Pain - Revision history

Tianchee: /* Metabolic Effects */

2012-10-19T11:18:23Z

Metabolic Effects

Tianchee: /* Sensitisation */

2012-10-19T11:17:47Z

Sensitisation

Bara at 18:41, 25 January 2011

2011-01-25T18:41:29Z

Bara at 15:18, 25 January 2011

2011-01-25T15:18:49Z

Suzannah.stacey at 16:46, 28 September 2010

2010-09-28T16:46:20Z

Suzannah.stacey: /* Analgesics */

2010-09-08T10:21:44Z

Analgesics

Suzannah.stacey: /* Analgesics */

2010-09-08T08:45:28Z

Analgesics

Suzannah.stacey at 08:43, 8 September 2010

2010-09-08T08:43:31Z

Suzannah.stacey at 08:36, 8 September 2010

2010-09-08T08:36:26Z

Oconnoan: /* Physiology and Pathophysiology of Pain Transmission */

2010-08-16T18:02:07Z

Physiology and Pathophysiology of Pain Transmission

@@ Line 24: / Line 24: @@
 ===Metabolic Effects===
-Pain may activate the stress response and hence hormone secretion from the pituitary glands, adrenal glands and pancreas. This leads to substrate mobilisation and catabolism, particularly protein wasting. These effects can impair wound healing, and in the long term result in immunosupression. They can also cause a negative energy balance, giving weight loss or poor growth in young animals. It is important to bear this fact in mind when considering the economics of analgesia in food animal production.
+Pain may activate the stress response and hence hormone secretion from the pituitary glands, adrenal glands and pancreas. This leads to substrate mobilisation and catabolism, particularly protein wasting. These effects can impair wound healing, and in the long term result in immunosuppression. They can also cause a negative energy balance, giving weight loss or poor growth in young animals. It is important to bear this fact in mind when considering the economics of analgesia in food animal production.
 ===Cardiovascular Effects===

@@ Line 16: / Line 16: @@
 ** Type A and C peripheral nociceptors are sensitised due to inflammatory mediators released by tissue damage. This lowers the response threshold of the receptors, or a greater response to the same stimulus is produced. Both mechanisms may work in conjunction.
 * Centrally, giving '''central sensitisation'''.
-** The exictability of spinal nociceptive neurons is enhanced, giving a hypersensitive and hyperactice nociceptive transmission system.
+** The excitability of spinal nociceptive neurons is enhanced, giving a hypersensitive and hyperactive nociceptive transmission system.
 ** Central sensitisation may be short-lived when it is associated with transient changes in neurotransmitter activity.
 ** Central sensitisation may be long-lived when it is associated with phenotypic changes in central neurons.

← Older revision		Revision as of 18:41, 25 January 2011
Line 46:		Line 46:

	[[Category:Anaesthesia]]		[[Category:Anaesthesia]]
		+	[[Category:Analgesia]]

← Older revision		Revision as of 15:18, 25 January 2011
Line 43:		Line 43:
	*[[Systemic Analgesia\|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor found within the entire body. Drug classes include opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.		*[[Systemic Analgesia\|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor found within the entire body. Drug classes include opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.
	*[[Local Analgesia\|Local analgesia/anaesthesia]] is used to desensitise a particular region of the body using techniques such as local infiltration, epidurals, paravertebral and specific nerve blocks, and intravenous regional anaesthesia		*[[Local Analgesia\|Local analgesia/anaesthesia]] is used to desensitise a particular region of the body using techniques such as local infiltration, epidurals, paravertebral and specific nerve blocks, and intravenous regional anaesthesia
		+
		+
		+	[[Category:Anaesthesia]]

