Cervical plexus block enhanced pain control for unilateral thermal ablation of thyroid nodules
Matrix Man Him Fung
, Yan Luk
, Brian Hung Hin Lang
Contributions: (I) Conception and design: MMH Fung; (II) Administrative support: Y Luk; (III) Provision of study materials or patients: MMH Fung, Y Luk; (IV) Collection and assembly of data: MMH Fung; (V) Data analysis and interpretation: MMH Fung; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors.
Background: Despite being minimally invasive, thermal ablation (TA) of thyroid nodules may still cause significant pain during and shortly afterwards. Conventional analgesia relies on perithyroidal local anesthesia (PLA) with or without sedation. The use of cervical plexus block (CPB) has been extensively studied in thyroidectomy, but never studied in TA of the thyroid gland. This study examined whether adding ultrasound-guided CPB to PLA and sedation could further reduce post-operative pain in unilateral TA of thyroid nodules.
Methods: Consecutive patients aged ≥18 years undergoing unilateral radiofrequency ablation (RFA) or microwave ablation (MWA) of thyroid nodules were reviewed. Group I patients did not receive CPB, and Group II patients received CPB by bupivacaine injection between the sternocleidomastoid muscle (SCM) and prevertebral fascia on the treatment side. Pain was charted immediately and 4 hours after ablation using a numeric rating scale (NRS) of 0–10. The Quality-of-Recovery-9 (QoR9) questionnaire was completed.
Results: Over an 18-month period, 100 patients underwent unilateral thyroid ablation (Group I, n=50; Group II, n=50). Comparable baseline patient demographics, nodule characteristics, ablation parameters were noted (P>0.05). Significantly lower immediate NRS {1 [0–3] vs. 4 [1.3–6], P<0.001}, 4-hour NRS {1 [0–3] vs. 2 [0–4], P=0.04}, and more zero immediate NRS (44% vs. 14%, P=0.001) was observed in Group II. Total QoR9 scores were comparable {16 [12–17] vs. 15 [12–17], P=0.72}. No adverse events occurred. All patients were discharged within the same day.
Conclusions: Adding ultrasound-guided CPB further enhanced pain control following unilateral TA of thyroid nodules, without compromising quality of recovery or same-day discharge.
Keywords: Thyroid nodule; pain; radiofrequency ablation (RFA); cervical plexus block (CPB); quality of recovery
Submitted Jun 05, 2024. Accepted for publication Aug 09, 2024. Published online Aug 28, 2024.
doi: 10.21037/gs-24-217
Highlight box
Key findings
• Cervical plexus block effectively reduced pain in unilateral thermal ablation of thyroid nodules.
What is known and what is new?
• The use of ultrasound guided cervical plexus block has not been studied in thermal ablation of thyroid nodules.
• This study showed that adding cervical plexus block enhanced pain control in unilateral thermal ablation of thyroid nodules, with 44% of patients having no pain at all after the procedure.
• The technique was safe and did not compromise quality of recovery or same-day discharge.
What is the implication, and what should change now?
• Cervical plexus block should be considered to optimize pain control in unilateral thermal ablation of thyroid nodules.
Introduction
Thermal ablation (TA) is an effective minimally invasive treatment for benign, symptomatic thyroid nodules (1-4). Currently, the most commonly performed TA procedures for thyroid nodules include radiofrequency ablation (RFA) and microwave ablation (MWA) (4-10). Both procedures require percutaneous insertion of an electrode into the target nodule. TA is usually well-tolerated under perithyroidal injection of local anesthesia (LA). Nevertheless, it can still cause significant pain, discomfort (11-14), cause unnecessary patient anxiety or movement, compromising patient experience and potentially the quality of ablation. A previous study has shown that adding intravenous sedation on top of perithyroidal LA reduced pain further (15), suggesting room for improvement in patient experience in the conventional set up with perithyroidal LA alone.
