Ignite Creation Date:
2024-05-06 @ 8:28 PM
Last Modification Date:
2024-10-26 @ 3:28 PM
Study NCT ID:
NCT06396767
Status:
RECRUITING
Last Update Posted:
2024-05-02
First Post:
2024-04-30
Brief Title:
Diaphragmatic Inspiratory Amplitude as a Prognosticator for Postoperative Pulmonary Complications After Cardiac Surgery
Sponsor:
Lawson Health Research Institute
Organization:
Lawson Health Research Institute
Study Overview
Official Title:
Diaphragmatic Inspiratory Amplitude Measured by Ultrasonography as a Prognosticator for Postoperative Pulmonary Complications After Cardiac Surgery a Prospective Observational Cohort Study
Status:
RECRUITING
Status Verified Date:
2024-10
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Cardiac surgery is a critical intervention for a variety of cardiovascular conditions yet it can frequently results in a spectrum of postoperative complications Amongst various morbidities Post-Operative Pulmonary Complications POPCs represent a significant clinical challenge leading to adverse outcomes like increased morbidity mortality and raised healthcare expenditures The diaphragm as the principal respiratory muscle plays a pivotal role in maintaining pulmonary function Diaphragmatic dysfunction DD in the perioperative period of Cardiac surgery has an incidence of up to 20 Understanding the impact of DD on postoperative pulmonary function is imperative for optimizing patient care and clinical outcomes Its occurrence has been linked to a spectrum of respiratory complications ranging from pneumonia to difficulty in weaning from mechanical ventilation In recent years the advent of point-of-care ultrasonogram POCUS has emerged as a promising modality for real-time monitoring of DD It offers a more accessible and feasible approach compared to traditional methods providing immediate feedback on diaphragmatic movement and facilitates timely intervention Ultrasound has been used to assess Diaphragmatic Inspiratory Amplitude DIA the expansion of the diaphragm when breathing DIA has been shown to decrease in the post-operative period after cardiac surgery which has been well-correlated with the occurrence of POPCs however its predictive value has not yet been studied in a cohort of cardiac surgical patients Hence we aim to address this gap by exploring the utility of DIA measured by ultrasonogram as a predictive tool in anticipating the occurrence of POPCs We hypothesize that DIA can predict the occurrence of POPC in cardiac surgical patients We will recruit 130 patients at University Hospital London Health Science Centre to this prospective observational study
Detailed Description:
Cardiac surgery represents a critical intervention for various cardiovascular pathologies yet it is frequently accompanied by a spectrum of postoperative complications1 Amongst various morbidities Post-Operative Pulmonary Complications POPC represent a significant clinical challenge leading to adverse outcomes like increased morbidity mortality and raised healthcare expenditures2
Despite significant advancements in surgical methods and perioperative care protocols POPCs still occur with the reported incidence of 3-16 after Coronary artery bypass grafting and 5-7 after valvular heart surgery3 POPCs encompass various problems such as atelectasis pneumonia cardiogenic pulmonary oedema acute respiratory distress syndrome pneumothorax pleural effusion phrenic nerve injury and prolonged mechanical ventilation PMV2
The diaphragm as the principal respiratory muscle plays a pivotal role in maintaining pulmonary function4 A normal diaphragmatic function is needed for optimal lung re- expansion post cardiac surgery especially where the work of breathing is high due to pain etc Its function is also crucial in aiding efficacious respiratory secretion clearance through adequate coughing2 Interventions that amplify the inspiratory muscle strength preoperatively via an incentive spirometer and usage of Non-invasive ventilation NIV in the postoperative period via mechanical unloading have demonstrated efficacy in attenuating the incidence of POPCs2
Diaphragmatic dysfunction DD in the perioperative period of Cardiac surgery has an incidence of up to 205 Diaphragmatic dysfunction after cardiac surgery constitutes a complex phenomenon with multifactorial aetiology encompassing phrenic nerve injury due to topical ice-slush usage surgical trauma or ligation of its blood supply during internal mammary artery dissection and the deleterious inflammatory sequelae from high level of cytokines and mitochondrial oxidative stress associated with cardiopulmonary bypass CPB6
Transient diaphragm impairment is a frequent occurrence in the immediate aftermath of cardiac surgery and can be attributed to various perioperative factors including sternotomy-associated pain mechanical constraints on thoracic dynamics electrolyte derangements and intrathoracic fluid accumulations7 However a subset of patients manifest significant DD which poses distinct challenges in clinical management and may exert profound ramifications on overall outcomes Understanding the impact of DD on postoperative pulmonary function is imperative for optimizing patient care and clinical outcomes Its occurrence has been linked to a spectrum of respiratory complications ranging from pneumonia to difficulty in weaning from mechanical ventilation7 Despite its clinical significance it remains an under evaluated cause of POPCs4
