Indian Journal of Surgery Medknow Publications on behalf of Association of Surgeons of India ISSN: 0972-2068 Vol. 67, Num. 6, 2005, pp. 316-319

Indian Journal of Surgery, Vol. 67, No. 6, November-December, 2005, pp. 316-319

Original Article

Thyroid surgery under local anaesthesia: an alternative to general anaesthesia

Shukla VK, Narayan S, Chauhan VS, Singh* DK

Departments of General Surgery and Anaesthesiology*, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221 005, India.

Correspondence Address: VK Shukla, Department of General Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221 005, India. E-mail: vkshuklabhu@satyam.net.in

Code Number: is05094

Abstract

Keywords: Local anaesthesia, thyroid surgery, general anaesthesia

Introduction

Thyroid surgery for benign and malignant diseases is most commonly performed under general anaesthesia. Historically, surgery in patients with thyroid disease especially thyrotoxicosis was performed using local anaesthesia.[1] As medical therapy evolved to provide reliable means of maintaining euthyroid state and as general anaesthesia became safer, many procedures including thyroid surgery are being done exclusively under general anaesthesia. However, over the last three decades, there has been resurgence in number of thyroid operations under local anaestheisa.[2],[3],[4] Local anaesthesia can provide good analgesia and avoids major side effects of general anaesthesia. In addition, the analgesia continues in the post operative period, thus modifying the autonomic and endocrine stress of surgery leading to rapid recovery.[3] Local anaesthesia is economical[5] and simpler to administer and thus fulfills the requirements for Day care surgery.[6],[7] A few surgeons in the west are carrying out thyroid surgery exclusively under local anaesthesia and cervical blocks after careful patient selection and propagating the effectiveness of such approach.[8]

We attempt to analyse the characteristics of patients undergoing surgery under local and general anaesthesia and evaluate the outcome measures in terms of the cost effectiveness, hospital stay and complications in this retrospective Cohort study. The aim of the study was to evaluate the efficacy of thyroid operations done under local anaesthesia and whether this can pave way for the development of thyroid surgery as an out patient procedure.

Material and Methods

The records of all patients who underwent thyroid surgery for benign and malignant thyroid diseases under local and general anaesthesia were evaluated. Hundred patients operated in a single surgical unit at University Hospital, Varanasi, India over the period of 1996 to 2003 were included. Local anaesthesia was discussed preoperatively with all patients and in general the patient made the decision regarding type of anaesthetic used during operation. The exclusion criteria for local anaesthesia were substernal goitre, allergy to local anaesthesia, obese short neck reoperation, concomitant procedures and neck dissections. Those who did not give consent for local anaesthesia were also excluded. All cases were performed by a single surgeon with a general surgery resident as the first assistant. The patients were allocated the anaesthetic group alternately on out patient basis and patients were informed about the procedure in detail. They were also informed that the procedure can be converted to general anaesthesia at any time, if circumstances so dictate.

Technique of Local Anaesthesia Administration

Patients were premedicated with 0.25 - 0.5 mg alprazolam orally at bed time on the night before surgery and repeated 2 hours before surgery in morning. Patients were sedated in the pre operating room using a mixture of pentazocine and promethazine according to body weight. They were able to respond to verbal commands depending upon their level of sedation. Local anaesthesia (0.5% lidocaine with 1:100000 adrenaline) was injected with 26 gauge needle, in the incision line first and then infiltrated in to superior and inferior skin flap. Surgery was performed in presence of an anaesthetist under constant monitoring. After operation, all patients were monitored in the recovery room. Antiemetics and analgesics were given as needed. Ceftriaxone 1gm IV were given as prophylactic antibiotics.

Technique of General Anaesthesia administration

Premedication with 0.25 - 0.5 mg of Alprazolam orally at bed time on the night before and repeated 2 hours before surgery in the morning. Patients were induced with propofol, succinyl choline or vecuronium, nitrous oxide and reversed by myostigmine and glycopyrollate. Monitoring was done in recovery room. Prophylactic antibiotics, antiemetics and analgesics were administered as before.

Statistical analysis

Student's t test has been used to measure the confidence interval in each group of patients for the variable like stay in hospital and cost incurred in the procedure.

Results

Patient charactertics

During January 1996 and September 2003, a total of 100 patients with both benign and malignant thyroid diseases were operated in a single surgical unit by a single surgeon under local anaesthesia. Age of the patients ranged from 12 - 55 years in local anaesthesia and 16 - 68 years in general anaesthesia group. The mean age in local anaesthesia group was 33.3 years and 38.4 years in general anaesthesia group.

The histopathological characteristics and operation done is given in [Table - 1].

Operative data

The mean operating time, defined from entry into operating room to entry in to recovery room, was 41.6 minutes (range 30.3 - 56.6 minutes) in local anaesthesia group and 74.5 minutes (range 61.5 - 90.4 minutes) in general anaesthesia group. The difference was statistically significant. There were no specific operative difficulties encountered in the local anaesthesia group. Drain was inserted below the strap muscle which were then approximated.

