial anesthesia.

More Details

Status
Completed
Sponsor
Vanderbilt University Medical Center

Study Contact

Detailed Description

Blood pressure management is an important part of anesthesia. Many factors contribute to a change in blood pressure during a surgical procedure, such as blood loss, manipulation by surgeons, and there are several mechanisms through which anesthesia itself changes blood pressure. Although a high blood pressure also occurs during anesthesia, most of these factors lower a patient's blood pressure. When a patient's blood pressure becomes too low, the internal organs become at risk of receiving not enough blood (low perfusion or hypoperfusion). This low perfusion state can result in organ damage (ischemia) because of an insufficient supply of oxygen and glucose. Hence the important task of anesthesia providers to maintain the blood pressure of patients, using a wide range of drugs and other interventions. A big challenge in blood pressure management is to know when a low blood pressure indeed results in low perfusion of organs. There is a large variation between patients in how susceptible they are to low blood pressure, as well as a difference between the organs in how easily they are damaged because of low perfusion. Elder patients, or patients with preexisting hypertension, heart problems or other cardiovascular diseases are more prone to a low blood pressure and are more likely to develop organ ischemia when there is a low blood pressure. The kidneys, the heart and the brain are the organs that are most at risk of organ damage. As one cannot measure the perfusion states of individual organs in individual patients, it is very difficult to know 'how low to go' with a patient's blood pressure. Recent studies have used large datasets of patients to demonstrate that there is statistical association between low blood pressure during surgery and various types of organ injury. As patients are already treated for low blood pressure by anesthesia providers, this suggests that patients have low organ perfusion states despite the current treatment standards. A patient's blood pressure is not simply a dial that can be adjusted to a specific level. Finding the right level of interventions can be difficult in some patients. Consequently, lower blood pressures are common in anesthesia, even with the current standards of blood pressure management. In this proposed study the investigators will implement two forms of decision support to assist anesthesia providers in blood pressure management. The decision support aims to educate anesthesia providers about the risks of low blood pressures in direct relation to the patients that they treat. One form of decision support will provide automated notifications through pagers and through the anesthesia information management system. These automated notifications pop up when the patient's blood pressure drops below a level that is associated with a risk of organ injury, and thus alerts the anesthesia provider of the blood pressure and its associated risk. The second form of decision support will send a postoperative email the day after the procedure when the patient has had a low blood pressure for particular duration. This email then provides feedback to the anesthesia provider by informing them of the increased risks of organ injury that are associated with that low blood pressure. The study will look at both a change in patient outcome and a change in blood pressure management and will be performed at the Vanderbilt University Medical Center (VUMC). The change in patient outcome will primarily be studied through the occurrence of acute kidney injury in the first days following the procedure at the VUMC. The change in blood pressure management (provider behavior) will be studied by observing the depth and duration of low pressures during anesthesia, and the number of interventions that have been used to treat the blood pressure. Patient outcome will be studied by comparison of a baseline phase - before the decision support is implemented and uses historic data- and the intervention phase - the period during which the intervention is active. Only routinely collected clinical data will be used for these analyses: no additional data collection is required. As it is impossible to know which form of decision support will be the most effective, the first three months of the intervention period will be a 'nested cluster-randomized trial'. The anesthesia providers (not the patients) will be randomized to either the automated notifications or the feedback emails. After three months all anesthesia providers will receive both forms of decision support for the remainder of the intervention period. The reason why anesthesia providers are randomized only during the first three months is that cross-over or contamination between the two groups is expected. This contamination could make it impossible to study the effect of the decision support on patient outcome, as there will be no longer any difference between the study groups.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.