Perioperative Point-of-Care Ultrasound (POCUS-RCT)

The goal of this study is to assess the impact of perioperative point-of-care ultrasound (POCUS) assessment on patient-important outcomes (e.g. hospital length of stay, length of stay in recovery, mortality etc.) and perioperative patient management strategies, in patients undergoing non-elective non-cardiac surgeries.

Preoperative patients undergoing emergency non-cardiac surgery will be approached for study recruitment and participation. Study participants will be randomized to receive, or not, a preoperative POCUS exam as part of their routine preoperative assessment. Patients randomized to receiving a POCUS exam will undergo a protocolized focused cardiac ultrasound, lung and pleural ultrasound and a gastric volume and content ultrasound assessment. Results of this exam will be disclosed to the anesthesiologist and primary care team. Randomization will be stratified by the presence of any sign(s) of cardiorespiratory failure. Signs of cardiorespiratory failure are defined as: systolic blood pressure <90 mmHg, heart rate>100, respiratory rate >24, Oxygen saturation <90%, requirement of supplemental oxygen or mechanical ventilation, new requirement of loop diuretics in current hospital admission, chest pain, newly diagnosed ECG changes, requirement of vasoactive drugs, signs of pre-renal azotemia (BUN:creatinine ratio >20). Outcome data will be collected prospectively. Investigators performing and interpreting the scan will disclose the results to the care team but will not participate in patient care. Primary and secondary outcome data collection will be performed by an investigator blinded to patient assignment. The primary outcome is post anesthetic care unit length-of-stay. The secondary outcomes are post-randomization hospital length of stay, number of operating room (OR) delays for optimization, alterations in anesthetic management (using a brief anesthesiologist-administered survey), intensiveness of OR management (invasive blood pressure monitoring, central venous pressure monitoring, intraoperative TEE), new peri-operative diuretic use, new intensive care admission rates, mortality during this admission, amount/frequency of postoperative investigations, rates of detection of new pathologies identified by preoperative POCUS exam and the rates of adequately diagnostic POCUS studies.

Patients randomized to the scan group (intervention arm) will receive a preoperative point-of-care ultrasound (POCUS) exam as an adjunct to their preoperative assessment, the results of which will be disclosed to the anesthesiologist and the patient care team. This POCUS exam will include a focused cardiac ultrasound, a lung and pleural ultrasound, and a gastric volume and content ultrasound assessment. Patients randomized to this arm may also receive repeat POCUS exams as needed and as clinical conditions change. These repeat exams may be requested by the anesthesiologist or patient care team.

Patients randomized to no scan (control arm) will not receive a preoperative point-of-care ultrasound exam. Patients in this arm will receive the standard-of-care; a routine preoperative assessment and physical examination by their attending anesthesiologist.

The preoperative point of care ultrasound includes a protocolized focused cardiac ultrasound, lung and pleural ultrasound and a gastric volume and content ultrasound assessment, all of which will be performed as an adjunct to the anesthesiologist's assessment. The result of this ultrasound examination will be disclosed to the anesthesiologist and patient care teams. Repeat ultrasounds may be done as the patient's clinical condition changes, or as requested by the anesthesiologist or patient care team.

From date of randomization until the date of hospital discharge or death from any cause, whichever came first, assessed up to 4 weeks.

New admissions to ICU in the immediate post operative period in patients previously on the ward or in the emergency department.

From time of randomization to the immediate postoperative period, assessed up to 6 hours after the conclusion of surgery.

New cardiac, pulmonary or gastric pathology detected by preoperative POCUS not known to be present previously. Examples include valve lesions, resting regional wall motion abnormalities, ventricular dysfunction, ventricular hypertrophy, pulmonary edema, consolidation and/or pleural effusion. This will be calculated only for participants randomized to the Scan Group.

From time of randomization to the time of interpretation of the last POCUS scan, assessed up to 2 weeks from randomization.

A survey will be administered to the anesthesiologist caring for the patient asking whether the POCUS exam findings influenced the anesthetic plan for the patient. If the answer is "yes, it did influence the anesthetic plan", subsequent questions will explore how it influenced anesthetic management. These will include questions of whether it influenced fluid management, anesthetic technique, choice of invasive lines, choice or dose of induction agents, or delay of surgery for optimization or further work-up. This will be calculated only in participants randomized to the Scan Group.

From time of randomization to the time of interpretation of the last POCUS scan, assessed up to 2 weeks from randomization.

During OR time post randomization, assessed until the patient is transferred from the OR to PACU, up to 7 days from randomization.

Frequency of post-randomization blood draws, frequency of post-randomization imaging studies (X-rays, CT's, MRI's, ultrasounds, echoes, and nuclear scans).

In-hospital post randomization mortality rate. Patients dying after transfer to another acute care hospital will also be counted as an in-hospital post randomization mortality.

Rates of adequately diagnostic focused cardiac ultrasounds, lung and pleural ultrasounds, and gastric volume/content assessments.

An adequately diagnostic focused cardiac ultrasound will be defined as a scan having two or more views showing at least 3 cardiac chambers with diagnostic quality. An adequately diagnostic lung and pleural scan will demonstrate a clear aeration pattern in both hemithoraces with visualization of the diaphragm or a corresponding curtain sign. An adequately diagnostic gastric ultrasound will be done in right lateral decubitus and demonstrate the liver in the near field, a great vessel (aorta or IVC) in the far field, and the stomach antrum deep to the liver in the near to mid-field with visualization of the hypo-echoic muscularis propria. These outcomes will be examined only in participants randomized to the Scan Group.

From time of randomization to the time of interpretation of the last POCUS scan, assessed up to 2 weeks from randomization.

From time of randomization to the time of interpretation of the last POCUS scan, assessed up to 2 weeks from randomization.

Inclusion Criteria: Patients aged >17 years Undergoing urgent or emergent non-cardiac surgery classified as intermediate or high risk according to American Heart Association(AHA)/American College of Cardiology(ACC) guidelines. These include vascular surgeries (supra or infra-inguinal), intraperitoneal surgeries, intra-thoracic surgeries, head and neck surgeries, spine surgeries, urologic surgeries, and proximal extremity orthopedic surgeries. Peripheral extremity surgeries (wrist or below, and ankle or below), in addition to appendectomies and cholecystectomy surgeries will be excluded from this study. Exclusion Criteria: Patients scheduled for elective or pre-booked surgeries Patients undergoing cardiac surgeries Patients undergoing low risk procedures e.g. endoscopic procedures, superficial skin, subcutaneous tissue, breast, ophthalmic, and ambulatory surgeries Patients undergoing orthopedic peripheral extremity surgeries (e.g. ankle, wrist, hand, foot) Patients who have had an echo during the current hospital admission prior to recruitment. Patients where the investigator performing or over-reading the POCUS scan is required to participate directly in perioperative patient care (e.g. anesthesiologist co-investigator performing or over-reading scan is on-call for this emergency case)

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Heiberg J, El-Ansary D, Canty DJ, Royse AG, Royse CF. Focused echocardiography: a systematic review of diagnostic and clinical decision-making in anaesthesia and critical care. Anaesthesia. 2016 Sep;71(9):1091-100. doi: 10.1111/anae.13525. Epub 2016 Jun 27.

Canty DJ, Royse CF, Kilpatrick D, Bowyer A, Royse AG. The impact on cardiac diagnosis and mortality of focused transthoracic echocardiography in hip fracture surgery patients with increased risk of cardiac disease: a retrospective cohort study. Anaesthesia. 2012 Nov;67(11):1202-9. doi: 10.1111/j.1365-2044.2012.07300.x. Epub 2012 Sep 5.