Frequency of neck pain and its associated factors among Post CABG patients

Background: Chronic postoperative pain (CPOP) is a well-recognized problem in Post-Coronary artery bypass grafting (CABG) patients. Post CABG upper extremity pain is found to be common among these patients effecting quality of life and hinders with the routine activities. The aim of this study was to identify the frequency of neck pain and its associated factors among post-operative CABG patients. Methodology: A cross-sectional study was conducted in Dow University of Health Science, Karachi between April 2018 to November 2018. The sample size 78 was calculated by open epi calculator. Both male and female Postoperative CABG patients with a one-year follow-up were selected with or without neck pain aged between 30-75 years from Outpatient Department. Patients below <30 years of age and those with any other surgeries before or any malignant disease were excluded from the study sample. A questionnaire was given to grade their overall experience of pain on Visual Analogue Scale (VAS) and to fill out Neck Disability Index (NDI) for their neck pain. The data was analysed using SPSS version 21 and Chi square T-test was applied to evaluate the significance. Results: Out of 78 patients there were 32 (41%) females and 46 (58%) males with a mean age range between 30-75 years. 51.3% had neck pain presented within 12 hours of onset of symptoms while 48% had no complaint of neck pain. After CABG, 40 (51.2%) patients developed pain in their neck within 1 year of follow up. the mean VAS score was 5.32 out of 10 points on the basis of which 38 patients didn’t experienced any pain while 20 suffered from moderate pain, 12 from severe pain and 8 patients from mild pain. Conclusion: Patients following CABG surgery develop neck pain within one-year follow-up associated with restricted neck and shoulder range of motion. They also experienced muscle tenderness in their trapezius and sternocleidomastoid muscles followed by frequent headaches.


