Decreased postoperative pain after reduction of fractured nasal bones using a nerve block of the anterior ethmoidal nerve

Abstract

There is consensus that all patients should experience minimal pain following reduction of a fractured nasal bone. The issue requiring further study is what technique will provide patients with the greatest pain relief following the reduction of nasal fractures. This study investigated the use of an anterior ethmoidal nerve block as preemptive analgesia for the management of postoperative pain associated with reduction of nasal bone fractures. The medical documents of 85 patients were reviewed for a retrospective case-controlled comparative study. Patients in the nerve block group ( n = 45) were injected with 2% lidocaine containing epinephrine into the anterior ethmoidal nerve and dorsal periosteum, and those in the control group ( n = 40) were not. The rate of patients requiring postoperative injectable analgesics was compared between the two groups. The rate of patients who received a postoperative analgesic injection was significantly lower in the nerve block group than in the control group ( P = 0.034). The use of an anterior ethmoidal nerve block and dorsal periosteal injection of anaesthetic solution during reduction of fractured nasal bones under general anaesthesia resulted in the effective reduction of postoperative pain. Thus, this is regarded as a good method for enhancing patient quality of care and compliance in the reduction of fractured nasal bones.

Because the nose is located on and protrudes from the centre of the face, it can easily be injured. Accordingly, nasal fractures are the most common of all facial fractures.

Closed reduction of a nasal bone fracture, one of the most common craniofacial surgeries, is a simple procedure, which can be performed under local anaesthesia in many cases. However, general anaesthesia is preferred because an operation can be performed with greater accuracy and less pain. Most studies have compared the surgical outcome related to the physiological function and appearance following general anaesthesia, local anaesthesia, and topical anaesthesia. However, few studies related to acute postoperative pain in closed reduction, other than the taking of oral medication or injection of analgesics, have been reported.

By administration of an analgesic before the painful stimulus, development of pain hypersensitization may be reduced or abolished, thus resulting in less post-stimulus pain. A wide variety of methods have been examined for their possible preemptive analgesic effects, including non-steroidal anti-inflammatory drugs (NSAIDs), intravenous opioids, epidural analgesia, and peripheral local anaesthetics in various odontogenic, abdominal, and orthopaedic procedures. Some drugs have proven useful in the control of pain, however these medications have caused an increase in side effects, such as nausea, vomiting, and sedation, with the exception of peripheral nerve block. Although early reviews of clinical findings have mostly been negative, there is still widespread belief in the efficacy of preemptive analgesia among clinicians.

The innervation of the anterior and internal portions of the nose is predominantly through branches of the sphenopalatine ganglion and the anterior ethmoidal nerves. Therefore, most postoperative pain is induced by stimulation of these nerve branches. In particular, the anterior ethmoidal nerves can easily be approached through a nasal cavity. We suggest that an anterior ethmoidal nerve block decreases the severity of pain after nasal bone reduction and that this effect is long-lasting, possibly through a preemptive mechanism.

In this study we used a nerve block on the anterior ethmoidal nerve and periosteal local injection for preemptive analgesia in the closed reduction of nasal bone fractures, a procedure that was introduced by the senior author (HKL). We report herein the effectiveness of controlling acute postoperative pain using this method in the closed reduction of nasal bone fractures under general anaesthesia.

Materials and methods

Patient group

A retrospective and patient–control group comparative study was conducted targeting a total of 201 patients who had undergone a closed reduction of a nasal bone fracture over the 15-month period between March 2010 and June 2011. Out of a total of 201 patients, 116 subjects were excluded from the current study for the following reasons: younger than 20 years or older than 65 years of age, concomitant disorders (i.e., nasal septum fracture or facial bone fracture), or had undergone surgery under local anaesthesia ( Table 1 ). Patient age, sex, past history, cause of injury, delay between the time of injury and surgery, intranasal packing, and control of postoperative pain after general anaesthesia, were investigated. In addition, classification of nasal bone fractures was based on computed tomography (CT) findings and the Stranc classification. A total of 85 patients were finally selected: 45 subjects who underwent closed reduction of a nasal bone fracture under general anaesthesia and who received anterior ethmoidal nerve block followed by local anaesthesia on the periosteum (nerve block group); and 40 subjects who underwent closed reduction of a nasal bone fracture under general anaesthesia (control group).

Table 1
Summary of patient exclusion criteria.
Exclusion criteria
Patient age <20 years and >65 years
Accompanied septal fracture
Nasal bone fracture with other kinds of facial fracture
Closed reduction under local anaesthesia

In order to increase the statistical significance of the effects of our approaches, the group of 85 patients was divided into two groups: those who received analgesic injections and those who did not receive analgesic injections. A comparative analysis was then performed using identical variables.

Procedure

After administration of general anaesthesia through endotracheal intubation, 0.3 ml of a mixture of 2% lidocaine and 1:100,000 of epinephrine was injected into both sides of the upper end of the nasal septum using 25-gauge long needles, and to the submucosa of the vestibular region ( Fig. 1 ). In addition, a percutaneous injection in the nasal dorsum periosteum was performed. The nasal cavity was filled with gauze soaked in a mixture of saline and 1:1000 of epinephrine ( Fig. 2 ). After 5 min, the gauze in the nasal cavity was removed, and a typical reduction was performed using a Dingman elevator and Asch forceps.

Fig. 1
Anterior ethmoidal nerve block on both sides of the upper end of the nasal septum using a 25-gauge long needle.

Fig. 2
Percutaneous injection of local anaesthetic on the nasal dorsum periosteum.