Post Operative Course

The patients were kept in the recovery room after surgery where monitoring was done for signs of bleeding respiratory obstruction and pain. The mean analgesia requirement was less in the post operative period in the local anaesthesia group. Intramuscular tramadol was used for post operative analgesia. None of the patients developed symptoms of hypocalcaemia or hypoparathyroidism. Oral feeding was started from the same evening. Drain was removed on the next morning.

Surgical complications

Surgical complications that were evaluated were bleeding, respiratory obstruction, hypoparathyroidism, hypocalcaemia, vocal cord paralysis, haematoma, seroma, infection and conversion to general anaesthesia. There were no episodes of hypocalcaemia, haematoma or infection. Seroma was seen at wound site in three patients of local anaesthesia group. Transient vocal cord paralysis was seen in 2 patients of general anaesthesia group. The seroma subsided spontaneously after aspiration of seroma with fine needle. None of the patients attempted under local anaesthesia required conversion to general anaesthesia [Table - 2]. Few patients had transient nausea and vomiting which subsided with medication.

Cost

Mean cost refers to the cost incurred on patient from admission till discharge. Mean cost incurred was Rs. 2189.32 in local anaesthesia group and Rs. 5520.00 in general anaesthesia group. The 95% confidence interval for the cost incurred by the patient who underwent surgery under local anaesthesia was 2135.22 - 2243.42 (p< 0.05) and for general anaesthesia was 5433.44 - 5606.559 (p< 0.05). to measure the differences in both the groups, 95% confidence limit of difference has been calculated with confidence interval of difference being - 5001.88 to 1659.48 (p< 0.05) which was statistically significant [Table - 3].

Length of stay

Length of stay refers to duration of stay in the hospital after operation. All the patients started taking orally in the evening of operation. Thirteen (26%) patients of local anaesthesia group were discharged within 24 hours of admission. Mean length of stay in local anaesthesia group was 39.26 hours and 71.06 hours in general anaesthesia group. The 95% confidence interval for the hospital stay of the patient who underwent surgery under local anaesthesia was 34.37 - 44.15 (p< 0.05) which was statistically significant and for general anaesthesia was 65.56 - 76.56 (p< 0.05). To measure the differences in both the groups, 95% confidence limit of difference has been calculated with confidence interval of difference being - 24.48 - 38.12 (p< 0.05) which was statistically significant (t α = 1.99) [Table - 4][Table - 5].

DISCUSSION

Since Koller[9] introduced local anaesthesia in 1884, the technique has undergone progressive refinement and it is now being increasingly accepted as a modality of choice in various surgical specialities.[10],[11],[12] Local anaesthesia is a safe alternative to general anaesthesia. The basic objective of our study was to review our experience with local anaesthesia concerning the safety and outcome in this approach. The reasons usually quoted for the failure of this technique are fear of failure, time taken for induction and fear of neurological complications.[13] Inadvertent intravascular injection of local anaesthesia may lead to seizure activity.[14] The systemic toxic effects of local anaesthesia are related to the blood concentrations of specific agents, which in turn are regulated by the rate of vascular absorption, tissue distribution, metabolism and excretion.[13]

Although we did not encounter any complication of local anaesthesia and there was no need of converting the procedure to general anaesthesia. Surgeries ranging from lobectomy to total thyroidectomy were performed using this method without any significant complication. Complication rates in local anaesthesia group were comparable to those of general anaesthesia (7.1% vs 7.3%) with no incidence of life threatening complications like haemorrhage laryngeal spasm, tetany hypocalcaemia, vocal cord paralysis infection or conversion to general anaesthesia. A few patients developed nausea and vomiting but could be managed symptomatically. Similar results have been reported by Hisham AN et al who operated 65 patients with comparable figures.[15] A large number of parathyroid surgeries and neck explorations are being performed under local anaesthesia.[16],[17],[18],[19] The technique of thyroid surgery under local anaesthesia and cervical blocks pioneered by surgeons such as Lo Gerfo[3] has indeed been a revolution. In spite of his excellent results, the concept has been plagued by controversies. He has modified the conventional techniques, though slightly, and brought out remarkable results.

Interestingly, thirteen (26%) patients were discharged within 24 hours of the surgery. Quick postoperative recovery and discharge from the hospital thus cut down the cost incurred by the patient. This is particularly important in a country where a vast majority of patients are poor and can't even afford the basic necessities of life. Also, due to limited number of trained anaesthesia personnel, and increasing burden of patients, the technique becomes a boon, being economically feasible. Pain analysis, both during and post operation was not carried out in our study. Advocators of local anaesthesia have carried out such analysis and found that it was much less than patients on general anaesthesia. When we compared the post operative requirement of analgesic, it was much less in the local anaesthesia group vis a vis general anaesthesia group in our study.

Our study highlights the emerging trend that thyroid surgery under local anaesthesia is as safe, efficacious and cost effective as under general anaesthesia. It might be performed as a day care surgery in future and thus improves the quality of life of these patients.

References

Copyright 2005 - Indian Journal of Surgery

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