Receptors, Neuropathways, and Mechanisms

Assessment and management of pain in pediatric otolaryngology

INTRODUCTION

Pain is a disease by itself and it's a public health concern of major implication in children, not just because of the emotional component of the child and his family, but also due to the potential morbidity and mortality involving it. A proper assessment of pain it's a challenge in the pediatric population, due to their lack of understanding and verbalization of hurt. Additionally, a satisfactory treatment of pediatric pain can be arduous due to a lack of clinical knowledge, insufficient pediatric research, and the fear to opioid side effects and addiction.

OBJECTIVES

The aim of this review is to address the current definitions of pain, its physiological mechanisms and the consequences of its inadequate management, as well as, to guide the clinicians in the assessment and management of pain in the pediatric population at otolaryngology services.

METHODOLOGY

Narrative review by selective MeSH search terms: Children, Pediatrics, Otolaryngology, Pain measurement, Pain Management, Analgesics and Analgesia, from databases: MEDLINE/PubMed, Cochrane, ISI, Current Contents, Scielo and LILACS, between January 2000 and May 2016.

RESULTS

129 articles were reviewed according to the requirements of the objectives. Pain measurement is a challenge in children as there are no physical signs that constitute an absolute or specific indicator of pain, and its diagnosis must rely on physiological, behavioral and self-report methods. Regarding treatment, a suitable alternative are the non-pharmacological cognitive/behavioral therapies helped by pharmacological therapies tailored to the severity of pain and the child's age. We provide evidence-based recommendations on pain treatment, including non-opioid analgesics, opioid analgesics and adjuvant medicines to improve the management of pain in children in otolaryngology services.

CONCLUSIONS

We present a global review about assessment and management of pain in pediatric otolaryngology, which leads to future specific reviews on each topic. Research gaps on pain assessment and pharmacological interventions in neonates, infants and children are very wide and it should be promoted ethical and safe research on pain control in this population.

Chemical analgesia for velvet antler removal in deer

There is a legal requirement to provide analgesia for velvet antler removal in New Zealand. Currently, this is achieved using local anaesthetic blockade, with or without systemically administered sedative/analgesic agents, or by compression in 1-year-old stags. Lignocaine hydrochloride 2% is most commonly used and is most effective when administered as a high-dose ring block. Combinations of various amino-amide local anaesthetic agents can achieve rapid onset and prolonged duration of analgesia, though concerns about drug residues and carcinogenic potential of a lignocaine metabolite have led to consideration of the amino-ester family of local anaesthetics as alternatives. Systemically administered analgesics, including opioids, alpha-2-adrenergic agents and ketamine provide dose-dependent sedation and analgesia. However, none are sufficient, alone or in combination, to produce surgical analgesia at currently recommended dose rates and when reversal agents are given, analgesic effects are usually reversed as well as sedation. Thus, local anaesthetic blockade is still indicated, though the potential for drug or drug-metabolite residues in velvet antler remains a concern. The need for and effectiveness of non-steroidal anti-inflammatory drugs (NSAIDs) for post-operative analgesia requires investigation. Amitriptyline, locally administered opioid agonists, tramadol and other systemically administered agents may warrant future investigation for surgical and post-operative analgesia for velvet antler removal.

Fish, amphibian, and reptile analgesia

Pain perception and appropriate behavioral responses are important for survival. The conservation of the opioid ligand and receptor suggests evolution of opioid receptors mediating antinociception throughout vertebrate phylogeny. Fish, amphibians, and reptiles have appropriate neurologic components, display the appropriate behavior in response to a painful stimulus, and possess antinociceptive mechanisms to modulate pain. Because pain perception in these species is therefore likely to be analogous to that of mammals, invasive and painful procedures should always be accompanied by appropriate analgesia and anesthesia. Although specific doses have not been established in clinical trials, clinicians should attempt to provide lower vertebrates with appropriate analgesia during painful procedures. Further experimental and clinical investigations are necessary to expand the current veterinary literature in the area of pain and analgesia in lower vertebrates such as fish, amphibians, and reptiles.

Physiology of pain

The substantial increase in our collective knowledge of pain physiology and pharmacology over the past decade has had a significant effect on the practice of clinical veterinary medicine. An overview of the basic anatomical and physiologic components of nociceptive processing is presented, as well as a discussion of the sensitizing events that occur within the nervous system in acute and chronic pathologic pain states. The unique features of visceral and neuropathic pain are also outlined. With the goal of improving the success of our therapeutic interventions, the final section is devoted to the various classes of analgesic drugs and techniques, and how they are best incorporated into pain management strategies.

Recent advances in our understanding of pain: how should they affect management?

Pain management continues to challenge the clinical veterinarian. It is important to appreciate that pain is not a monolithic syndrome; many variables associated with pain origin, transmission, perception, and response must be understood in order to provide the best pain relief in a clinical patient. Rational pain management requires an understanding of underlying mechanisms involved in pain and an appreciation of how analgesic agents act to disrupt them. The goal of this presentation is to acquaint you with the fundamentals associated with pain physiology and how clinical pain management may modify these mechanisms to benefit the patient.