Is Prophylactic Antibiotic Therapy Needed in Thyroidectomy?

Abstract

Antibiotics have been traditionally prescribed for any open head and neck surgery. With classification of wound and wound contamination and various published guidelines the practice is still widely prevalent. Thyroidectomy being a clean surgery does not warrant the use of antibiotics at all. We performed an interventional prospective study to see the occurrence of wound infection in patients who received antibiotic prophylaxis as compared to those who did not. A total of 71 patients were recruited in the study who were randomly divided into two groups, one received antibiotic prophylaxis and other did not. Both the groups did not show any marked change in the incidence of wound infection hence highlighting the unnecessary use of prophylactic antibiotics in thyroid surgeries.

Introduction

The rationale of systemic antibiotic prophylaxis is to reduce the incidence of surgical infections in the surgical site. Antibiotic prophylaxis in head and neck should be instituted only in clean-contaminated surgical procedures or in clean surgical procedures associated with other co morbidities in which an infective complication may pursue, or in clean procedures in which prosthetic implants or other exogenous materials are being used or exposure to saliva [1].

In clean surgical cervical procedures like thyroidectomy the bacterial and/or mycotic secondary infections are remote with documented incidence of infections from 2 to 5%. Therefore, antibiotics should be used judiciously and avoided in situations where the potential risk of side effect of antibiotics and the emergence of bacterial resistant strains outweighs the possible benefits of its use [2, 3].

This study is intended to demonstrate that thyroidectomy needs no prophylactic antibiotic therapy thereby reducing the cost of treatment and prevent development of antibiotic resistance that ensues due to injudicious use.

Aim and Objectives

• To assess and compare the occurrence of surgical site infections in patients undergoing thyroidectomy with and without prophylactic antibiotics.

Materials and Methods

An Interventional prospective study was conducted in a tertiary care hospital of Mangalore. Institutional ethical committee clearance was obtained and quality control guidelines were followed. 67 patients were included in the study. Informed consent was taken and was randomly allocated into two groups. In Group A where no prophylactic antibiotic was given prior or following surgery and Group B where three doses of antibiotic (Inj cefuroxime 1 gm) was given every eighth hourly, starting from the time of induction of anaesthesia.

Inclusion Criteria

Men or women between age 16 and 80 years with a preoperative diagnosis of benign thyroid disease willing to participate in the study were included.

Exclusion Criteria

Patients with age < 16 and > 80 years, associated metabolic (diabetes), infective and hematologic pathologies and presence of other source of infection like ulcer, URTI, UTI. Patients with BMI > 25, on corticosteroid or immunosuppressive therapy and those with preoperative diagnosis of malignancy. Those with drain > 70 ml in postoperative period.

Patient Preparation

All the patients received the same pre and postoperative protocol. The patient took a shower the morning of the operative procedure with bathing soap. The men shaved their beards the morning of the operation. The surgeons and nurses performed a preoperative surgical scrub (hands and forearms up to the elbows) for at least 2–5 min using an appropriate antiseptic (Microshield handrub—70% v/v ethanol and 0.5% w/v chlorhexidine gluconate). The entry of other personnel was restricted inside the operation theatre.

The surgeon washed and cleaned around the incision site before performing antiseptic skin preparation with an approved agent (povidoneiodine-Betadine) for 2–5 min. The skin was prepared with an antiseptic antimicrobial preparation (0.25 g benzalkonium chloride and 70 g 96% alcohol) in concentric circles from the incision site (3 times).

All patients underwent near total or hemi thyroidectomy depending on surgeons decision. Adequate haemostasis was followed during the procedure.

Drains were removed on post operative day one if less than 70 ml.

Data Collection and Analysis

The data collected included the personal profile of the patient, FNAC report, preoperative diagnosis, final histopathology report and evidence of surgical site infection (SSI) which was graded according to Southamptons grading scale (Table 1). Grade > 1 was considered for antibiotic prophylaxis. Patients were assessed daily for 2 days following surgery and then discharged. Sutures were removed after one week followed by a visit at 6 weeks. They were instructed to follow up in the emergency or outpatient department in case of any signs of inflammation or infection.

Table 1.

Southhamptons criteria [4]

Grade o	Normal healing
Grade 1	Normal healing with mild bruising or erythema
Grade 2	Erythema plus other signs of inflammation
Grade 3	Clear or hemoserous discharge
Grade 4	Pus
Grade 5	Deep or severe wound infection with or without tissue breakdown or haematoma requiring aspiration

Statistical Analysis

Categorical data was analysed by Chi square test or Fishers exact test. Data was summarised as ODDS ratio with 95% Confidence Interval. p value < 0.05 will be considered statistically significant.

Results

Total of 71 patients were included in the study and were randomly assigned to the two groups with 37 and 34 patients in group A (no antibiotic) and B (antibiotic) respectively, out of those 67 completed the study. Thyroid disorders were found to be in general more common in females. The mean age in both the groups were 43.11 and 44.33 yrs with standard deviation 6.7 and 7.9 respectively hence they were evenly matched.

In group A, 3 patients were excluded as 2 had drain > 70 ml and 1 had to be re-explored in lieu of immediate post op hematoma. Of the 34 patients, only 3 developed wound infection and the rest 31 showed no signs of wound infection. In group B one patient was lost in follow up. Of the 33 patients, all received antibiotic therapy. 3 showed signs of wound infection and 30 did not. (Table 2).

