Prognostic Value of Lung Ultrasound in Predicting Intensive Care Unit Length of Stay in Adult Cardiac Surgery

Prognostic Value of Lung Ultrasound in Predicting Intensive Care Unit Length of Stay in Adult Cardiac Surgery: A Prospective Observational Study

Being easy, bedside, non-expensive, noninvasive and radiation free, there has been a growing interest in the implementation of lung ultrasound in critical care management in the last decade, cardiac surgery was not an exception in both adult and pediatric surgeries Many predictors for open heart surgery outcomes have been studied in past years including The Society of Thoracic Surgeons (STS) risk score and the EuroSCORE (ES), preoperative clinical condition, associated chronic diseases, type of surgery, age, duration of cardiopulmonary bypass and brain natriuretic peptide (BNP), cystatin-C A recent study described the use of a novel postoperative lung ultrasound score scanning for B lines which denote subpleural interstitial edema in various lung regions for predicting critical care length of stay in pediatric cardiac surgeries.

The objective of the current study is to evaluate the role of the new lung ultrasound score in predicting the length of postoperative intensive care stay after adult open heart surgeries.

Study Overview

• Status: Completed
• Conditions: Coronary Artery Disease; Valvular Heart Disease
• Intervention / Treatment: Diagnostic test: Lung ultrasound scan

Detailed Description

After approval of the local institutional ethics committee and local institutional review board. All patients scheduled for open heart surgery in Fayoum university hospital starting from August 2020 will be enrolled in this prospective observational study until fulfilling sample size. A detailed informed consent will be signed by the eligible participants before recruitment ANESTHETIC TECHNIQUE All patients will be preoperatively assessed and investigated by complete blood count, coagulation profile, Liver and kidney functions and serum electrolytes. Chest X-ray, Electrocardiography (ECG) and echocardiography will be routinely done. Coronary angiography and carotid arterial duplex will be requested if needed.

Patient will be premedicated by 10 mg morphine intramuscularly at morning of the operation. Prior to induction of anesthesia, standard monitoring will be applied including a five-lead electrocardiography system, a pulse oximeter probe. A peripheral intravenous (IV) cannula will be placed. An arterial will be inserted using a 20 G cannula either right or left radial artery under local anesthesia. After pre-oxygenation, general anesthesia will be induced using midazolam 2-5 mg, fentanyl (3-10 μg/kg), propofol (1-1.5 mg/Kg), followed by atracurium (0.5 mg/kg).

After trachea intubation, patients will be mechanically ventilated with oxygen in air so as to achieve normocarbia. A main stream capnogram, an esophageal temperature probe and a Foley catheter will also be placed. A triple-lumen central venous catheter will be placed usually through the right internal jugular vein.

Maintenance of anesthesia will be achieved by inhaled Isoflurane 0.4 to 1% and atracurium infusion at a rate of 0.5 mg/kg/h. After initiating extracorporeal circulation, Propofol infusion at a rate of 50-100 µg/kg/min will be added to replace isoflurane inhalation.

Patients will receive intravenous heparin (300-500 IU/kg body weight) before the initiation of cardiopulmonary bypass (CPB) to achieve an activated clotting time (ACT) of more than 480 seconds. Cardiopulmonary bypass was instituted with the use of a non-pulsatile blood flow at 2.4 L/min/m2, a non-heparin-coated circuit, and a membrane oxygenator. Mean arterial pressure will be adjusted to exceed 60mmHg before, during and after cardiopulmonary bypass (CBP) . Cardiac arrest will be induced using St Thomas crystalloid solution (Hamburg). Lactated Ringer's solution will be added to the CPB circuit to maintain reservoir volume if needed, and packed red blood cells will be infused when hemoglobin level drops to less than 7g/dl. After rewarming the patient to 37°C and weaning from CPB; Protamine sulfate will be used to reverse the effect of heparin.

After skin closure and wound dressing, patients will be transferred to the intensive care unit intubated with manual ventilation and full monitoring during transfer.

Intensive care Tracheal extubation will be performed when the patient meets the following criteria: awake or arousable, hemodynamically stable, no ongoing active bleeding, warm extremities, no electrolyte abnormalities, no or minimal inotropic support and a satisfactory arterial blood gas with a fraction of inspired oxygen (FiO2) < 0.5, Ventilator pressure support reduced to 10 CmH2O with Positive End Expiratory Pressure (PEEP) 5-7 CmH2O.