Cervical plexus block (CPB) has been extensively studied and used in peri-operative analgesia for open thyroidectomy (16-25). It is an effective, simple and safe procedure that could be carried out quickly. Since TA with RFA and MWA also involves a skin wound and manipulation of the thyroid gland, it is postulated that CPB could reduce pain experienced in RFA and MWA. Understandably, both RFA and MWA differ from surgery by being minimally invasive procedures with only one to two tiny skin punctures, and the pain induced by heat within the thyroid gland may be different from that of removing the entire gland and capsular dissection in open surgery. The role of CPB in TA of thyroid nodules has never been studied. This study sets out to be the first study investigating whether the addition of CPB to perithyroidal LA and sedation could further reduce post-operative pain in unilateral TA of thyroid nodules. We present this article in accordance with the STROBE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-24-217/rc).
Methods
This study was approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (No. UW 22-506). All participants gave informed consent. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013).
Patients and technique of CPB
From November 2022 to April 2024, consecutive patients who underwent RFA or MWA for unilateral benign thyroid nodules in two tertiary endocrine surgery centers were reviewed. The same surgical team performed all procedures. Exclusion criteria include inability to report pain scores reliably, and/or complete a recovery questionnaire. Before ablation, all received intravenous Midazolam (Cheplarpharm, Greifswald, Germany) (1–3 mg, <0.05 mg/kg), Pethidine (Martindale Pharmaceuticals, Romford, Essex, UK) (15–30 mg, <0.5 mg/kg), and perithyroidal 1% lidocaine (Hospira Inc., Lake Forest, IL, USA) under standardized protocol. In the first half of the study period, patients did not receive CPB (Group I). In the second half of the study period, patients received CPB in addition to perithyroidal LA and sedation (Group II).
For Group II patients, CPB was performed on the treatment side before ablation. Under ultrasound guidance, a 21 G needle was inserted at the midpoint of the neck between the clavicle and mandible. The needle was inserted from medial to lateral through the sternocleidomastoid muscle (SCM), aiming lateral and away from the carotid sheath structures (Figures S1,S2); 10 mL 0.25% bupivacaine was injected between the SCM and prevertebral fascia (Figure 1). Patients’ vital signs (respiratory rate, oxygen saturation, blood pressure, pulse rate) were monitored from beginning of procedure to discharge. Intra-operative laryngeal ultrasonography was performed after CPB injection, and throughout the ablation procedure to monitor the vocal cord status (26).
Outcomes
The primary outcome of the study is the post-operative pain score. It is rated by a 0–10 numeric rating scale (NRS). A score of 10 indicates the most severe pain and a score of 0 indicates no pain. NRS was charted immediately after TA, and also 4 hours after TA.
The other outcomes include quality of recovery, and any complications related to CPB. Quality of recovery after TA was assessed by the Quality-of-Recovery-9 (QoR9) questionnaire just before discharge, which is 4–6 hours after TA when patients have already regained consciousness fully. This is a questionnaire that consists of nine items, each carrying two points. The total score would range from 0 to 18. The higher the total score, the better the quality of recovery. This questionnaire has been widely validated and shown to correlate with post-operative quality of recovery (27-29). It is easy to fill in. Since our cohort consists of Chinese patients, a validated Chinese version was also provided in addition to the original English version of the questionnaire to our patients to ensure good understanding (30).
Statistical analysis
Normally distributed data were described with means ± standard deviations, and non-normally distributed data were described with medians (interquartile range). The paired t-test, Man Whitney-U test were used to compare continuous variables. The Chi-squared test and Fisher’s exact test were used to compare categorical variables. Missing data, if any, were removed from analysis. A P value of <0.05 was defined as being statistically significant. The software IBM SPSS (version 28, IBM Corp., Armonk, NY, USA) was used for all analyses.
