INTRODUCTION-

Pain is conducted in the nervous system originated with the specific theory of Johannes P. Müller, described in 1826. This was followed by the alternate intensity theory of Erb in 1874 (Dallenbach, 1939), an idea that later culminated in the gate theory of pain by Melzack and Wall in 1965. Anesthesia is the partial or complete loss of sensation, with or without loss of consciousness. Regional anesthesia is a type of pain management for surgery that numbs a large part of the body¹. Regional anesthesia is very safe and doesn’t involve the potential complications and side effects that can happen with sedation and general anesthesia¹.

Trauma is one of the leading causes of death amongst the population under the age of 40 years². The main causes of maxillofacial fractures worldwide are traffic accidents, assaults, falls, and sport-related injuries². The mandible is the second most common facial fracture³. Odontogenic infection is the most prevalent disease worldwide and is the principal reason for seeking dental care. The commonest odontogenic infections are periapical abscess, pericoronitis, and periodontal abscess. Spreading odontogenic infections are the most common type of serious oro-facial infections encountered by oral and maxillofacial surgeons. Infection from the original focus can spread along with the tissue spaces and lead to facial cellulitis involving deeper fascial spaces⁴. Submandibular space was the most common primary space involved (46.45%) followed by buccal space (30.32%) ⁴. Mandibular fractures and facial space infections can be treated under general anesthesia, sedation, local anesthesia, sedation, and local anesthesia.

General anesthesia has its downsides high economic cost, a number of highly trained personnel required, morbidity and mortality, and high-cost equipment⁵. On the other hand, regional anesthesia has a number of advantages: Stress-free anesthesia, Lower rates of postoperative pulmonary embolism and thrombosis, Easy to perform techniques, and Lower morbidity rates. The regional anesthesia of the superficial cervical plexus (SCP) is commonly and frequently used in a variety of disciplines like carotid endarterectomy, thyroid surgeries, vocal cord surgeries etc^6-8. Many techniques can be employed to achieve anesthesia of the dentition and surrounding hard and soft tissues of the maxilla and mandible. The superficial cervical plexus block (SCPB) is simple and easy to perform, but unfortunately, it is often overlooked as an option to general anesthesia¹¹. Its application in oral and maxillofacial surgical (OMFS) has been in surgical drainage of an abscess in the perimandibular region, excisions of superficial lesions, skin suturing in the corresponding dermatome, and in management of mandibular fractures^{5, 9-10}. 

We will be conducting a prospective, cohort Randomised Controlled Trials (RCT) to evaluate the EFFICACY OF SUPERFICIAL CERVICAL PLEXUS NERVE BLOCK IN MANAGEMENT OF MANDIBULAR FRACTURES AND PERIMANDIBULAR SPACE INFECTION.

SIGNIFICANCE OF THE STUDY

      I.         Superficial cervical plexus nerve block delivers analgesia which decreases the time of surgery.

     II.         Risks and complications of general anesthesia (GA) is avoided.

   III.         Pain management during the treatment of mandibular fractures and perimandibular space infection will be more precise.

REVIEW OF LITERATURE

1.     Michael F. Mulroy MD, Christopher M. Bernards MD, Susan B. McDonald MD,Francis V. Salinas.-A Practical Approach to Regional Anesthesia Fourth Edition¹.

2.     Moshe Shteif et al. The Use of the Superficial Cervical Plexus Block in the Drainage of Submandibular and Submental Abscesses—An Alternative for General Anesthesia. J Oral Maxillofac Surg 66:2642-2645, 2008

3.     Roger D (1995) Superficial and deep cervical plexus block: technical considerations. J Am Assoc Nurse Anesth 63(3):235–243¹¹.

4.     Tajamul Ahmad Hakim et al. The Safety and Effectiveness of Superficial Cervical Plexus Block in Oral and Maxillofacial Surgery as an Alternative to General Anesthesia in Selective Cases: A Clinical Study. J. Maxillofac. Oral Surg. DOI 10.1007/s12663-017-1029-4¹⁰.

5.     Kamal Kanthan R. The use of superficial cervical plexus block in oral and maxillofacial surgical practice as an alternative to general anesthesia in selective cases. Annals of Maxillofacial Surgery | January - June 2016 | Vol-6 Issue 1⁹.

AIM-

To evaluate the efficacy of superficial cervical plexus nerve block in the management of mandibular fractures and perimandibular space infection.

