Comparative effects of plain and epinephrine-containing bupivacaine on the hemodynamic response to cervical plexus anesthesia in patients undergoing carotid endarterectomy

Ultrasound-guided bilateral superficial cervical plexus block for thyroid surgery: The effect of dexmedetomidine addition to bupivacaine-epinephrine

Background:

The thyroid gland surgery is a common and painful procedure demanding analgesia. Many regional techniques are applied for anterior neck surgeries mostly assigned in relation to the involved cervical fascia. Dexmedetomidine (Precedex) is a selective alpha 2 adrenoceptor agonist which prolongs the sensory blockade duration of local anesthetics. Our study hypothesis is that ultrasound (US)-guided bilateral superficial cervical plexus block (BSCPB) may provide longer analgesia when adding dexmedetomidine to bupivacaine-epinephrine.

Purpose:

The aim of this study is to evaluate the analgesic efficacy and possible side effects of US-guided BSCPB and the effect of dexmedetomidine addition to bupivacaine-epinephrine in patients undergoing thyroid surgery.

Methods:

This prospective, double-blind, randomized study was performed on 42 patients randomized into two equal groups each of 21; bupivacaine Group B and dexmedetomidine Group D. Patients with contraindications to regional anesthesia or uncontrolled comorbidities were excluded from the study. Total pethidine consumption in 24 h is the primary outcome. The visual analog scale, timing of the first opioid request, and hemodynamics are the secondary outcomes.

Results:

In Group D, there was a longer time to the first request of opioid postoperatively, a lower total pethidine consumption and pain score postoperatively, and lower fentanyl requirements intraoperatively.

Conclusions:

Sonographic-guided bilateral SCPB using a combination of bupivacaine, dexmedetomidine, and epinephrine was superior to bupivacaine for prolonged analgesia with less intra- and postoperative opioid consumption and lower side effect profile during thyroid surgery.

Additives to local anesthetics for peripheral nerve blocks or local anesthesia: a review of the literature

SUMMARY 

A multitude of studies have focused on individual additives to local anesthetics and their effect on quality, onset, duration, spread and selectivity, as well as the potential toxic effects of their use. This review aims to give a broad overview of the current evidence in this developing field, based on beneficial and adverse effects of these drugs. We discuss the limitations of the available data and hope to convey implications and future perspectives for clinicians and researchers alike.

Superficial or deep cervical plexus block for carotid endarterectomy: a systematic review of complications †

Carotid endarterectomy is commonly conducted under regional (deep, superficial, intermediate, or combined) cervical plexus block, but it is not known if complication rates differ. We conducted a systematic review of published papers to assess the complication rate associated with superficial (or intermediate) and deep (or combined deep plus superficial/intermediate). The null hypothesis was that complication rates were equal. Complications of interest were: (1) serious complications related to the placement of block, (2) incidence of conversion to general anaesthesia, and (3) serious systemic complications of the surgical-anaesthetic process. We retrieved 69 papers describing a total of 7558 deep/combined blocks and 2533 superficial/intermediate blocks. Deep/combined block was associated with a higher serious complication rate related to the injecting needle when compared with the superficial/intermediate block (odds ratio 2.13, P = 0.006). The conversion rate to general anaesthesia was also higher with deep/combined block (odds ratio 5.15, P < 0.0001), but there was an equivalent incidence of other systemic serious complications (odds ratio 1.13, P = 0.273; NS). We conclude that superficial/intermediate block is safer than any method that employs a deep injection. The higher rate of conversion to general anaesthesia with the deep/combined block may have been influenced by the higher incidence of direct complications, but may also suggest that the superficial/combined block provides better analgesia during surgery.

Altered Autonomic Cardiovascular Regulation After Combined Deep and Superficial Cervical Plexus Blockade for Carotid Endarterectomy

Compromised cardiac autonomic modulation can produce cardiovascular disturbances. We investigated whether combined deep and superficial cervical plexus (CP) blockade for carotid endarterectomy (CEA) produces changes in autonomic cardiovascular regulation. To estimate alterations in cardiovascular autonomic control before and after combined CP blockade in 22 patients undergoing CEA, the heart rate (HR) variability, systolic blood pressure (SBP) variability, and baroreflex sensitivity were analyzed. We found that SBP (157 +/- 28 mm Hg versus 191 +/- 38 mm Hg before and after combined CP blockade, respectively) and HR (68 +/- 10 bpm versus 84 +/- 9 bpm) increased after combined CP blockade. The high frequency power of HR variability (3.7 +/- 0.9 versus 2.2 +/- 1.2 ln/ms2) decreased (decrease in parasympathetic drive), whereas the low frequency power of SBP variability (5.5 +/- 4.7 versus 8.6 +/- 9.4 mm Hg2) increased (increase in vascular sympathetic outflow). Baroreflex sensitivity decreased, and this decrease was negatively correlated with a SBP increase (r = -0.455). The present results suggest that combined CP blockade impairs autonomic cardiovascular homeostasis and suggests an association between combined CP blockade and intraoperative or postoperative adverse cardiovascular events in high-risk cardiac patients undergoing CEA that merits further studies.

A comparison of dexmedetomidine versus conventional therapy for sedation and hemodynamic control during carotid endarterectomy performed under regional anesthesia

The properties of dexmedetomidine (DEX) that result in titratable sedation and sympathetic modulation suggest that it would be suitable for use during carotid endarterectomy (CEA) performed under regional anesthesia. We performed a randomized, double-blind study in 56 patients having CEA under regional anesthesia and compared hemodynamic control using DEX versus a conventional sedation technique using midazolam and fentanyl standard (STD). Sedation was titrated to a Ramsay Sedation Score of 2-4 in both groups. The primary outcome was the number of pharmacological interventions required to treat deviations of arterial blood pressure and heart rate outside of predetermined limits. We also compared recovery hemodynamic profiles, patient satisfaction, and adverse cardiac and neurological events. There was no difference in the overall rate of hemodynamic interventions (DEX 80% versus STD 79%; P = 1.0). However, the nature of interventions differed in that patients in the DEX group were less likely to require treatment for hypertension and/or tachycardia (DEX 40% versus STD 72%; P = 0.03). The number of interventions per patient for hypertension and/or tachycardia was also lesser in the DEX group (P = 0.02). There were no significant differences in the numbers of patients needing intraoperative treatment for hypotension or bradycardia or in the need for intraarterial shunting. In the postanesthesia care unit, more patients in the DEX group required hemodynamic drug interventions (DEX 11, 44%, versus STD 4, 14%; P = 0.03). These were primarily for hypotension (DEX 7, 28% versus STD 3, 11%; P = 0.16). The number of patients requiring no additional pain relief in the postanesthesia care unit was significantly larger for patients in the DEX group (DEX 18, 72% versus STD 11, 38%; P = 0.027). DEX provides an acceptable alternative, without superiority to standard techniques for sedation during awake CEA.