Results
Over the study period, 104 consecutive patients undergoing unilateral RFA or MWA were considered. After excluding four patients who could not reliably report pain scores and fill in questionnaires due to cognitive impairment, 100 patients were included. Fifty patients belonged to Group I (no CPB), and 50 belonged to Group II (CPB). Table 1 showed the baseline characteristics between the two groups. Group II patients had older age (54±14 vs. 49±13 years, P=0.03), but otherwise comparable baseline characteristics with Group I in terms of sex, body mass index (BMI), thyroid function and comorbidities. Nodule characteristics were comparable in terms of indication for ablation, number of nodules ablated, laterality and method of ablation (P>0.05). There was no statistically significant difference in terms of nodule volume, although a trend of larger nodule volume for Group II was observed (P=0.16). Similarly, no significant difference was observed for the total energy applied, energy applied per unit volume, total ablation time and ablation time per unit volume (P>0.05), although a trend of greater ablation energy and ablation time was noted in Group II. Other treatment parameters in terms of number of skin punctures, lidocaine, midazolam and pethidine dosages were comparable (Table 2).
Table 1
| Characteristics | Group I (n=50) | Group II (n=50) | P value |
|---|---|---|---|
| Age at treatment (years) | 49±13 | 54±14 | 0.03 |
| Sex | 0.61 | ||
| Male | 1 [2] | 2 [4] | |
| Female | 49 [98] | 48 [96] | |
| BMI (kg/m2) | 23.9±3.5 | 24.1±4.0 | 0.32 |
| Smoking | 2 | 2 | >0.99 |
| Drinking | 0 | 0 | >0.99 |
| Diabetes mellitus | 2 | 1 | >0.99 |
| Baseline TSH (mIU/L) | 1.41±0.94 | 1.23±0.77 | 0.55 |
| Baseline fT4 (pmol/L) | 16.6±5.2 | 15.7±2.3 | 0.64 |
| Indication for ablation | 0.49 | ||
| Benign non-functional thyroid nodule | 49 [98] | 50 [100] | |
| Toxic thyroid nodule | 1 [2] | 0 | |
| Number of nodules ablated in the same session | 0.09 | ||
| Single nodule | 37 [74] | 29 [58] | |
| Multiple nodules | 13 [26] | 21 [42] | |
| Method of ablation | 0.42 | ||
| RFA | 24 [48] | 28 [56] | |
| MWA | 26 [52] | 22 [44] | |
| Laterality of ablation | |||
| Right | 24 | 30 | 0.27 |
| Left | 25 | 20 | |
| Nodule width | 2.73 [2.23–3.73] | 3.23 [2.52–4.04] | 0.11 |
| Nodule length | 3.52 [2.87–4.20] | 3.78 [3.03–4.50] | 0.32 |
| Nodule depth | 2.28 [1.72–2.76] | 2.39 [1.95–2.84] | 0.29 |
| Nodule volume | 11.3 [5.7–21.4] | 14.9 [7.2–27.6] | 0.16 |
| Solid component (%) | 100 [80–100] | 100 [100–100] | 0.08 |
Group I did not receive CPB and Group II received ultrasound-guided CPB. Data are presented as mean ± standard deviation, n [%] or median [interquartile range] as appropriate. BMI, body mass index; TSH, thyroid stimulating hormone; fT4, free T4; RFA, radiofrequency ablation; MWA, microwave ablation; CPB, cervical plexus block.
Table 2
| Treatment parameter | Group I (n=50) | Group II (n=50) | P value |
|---|---|---|---|
| Total ablation energy (Joule) | 18,735 [9,900–35,333] | 31,672 [12,570–49,915] | 0.11 |
| Energy applied per unit volume (Joule/mL) | 1,697 [1,121–2,690] | 2,034 [1,527–2,460] | 0.56 |
| Total ablation time (seconds) | 630 [279–965] | 814 [434–1,208] | 0.09 |
| Ablation time per unit volume (seconds/mL) | 49 [38–76] | 53 [38–68] | 0.81 |
| Number of skin punctures per patient | 1 [1–2] | 1 [1–1] | >0.99 |
| Volume of perithyroidal 1% lidocaine/kg body weight (mL/kg) | 0.11 [0.07–0.14] | 0.11 [0.07–0.15] | 0.78 |
| Midazolam per kg body weight (mg/kg) | 0.04 [0.04–0.05] | 0.05 [0.04–0.05] | 0.11 |
| Pethidine per kg body weight (mg/kg) | 0.4 [0.4–0.5] | 0.4 [0.4–0.5] | 0.51 |
Group I did not receive CPB and Group II received ultrasound-guided CPB. Data are presented as median [interquartile range]. CPB, cervical plexus block.