Conventional diagnostic modalities to study DD notably transdiaphragmatic pressure measurements furnish valuable insights into diaphragmatic function albeit encumbered by inherent invasiveness and limitations in discerning unilateral dysfunction8 In recent years the advent of point-of-care ultrasonogram POCUS has emerged as a promising modality for real-time monitoring of DD It offers a more accessible and feasible approach compared to traditional methods providing immediate feedback on diaphragmatic movement and facilitates timely interventions like draining a pleural effusion or instituting NIV as needed9
Ultrasound guided diaphragmatic function has so far been studied through metrics of Diaphragmatic Inspiratory Amplitude DIA also known as diaphragmatic excursion DEand Diaphragmatic thickeningthickening fraction9 Both the measurements have been shown to decrease in the post operative period of cardiac surgery and are well correlated with occurrence of POPCs6
The thickening fraction has also been examined for its predictive value and its reliability in comparison to conventional diagnostic modalities It has been established as a reliable tool2 However it has been observed that the reproducibility ease of doing it bedside are inferior as compared to DEDIA with higher interobserver variability plaguing its widespread usage9 DIADE is proven to be an easier measurement in a point of care situation9 However its predictive value has so far not been studied in cardiac surgical patient cohort
Hence we aim to address this gap by exploring the utility of DIA measured by ultrasonogram as a predictive tool in anticipating the occurrence of POPCs We hypothesize that DIA can predict the occurrence of POPC in cardiac surgical patients
Ultrasonographic measurements will be done preoperatively a day before surgery T0 and on Postoperative day 1T1 in Cardiac Surgery Recovery Unit CSRU Measurements will be done on both right and left sides during Quiet Q and Deep D breathing in semi- recumbent posture 30-450 recline of the bed
Three measurements will be taken during both quiet and deep breathing and an average value will be derived Qavg and Davg this will be done for both right and left hemidiaphragms both pre-surgery and post-surgery So for each patient a total of 8 diaphragmatic measurements will be obtained 4 in the pre-surgery period and another 4 in post-surgery period
Measurement technique and definition of Diaphragmatic Inspiratory Amplitude
All examinations will be performed by Sonosite SII ultrasound machine FUJIFILM Sonosite Inc Bothell WA USA using a 35- to5 MHz phased array probe or a 3-12 MHz linear probe The investigator will stand on the right side of the patient In each patient to ensure that all measurements are made from the same acoustic window the distance between probe placement and the lower extremity of the ribcage on the mid-axillary line will be measured and used as the reference site for the subsequent exam in the postoperative period
Right hemidiaphragm assessment
The ultrasound probe will be placed on the right anterior chest wall between midclavicular line and anterior axillary line at the ninth intercostal space The probe will be positioned craniocaudally and will be directed cephalad medially and dorsally This probe orientation and manoeuvring will help visualize the posterior third of hemi-diaphragm where diaphragmatic movement will be the greatest in the anterior subcostal view The diaphragm will be imaged using Brightness mode B mode The probe will be adjusted to obtain a continuous trace of the diaphragm against the acoustic window of the liver with the confluence of the portal vein in view Once the diaphragm movement is obtained the settings will be changed to Motion mode M mode The cursor in M mode will be placed perpendicular to the diaphragm movement The sweep speed will be set at 10second during this examination The sine wave obtained from diaphragmatic to and from movement will be frozen The distance from the sine waves trough to the highest echogenic line and the sine waves peak to the highest echogenic line will be measured The DIA value will be obtained as difference between the above two distances Brightness mode imaging will be repeated after this with patient taking a deep breath If the rib shadows interfere with the imaging the probe will be moved caudally until a good diaphragmatic excursion is possible to image At that point the measurements will be repeated in M mode during deep breathing
Left hemidiaphragm measurement
