In the United States of America, acute pain, and the expectation of pain management is one of the primary reasons that prehospital providers receive calls. By definition from the International Association for the Study of Pain, "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage." As such, pain or the perception of pain can have both physiological and psychological impact on patients that interferes with their activities of daily living, causes a delay in healing and recovery and ultimately impacting the quality of life of the patient. Based upon NEMSIS v2, 33.1% of the complaints to 911 are for pain-related syndromes with chest pain accounting for 10.2% of all calls. The most common provider impression based upon this 2016 data includes traumatic injuries at 21.8%, abdominal pain at 12.2%, and chest pain at 10%. This data means that almost half of all provider impressions are dealing with some form of a pain-related syndrome. A similar study looking at the national electronic prehospital patient records of 41,241 patients transported by EMS providers in Denmark showed a 28% moderate or severe pain level with an additional 32% of unknown pain status. Galinski et al. in the prevalence and management of acute pain in the prehospital emergency medicine, indicated that 42% of the individuals having acute pain with 64% of those patients having intense to severe pain. The National Association of EMS Physicians (NAEMSP) believes that relieving pain and suffering of patients is of necessity a priority for every emergency medical services (EMS) system. The 2018 EMS Scope of Practice Model looked at pain management for acute traumatic events as a high priority issue requiring a systematic review of the literature.
Prehospital providers have to perform appropriate pain assessment and understand options for the treatment of acute pain. Pain assessment and treatment can be difficult based upon several different factors, including patient's age, race, location, EMS provider's ability or reluctance to administer pain medication, and the medical director's authority on the administration of pain medication. There is also a growing concern that the administration of opiate or opioid medication will cause addiction and abuse. One of the major hurdles for pain medication administration in the United States before 2014 was that prehospital providers would use standing orders to administer controlled substances for pain control. This administration of pain medication was based upon the 1970 Controlled Substances Act with an interpretation that EMS providers were allowed to administer pain medication under the DEA registration of the medical director or hospital system. The DEA rejected standing orders for controlled substances for prehospital providers. Congress passed the Protecting Patient Access to Emergency Medications Act of 2017, which modified the Controlled Substances Act of 1970 to allow for EMS agencies to be registered with the DEA and use standing orders. The Act also gives specific instructions on the storage of controlled substances, provides for the restocking of EMS vehicles at hospitals, requires maintenance of controlled substance records, and holds EMS agency liable for controlled substances.
The 2003 position paper from NAEMSP believes that every EMS protocol should have (8) components: (1) mandatory assessment of both the presence and severity of pain, (2) use of reliable tools for the assessment of pain, (3) indications and contraindications for prehospital pain management, (4) non-pharmacologic interventions for pain management, (5) pharmacologic interventions for pain management, (6) mandatory patient monitoring and documentation before and after analgesic administration, (7) transferal of relevant patient care information to receiving medical personnel and (8) quality improvement and close medical oversight to ensure appropriate use of prehospital pain management. The Declaration of Montreal from the International Pain Summit indicates that the relief of pain is a global issue and that healthcare providers, including the prehospital providers, have a humanitarian responsibility to provide access and management of pain.
The problem at hand for most prehospital providers deals with the ability to perform an appropriate pain assessment and then deciding which analgesia to use for the perceived pain. The measurement of pain and relief of pain is a complex entity with limited literature on education, research, agent availability, state and federal regulations on controlled substances, and the perception of pain based upon race, age, gender, and cultural beliefs.  Porter et al. (1999) and Johnston et al. (1997) show that neonates undergoing painful procedures in the NICU rarely received analgesic agents (6.8% and 10% respectively) with the literature showing that early pain experiences can have long-term sequela to the patients. Lord et al. concluded that there is no difference between genders receiving analgesia, but did indicate that there is a difference between the types of medication given. Perception of acute pain assessment and providing analgesia from paramedics shows that children and adolescents continue to receive fewer analgesic interventions compared to adults. Prehospital pain management has evolved over the years, and education on pain management has improved. In a six-year follow-up study, the knowledge, perceptions, and management of pain by paramedics from an urban/suburban fire department showed improvement for treating pain based upon the quality improvement program and educational interventions.