The early post-TA outcomes were compared in Table 3. In Group II (CPB), NRS were significantly lower than Group I at both immediately {1 [0–3] vs. 4 [1.3–6], P<0.001} and 4 hours {1 [0–3] vs. 2 [0–4], P=0.04} after TA. Notably, 44% of Group II patients experienced no pain at all immediately after ablation, versus only 14% of Group I patients had this favourable outcome (P=0.04). Both groups had comparable QoR9 scores (P=0.72), indicating no additional negative effect of CPB on quality of recovery from TA. There were no complications from both groups in terms of vocal cord palsy, skin complications, nodule rupture, hematoma requiring operation and complications from sedation including cardiopulmonary suppression and neuropsychiatric complications. No complications related to CPB occurred. All patients of both groups could be discharged on the day of treatment.
Table 3
| Outcome | Group I (n=50) | Group II (n=50) | P value |
|---|---|---|---|
| Pain NRS immediately after ablation | 4 [1.3–6] | 1 [0–3] | <0.001 |
| Number of patients with zero NRS immediately after ablation, i.e., no pain | 7 [14] | 22 [44] | 0.001 |
| Pain NRS at 4 hours after ablation | 2 [0–4] | 1 [0–3] | 0.04 |
| Total QoR9 score upon discharge | 15 [12–17] | 16 [12–17] | 0.72 |
| Post-operative unilateral VCP | 0 | 0 | >0.99 |
| Skin complications | 0 | 0 | >0.99 |
| Nodule rupture | 0 | 0 | >0.99 |
| Hematoma requiring operation | 0 | 0 | >0.99 |
| Severe complications from sedation | 0 | 0 | >0.99 |
| Complications from CPB | 0 | 0 | >0.99 |
| Discharge within the same day | 50 [100] | 50 [100] | >0.99 |
Group I did not receive CPB and Group II received ultrasound-guided CPB. Data are presented as median [interquartile range] or n [%]. NRS, numeric rating scale; QoR9, Quality-of-Recovery-9 score; VCP, vocal cord palsy; CPB, cervical plexus block.
Discussion
To our knowledge, the current study is the first that investigated the use of CPB in TA of thyroid nodules. We found that, in addition to perithyroidal LA and sedation, CPB further reduced procedural related pain immediately and 4 hours after TA. We find this technique helpful in optimizing pain control and improving the overall experience of our patients.
Despite the smaller wounds involved in TA when compared to open thyroidectomy which may mean less pain, CPB still further improved the pain experience when compared with no CPB. Notably, almost half of our patients experienced no pain at all, suggesting CPB being highly effective. It is important to note that, albeit the difference being statistically insignificant, Group II (CPB) patients had a trend of receiving greater ablation energy, and longer duration of ablation. Receiving more heat energy, and a longer ablation time would generally mean more discomfort and pain to patients, yet Group II (CPB) patients experienced less pain. This further proved the effectiveness of CPB in pain control. In fact, the good pain control provided by CPB may allow more thorough ablations with more energy and time. It would be interesting and important to compare the volume reduction rates of Group I (no CPB) and Group II (CPB) nodules in future follow-up studies, in order to prove this hypothesis.