The probe will be placed on the lateral chest wall on the left side between the anterior and posterior axillary lines The probe will be positioned in a craniocaudal orientation with a cephalad medial and dorsal direction Brightness mode and Motion mode imaging will be performed as described above DIA measurements will be calculated as elaborated previously
Patient will be accompanied into the OR once all the consents anesthesia and surgical are obtained Patient will be connected to various monitoring equipment as per American Society of Anesthesiologists guidelines All the required invasive cannulae venous and arterial will be accessed and secured as per standard institutional protocols General anaesthesia GA will be induced as per Institutional protocols using 2- 5µgkg of Fentanyl 20-30µgkg of midazolam and 2-25mgkg of Propofol for a target Bi- Spectral Index BIS of 60 Muscle relaxation will be obtained using 01mgkg of vecuronium All patients will receive controlled ventilation with a 6mlkg tidal volume and positive end expiratory pressure of 5cm water GA will be maintained with sevoflurane delivered in airoxygen mixture with a target end-tidal minimum alveolar concentration 08-1 and BIS between 40-60 The neuromuscular block will be maintained with intermittent doses of 025mgkg vecuronium guided by neuromuscular monitoring This is all standard of care
For all surgeries requiring cardiopulmonary bypass CPB the institution and weaning from CPB will be as per standard institutional protocols Post completion of Surgery all patients will be shifted to Cardiac Surgical Recovery Unit CSRU for further monitoring and management
Post surgery DIA measurement
Ultrasound examination will be performed on extubated patients breathing spontaneously in semi-recumbent posture 30-450 of incline The measurements will be taken only if patients pain score on Visual Analog Scale is 3 If the score is 3 then patients will be given 15mgkg paracetamol intravenously and re-assessed 30 minutes later All patients will be mobilized by second postoperative day
The general post cardiac surgical care like hemodynamic management decisions of when to extubate when to institute Non-invasive ventilation NIV when to re-intubate when to provide oxygen therapy in CSRU will be delivered by the in-charge staff cardiovascular anaesthesiologist and the cardiac anaesthesia fellows who arent aware of DIA values The postop pain will be managed using multimodal analgesia approach as per institutional protocol and will be standard of care
Values that are not obtained on any day due to difficulties with visualization will be considered as missing values If the values are not obtained for longer than a day for any patient either due to technical difficulties or the requirement of continuous mechanical ventilatory support beyond the first 48 hours post-surgery then they were excluded from further analysis Patients in whom intermittent non-invasive ventilation is required the values will be obtained when they are off NIV and comfortable If the patient is receiving continuous NIV throughout the day then USG will not be done on that day However it will be done the next day when patent is off NIV
POPC will be diagnosed based on European perioperative clinical outcome guidelines10 and they will be graded for their severity based on the Clavien-Dindo11 classification The three main components of POPC which are of interest to our study are the occurrence of pneumonia clinically significant atelectasis or prolonged mechanical ventilation These are of particular interest because they have a significant impact on patient outcomes and very possibly are influenced by respiratory muscle strength Patients will be followed up for the development of POPC till postop day 5 this includes days in CSRU plus the days in the post cardiac surgical ward or the day of discharge from hospital whichever is earlier POPC diagnosis and assessment will be done by an independent investigator who will not know the DIA values Observation of patients in this patient population for POPCs following surgery is standard of care
Despite significant advancements in surgical methods and perioperative care protocols POPCs still occur with the reported incidence of 3-16 after Coronary artery bypass grafting and 5-7 after valvular heart surgery3 POPCs encompass various problems such as atelectasis pneumonia cardiogenic pulmonary oedema acute respiratory distress syndrome pneumothorax pleural effusion phrenic nerve injury and prolonged mechanical ventilation PMV2
The diaphragm as the principal respiratory muscle plays a pivotal role in maintaining pulmonary function4 A normal diaphragmatic function is needed for optimal lung re- expansion post cardiac surgery especially where the work of breathing is high due to pain etc Its function is also crucial in aiding efficacious respiratory secretion clearance through adequate coughing2 Interventions that amplify the inspiratory muscle strength preoperatively via an incentive spirometer and usage of Non-invasive ventilation NIV in the postoperative period via mechanical unloading have demonstrated efficacy in attenuating the incidence of POPCs2