ICU management and decisions will be left to the intensivist who is responsible of the postoperative cardiac critical care.

Patient will be discharged from ICU when the following criteria are met: Awake patient with oxygen saturation (SpO2) < 90% at FIO2 > 0.5 by facemask, adequate cardiac stability, no intravenous inotropic or vasopressor supportive therapy, no hemodynamically significant arrhythmia, not dependent on epicardial external pacing no major bleeding i.e. chest tube drainage less than 50 ml/h, urine output of more than 0.5 ml/kg/h and no vital threats to other organ systems such as kidneys and liver.

Lung Ultrasound scan (LUS) All patients will be examined at 12 hours postoperatively as per our institution routine using a convex ultrasound probe, any other LUS will be done upon demand.

LUS will be performed by an experienced radiologist according to standardized protocols.

This will be used to calculate total LUS-score (calculated as a sum of all quadrants score) and individual areas score.

Sample size was calculated using (G power). Minimal sample size of patients was 191 needed to get power level 0.80, alpha level 0.05 (two tailed) and 0.20 as expected β (slope of regression line) for predicting intensive care Length of stay .

Data management will be performed using the Statistical Package for Social Sciences (version 22.0; SPSS Inc., Chicago, IL, USA). Descriptive statistics (mean, standard deviation for quantitative data, and number and percentages for qualitative data) will be used to summarize the data. Nominal data will be analyzed using simple chi squared test, while independent sample t-test or one-way ANOVA procedure will be used to compare means for two or three groups of cases, respectively. Regression analysis will be performed to determine the predictors for LOS. A probability value (P value) ≤ 0.05 is considered significant.

• Study Type: Observational
• Enrollment (Actual): 191

Contacts and Locations

Study Locations

• Egypt
  • Faiyum Governorate
    • Madīnat al Fayyūm, Faiyum Governorate, Egypt, 63514
      • Fayoum University hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

patients admitted in Fayoum uniersity hospital who are candidates for open heart surgeries

Description

Inclusion Criteria:

• all patients Scheduled for elective cardiac surgery for valve replacement, CABG or adult congenital (VSD or ASD) via median sternotomy

Exclusion Criteria:

• subjects with inadequate acoustic windows or incomplete examinations (as defined below),
• Patients with emergency surgeries.
• Patients with thoracic deformities or preexisting pulmonary pathology

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intensive care Length of stay	in days	from ICU admission till patient discharge to ward assessed up to 30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
EURO Score II	calculated preoperatively using different variables which are age, gender, renal impairment, extracardiac arteriopathy, poor mobility, previous cardiac surgery, chronic lung disease, critical preoperative state, presence of insulin dependent diabetes, New York Heart Association (NYHA) classification, Canadian cardiovascular society (CCS) class, left ventricular function, recent myocardial infarction, pulmonary hypertension, urgency and weight of the operation and whether thoracic aorta is involved in surgery.18 Score will be calculated using an online calculator by QxMD website.	24 hours before operation
previous associated comorbidities	Diabetes, hypertension, chronic renal failure, liver impairment	24 hours before operation
primary pathology	Coronary artery disease, valvular heart disease	24 hours before operation
planned operative procedure	Coronary artery bypass graft, valve replacement, Ventricular Septal Defect repair	24 hours before operation
liver enzymes	ALT	24 hours before operation and 1 hour after operation
sodium level	before and after the operation	24 hours before operation and 1 hour after operation
potassium level	before and after the operation	24 hours before operation and 1 hour after operation
creatinine	before and after the operation	24 hours before operation and 1 hour after operation
urea	before and after the operation	24 hours before operation and 1 hour after operation
hemoglobin	before and after the operation	24 hours before operation and 1 hour after operation
platelet count	before and after the operation	24 hours before operation and 1 hour after operation
prothrombin concentration	before and after the operation	24 hours before operation and 1 hour after operation
prothrombin time	before and after the operation	24 hours before operation and 1 hour after operation
Cardiopulmonary Bypass (CPB) time	in minutes	assessed at the end of CBP up to 12 hours from start of operation
Concomitant vasoactive medications	Noradrenaline, adrenaline, dobutamine	assessed at te end of the operation up to 12 hours from the start of the operation
Arterial blood gas values	baseline after induction , before and after weaning from CBP and postoperatively in critical care with LUS	assessed up to 24 after the end of operation
Intra and post-operative invasive BP	(invasive BP measured in mmhg	assessed up to 24 hours postoperatively
Intra and post-operative heart rate	Heart rate measured in beats per minute	assessed up to 24 hours postoperatively
Postoperative total LUS score	as a sum af all areas assessed by ultrasound	assessed 12 hours after the end of the operation
individual lung areas score	(Anterior, Lateral and Posterior).	assessed 12 hours after the end of the operation
extubation time	time from ICU admission till Endotracheal tube removal	assessed up to 30 days
in-hospital mortality	death before hospital discharge	until patient discharge assessed up to 30 days
Post-operative complications	Myocardial infarction, atrial fibrillations, Cerebral stroke or bleeding, GI bleeding	assessed until patient discharge or up to 30 days postoperatively