Table 2.

Wound infection rates in all types of thyroid surgeries

Antibiotic prophylaxis for all thyroid surgeries	Wound infection		Total
	No	Yes
Group A—no antibiotic	31	3	34
Group B—antibiotic	30	3	33
Total	61	6	67

Fishers exact—0.64, not significant. Odds ratio—0.97, 95% CI 0.18–5.1

When statistically evaluated with Fisher’s exact test the results were not significant (p 0.64) with odds ratio of 0.97 (95% CI 0.18–5.1).

When a more precise data of only total thyroidectomies was analyzed it was found that antibiotic group faired similar to no antibiotic group (p of 0.64) and Odds ratio of 1.04 (95% CI 0.19–5.64) drawing a poor association. (Table 3).

Table 3.

Wound infection rates in total thyroidectomies

Antibiotic prophylaxis for total thyroidectomy	Infection		Total
	No	Yes
Group A—no antibiotic	25	3	28
Group B—antibiotic	26	3	29
Total	51	6	57

Fishers exact—0.64, not significant. Odds ratio—1.04, 95% CI 0.19–5.64

Discussion

Thyroidectomy is a relatively common surgical procedure done across different specialities. Benign thyroid swellings often end up under the surgeon’s blade which is classified as clean surgery [5, 6]. Here the incision is small and the duration is short with no contamination.

The surgical procedures are classified into four types in relation to the increasing risk of bacterial contamination and infection. Clean surgical procedures like thyroid surgery carry a very low risk of infection (0.6–5%) which is attributed to strict aseptic surgical practices. However clean—contaminated and contaminated surgical procedures carry much higher infection rates of 10–20% respectively and dirty surgical procedures are the highest with 40% [6]. Even with good asepsis these figures are high because of contamination, making it single most important factor predisposing to higher infection rates. This risk increases further in presence of co-morbidities.

Across the globe universal guidelines suggest judicious use of antibiotics in clean surgeries but they’re often disregarded. In a study done by Moalem et al. [7] where they observed pattern of antibiotic prophylaxis in thyroidectomy across different countries, they found that > 90% of the surgeons prescribed antibiotic prophylaxis. They also found that surgeons in Asia were the only group in their analysis who were more likely to almost always use antibiotic prophylaxis before thyroidectomy or parathyroidectomy (58.3%), significantly more often than surgeons in the United States (27.9%) and Europe (8.8%). In the same study they also observed that the same surgeons would not want antibiotic prophylaxis if they were to undergo thyroidectomy unless indicated. However many concurred with use of antibiotics to wade of suspected respiratory infections and routinely prescribe in immunocompromised patients and in some studies they’ve pointed towards possible medicolegal issues which may arise by not prescribing antibiotics [8]. Their study had few notable limitations like recall bias, lack of follow up and no physical examination so, in many ways the results might have be undermined but it throws light on worldwide practice.

A retro prospective data of 1030 patients was published by Qin et al. [9] where they reported SSI rates of 0.09%. Patients with co morbidities were excluded and thyroid surgeries for various pathologies like neoplasm were included which could be managed by a single horizontal linear incision. None of the patients received antibiotic prophylaxis except one. It was a single large retrospective study where wound examination was not graded which may be a shortcoming of the study. However the author emphasized against the need for antibiotic prophylaxis even in extended indications for thyroidectomy. We had three cases in each group who developed SSI, perhaps factors like improper wound care or unclean practices may have contributed to it.

Often post-operative drain is considered as an indicator for the use of antibiotic prophylaxis but in a systematic review of RCTs by Samaraj and Gurusamy [10] where they compared wound infection in patients with and without drain. They concluded that presence of drain has no influence on occurrence of wound infection and stressed on strict asepsis like others [9]. In our study all the patients had a drain and only those with < 70 ml were included hence we cannot comment on outcome without drain. Many local complications like hematoma and seroma can occur in absence of drain which can act as a template for infection. Moreover in our study the patients were operated by different surgical teams making it difficult to undercut certain key surgical practices like keeping a post op drain.

In a study published by Fachinetti et al. [11] where they reviewed recent novel practices and antibiotic prophylaxis. Patients undergoing video assisted endoscopic thyroid surgery showed decreased local inflammatory immune response and shorter surgical time, obviating the use of antibiotic prophylaxis. Even use of harmonic scalpel for upper pole ligation is observed as less traumatic procedure compared to conventional ligation thereby reducing immune response [11, 12]. All these factors leads to better wound healing.

The only legible indication where antibiotic prophylaxis should be considered is transoral robotic thyroidectomy as the cervical bed would be contaminated due to transoral approach [13]. We have limited data on these newer practices, perhaps large population based RCT in future may refute this claim and draft newer guidelines.

Antibiotic prophylaxis is widely practiced Indian subcontinent in spite of guidelines in place. Changing paradigms of clinical practice have ushered greater acceptance if these guidelines in recent times and, our study further validates that with reference to our population. Based on our study a larger randomized controlled study can be drawn to include a wider set of surgeries and practices.

Conclusion

Surgeries for benign thyroid disease in patients having no co- morbidities may not need routine antibiotic prophylaxis to control local wound infection. The unreasonable use of prophylactic antibiotic therapy will increase the economical burden, drug related complications and increases risk of development of multiple drug resistant bacterial strains. This is a major cause of the failure of therapy in many prevailing human infections and cause for emerging hard-to-treat infection.