Pain is one of the common health problems that prompt immediate medical attention. Pain, a normal bodily response to negative stimuli, can negatively affect one’s quality of life if treatment is not readily administered or applied (Baliki, Geha, Apkarian, and Chialvo, 2008). Pain, as described by The International Association for the Study of Pain (IASP), is considered as the unpleasant sensation felt by a patient in the event of potential or actual exposure to any forms of tissue damage (Kyranou and Puntillo, 2012). Pain serves as an automatic withdrawal reflex that signals the occurrence of a potential or actual harm (Kyranou and Puntillo, 2012). The sensory process associated with pain or the detection of harmful stimuli in relation to tissue damage is called the nociception (Kyranou and Puntillo, 2012). Nociception manifests as hypersensitivity towards any mechanical, chemical, or thermal stimuli that may bring about tissue damage (Kyranou and Puntillo, 2012). Acute, chronic, and referred pain are all affected by the nociception but the varying levels at which such sensory process functions are what make each type of pain different from the others.
Acute pain is the severe pain that immediately affects the site of injury at the very moment it takes place (Kyranou and Puntillo, 2012). Characterized by the hypersensitivity caused by the sensory process, nociception, acute pain usually lasts for hours or days or even up to several months (Kyranou and Puntillo, 2012). Chronic pain, as the name suggests, is the recurring pain that persists even after the wound or the injury has healed (Kyranou and Puntillo, 2012; Voscopoulos and Lema, 2010). Like acute pain, chronic pain is also characterized by long durations (Kyranou and Puntillo, 2012). The long durations of persistence common to both acute and chronic pains are common causes of misdiagnosis and wrong identification but a close investigation of the pathophysiology of the acute and chronic pain will reveal clear distinctions between them. While acute pain is largely caused by the injury per se (Kyranou and Puntillo, 2012), chronic pain is the opposite as it occurs despite the total recovery of injured tissue (Voscopoulos and Lema, 2010). Acute pain is directly caused by the peripheral sensitization or the exposure of nocireceptors to agents that cause inflammation (Kyranou and Puntillo, 2012). Peripheral sensitization is a normal bodily response that gradually decreases and eventually ceases as the damaged tissue or the main source of pain starts to heal which usually takes a matter of days or weeks (Kyranou and Puntillo, 2012). The pain accompanying peripheral sensitization is the acute pain (Kyranou and Puntillo, 2012). But acute pain can develop into chronic pain after a series of alterations in the normal process of healing and pain reception take place (Voscopoulos and Lema, 2010). The development of chronic pain is often associated with surgical-related procedures whose alterations to the body often cause abnormal and prolonged sensitization and chronic nerve stretching (Voscopoulos and Lema, 2010). Such alterations to the normal response of the body to pain causes abnormal and enhanced hypersensitivity that may be stimulated even by activities that do not induce potential or actual pain (Baliki et al., 2008). In one study, it is concluded that chronic pain alters the part of the brain called the “default mode network” or DMN which affects a patient’s cognition and behavior (Baliki et al., 2008). Aside from the acute and chronic pain, there is another type of pain called as the referred pain. Referred pain is the pain felt at the other parts of the body distant from the injury or the uninjured sites (Physiopedia, n. d.). Occurrence of referred pain is considered to be caused by the radiation of nerves that transmit signals that stimulate pain reaction (Physiopedia, n.d.).
Gender, psychosocial issues, nerve damage, type of trauma in relation to surgery, preoperative pain associated with the injury subjected to surgery, site of injury and operation, type of disease, and innate inflammatory responses are some of the common predisposing factors that determine the occurrence of pain (Voscopoulos and Lema, 2010). Younger patients are more commonly affected by pain (Voscopoulos and Lema, 2010), probably because youths have less-developed bodies as well as recovery processes. The duration of operation is also a common predisposing factor in the development of pain (Voscopoulos and Lema, 2010).
Treatment of pain often includes multimodal interventions which target the physical and psychological aspects of pain (Ryder and Stannard, 2005). Non-steroidal, anti-inflammatory drugs are the common contents of prescription to resolve pain (Ryder and Stannard, 2005). Acetaminophen combined with opioids such as codeine is also commonly prescribed to treat pain (Ryder and Stannard, 2005). Narcotics are also among the most commonly prescribed drugs that treat chronic pain (Olsen and Daumit, 2002). Aside from drugs, therapies such as acupuncture, trigger-point injections, osteopathic manual medicine techniques, and laser therapy are commonly used nowadays to alleviate and manage pain (Physiopedia, n.d.).
References
Baliki, M.N., Geha, P.Y., Apkarian, A.V., and Chialvo, D.R. (2008). Beyond Feeling: Chronic Pain Hurts the Brain, Disrupting the Default-Mode Network Dynamics. The Journal of Neuroscience, 28(6), 1398-1403. DOI: 10.1523/JNEUROSCI.4123-07.2008
Kyranou, M., and Puntillo, K. (2012). The transition from acute to chronic pain: intensive care unit patients be at risk? Annals of Intensive Care, 2(36), 1-11. DOI: 10.1186/2110-5820-2-36
Olsen, Y., and Daumit, G.L. (2002). Chronic Pain and Narcotics: A Dilemma for Primary Care. Journal of General Internal Medicine, 17(3), 238-240. DOI: 10.1046/j.1525-1497.2002.20109.x
Physiopedia. (no date). Referred Pain. Retrieved from http://www.physio-pedia.com/Referred_Pain
Ryder, S.A., and Stannard, C.F. (2005). Treatment of chronic pain: antidepressant, antiepileptic and antiarrhythmic drugs. Continuing Education in Anesthesia, Critical Care & Pain, 5(1), 18-21. DOI: 10.1093/bjaceaccp/mki003
Voscopoulos, C., and Lema, M. (2010). When does acute pain become chronic? British Journal of Anaesthesia, 105(51), i69-i85. DOI: 10.1093/bja/aeq323