Collaborators and Investigators

• Sponsor: Fayoum University Hospital
• Investigators: Principal Investigator: Mohamed A Hamed, MD, Faculty of medicine, Fayoum university

Publications and helpful links

General Publications

• Cantinotti M, Giordano R, Volpicelli G, Kutty S, Murzi B, Assanta N, Gargani L. Lung ultrasound in adult and paediatric cardiac surgery: is it time for routine use? Interact Cardiovasc Thorac Surg. 2016 Feb;22(2):208-15. doi: 10.1093/icvts/ivv315. Epub 2015 Nov 18.
• Mojoli F, Bouhemad B, Mongodi S, Lichtenstein D. Lung Ultrasound for Critically Ill Patients. Am J Respir Crit Care Med. 2019 Mar 15;199(6):701-714. doi: 10.1164/rccm.201802-0236CI. Erratum In: Am J Respir Crit Care Med. 2020 Apr 15;201(8):1015. Am J Respir Crit Care Med. 2020 Jun 1;201(11):1454.
• Bouabdallaoui N, Stevens SR, Doenst T, Petrie MC, Al-Attar N, Ali IS, Ambrosy AP, Barton AK, Cartier R, Cherniavsky A, Demondion P, Desvigne-Nickens P, Favaloro RR, Gradinac S, Heinisch P, Jain A, Jasinski M, Jouan J, Kalil RAK, Menicanti L, Michler RE, Rao V, Smith PK, Zembala M, Velazquez EJ, Al-Khalidi HR, Rouleau JL; STICH Trial Investigators. Society of Thoracic Surgeons Risk Score and EuroSCORE-2 Appropriately Assess 30-Day Postoperative Mortality in the STICH Trial and a Contemporary Cohort of Patients With Left Ventricular Dysfunction Undergoing Surgical Revascularization. Circ Heart Fail. 2018 Nov;11(11):e005531. doi: 10.1161/CIRCHEARTFAILURE.118.005531.
• Wynne R. Variable definitions: implications for the prediction of pulmonary complications after adult cardiac surgery. Eur J Cardiovasc Nurs. 2004 Apr;3(1):43-52. doi: 10.1016/j.ejcnurse.2003.11.001.
• Rouby JJ, Arbelot C, Gao Y, Zhang M, Lv J, An Y, Chunyao W, Bin D, Valente Barbas CS, Dexheimer Neto FL, Prior Caltabeloti F, Lima E, Cebey A, Perbet S, Constantin JM; APECHO Study Group. Training for Lung Ultrasound Score Measurement in Critically Ill Patients. Am J Respir Crit Care Med. 2018 Aug 1;198(3):398-401. doi: 10.1164/rccm.201802-0227LE. No abstract available.

Helpful Links

• Euro score II

Study record dates

Study Major Dates

• Study Start (Actual): August 30, 2020
• Primary Completion (Actual): July 30, 2022
• Study Completion (Actual): July 30, 2022

Study Registration Dates

• First Submitted: July 26, 2020
• First Submitted That Met QC Criteria: July 30, 2020
• First Posted (Actual): August 5, 2020

Study Record Updates

• Last Update Posted (Actual): October 19, 2022
• Last Update Submitted That Met QC Criteria: October 18, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: Lung ultrasound; coronary artery bypass graft (CABG); open heart surgery; ICU LOS
• Additional Relevant MeSH Terms: Myocardial Ischemia; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Heart Diseases; Coronary Artery Disease; Heart Valve Diseases
• Other Study ID Numbers: D230

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No