dexmedetomidine

To place the PV catheter at the T4-5 level, the authors used an in-plane transverse technique under ultrasound guidance, with the probe in a transverse orientation. After identifying the anatomic landmarks on ultrasound, a 17-gauge Tuohy needle was advanced in a lateral to medial direction, until the tip was beneath the transverse process. For all recipients in the study, the authors further confirmed correct PV catheter placement with real-time infusion of a local anesthetic (1-3 mL of 1.5% lidocaine with epinephrine 1:200,000); they were able to visualize on ultrasound the spread from the tip of the catheter.

Once it was confirmed that the tip remained in position, the PV catheter was secured with skin glue (Dermabond^®, Ethicon, Inc.; Somerville, NJ). Next, at the PV catheter insertion site, the authors placed an occlusive dressing on a chlorhexidine-impregnated sponge (BioPatch^®, Johnson & Johnson Wound Management, a division of Ethicon, Inc.; Somerville, NJ). The PV catheter was connected to an elastomeric pump (ON-Q^®, Halyard Health, Alpharetta, GA), an infusion of 0.2% ropivacaine was started at a rate of 0.2 to 0.25 mL/kg/h; the maximum dose was 7 mL/h per side in bilateral lung transplant recipients and 14 mL/h in unilateral single-lung transplant recipients.

Ultrasound-Guided Serratus Anterior Plane Block Versus Thoracic Epidural Analgesia for Thoracotomy Pain. JCVA February 2017. Volume 31, Issue 1, Pages 152–158.

Under sterile conditions and while patients still were in the lateral position with the diseased side up, a linear ultrasound transducer (10-12 MHz) was placed in a sagittal plane over the midclavicular region of the thoracic cage. Then the ribs were counted down until the fifth rib was identified in the midaxillary line (Fig 1).¹⁸ The following muscles were identified overlying the fifth rib: the latissimus dorsi (superficial and posterior), teres major (superior), and serratus muscles (deep and inferior). The needle (a 22-gauge, 50-mm Touhy needle) was introduced in plane with respect to the ultrasound probe, targeting the plane superficial to the serratus anterior muscle (Fig 2). Under continuous ultrasound guidance, 30 mL of 0.25% levobupivacaine was injected, and then a catheter was threaded. A continuous infusion of 5 mL/hour of 0.125% levobupivacaine then was started through the catheter.

Figure-17-Nagdev-2017-ACEP-Now-Ultrasound-Guided-Serratus-Anterior-Plane-Block-Can-Help-Avoid-Opioid-Use-for-Patients-with-Rib-Fractures- — From http://painandpsa.org/rnb/

Erector Spinae Plane Block

Effect of Continuous Paravertebral Dexmedetomidine Administration on Intraoperative Anesthetic Drug Requirement and Post-Thoracotomy Pain Syndrome After Thoracotomy: A Randomized Controlled Trial. JCVA February 2017. Volume 31, Issue 1, Pages 159–165.

Adjuvants to prolong regional anesthesia

For my single shot blocks, I’m always looking for ways to prolong my regional anesthetic effect. For awhile, Exparel was the most talked about drug to have a 72 hour blockade. We don’t have this medication available to us at the hospital. Therefore, it’s time to get creative and hit the literature to see what has worked for prolonging our blocks.

Prolonging blockade with adjuvants:

IOSR J of Dental and Medical Sci; Dec 2015. Comparative study of bupiv with dexamethasone and bupi with clonidine through single space PVB for post op analgesia in thoracic and abdominal surgeries.
- 0.125% Bupiv + clonidine (1mcg/kg) vs 0.125% bupiv + dexamethasone (4mg): greater duration of analgesia in the dexamethasone group.

Facilitatory effects of perineural dexmedetomidine on neuraxial and peripheral nerve block: a systematic review and meta-analysis. British Journal of Anaesthesia 110 (6): 915–25 (2013).
- Sensory block duration was prolonged by 150 min [95% confidence interval (CI): 96, 205, P,0.00001] with intrathecal dexmedetomidine. Perineural dexmedetomidine used in brachial plexus (BP) block may prolong the mean duration of sensory block by 284 min (95% CI: 1, 566, P¼0.05), but this difference did not reach statistical significance. Motor block duration and time to first analgesic request were prolonged for both intrathecal and BP block. Dexmedetomidine produced reversible bradycardia in 7% of BP block patients, but no effect on the incidence of hypotension. No patients experienced respiratory depression.
- Considerable differences existed in the doses of perineural dexmedetomidine; doses varied between 3, 5, 10, or 15 mcg for the intrathecal route, and 30, 100, 0.75, 1 mcg/kg for the peripheral route.

Investigating the Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthesia in Brachial Plexus Block: A Systematic Review and Meta-Analysis of 18 Randomized Controlled Trials. Regional Anesthesia and Pain Medicine: March/April 2017 – Volume 42 – Issue 2 – p 184–196.

Effective Dose of Intravenous Dexmedetomidine to Prolong the Analgesic Duration of Interscalene Brachial Plexus Block: A Single-Center, Prospective, Double-Blind, Randomized Controlled Trial. Regional Anesthesia and Pain Medicine: July 2018 – Volume 43 – Issue 5 – p 488–495.
- Intravenous DEX at a dose of 2.0 μg/kg significantly increased the duration of ISBPB analgesia without prolonging motor blockade and reduced the cumulative opioid consumption at the first 24 hours in patients undergoing arthroscopic shoulder surgery.

