Various modalities have been proposed for real-time confirmation of loss of resistance (LOR) for thoracic epidural blocks. With real-time ultrasound (US) guidance, the anesthesiologist attempts to visualize the sonographic advancement of the epidural needle and penetration of the epidural space (as detected by LOR) This observational study is set out to confirm the reliability of real-time ultrasound guidance as an adjunct to LOR for thoracic epidural blocks.
Study Type
OBSERVATIONAL
Enrollment
100
With an US-guided parasagittal oblique approach, the interlaminar space at the union between laminas and spinous processes at the predefined insertion level will be identified. A skin wheal will be raised with 3 mL of lidocaine 1%. Afterward, an 18-gauge Tuohy epidural block needle will be advanced under direct US vision until the tip is insinuated between the laminas and anchored to the flavum ligament. Then the needle will be attached to a low resistance syringe prefilled with saline solution and advanced until LOR to injection is confirmed. Then a 20-Gauge epidural catheter will be inserted 3-5 cm beyond the needle tip inside the epidural space and the needle removed.
Hospital Clínico Universidad de Chile
Santiago, Metropolitan, Chile
Percentage of successful epidural blocks after US-guided insertion of epidural catheters
After fifteen minutes of local anesthetic administration (4- mL dose of lidocaine 2% with epinephrine 5 μg/mL ), an investigator will apply ice to the T1 to L4 dermatomes bilaterally. The criterion standard for success will be the presence of an epidural block, defined as a block to ice in at least 2 dermatomes bilaterally. If operators could not advance the catheter past the needle tip after 2 attempts despite a 180-degree rotation of the bevel between the first and second attempts, epidural blocks will be considered failures.
Time frame: 15 minutes after the local anesthetic injection through the epidural catheter
Number of blocked dermatomes
Number of blocked dermatomes after injection of local anesthetics through the epidural catheter.
Time frame: 15 minutes after the local anesthetic injection through the epidural catheter
Localization of blocked dermatomes
Localization of blocked dermatomes after injection of local anesthetics through the epidural catheter.
Time frame: 15 minutes after the local anesthetic injection through the epidural catheter
Image time
Needed time (minutes and seconds) to obtain an adequate image of the interlaminar space
Time frame: Up to 30 minutes after skin disinfection
Needle time
Needed time (minutes and seconds) to insert the Tuohy needle tip in the interlaminar space and confirm a loss of resistance
Time frame: Up to 30 minutes after skin disinfection
Catheter installation time
Elapsed time (minutes and seconds) from loss of resistance acquisition until the catheter is secured
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: Up to 30 minutes after skin disinfection
Block performance time
Time (minutes and seconds) between skin disinfection and once the catheter is secured in place.
Time frame: Up to 30 minutes after skin disinfection
Epidural block-related complications
Incidence of adverse events related to epidural block or local anesthetic injection (i.e. paresthesia, accidental dural puncture, intravascular or subarachnoid position of catheters, intravascular, subarachnoid or subdural injection, local anesthetic systemic toxicity)
Time frame: Up to 30 minutes after skin disinfection