Introduction
The major cause of mortality across the world is Cardio vascular diseases (CVD). According to the global burden disease study (2013) it was evaluated that 30 % of deaths across the world was caused by CVD, majority are due to the Coronary heart disease (CHD) 1 . For the treatment of CHD most frequently performed surgical procedure is CABG, which was introduced in 1960 2 . In this procedure the artery or vein which tends to block the oxygen rich blood supply to the heart is unblocked to release the pressure. Frequency of CABG is found to be raised since last decades, but quality of life and wellbeing is improved by successful procedure of CABG on patients with CHD 2 .This technique is commonly performed by cardiac surgeons on patients whose arteries are filled with plaque formation known as (Atherosclerosis), commonly called as Coronary artery disease (CAD) 3 .
Patients undergoing CABG have remarkable enhancement which can upgrade the standard of life and expand the life expectancy and survival rates. This technique also decreases the heart related death rates in patients with numerous cardiovascular diseases when comparing with another therapeutic regimes 2&3 . CAD mortality rates will double from 1990 to 2020, with approximately 82% of the increase in the developing countries as reported by American Heart Journal in 2004. Existing results reported that rapid socioeconomic growth in developing countries and its increasing exposure to risk factors for CAD, such as diabetes, genetic factors, hypertension, and smoking will lead to disease 4 . 25% of patient's complaint of musculoskeletal pain enrolled in early outpatient cardiac rehabilitation while pain aggravated with common daily activities among 32% of patients 5 . The mortality rate of CAD in Pakistan is about 35-45% mainly because of unhealthy diet, lack of exercise, smoking and hypertension. According to a research, population of Pakistan is on a highest risk of developing CHD 6 .
It was estimated by a retrospective study that, patients with chronic Post sternotomy pain (CPSP) complained of neck pain 33%, shoulder pain 47%, chest wall pain 22%, intrascapular pain 42%, and elbow pain 10% out of which neck pain causes persistent pain in upper limb with restricted movements in daily living activities 7 . Musculoskeletal disorders comprise most commonly upper extremity and chest pain in post sternotomy patients 8 .
Neck pain is at 2 nd position after sternum pain, causing pain due to insertion of central venous catheter (CVC) in the jugular vein which might leads to pneumothorax 9 . CVC is inserted to gain blood tests, measure central venous pressure and deliver medications. It stays in position for several hours after surgery. Hygiene level should be high because there is an increased risk of infection and due to its placement position neck and shoulder movements are restricted 10 .
Both physical and psychological health is affected due to CPSP which can prolong the healing time and causes a bad impact on the quality of life 10 . 25% of patients are affected by post-operative chronic pain, out of which 80% had pain for 2 or more days per week. These patients are also at a higher risk of anxiety and depression levels 10 . The purpose of the research project is to identify the frequency of neck pain and its associated factors among Postoperative CABG patients. Occurrence of chronic pain after cardiac surgery varies from 18-61% which affects the standard of life and causes restrictions on daily activities 8 . About 30% of cases reports that chronic postoperative pain (CPOP) is present at the site of surgery along with the upper part of the body (head and neck) and at the back 9 . Effects of CPSP should not be avoided, because it has a significant impact in on our daily living activities 10 . Postoperative CABG patients with 1 year follow up were asked to fill the pain questionnaire. All patient gave there informed consent. As a next step, the patients were asked to grade their pain on VAS 11 . The patients in the study were asked to fill a questionnaire of NDI 12 Table 3 describes the 10 sections of NDI (Neck Disability Index) each. Participants found difficulty in doing recreational activities (30%), driving (25%), work (26%), and lifting weights (22%) while they can manage personal care, reading and concentration with less pain.  Table 4 shows significant P-value were observed for patients with neck pain as compared to sleeping, driving, washing and carrying heavy objects. While we found 51.3% (Table 1) prevalence of neck pain, other studies have showed that musculoskeletal pain was most prevalent in neck, shoulder and upper region of the body from 1 st Postoperative day till 6 th week 13 . According to a prospective study it was estimated that the overall percentage of noncardiac pain after sternotomy for cardiac surgery is quite prevalent (28%). Most of the patients reveals moderate pain intensity but some (1%) report severe pain, never being lower than 54 mm on VAS 13 .
Our study results also shows that on NDI, 16 (20.5%) patients were experiencing moderate pain at the time of study, 11.5% patients were having worst imaginable pain, 7.7% patients complain fairly severe pain, 6.4% have very severe pain (Table 2). In our study patients who filled the NDI revealed that 16(20.%), were facing moderate pain, 18 (23.1%) were experiencing moderate headaches and cannot lift heavy weights because of pain, 20 (25.6%) cannot read and 15(19.2%) experience difficulty in taking care of themselves like bathing, dressing etc. (Table 3).
Post-sternotomy pain always remain the complication of cardiac surgery but this pain syndrome is always poorly evaluated and no preventive measures is taken to prevent it. A two year multicentre prospective study was conducted in 2014 to investigate the prevalence and risk factors for persistent postoperative non-anginal pain after cardiac surgery 8 . A total number of 1247 patients completed the preoperative assessment and follow-up were taken at 3 and 24 months. 84% of patients were having pain at three month and 78% were having pain even after two years of surgery. Another study addressed the prevalence, characteristics, effect, and predictors of CPOP 1-3 years after cardiac surgery. This concluded that non-anginal CPOP affected 23% of patients 9 . High-level of anxiety, sleep disturbance and depression also seem to affect their quality of life.
A research was conducted in Department of Cardiac Rehabilitation Rawalpindi and Okara Pakistan and it was estimated that chronic neck and chest pain was more common in Postoperative CABG patients 14  A study was conducted in 2017 and it was stated that severe intense CPSP is present in about 38% of patients which was moderate to severe 11 . The most contributing factor to this pain is highest level of anxiety. In this study none of the patient reported the neck pain or stiffness or any presence of trigger points in muscles around neck region. CPSP is the main problem in Health-related Quality of life according to this study and starting early pain management will decrease the prevalence of this CPSP 11 .

Conclusion
This cross-sectional survey shows that the overall incidence of neck pain after CABG is 51.3%. Most of the patients experience a moderate pain intensity which obstruct daily living activities and decrease quality of life. CPSP is an important complication that may have a significant impact on the patient's everyday life. Future studies will show whether minimizing complications, improving postoperative care and starting early adequate pain management will reduce the incidence of musculoskeletal disorders among patients. Longitudinal prospective studies are needed to further evaluate risk factors, including inadequate postoperative pain relief in both acute and chronic period.

Conflicts of Interest
None.