Diaphragmatic dysfunction DD in the perioperative period of Cardiac surgery has an incidence of up to 205 Diaphragmatic dysfunction after cardiac surgery constitutes a complex phenomenon with multifactorial aetiology encompassing phrenic nerve injury due to topical ice-slush usage surgical trauma or ligation of its blood supply during internal mammary artery dissection and the deleterious inflammatory sequelae from high level of cytokines and mitochondrial oxidative stress associated with cardiopulmonary bypass CPB6
Transient diaphragm impairment is a frequent occurrence in the immediate aftermath of cardiac surgery and can be attributed to various perioperative factors including sternotomy-associated pain mechanical constraints on thoracic dynamics electrolyte derangements and intrathoracic fluid accumulations7 However a subset of patients manifest significant DD which poses distinct challenges in clinical management and may exert profound ramifications on overall outcomes Understanding the impact of DD on postoperative pulmonary function is imperative for optimizing patient care and clinical outcomes Its occurrence has been linked to a spectrum of respiratory complications ranging from pneumonia to difficulty in weaning from mechanical ventilation7 Despite its clinical significance it remains an under evaluated cause of POPCs4
Conventional diagnostic modalities to study DD notably transdiaphragmatic pressure measurements furnish valuable insights into diaphragmatic function albeit encumbered by inherent invasiveness and limitations in discerning unilateral dysfunction8 In recent years the advent of point-of-care ultrasonogram POCUS has emerged as a promising modality for real-time monitoring of DD It offers a more accessible and feasible approach compared to traditional methods providing immediate feedback on diaphragmatic movement and facilitates timely interventions like draining a pleural effusion or instituting NIV as needed9
Ultrasound guided diaphragmatic function has so far been studied through metrics of Diaphragmatic Inspiratory Amplitude DIA also known as diaphragmatic excursion DEand Diaphragmatic thickeningthickening fraction9 Both the measurements have been shown to decrease in the post operative period of cardiac surgery and are well correlated with occurrence of POPCs6
The thickening fraction has also been examined for its predictive value and its reliability in comparison to conventional diagnostic modalities It has been established as a reliable tool2 However it has been observed that the reproducibility ease of doing it bedside are inferior as compared to DEDIA with higher interobserver variability plaguing its widespread usage9 DIADE is proven to be an easier measurement in a point of care situation9 However its predictive value has so far not been studied in cardiac surgical patient cohort
Hence we aim to address this gap by exploring the utility of DIA measured by ultrasonogram as a predictive tool in anticipating the occurrence of POPCs We hypothesize that DIA can predict the occurrence of POPC in cardiac surgical patients
Ultrasonographic measurements will be done preoperatively a day before surgery T0 and on Postoperative day 1T1 in Cardiac Surgery Recovery Unit CSRU Measurements will be done on both right and left sides during Quiet Q and Deep D breathing in semi- recumbent posture 30-450 recline of the bed
Three measurements will be taken during both quiet and deep breathing and an average value will be derived Qavg and Davg this will be done for both right and left hemidiaphragms both pre-surgery and post-surgery So for each patient a total of 8 diaphragmatic measurements will be obtained 4 in the pre-surgery period and another 4 in post-surgery period
Measurement technique and definition of Diaphragmatic Inspiratory Amplitude
All examinations will be performed by Sonosite SII ultrasound machine FUJIFILM Sonosite Inc Bothell WA USA using a 35- to5 MHz phased array probe or a 3-12 MHz linear probe The investigator will stand on the right side of the patient In each patient to ensure that all measurements are made from the same acoustic window the distance between probe placement and the lower extremity of the ribcage on the mid-axillary line will be measured and used as the reference site for the subsequent exam in the postoperative period
Right hemidiaphragm assessment
