Determination and prediction of the appropriate depth of right internal jugular vein catheterization via the middle approach in adults using transesophageal echocardiography

Optimal insertion depth of subclavian vein catheterization via the right supraclavicular approach in children

BACKGROUND

Methods to determine the optimal insertion depth of ultrasound-guided supraclavicular approach to the subclavian vein (SCV) catheterization, alternatively used for central venous access, are debatable in children.

AIM

We investigated the applicability and reliability of the modified formula for determining the depth of SCV catheterization using an ultrasound-guided supraclavicular approach in children.

METHODS

This prospective observational study included 36 children (age <6 years; weight ≥5 kg) scheduled to undergo congenital heart disease surgery. After intubation, ultrasound-guided supraclavicular approach to the SCV catheterization was performed. Actual insertion depth was determined by real-time transesophageal echocardiography. Insertion depth was calculated by subtracting 1 cm from the sum of the distance from the insertion point to the sternal head of the right clavicle and that from the latter point to the midpoint of a perpendicular line drawn from the sternal head of the right clavicle to the line connecting the nipples.

RESULTS

Insertion depth calculated with the modified formula and actual insertion depth of the SCV catheter correlated strongly (r = .806, 95% confidence interval [CI]: 0.658-0.908; p < .001). Bland-Altman analysis showed a mean bias and precision of 0.36 and 0.65 cm, respectively (95% CI: 0.14-0.58, 95% limits of agreement: -0.92, 1.64). All plots were above the -1.0 line, indicating no catheter tip insertion into the right atrium.

CONCLUSIONS

Optimal insertion depth for an ultrasound-guided supraclavicular approach to the SCV catheterization can be calculated using modification of a surface landmark formula in children younger than 6 years and weight heavier than 5 kg.

A bedside rescue method for retrieving retained guidewires: The 'Suck Out' technique

BACKGROUND

Central venous catheter guidewire retention is classed as a 'never event' in the United Kingdom, with the potential for significant patient harm. If the retained guidewire remains within the central venous catheter lumen, bedside techniques may facilitate guidewire retrieval. However, these techniques may be ineffective if the guidewire has already passed below skin level. We investigated a novel 'suck out' technique for bedside guidewire retrieval and compared this against traditional retrieval methods.

METHODS

Simulation 1: in a benchtop model, seven different central venous catheters had their corresponding guidewire placed in the last 2 cm of the catheter tip which was immersed horizontally in fluid. A 50-mL syringe was attached to the distal lumen central venous catheter hub and suction applied for 5 s, and the distance of guidewire retraction was recorded. Simulation 2: a central venous catheter guidewire was intentionally retained within the catheter at either 5 cm above or below skin level in a pigskin model. Simple catheter withdrawal, catheter clamping withdrawal and the 'suck out' method were compared for efficacy using Fisher's exact test.

RESULTS

Simulation 1: retained guidewires were retracted by 13 cm on average. Simulation 2: when guidewires were retained 5 cm above skin level, all retrieval methods were 100% effective; however, when retained 5 cm below skin level, simple catheter withdrawal was ineffective, clamping and withdrawal was only 10% effective and the 'suck out' technique was 90% effective (p < 0.001).

CONCLUSION

The 'suck out' technique can effectively retract guidewires retained within central venous catheter lumens and demonstrates superiority over traditional methods of retained guidewire extraction in simulated models.