Pain Assessment Tools
The use of validated pain assessment tools is an integral part of the assessment and treatment of patients with acute pain. Prehospital healthcare protocols or guidelines should include specific validated tools based upon the patient type to include age and ability to communicate. There are several different pain scales based upon age that ranges from preterm to adulthood. Srouji et al. have listed over 20 different pain scales for preterm to 18 years of age. Additional scales include those for the non-verbal patients as well as those with dementia. The measurement of pain and pain intensity can be performed by several methods, which include: behavioral, physiological measures, and self-reporting. The most widely used pain assessment scales utilize the self-reporting method, which has the most valid and optimal measurements, but these scales are limited in the pediatric population because of the cognitive and language development of children and lack of the younger child's ability to describe the pain. These scales also have limited utility for the non-verbal patient because of the inability to vocalize. Pain assessment for the younger patient, as well as the non-verbal patient is then based upon the behavioral and physiological measurements. Body posture and movements, crying, and facial expressions are examples of behavioral measures. Physiological measures would include key vital signs of heart rate, blood pressure, respiration, and oxygen saturation, as well as palmer sweating and other neuroendocrine responses. Some popular tools include:
Prehospital pain management can occur via the non-pharmacologic and pharmacologic means. Pak et al. performed a review of the literature for non-pharmacological interventions for pain management, which includes: distraction, stress management, hypnosis, acupuncture, acupressure, transcutaneous electrical nerve stimulation, and physical therapies (including massage, heat/cold, physiotherapy, osteopathy, and chiropractic). Additional treatment options for newborn and infant children include repositioning, singing or soft music, rocking the child, swaddling, use of a pacifier, gentle stroking, and allowing the newborn or infant to hold a comfort item or blanket. Oral sucrose administration, as well as breastfeeding or breast milk, can reduce the pain in newborns.
Opiates by and large are the primary agents for pharmacologic pain management in the prehospital system, with morphine and fentanyl being the primary forms of opiates used. Additional pharmacologic interventions would include NMDA receptor antagonists (ketamine), benzodiazepines (diazepam, lorazepam, and midazolam), nonsteroidal anti-inflammatories (ibuprofen, ketorolac) and other non-opiate pain medications (acetaminophen/paracetamol).
"Among the remedies which it has pleased Almighty God to give to man to relieve his sufferings, none is so universal and so efficacious as opium" Sir Thomas Sydenham, 1680. Opiate pain medications bind directly to (3) different receptors in the brain to include: mu, delta, and kappa. The mu receptor is the primary receptor for opiates and was first described in the 1800s after the formulation discovery for morphine, named after the Greek God of Sleep Morpheus. Opiates work by activating a g-protein secondary message system through the coupling of the opiate with the mu-opioid receptor (MOR) in the central nervous system. Mu receptors are located throughout the body, but specifically in the periaqueductal gray (PAG) found in the midbrain. One of the functions of the PAG is to control descending pain modulation through the suppression of pain via enkephalin-producing cells. Gamma-aminobutyric acid (GABA), which is the chief inhibitory neurotransmitter, plays an important role in the suppression of pain by preventing the transmission of pain signals along the nerve. Opiate medications will decrease glutamatergic (excitatory) and GABAergic (inhibitory) activity depending upon the location within the brain and spinal cord. The reduction of glutamatergic synaptic transmission will give the desired properties of analgesia. The reduction in GABAergic activity specifically within the nucleus accumbens allows for an increase in dopamine and thus gives the "reward" or euphoric effects associated with opiates.
Benzodiazepine (BZD) is a classification of medications that act as positive allosteric modulators at the BZD receptor (gamma-aminobutyric acid (GABA)-A receptor) site which is a ligand-gated chloride-selective ion channel. GABA is the primary inhibitory neurotransmitter in the central nervous system. BZDs classification is in terms of the half-life elimination with a short-acting half-life of 1 to 12 hours, the intermediate-acting half-life of 12 to 40 hours, and long-acting of 40 to 250 hours. Common side effects for all BZDs include lethargy, fatigue, and drowsiness. Impaired motor coordination, blurring of vision, slurring of speech, mood swings, with feelings of euphoria can present in patients with higher dosage consumption. The different formulations of benzodiazepines have different routes of degradation, with the majority of them being first metabolized by hepatic oxidation and then undergo glucuronidation, these being chlordiazepoxide, diazepam, and midazolam. There are (3) that only undergo hepatic glucuronidation, which is lorazepam, oxazepam, and temazepam. Administration of benzodiazepine type medication to elderly patients and those persons with liver disease requires careful consideration because the benzodiazepine oxidation decreases.
NMDA (N-methyl-D-aspartate) receptor antagonists are a group of medications that can induce a state of dissociation and, therefore, can produce anesthesia characterized by loss of short term memory (amnesia), inability to feel pain (analgesia) and decreased sensitivity to pain (catalepsy). The primary role is to inhibit the action of glutamate, which is the primary excitatory neurotransmitter of the brain and spinal cord. These medications have been used to treat acute and chronic pain syndromes.