The ultrasound probe will be placed on the right anterior chest wall between midclavicular line and anterior axillary line at the ninth intercostal space The probe will be positioned craniocaudally and will be directed cephalad medially and dorsally This probe orientation and manoeuvring will help visualize the posterior third of hemi-diaphragm where diaphragmatic movement will be the greatest in the anterior subcostal view The diaphragm will be imaged using Brightness mode B mode The probe will be adjusted to obtain a continuous trace of the diaphragm against the acoustic window of the liver with the confluence of the portal vein in view Once the diaphragm movement is obtained the settings will be changed to Motion mode M mode The cursor in M mode will be placed perpendicular to the diaphragm movement The sweep speed will be set at 10second during this examination The sine wave obtained from diaphragmatic to and from movement will be frozen The distance from the sine waves trough to the highest echogenic line and the sine waves peak to the highest echogenic line will be measured The DIA value will be obtained as difference between the above two distances Brightness mode imaging will be repeated after this with patient taking a deep breath If the rib shadows interfere with the imaging the probe will be moved caudally until a good diaphragmatic excursion is possible to image At that point the measurements will be repeated in M mode during deep breathing
Left hemidiaphragm measurement
The probe will be placed on the lateral chest wall on the left side between the anterior and posterior axillary lines The probe will be positioned in a craniocaudal orientation with a cephalad medial and dorsal direction Brightness mode and Motion mode imaging will be performed as described above DIA measurements will be calculated as elaborated previously
Patient will be accompanied into the OR once all the consents anesthesia and surgical are obtained Patient will be connected to various monitoring equipment as per American Society of Anesthesiologists guidelines All the required invasive cannulae venous and arterial will be accessed and secured as per standard institutional protocols General anaesthesia GA will be induced as per Institutional protocols using 2- 5µgkg of Fentanyl 20-30µgkg of midazolam and 2-25mgkg of Propofol for a target Bi- Spectral Index BIS of 60 Muscle relaxation will be obtained using 01mgkg of vecuronium All patients will receive controlled ventilation with a 6mlkg tidal volume and positive end expiratory pressure of 5cm water GA will be maintained with sevoflurane delivered in airoxygen mixture with a target end-tidal minimum alveolar concentration 08-1 and BIS between 40-60 The neuromuscular block will be maintained with intermittent doses of 025mgkg vecuronium guided by neuromuscular monitoring This is all standard of care
For all surgeries requiring cardiopulmonary bypass CPB the institution and weaning from CPB will be as per standard institutional protocols Post completion of Surgery all patients will be shifted to Cardiac Surgical Recovery Unit CSRU for further monitoring and management
Post surgery DIA measurement
Ultrasound examination will be performed on extubated patients breathing spontaneously in semi-recumbent posture 30-450 of incline The measurements will be taken only if patients pain score on Visual Analog Scale is 3 If the score is 3 then patients will be given 15mgkg paracetamol intravenously and re-assessed 30 minutes later All patients will be mobilized by second postoperative day
The general post cardiac surgical care like hemodynamic management decisions of when to extubate when to institute Non-invasive ventilation NIV when to re-intubate when to provide oxygen therapy in CSRU will be delivered by the in-charge staff cardiovascular anaesthesiologist and the cardiac anaesthesia fellows who arent aware of DIA values The postop pain will be managed using multimodal analgesia approach as per institutional protocol and will be standard of care
Values that are not obtained on any day due to difficulties with visualization will be considered as missing values If the values are not obtained for longer than a day for any patient either due to technical difficulties or the requirement of continuous mechanical ventilatory support beyond the first 48 hours post-surgery then they were excluded from further analysis Patients in whom intermittent non-invasive ventilation is required the values will be obtained when they are off NIV and comfortable If the patient is receiving continuous NIV throughout the day then USG will not be done on that day However it will be done the next day when patent is off NIV
POPC will be diagnosed based on European perioperative clinical outcome guidelines10 and they will be graded for their severity based on the Clavien-Dindo11 classification The three main components of POPC which are of interest to our study are the occurrence of pneumonia clinically significant atelectasis or prolonged mechanical ventilation These are of particular interest because they have a significant impact on patient outcomes and very possibly are influenced by respiratory muscle strength Patients will be followed up for the development of POPC till postop day 5 this includes days in CSRU plus the days in the post cardiac surgical ward or the day of discharge from hospital whichever is earlier POPC diagnosis and assessment will be done by an independent investigator who will not know the DIA values Observation of patients in this patient population for POPCs following surgery is standard of care
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None