1.Enhanced accuracy in gravity-based intravenous infusion using pulse oximeter drop counting and measured single-drop weights
Daeseok OH ; Myoung Jin KO ; Jae Hwan KIM ; Yeiheum PARK ; Sungho MOON
Anesthesia and Pain Medicine 2025;20(3):230-241
Background:
Intravenous (IV) fluid therapy is essential and widely used; however, it is associated with high error rates, largely due to human factors, necessitating constant and careful monitoring by medical staff. Gravity-based systems are prone to errors, whereas electronic pumps, though more accurate, are limited by size, cost, and complexity. In this study, the impact of single-drop weight measurement and real-time light source monitoring on the accuracy of gravity-based infusion systems was evaluated.
Methods:
Gravity-based IV sets with IV infusion flow regulators (IIFRs) from three manufacturers were tested using 1,000 ml of 0.9% saline. The drops per min and the drop weight were recorded using a pulse oximeter, which served as a light source. The flow rates from the pulse oximeter group (PO) were compared with those from the manufacturer’s drop volume (C) and the IIFR groups. The mean absolute percentage error (MAPE) of predicted versus actual volumes was analyzed along with correlations between the residual volume and drop rate.
Results:
The PO group values were statistically closer to those of the actual measurements than the C and IIFR groups values (P < 0.05), demonstrating higher accuracy and lower MAPE, except at 300 ml/h when than those of the C group, independent of residual volume. The residual volume strongly correlated with the drop rate (r > 0.9).
Conclusions
Real-time drop measurements using light sources combined with single-drop weight assessment improve the accuracy of these systems. Integrating pulse oximeters into IV sets may enhance clinical precision and reduce provider workload.
2.A rare subclavian artery aneurysm potentially misidentified as the internal jugular vein in ultrasound-guided central venous catheterization -a case report-
Korean Journal of Anesthesiology 2024;77(6):635-639
Background:
Central venous catheterization by anesthesiologists carries risks such as accidental arterial puncture. This case report highlights a rare subclavian artery aneurysm (SAA) detected during ultrasound-guided internal jugular vein (IJV) access, emphasizing the importance of recognizing anatomical variations.Case: An 88-year-old female with hypertension and atrial fibrillation was scheduled for lumbar laminectomy and posterior fusion. Preoperative evaluation revealed right lower lobe atelectasis and mild aortic sclerosis. During ultrasonography for right IJV catheterization, two vessels of different diameters were observed on the common carotid artery’s lateral side. The larger vessel disappeared at the upper neck level, showing arterial pulsation on Color Doppler. Postoperative neck computed tomography confirmed a right SAA and a 5-mm saccular aneurysm in the left intracranial artery. The patient had no vascular disease, trauma, or relevant family histories.
Conclusions
Anesthesiologists should be aware of anatomical variations during IJV catheterization. Ultrasound with Doppler is crucial for accurate artery identification.
3.A rare subclavian artery aneurysm potentially misidentified as the internal jugular vein in ultrasound-guided central venous catheterization -a case report-
Korean Journal of Anesthesiology 2024;77(6):635-639
Background:
Central venous catheterization by anesthesiologists carries risks such as accidental arterial puncture. This case report highlights a rare subclavian artery aneurysm (SAA) detected during ultrasound-guided internal jugular vein (IJV) access, emphasizing the importance of recognizing anatomical variations.Case: An 88-year-old female with hypertension and atrial fibrillation was scheduled for lumbar laminectomy and posterior fusion. Preoperative evaluation revealed right lower lobe atelectasis and mild aortic sclerosis. During ultrasonography for right IJV catheterization, two vessels of different diameters were observed on the common carotid artery’s lateral side. The larger vessel disappeared at the upper neck level, showing arterial pulsation on Color Doppler. Postoperative neck computed tomography confirmed a right SAA and a 5-mm saccular aneurysm in the left intracranial artery. The patient had no vascular disease, trauma, or relevant family histories.
Conclusions
Anesthesiologists should be aware of anatomical variations during IJV catheterization. Ultrasound with Doppler is crucial for accurate artery identification.
4.A rare subclavian artery aneurysm potentially misidentified as the internal jugular vein in ultrasound-guided central venous catheterization -a case report-
Korean Journal of Anesthesiology 2024;77(6):635-639
Background:
Central venous catheterization by anesthesiologists carries risks such as accidental arterial puncture. This case report highlights a rare subclavian artery aneurysm (SAA) detected during ultrasound-guided internal jugular vein (IJV) access, emphasizing the importance of recognizing anatomical variations.Case: An 88-year-old female with hypertension and atrial fibrillation was scheduled for lumbar laminectomy and posterior fusion. Preoperative evaluation revealed right lower lobe atelectasis and mild aortic sclerosis. During ultrasonography for right IJV catheterization, two vessels of different diameters were observed on the common carotid artery’s lateral side. The larger vessel disappeared at the upper neck level, showing arterial pulsation on Color Doppler. Postoperative neck computed tomography confirmed a right SAA and a 5-mm saccular aneurysm in the left intracranial artery. The patient had no vascular disease, trauma, or relevant family histories.
Conclusions
Anesthesiologists should be aware of anatomical variations during IJV catheterization. Ultrasound with Doppler is crucial for accurate artery identification.
8.A rare subclavian artery aneurysm potentially misidentified as the internal jugular vein in ultrasound-guided central venous catheterization -a case report-
Korean Journal of Anesthesiology 2024;77(6):635-639
Background:
Central venous catheterization by anesthesiologists carries risks such as accidental arterial puncture. This case report highlights a rare subclavian artery aneurysm (SAA) detected during ultrasound-guided internal jugular vein (IJV) access, emphasizing the importance of recognizing anatomical variations.Case: An 88-year-old female with hypertension and atrial fibrillation was scheduled for lumbar laminectomy and posterior fusion. Preoperative evaluation revealed right lower lobe atelectasis and mild aortic sclerosis. During ultrasonography for right IJV catheterization, two vessels of different diameters were observed on the common carotid artery’s lateral side. The larger vessel disappeared at the upper neck level, showing arterial pulsation on Color Doppler. Postoperative neck computed tomography confirmed a right SAA and a 5-mm saccular aneurysm in the left intracranial artery. The patient had no vascular disease, trauma, or relevant family histories.
Conclusions
Anesthesiologists should be aware of anatomical variations during IJV catheterization. Ultrasound with Doppler is crucial for accurate artery identification.

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