Dexmedetomidine prolongs the effect of bupivacaine in supraclavicular brachial plexus block. J Anaesthesiol Clin Pharmacol. 2014 Jan-Mar; 30(1): 36–40.
- 30 ml of 0.325% bupivacaine + 1 ml (100 μg) dexmedetomidine were given for supraclavicular brachial plexus block using the peripheral nerve stimulator.

Effects of perineural administration of dexmedetomidine in combination with bupivacaine in a femoral-sciatic nerve block. Saudi J Anaesth. 2016 Jan-Mar; 10(1): 18–24.
- Below knee surgery under combined femoral-sciatic nerve block were randomly allocated into two groups to have their block performed using bupivacaine 0.5% alone (group B) or bupivacaine 0.5% combined with 100 μg bupivacaine-dexmedetomidine

IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block: A Randomized, Three-arm, Triple-masked, Placebo-controlled Trial. Anesthesiology 3 2016, Vol.124, 683-695.
- Randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 μg/kg dexmedetomidine administered perineurally (Dex_P group), intravenously (Dex_IV group), or none (control group). Dex_IV was noninferior to Dex_P for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade.

Evidence basis for using perineural dexmedetomidine to enhance the quality of brachial plexus nerve blocks: a systematic review and meta-analysis of randomized controlled trials. BJA: British Journal of Anaesthesia, Volume 118, Issue 2, 1 February 2017, Pages 167–181.
- Upper limb block. A 50-60µg dexmedetomidine dose maximized sensory block duration while minimizing haemodynamic side-effects.

Review of Dexmedetomidine (Precedex) for Acute Pain and Analgesia. ASRA News, August 2018.

Awake Tracheostomy

They say that anesthesiology is 95% comfy and relaxed and the other 5% is “oh shit”! It’s a great career choice — pretty flexible hours, great patient contact, broad spectrum medicine, crisis management, leadership role, etc.

There happened to be an interesting case in the OR — awake tracheostomy for a patient coming in from home.

What’s a tracheotomy?

Evaluation of the airway PPT

The Difficult Airway in Head and Neck Tumor Surgery

Anesthesia for tracheostomy for huge maxillofacial tumor. From SJA: CASE REPORT Year : 2014 | Volume : 8 | Issue : 1 | Page : 124-127

Our patient had two prior tracheotomies all with successful decannulation. His most recent trach was about 2.5 months ago (which a fiberoptic intubation was used with a 6.0 ETT). He had a neck cancer with a rapidly growing tongue base tumor that seems to be less responsive to chemo than his shrinking neck tumor. Because of the enlarging size of the tongue base tumor, he is starting to notice worsening stridor without his trach. The ENT surgeon evaluated his airway just days before and deemed it unintubateable. Therefore, my plan was to have a pedi FO scope with 5.0 cuffed ETT (smallest available in our OR), glidescope, emergency cric supplies (14g angio cath, 3cc syringe with plunger removed and 7.0 ETT adapter hooked into the end of the syringe), jet ventilator and tubes, and ENT surgeon.

We decided to use a bit of midazolam as well as Precedex for the awake trach. The dosing on the package says 1 mcg/kg for 10 minutes then 0.7 mcg/kg/hr. We started with 0.5 mcg/kg for 10 minutes then 0.5 mcg/kg/hr. This regimen worked well as we started it in preop and monitored his SpO2 as he dozed off but was easily aroused to voice and gentle touch.

The Role of Dexmedetomidine for Awake Trach

Monitors were placed in the OR and we used a face mask running 10 L/min O2 with ETCO2 monitoring. Every now and then he would obstruct while lying supine, therefore, we placed a nasal trumpet to aid the obstruction. The surgeon localized the surgical area. See video for procedure.

The patient coughed once the trachea was perforated, but it was short lived as the surgeons were able to place the trach and hookup to our anesthesia circuit. After confirming ETCO2, we pushed propofol IV and the remainder of the case was performed under general anesthesia (direct laryngoscopy and biopsy by surgeon).

Key take home points

Effective communication with the patient pre-op: expectations, sedation, potential complications.
Arm yourself! Do this like you would a difficult airway! Fiberoptic intubation supplies, glidescope, emergency cricothyroidotomy supplies, backup LMA, extra hands on deck (grab your anesthesia colleagues, anesthesia techs, extra help!), ENT… it never hurts to be over prepared!
Deliberate, effective communication with the ENT colleague across the drape.
Document any intubation performed, tools used, trachs placed so your anesthesia colleagues will know what worked in the past to secure an airway.
Breathe a sigh of relief bc these kind of cases are extremely uncommon! Pat yourself on the back for a job well-done!

Now check out this amazing Case Report on a patient with a massive maxillofacial tumor!

The comparison of the effects of dexmedetomidine, fentanyl and esmolol on prevention of hemodynamic response to intubation

A study out of Turkey…

Curious to see how this works in our ASA 3 and 4 CABG cases.

The comparison of the effects of dexmedetomidine, fentanyl and esmolol on prevention of hemodynamic response to intubation.
Rev. Bras. Anestesiol. vol.64 no.5 Campinas Sept./Oct. 2014