(kinectics / dynamics / dosages / precautions obtained from PEPID online)
From the five known most frequent causes for individuals to call for emergency services, three of them are pain-related ("wounds, fractures, minor injuries," "accidents," "chest pain/heart disease"). This means that prehospital providers have a potential impact on the pain/suffering of individuals that rely on the services provided. Prehospital providers need to assess patients for pain with appropriate validated tools. Prehospital providers have pharmacologic and non-pharmacologic modalities at their disposal to render compassionate care to the individuals they are treating. It is crucial to be familiar with the different agents available to include indications, contraindications, adverse risk factors, dosages, and potential reversal agents. Likewise, prehospital providers should be more willing to utilize non-pharmacologic modalities for pain management.
|||McGuire DB,Kaiser KS,Haisfield-Wolfe ME,Iyamu F, Pain Assessment in Noncommunicative Adult Palliative Care Patients. The Nursing clinics of North America. 2016 Sep [PubMed PMID: 27497016]|
|||Anand KJ,Hickey PR, Pain and its effects in the human neonate and fetus. The New England journal of medicine. 1987 Nov 19 [PubMed PMID: 3317037]|
|||Møller TP,Ersbøll AK,Tolstrup JS,Østergaard D,Viereck S,Overton J,Folke F,Lippert F, Why and when citizens call for emergency help: an observational study of 211,193 medical emergency calls. Scandinavian journal of trauma, resuscitation and emergency medicine. 2015 Nov 4 [PubMed PMID: 26530307]|
|||Parker M,Rodgers A, Management of pain in pre-hospital settings. Emergency nurse : the journal of the RCN Accident and Emergency Nursing Association. 2015 Jun [PubMed PMID: 26050779]|
|||Friesgaard KD,Riddervold IS,Kirkegaard H,Christensen EF,Nikolajsen L, Acute pain in the prehospital setting: a register-based study of 41.241 patients. Scandinavian journal of trauma, resuscitation and emergency medicine. 2018 Jul 3 [PubMed PMID: 29970130]|
|||Galinski M,Ruscev M,Gonzalez G,Kavas J,Ameur L,Biens D,Lapostolle F,Adnet F, Prevalence and management of acute pain in prehospital emergency medicine. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. 2010 Jul-Sep [PubMed PMID: 20507221]|
|||Alonso-Serra HM,Wesley K, Prehospital pain management. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. 2003 Oct-Dec [PubMed PMID: 14582104]|
|||Cousins MJ,Lynch ME, The Declaration Montreal: access to pain management is a fundamental human right. Pain. 2011 Dec [PubMed PMID: 21995880]|
|||McManus JG Jr,Sallee DR Jr, Pain management in the prehospital environment. Emergency medicine clinics of North America. 2005 May [PubMed PMID: 15829390]|
|||Page GG, Are there long-term consequences of pain in newborn or very young infants? The Journal of perinatal education. 2004 Summer [PubMed PMID: 17273395]|
|||Srouji R,Ratnapalan S,Schneeweiss S, Pain in children: assessment and nonpharmacological management. International journal of pediatrics. 2010 [PubMed PMID: 20706640]|
|||Lord B,Cui J,Kelly AM, The impact of patient sex on paramedic pain management in the prehospital setting. The American journal of emergency medicine. 2009 Jun [PubMed PMID: 19497456]|
|||Hennes H,Kim MK,Pirrallo RG, Prehospital pain management: a comparison of providers' perceptions and practices. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. 2005 Jan-Mar [PubMed PMID: 16036825]|
|||French SC,Chan SB,Ramaker J, Education on prehospital pain management: a follow-up study. The western journal of emergency medicine. 2013 Mar [PubMed PMID: 23599840]|
|||[PubMed PMID: 12670671]|
|||[PubMed PMID: 27073748]|
|||Merkel SI,Voepel-Lewis T,Shayevitz JR,Malviya S, The FLACC: a behavioral scale for scoring postoperative pain in young children. Pediatric nursing. 1997 May-Jun [PubMed PMID: 9220806]|