None of the patients who received CPB had complications, proving the safety of CPB. Moreover, CPB did not affect quality of recovery. All patients that received CPB could be discharged in the same day. These suggest that CPB could be safely added to TA, without compromising the advantages of it being an ambulatory procedure. In our previous paper, we find intravenous sedation safe and effective in pain control for TA, without compromising quality of recovery or same-day discharge. However, the authors acknowledge that there are certain centers where only qualified professionals, such as an anesthetist or someone who is not conducting the ablation, are permitted to administer intravenous sedation. This would have increased the cost of TA. Therefore, in settings where intravenous sedation is not practical, CPB may be a good alternative to enhance pain control, in addition to perithyroidal LA. We understand that it would take another study with subjects not receiving sedation at all to allow a more robust proof to this hypothesis.
We find the technique of ultrasound-guided CPB easy to learn, as thyroid TA operators are already familiar with the anatomy of the neck and also needle manipulation under ultrasound guidance. We suggest a technique of injecting CPB from medial to lateral through the SCM, into the space between the SCM and prevertebral fascia where the cervical plexus traverses. With this technique, the needle orientation and angulation would be similar to that to the trans-isthmic approach in TA, which TA operators are familiar with. Moreover, since the needle tip is always aiming lateral and away from the carotid sheath structures, we find this technique helpful in avoiding accidental injection into the carotid sheath. Injection into the carotid sheath could cause paralysis of the vagus nerve and hence vocal cord paralysis. Although this is usually a transient condition, it would complicate the scenario in thyroid TA. This is because it would be difficult to differentiate true recurrent laryngeal nerve (RLN) injury due to overheating/accidental ablation of the RLN which would mean true damage which typically puts an end to the procedure, versus a transient reversible event due to incorrect injection of anaesthesia into the carotid sheath. With our medial to lateral technique, there were no cases of vocal cord paralysis caused by CPB. This highlighted the merits of our approach of CPB injection.
The limitations of this study included: first, the cohort consisted of all ethnic Chinese. This may make our findings less generalizable. Second, whether CPB could achieve equally effective pain control in a setting without sedation remains to be elucidated. This is particularly relevant to centers in which sedation was not routine or difficult to arrange. Third, numbness was not evaluated objectively. It is possible that prolonged numbness potentially caused by CPB could impair patient experience. Nevertheless, the comparable QoR scores would suggest that the patient discomfort induced by CPB was minimal. Forth, although both groups received comparable amount of perithyroidal LA, the fact that Group II receiving an overall higher volume of anesthetic drug itself, due to the addition of 10 mL of 0.25% bupivacaine for CPB, may somehow account for the better pain control. It was not shown in this study whether simply adding a 10 mL volume to perithyroidal LA alone (i.e., a total of 15 to 20 mL for a unilateral ablation) would achieve comparable results to the combined approach of CPB plus perithyroidal LA. Nevertheless, the rationale of utilizing CPB was never to replace perithyroidal LA, but rather, to further optimize pain control by adding the element of regional anesthesia in addition to LA for the procedure. Moreover, flooding the perithyroidal space with large doses of local anesthetic drug carries the risk of drug seepage posteriorly and medially into the tracheal esophageal groove, which may lead to RLN paralysis. Therefore, we find it reasonable and safe to use a combined approach of CPB plus perithyroidal LA. Finally, this study only addressed the effect of CPB in unilateral ablation. It would be important to study whether bilateral CPB could be safely given in bilateral ablations, and achieve equally good pain control.
Conclusions
Adding ultrasound guided CPB to perithyroidal local anesthesia (PLA) and sedation further enhanced pain control in unilateral TA of thyroid nodules. The technique was safe and did not compromise quality of recovery or same-day discharge.
Acknowledgments
Funding: None.