The final step involved placement of a splint, which was conducted by filling the nasal cavity using polyvinyl acetal sponge material (Merocel ® , Medtronic Xomed, Jacksonville, FL, USA) and using a thermoplastic external nasal splint (WFR Aquaplast ® , Keosan, Seongdong-gu, Seoul, Republic of Korea). In the control group, the same steps, except for the anterior ethmoidal nerve block and dorsal periosteum injection, were applied for the closed reduction.

For the control of postoperative pain, in addition to injections (diclofenac; Dibeta-C, Dae Hwa Pharm Co., Seoul, Republic of Korea), oral analgesics (acetaminophen; Suspen, Han Mi Pharm Co., Seoul, Republic of Korea) were used primarily in cases of severe pain. Responses to pain were investigated by the 24-h postoperative use of analgesic injections. In accordance with the treatment protocols of our hospital, all patients were discharged the day after surgery (within 24 h); on the third postoperative day, the patients attended for removal of the intranasal packing.

Statistical analysis

SPSS version 20.0 (SPSS Inc., Chicago, IL, USA) was used for the data analysis. Differences in age and delays between the time of injury and surgery between the two groups were tested using the independent t -test. Other differences in variables between the two groups were tested using the χ 2 test. A P -value of 0.05 was considered statistically significant.

Results

In the current study, the subjects ranged in age from 20 to 63 years (mean age 37.5 years), the male to female ratio was 5.1:1, and the mean time period between injury and operation was 6.8 days. According to the patient medical records, there were five cases involving systemic diseases, such as hypertension and diabetes, five cases were of local diseases, such as allergic rhinitis, and two cases had psychological diseases, such as post-traumatic stress disorder and alcohol dependence. Regarding the cause of the nasal bone fractures, sports was the most common reason, with 29 cases, followed by assault, fall and slip down, traffic accident, and work-related. According to the Stranc classification of nasal bone fractures, lateral fractures (49 cases) were more common than frontal fractures (36 cases). Thirty-eight patients received postoperative pain control in the recovery room. After reduction, 80 patients had intranasal packing on both sides and five had it on a single side.

No statistically significant differences were observed between the nerve block group and the control group in terms of age, sex, the time period between injury and operation, past history, cause of injury, classification of nasal bone fracture, intranasal packing, and treatment of pain in the recovery room ( P > 0.05, Table 2 ). In the comparison between the groups in which analgesic injection was done or not, no statistically significant differences were observed among identical variables ( P > 0.05, Table 3 ).

Table 2
Selected patient demographics: nerve block group vs control group.
Nerve block group ( n = 45) Control group ( n = 40) P -value
Age (years), median (range) 36.2 (20–63) 38.8 (20–60) 0.311 *
Sex ratio, male:female 38:7 33:7 0.809
No. days before reduction 6.53 7.18 0.287 *
Past history, n (%) 0.483
Systemic disease 3 (6.7%) 2 (5%)
Local disease 3 (6.7%) 2 (5%)
Psychological disease 0 (0.0%) 2 (5%)
None 39 (86.6%) 34 (85%)
Cause, n (%) 0.416
Assault 12 (26.7%) 10 (25%)
Traffic accident 5 (11.1%) 3 (7.5%)
Sports 17 (37.8%) 12 (30%)
Fall and slip down 10 (22.2%) 10 (25%)
Work-related 1 (2.2%) 5 (12.5%)
Stranc classification, n (%) 0.629
Plane I frontal impact 21 (46.7%) 15 (37.5%)
Plane I lateral impact 10 (22.2%) 12 (30%)
Plane II lateral impact 14 (31.1%) 13 (32.5%)
Intranasal packing, n (%) 0.173
Bilateral 43 (95.6%) 37 (92.5%)
Unilateral 2 (4.4%) 3 (7.5%)
Pain control at recovery room, n (%) 42 (60.0%) 33 (54.1%) 0.495

* Independent t -test.

χ 2 test.

Table 3
Selected patient demographics: those who received analgesics vs those who did not.
Received analgesics group ( n = 19) Did not receive analgesics group ( n = 66) P -value
Age (years), median (range) 41.7 (20–60) 36.2 (20–63) 0.067 *
Sex ratio, male:female 15:4 56:10 0.541
No. days before reduction 6.68 6.88 0.788 *
Past history, n (%) 0.065
Systemic disease 1 (5.3%) 4 (6.1%)
Local disease 2 (10.5%) 3 (4.5%)
Psychological disease 2 (10.5%) 0 (0%)
None 14 (73.7%) 59 (89.4%)
Cause, n (%) 0.585
Assault 6 (31.8%) 16 (24.2%)
Traffic accident 3 (15.7%) 5 (7.6%)
Sports 5 (26.3%) 24 (36.4%)
Fall and slip down 3 (15.7%) 17 (25.8%)
Work-related 2 (10.5%) 4 (6.0%)
Stranc classification, n (%) 0.555
Plane I frontal impact 6 (31.6%) 30 (37.5%)
Plane I lateral impact 6 (31.6%) 16 (30.0%)
Plane II lateral impact 7 (36.8%) 20 (32.5%)
Intranasal packing, n (%) 0.896
Bilateral 18 (94.7%) 62 (93.9%)
Unilateral 1 (5.3%) 4 (6.1%)
Pain control at recovery room, n (%) 9 (47.4%) 29 (43.9%) 0.053
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Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Decreased postoperative pain after reduction of fractured nasal bones using a nerve block of the anterior ethmoidal nerve

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