Electrical velocimetry (ICON cardiometry) assessment of hemodynamic changes associated with different inflation pressures during pediatric thoracoscopic surgery: a pilot study

Background
Advances in endoscopic equipment and techniques have led to the use of minimally invasive thoracic surgery in an increasing number of pediatric surgical procedures. Logically, thoracoscopic surgery and anesthesia can induce significant physiologic changes; here comes the importance of an accurate, noninvasive cardiac output (CO) monitor for early diagnosis and management for any significant complications.
Aims
This study aimed to assess the effect of different intrathoracic pressures (ITP; insufflation pressures 4, 5, and 6 mmHg) during thoracoscopic surgeries in neonates and infants on hemodynamics using electrical velocimetry (ICON) as a noninvasive monitoring technique.
Patients and methods
This prospective pilot study was conducted in Abu El-Reesh Children’s Hospital, Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University, from November 2019 to January 2020. After obtaining ethical committee approval (D-6-2019) and registering at with the number NCT04131699, and after obtaining the consent of parents/legal guardians, 12 neonates and infants who presented for thoracoscopic surgery and met our selection criteria were included in the study. After standard premedication, monitoring, and anesthesia induction, for electrical velocimetry, an ‘ICON CARDIOTRONIC, OSYPKA MEDICAL’ continuous noninvasive CO monitor was attached to the patients according to the manufacturer’s instructions in neonates and infants. All patients’ data, including sex, height, and weight, were entered into the device, which estimated cardiovascular parameters at a 20-beat moving average recorded every 10 s. Cardiac index, CO, stroke volume, noninvasive arterial blood pressure, and heart rate readings had been taken in every patient. Records were taken before inflation of the chest as a baseline reference, 1 min after inflation of the chest as the ITP reaches 4 mmHg, then the ITP was increased to 5 mmHg, and the readings were taken after an extra 1 min. Finally, the ITP was increased to 6 mmHg, and the readings were taken after an additional 1 min.
Results
A total of 14 patients were screened for eligibility; of them, two patients were excluded for not meeting the inclusion criteria, and 12 patients were included. The median (interquartile range) age of patients was 4.5 (3–28) days. Sex distribution was equal (six males and six females). The cardiac index showed no significant increase with raising the pleural pressure (PP) by CO insufflation and postdeflation in comparison with baseline (preinsufflation). The CO showed no significant increase with raising the PP by CO insufflation in comparison with baseline (preinsufflation). Mean arterial blood pressure showed no significant change with gradual increase in PP and after deflation in comparison with preinflation readings; however, heart rate showed significant decrease after deflation in comparison with baseline (preinsufflation).
Conclusion
Hemodynamic stability was maintained during thoracoscopic surgery in neonates as measured by ICON. Further studies including systemic vascular resistance need to be done to give more explanation about hemodynamic affection during positive PP inflation. Moreover, different age groups, different patients’ positions, and patients with cardiac and pulmonary lesions need to be included to assess the various effects of pleural insufflation on these populations.