Footnote
Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-24-217/rc
Data Sharing Statement: Available at https://gs.amegroups.com/article/view/10.21037/gs-24-217/dss
Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-24-217/prf
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-24-217/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). This study was approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (No. UW 22-506). All participants gave informed consent.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
References
- Kim JH, Baek JH, Lim HK, et al. 2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology. Korean J Radiol 2018;19:632-55. [Crossref] [PubMed]
- Kuo JH, Lee JA. The Adoption of Ultrasound-guided Radiofrequency Ablation of Thyroid Nodules in the United States. Ann Surg 2021;273:e10-2. [Crossref] [PubMed]
- National Institute for Health and Care Excellence. Interventional procedures guidance. 2016. Ultrasound-guided percutaneous radiofrequency ablation for benign thyroid nodules. Available online: https://www.nice.org.uk/guidance/ipg562
- Papini E, Pacella CM, Solbiati LA, et al. Minimally-invasive treatments for benign thyroid nodules: a Delphi-based consensus statement from the Italian minimally-invasive treatments of the thyroid (MITT) group. Int J Hyperthermia 2019;36:376-82. [Crossref] [PubMed]
- Bernardi S, Giudici F, Cesareo R, et al. Five-Year Results of Radiofrequency and Laser Ablation of Benign Thyroid Nodules: A Multicenter Study from the Italian Minimally Invasive Treatments of the Thyroid Group. Thyroid 2020;30:1759-70. [Crossref] [PubMed]
- Lee M, Baek JH, Suh CH, et al. Clinical practice guidelines for radiofrequency ablation of benign thyroid nodules: a systematic review. Ultrasonography 2021;40:256-64. [Crossref] [PubMed]
- Orloff LA, Noel JE, Stack BC Jr, et al. Radiofrequency ablation and related ultrasound-guided ablation technologies for treatment of benign and malignant thyroid disease: An international multidisciplinary consensus statement of the American Head and Neck Society Endocrine Surgery Section with the Asia Pacific Society of Thyroid Surgery, Associazione Medici Endocrinologi, British Association of Endocrine and Thyroid Surgeons, European Thyroid Association, Italian Society of Endocrine Surgery Units, Korean Society of Thyroid Radiology, Latin American Thyroid Society, and Thyroid Nodules Therapies Association. Head Neck 2022;44:633-60. [Crossref] [PubMed]
- Guo DM, Chen Z, Zhai YX, et al. Comparison of radiofrequency ablation and microwave ablation for benign thyroid nodules: A systematic review and meta-analysis. Clin Endocrinol (Oxf) 2021;95:187-96. [Crossref] [PubMed]
- Du JR, Li WH, Quan CH, et al. Long-term outcome of microwave ablation for benign thyroid nodules: Over 48-month follow-up study. Front Endocrinol (Lausanne) 2022;13:941137. [Crossref] [PubMed]
- Jin H, Fan J, Lu L, et al. A Propensity Score Matching Study Between Microwave Ablation and Radiofrequency Ablation in Terms of Safety and Efficacy for Benign Thyroid Nodules Treatment. Front Endocrinol (Lausanne) 2021;12:584972. [Crossref] [PubMed]
- Baek JH, Ha EJ, Choi YJ, et al. Radiofrequency versus Ethanol Ablation for Treating Predominantly Cystic Thyroid Nodules: A Randomized Clinical Trial. Korean J Radiol 2015;16:1332-40. [Crossref] [PubMed]
- Sung JY, Baek JH, Kim KS, et al. Single-session treatment of benign cystic thyroid nodules with ethanol versus radiofrequency ablation: a prospective randomized study. Radiology 2013;269:293-300. [Crossref] [PubMed]
