The Association Between Intestinal Perfusion and Prolonged Mechanical Ventilation in Patients After Cardiac Valve Surgery

The Association Between Doppler Parameters of Superior Mesenteric Artery(SMA) and Prolonged Mechanical Ventilation(PMV) in Patients After Cardiac Valve Surgery

Background This study aimed to confirm that alterations in Doppler parameters of superior mesenteric artery(SMA) blood flow caused by intestinal hypoperfusion are associated with prolonged mechanical ventilation(PMV) in patients after cardiac valve surgery.

Methods The patients' basic hemodynamics parameters, and the SMA blood flow parameters monitored by Doppler ultrasound were collected in the supine position at admission. The length of mechanical ventilation continued to be monitored. The SMA Doppler parameters were measured again when the patient was extubated. PMV was defined as MV≥96 hours.

Study Overview

• Status: Completed
• Conditions: Patient After Cardiac Valve Surgery; Patient With Prolonged Mechanical Ventilation
• Intervention / Treatment: Other: no intervention

Detailed Description

Patient enrollment This prospective observational study was performed in the 15-bed adult critical care unit in Adult General Hospital from January 2021 to March 2022.

The inclusion criteria were as follows: 1) patients admitted to ICU immediately after cardiac valve surgery; 2) age 18-80 years; 3) sinus rhythm; 4) without active bleeding or pneumothorax, and 5) complete measurement data.

The exclusion criteria were as follows: 1) history of peripheral vascular disease, 2) patients with severe stenosis defined as SMA peak systolic velocity (SMA-PSV >275 cm/s or SMA-PSV/abdominal aorta peak velocity of >3, 3) hepatic dysfunction or liver cirrhosis, portal hypertension, 4) cancer or end-stage renal diseases, 5) poor quality of abdominal ultrasound images.

Doppler ultrasound monitoring Doppler ultrasound was performed with an ultrasound system consisting of a 2-5 MHz C60xp Probe (X-Porte Ultrasound System, FUJIFILM SONOSITE, INC., USA). Blood flow parameters were measured by two physicians, each physician measured twice and averaged, and then averaged the two results. Each of the two ICU physicians had more than four years of experience in critical ultrasound and obtained certification from the Chinese Critical Ultrasound Study Group. Two skilled physicians conducted a total of 40 measurements on ten patients after cardiac valve surgery to evaluate inter-observer reproducibility.

The SMA flow was measured 1 cm proximal to the abdominal aorta. The angle of insonation was < 60°. The time-velocity waveform readings were used to measure the peak systolic velocity (PSV), end-diastolic velocity(EDV), resistance index(RI), time-averaged mean velocity(TAMV), pulsatility index (PI), according to the calculation software carried by the ultrasound. PI=(PSV-EDV)/TAMV, and RI=(PSV-EDV)/PSV.

Data collection Demographic information was recorded for further analyses (e.g., age, gender, EuroSCORE-II, sequential organ failure assessment (SOFA) score, body mass index (BMI), and hemodynamic parameters and blood gas analysis data). In addition, types of operation and operation time were collected. Moreover, outcome variables (e.g., hospital mortality, time of MV, length of ICU stay) were recorded for further comparison.

Statistical analysis The median plus the interquartile range (IQR) or mean standard deviation is used to show demographic data. The Shapiro-Wilk test was used to evaluate normality. The differences between groups were compared using the student's t-test for continuous variables with normality distribution and the Mann-Whitney U test for those without normality distribution. The differences between groups for categorical variables were compared by performing a Chi-square test. Correlations between variables and PMV were assessed by conducting logistic regression analysis. Variables showing statistical significance in the univariate logistic regression were selected covered in the multivariate logistic regression. Furthermore, to evaluate the predictive ability of the variables for PMV, a receiver operating characteristic (ROC) curve was applied. Statistical significance was set at P < 0.05. All analyzed P-values were two-sided. Statistical analyses were performed using the SPSS 25.0 software package (SPSS, Chicago). Bland-Altman plots with the mean difference and 95 percent limit of agreement (LOA) were used to assess inter-observer agreement, and statistical analyses were done using MedCalc Statistical software.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100730
      • Peking Union Medical College 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

The patient was enrolled in the 15-bed adult critical care unit in Adult General Hospital

Description

Inclusion Criteria:

1) patients admitted to ICU immediately after cardiac valve surgery; 2) age 18-80 years; 3) sinus rhythm; 4) without active bleeding or pneumothorax, and 5) complete measurement data.

Exclusion Criteria:

1) history of peripheral vascular disease, 2) patients with severe stenosis defined as SMA peak systolic velocity (SMA-PSV >275 cm/s or SMA-PSV/abdominal aorta peak velocity of >310, 3) hepatic dysfunction or liver cirrhosis, portal hypertension, 4) cancer or end-stage renal diseases, 5) poor quality of abdominal ultrasound images.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
prolonged mechanical ventilation group; patients had 96 hours or more (PMV group).	Other: no intervention; no intervention
control group; patients had less than 96 hours of mechanical ventilation (control group)	Other: no intervention; no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
hours of mechanical ventilation	hours of mechanical ventilation	within 30mins at ICU admission

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ICU residence time	ICU residence time	within 30mins at ICU admission

Collaborators and Investigators

• Sponsor: Peking Union Medical College Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2021
• Primary Completion (Actual): March 1, 2022
• Study Completion (Actual): March 1, 2022

Study Registration Dates

• First Submitted: August 11, 2022
• First Submitted That Met QC Criteria: August 11, 2022
• First Posted (Actual): August 15, 2022

Study Record Updates

• Last Update Posted (Actual): August 15, 2022
• Last Update Submitted That Met QC Criteria: August 11, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Keywords: Pulsatility index of the superior mesenteric artery; Prolonged Mechanical Ventilation; cardiac valve surgery; intestinal perfusion
• Other Study ID Numbers: ZS-3088

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

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