|||Voepel-Lewis T,Zanotti J,Dammeyer JA,Merkel S, Reliability and validity of the face, legs, activity, cry, consolability behavioral tool in assessing acute pain in critically ill patients. American journal of critical care : an official publication, American Association of Critical-Care Nurses. 2010 Jan [PubMed PMID: 20045849]|
|||Wong DL,Baker CM, Pain in children: comparison of assessment scales. Pediatric nursing. 1988 Jan-Feb [PubMed PMID: 3344163]|
|||Haefeli M,Elfering A, Pain assessment. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2006 Jan [PubMed PMID: 16320034]|
|||Pak SC,Micalos PS,Maria SJ,Lord B, Nonpharmacological interventions for pain management in paramedicine and the emergency setting: a review of the literature. Evidence-based complementary and alternative medicine : eCAM. 2015 [PubMed PMID: 25918548]|
|||Taddio A,Shah V,Hancock R,Smith RW,Stephens D,Atenafu E,Beyene J,Koren G,Stevens B,Katz J, Effectiveness of sucrose analgesia in newborns undergoing painful medical procedures. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne. 2008 Jul 1 [PubMed PMID: 18591525]|
|||Fleischman RJ,Frazer DG,Daya M,Jui J,Newgard CD, Effectiveness and safety of fentanyl compared with morphine for out-of-hospital analgesia. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. 2010 Apr-Jun [PubMed PMID: 20199230]|
|||Saad J,Pellegrini MV, Nonsteroidal Anti-Inflammatory Drugs (NSAID) Toxicity . 2019 Jan [PubMed PMID: 30252262]|
|||Ershad M,Vearrier D, Ibuprofen Toxicity . 2019 Jan [PubMed PMID: 30252334]|
|||[PubMed PMID: 10779131]|
|||[PubMed PMID: 24799809]|
|||Traynor J, μ-Opioid receptors and regulators of G protein signaling (RGS) proteins: from a symposium on new concepts in mu-opioid pharmacology. Drug and alcohol dependence. 2012 Mar 1 [PubMed PMID: 22129844]|
|||[PubMed PMID: 15578966]|
|||Kelly E, Efficacy and ligand bias at the μ-opioid receptor. British journal of pharmacology. 2013 Aug [PubMed PMID: 23646826]|
|||Murphy PB,Barrett MJ, Morphine . 2019 Jan [PubMed PMID: 30252371]|
|||Ramos-Matos CF,Lopez-Ojeda W, Fentanyl . 2019 Jan [PubMed PMID: 29083586]|
|||Abi-Aad KR,Derian A, Hydromorphone . 2019 Jan [PubMed PMID: 29261877]|
|||[PubMed PMID: 48347]|
|||Griffin CE 3rd,Kaye AM,Bueno FR,Kaye AD, Benzodiazepine pharmacology and central nervous system-mediated effects. The Ochsner journal. 2013 Summer [PubMed PMID: 23789008]|
|||Peppers MP, Benzodiazepines for alcohol withdrawal in the elderly and in patients with liver disease. Pharmacotherapy. 1996 Jan-Feb [PubMed PMID: 8700792]|
|||Ghiasi N,Bhansali RK,Marwaha R, Lorazepam . 2019 Jan [PubMed PMID: 30422485]|
|||Silbergleit R,Lowenstein D,Durkalski V,Conwit R, Lessons from the RAMPART study--and which is the best route of administration of benzodiazepines in status epilepticus. Epilepsia. 2013 Sep [PubMed PMID: 24001080]|
|||Shtull-Leber E,Silbergleit R,Meurer WJ, Pre-hospital midazolam for benzodiazepine-treated seizures before and after the Rapid Anticonvulsant Medication Prior to Arrival Trial: A national observational cohort study. PloS one. 2017 [PubMed PMID: 28306741]|
|||Silbergleit R,Lowenstein D,Durkalski V,Conwit R, RAMPART (Rapid Anticonvulsant Medication Prior to Arrival Trial): a double-blind randomized clinical trial of the efficacy of intramuscular midazolam versus intravenous lorazepam in the prehospital treatment of status epilepticus by paramedics. Epilepsia. 2011 Oct [PubMed PMID: 21967361]|
|||Silverman EC,Sporer KA,Lemieux JM,Brown JF,Koenig KL,Gausche-Hill M,Rudnick EM,Salvucci AA,Gilbert GH, Prehospital Care for the Adult and Pediatric Seizure Patient: Current Evidence-based Recommendations. The western journal of emergency medicine. 2017 Apr [PubMed PMID: 28435493]|
|||[PubMed PMID: 27965560]|
|||Rosenbaum SB,Palacios JL, Ketamine . 2019 Jan [PubMed PMID: 29262083]|
|||Sinner B,Graf BM, Ketamine. Handbook of experimental pharmacology. 2008 [PubMed PMID: 18175098]|
|||Gao M,Rejaei D,Liu H, Ketamine use in current clinical practice. Acta pharmacologica Sinica. 2016 Jul [PubMed PMID: 27018176]|