- Valcavi R, Tsamatropoulos P. Health-related quality of life after percutaneous radiofrequency ablation of cold, solid, benign thyroid nodules: a 2-year follow-up study in 40 patients. Endocr Pract 2015;21:887-96. [Crossref] [PubMed]
- Hamidi O, Callstrom MR, Lee RA, et al. Outcomes of Radiofrequency Ablation Therapy for Large Benign Thyroid Nodules: A Mayo Clinic Case Series. Mayo Clin Proc 2018;93:1018-25. [Crossref] [PubMed]
- Fung MMH, Lang BH. A prospective study evaluating the use of low-dose intravenous sedation and analgesia during radiofrequency ablation of symptomatic, benign thyroid nodules. Am J Surg 2022;224:928-31. [Crossref] [PubMed]
- Aweke Z, Sahile WA, Abiy S, et al. Effectiveness of Bilateral Superficial Cervical Plexus Block as Part of Postoperative Analgesia for Patients Undergoing Thyroidectomy in Empress Zewditu Memorial Hospital, Addis Ababa, Ethiopia. Anesthesiol Res Pract 2018;2018:6107674. [Crossref] [PubMed]
- Mayhew D, Sahgal N, Khirwadkar R, et al. Analgesic efficacy of bilateral superficial cervical plexus block for thyroid surgery: meta-analysis and systematic review. Br J Anaesth 2018;120:241-51. [Crossref] [PubMed]
- Ozgun M, Hosten T, Solak M. Effect of Bilateral Superficial Cervical Plexus Block on Postoperative Analgesic Consumption in Patients Undergoing Thyroid Surgery. Cureus 2022;14:e21212. [Crossref] [PubMed]
- Senapathi TGA, Widnyana IMG, Aribawa IGNM, et al. Ultrasound-guided bilateral superficial cervical plexus block is more effective than landmark technique for reducing pain from thyroidectomy. J Pain Res 2017;10:1619-22. [Crossref] [PubMed]
- Woldegerima YB, Hailekiros AG, Fitiwi GL. The analgesic efficacy of bilateral superficial cervical plexus block for thyroid surgery under general anesthesia: a prospective cohort study. BMC Res Notes 2020;13:42. [Crossref] [PubMed]
- Creighton EW, Stack BC Jr. Perioperative and Outpatient Pain Management in Endocrine Neck Surgery Patients. Journal of Surgical Endocrinology 2018. doi:
10.36959/608/439 . - Ferrell JK, Shindo ML, Stack BC Jr, et al. Perioperative pain management and opioid-reduction in head and neck endocrine surgery: An American Head and Neck Society Endocrine Surgery Section consensus statement. Head Neck 2021;43:2281-94. [Crossref] [PubMed]
- Ferrell JK, Singer MC, Farwell DG, et al. Evaluating contemporary pain management practices in thyroid and parathyroid surgery: A national survey of head and neck endocrine surgeons. Head Neck 2019;41:2315-23. [Crossref] [PubMed]
- Creighton EW, Dayer L, King D, et al. Remote smart pill cap monitoring of post-surgical pain management in thyroid and parathyroid surgery. Am J Surg 2023;225:988-93. [Crossref] [PubMed]
- Peckham M, Creighton E, Troughton M, et al. Enhanced Recovery After Surgery Protocol for Opioid Use Reduction in Ambulatory Thyroid and Parathyroid Surgery. VideoEndocrinology 2022; [Crossref]
- Fung MMH, Lang BHH. Using Intra-Operative Laryngeal Ultrasonography as a Real-Time Tool in Assessing Vocal Cord Function During Radiofrequency Ablation of the Thyroid Gland. World J Surg 2022;46:2206-11. [Crossref] [PubMed]
- Myles PS, Reeves MD, Anderson H, et al. Measurement of quality of recovery in 5672 patients after anaesthesia and surgery. Anaesth Intensive Care 2000;28:276-80. [Crossref] [PubMed]
- Myles PS. Measuring quality of recovery in perioperative clinical trials. Curr Opin Anaesthesiol 2018;31:396-401. [Crossref] [PubMed]
- Eberhart LH, Greiner S, Geldner G, Wulf H. Patient evaluation of postoperative recovery. An evaluation of the QoR scores in 577 patients. Anaesthesist 2002;51:463-6. [Crossref] [PubMed]
- Chan MT, Lo CC, Lok CK, et al. Psychometric testing of the Chinese quality of recovery score. Anesth Analg 2008;107:1189-95. [Crossref] [PubMed]