OBJECTIVES-

1.     To study pain immediately after block, intraoperative, and immediately postoperatively on the VAS scale.

2.     To evaluate the time of onset anesthesia.

3.     Check the duration of anesthesia.

4.     To evaluate the time interval until the first analgesic request.

5.     To evaluate Intraoperative analgesic/anesthetic requirements.

6.     To evaluate changes in the pulse and blood pressure preoperatively and intraoperative at two intervals after 15 minutes and after 30 minutes of giving block/infiltration.

7.     To check the complications of SCNB and infiltrations.

TYPE OF STUDY- a Prospective, Randomised Clinical Trial (RCT)

MATERIAL & METHODOLOGY-

STUDY DESIGN-

Ø  This prospective, cohort, Randomised Clinical Trial (RCT)-Double blind study will be conducting the Department of Oral & Maxillofacial Surgery, Government Dental College & Hospital, Mumbai from July 2019.

Ø  The study population will be selected by randomization from the outpatient department (OPD) of Dept. Oral and Maxillofacial Surgery, Govt. Dental College and Hospital, Mumbai which will be divided into two arms (control arm (CA) & experimental arm (EA). Minimum 12 patients in each group will be included, as per the sample size formulae used as follows: (statistician sample certificate is attached)

                        n   =            2 (Z_α+ Z_β)²  [s]²

                                                     d²

where Z_α is the z variate of alpha error i.e. a constant with value 1.96, Z_β  is the z variate of beta error i.e. a constant with value 0.84

(Reference: Allen JC. Sample Size Calculation for Two Independent Groups: A Useful Rule of Thumb. Proceedings of Singapore Healthcare 2011:20(2); 138-40) 

Approximate estimates: 

1. 80% power 
2. Type I error to be 5%
3. Type II error to be 20%
4. The true difference of at least 2.1 units between the groups 
5. The pooled standard deviation of 1.8

Substituting the values,

                       n   =                        2 (2.8)²  [1.8]²

                                                             (2.1)²

                                              n = 11.52

Approximately 12 subjects per group need to be taken in the present study. 

NOTE: Sample Size estimates indicate the minimum no of subjects/samples to be recruited in the study, however they do not guarantee whether statistical significance may be achieved or not as it depends on various other factors also.

For follow-up studies, to avoid loss by loss to follow up / attrition, kindly consider recruiting 5-25% more subjects so that even after attrition, we would be able to achieve the required minimum sample size.

PROCEDURE DETAILS

A)    Control Arm (CA):

                                Under all aseptic precautions and standard aseptic protocol Patients in the control arm will be treated under indicated nerve block and infiltration externally in the skin. After the management of mandibular fracture and/or perimandibular space infection Postoperative medications will be prescribed and written instructions will be given to the patient.

B)    Experimental Arm (EA):

Under all aseptic precautions and standard aseptic protocol Patients in the experimental arm will be treated under indicated nerve block and superficial cervical plexus nerve block (SCNB). 

PATIENT POSITIONING

The patient is placed in a supine position, with his head turned to the side contrary to the one to be blocked. After skin cleansing with an antiseptic solution, a skin wheel is raised at the site of the needle insertion using a 25-gauge needle. Next, using a “fan” technique with superior-inferior needle redirections, the local anesthetic is injected alongside the posterior border of the sternocleidomastoid muscle, 2 to 3 cm below and above the needle insertion site. This injection technique should be adequate to achieve blockade of all 4 major branches of the SCP. After the management of mandibular fracture and/or perimandibular space infection Postoperative medications will be prescribed and written instructions will be given to the patient.

DATA ANALYSIS

·      Data collected will be compiled on to an MS Office excel worksheet and will be subjected to statistical analysis using an appropriate package like SPSS software.

·      Normality of data will be checked using the Shapiro – Wilk test or Kolmogorov-Smirnov test. Depending on the normality of data, statistical tests will be determined. 

·      For a numerical continuous data following a normal distribution, intergroup comparison (2 groups) will be done using an appropriate test, else a non-parametric substitute like appropriate test will be used. 

·      Association of variables (2 categorical) will be done using a suitable test.

·      Intragroup comparisons for a numerical continuous data following a normal distribution will be done by applying appropriate test (for observations), else a non-parametric substitute like Wilcoxon signed-rank test (for 2 observations) or Friedman’s test for >2 observations will be used. 

·      Keeping alpha error at 5% and Beta error at 20%, power at 80%, p<0.05 will be considered statistically significant. 

FINDINGS OF TRIAL-

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