@@ Line 1: / Line 1: @@
 ==What is Pain?==
 '''''Nociception''''' is the process of neurotransmission that transmits and processes information relating to tissue damage. It originates from sensory receptors known as ''nociceptors''. '''''Pain''''', on the other hand, is a conscious experience arising from nociception. It has previously been described as:
 # "An unpleasant sensory or emotional experience associated with actual or potential tissue damage." (International Association for the Study of Pain, 1978).
@@ Line 14: / Line 5: @@
 ==Physiology and Pathophysiology of Pain Transmission==
 Two types of nocieptive fibres (neurons) exist. C-fibres are slow-conducting and unmyelinated, whereas A-delta-fibres are small, fast-conducting, myelinated structures. The cell bodies of these neurons are located in the dorsal root ganglion, and the neurons are bipolar. The sensory nerve endings conduct afferent impulses to the cell body, and fibres then extend to the dorsal horn of the spinal cord. Here, ascending information is transmited to the cortex via several "relay stations", including the [[Forebrain - Anatomy & Physiology|thalamus]], the reticular formation, the [[Hindbrain - Anatomy & Physiology#Pons|pons]] and the amygdala. These modulate the signal on its journey towards conscious perception. Local [[Reflex Arcs - Anatomy & Physiology|reflex arcs]] may also be stimulated in the dorsal horn, producing spinal reflexes such as the withdrawal reflex.
@@ Line 20: / Line 10: @@
 ===Sensitisation===
 Hypersensitisation of the pain transmission can occur at any level of the neuraxis. This can result in two phenomena: '''hyperalgesia''', where an exaggerated response to a noxious stimulus is experienced, and '''allodynia''', where a non-noxious stimulus (such as gentle touch) elicits a painful response.
@@ Line 32: / Line 21: @@
 ==Physiological Effects==
 Pain has adverse physiological effects, which include metabolic and cardiac effects.
 ===Metabolic Effects===
 Pain may activate the stress response and hence hormone secretion from the pituitary glands, adrenal glands and pancreas. This leads to substrate mobilisation and catabolism, particularly protein wasting. These effects can impair wound healing, and in the long term result in immunosupression. They can also cause a negative energy balance, giving weight loss or poor growth in young animals. It is important to bear this fact in mind when considering the economics of analgesia in food animal production.
 ===Cardiovascular Effects===
 Pain can cause '''hypertension''' and '''tachycardia'''. This is of particular importance in surgical scenarios: poor peri-operative pain management will contribute to poor recovery from anaesthesisa and increase the risk of post-operative complications.
 ===Chronic Pain===
 Severe or persistent pain can lease to pathophysiological "chronic" pain. Increased risks of auto-mutilation or wound biting are associated with this, proving proper peri-operative pain relief again to be very important.
 ==Assessment of Animal Pain==
 Assessment of pain in animals is neither easy nor, often, intuitive. Usually, vets make observations of behaviour in order to assess their patients' well-being. They must however bear in mind that pain is a subjective experience that varies greatly between individuals. The expression of pain behaviour is also highly species specific. Pain behaviour is influenced by many extrinsic factors, such as previous conditioning, social dominance and overall health status, which may contort the observations. Finally, since animals cannot verbally describe their pain, bias of the observer is inevitable. Therefore knowledge of an individual's behaviour and the assessor's observational skills and attitude towards pain will influence how pain is assessed and consequently managed.

@@ Line 56: / Line 56: @@
 ==Analgesics==
-[[Systemic Analgesia|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor that can be found across the body. Classes of drugs includes opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.
+Analgesia can be defined as the absence of pain. The term 'analgesics' commonly refers to drugs that produce analgesia. They are categorised into two specific types according to their mode of action:
+*[[Systemic Analgesia|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor found within the entire body. Drug classes include opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.
-[[Local Analgesia|Local analgesia/anaesthesia]] is used in patient to desensitise a particular region of the body using techniques such as local infiltration, epidural, paravertebral and specific nerve blocks, and intravenous regional anaesthesia
+*[[Local Analgesia|Local analgesia/anaesthesia]] is used to desensitise a particular region of the body using techniques such as local infiltration, epidurals, paravertebral and specific nerve blocks, and intravenous regional anaesthesia

← Older revision		Revision as of 08:45, 8 September 2010
Line 57:		Line 57:
	==Analgesics==		==Analgesics==
	[[Systemic Analgesia\|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor that can be found across the body. Classes of drugs includes opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.		[[Systemic Analgesia\|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor that can be found across the body. Classes of drugs includes opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.
		+
		+	[[Local Analgesia\|Local analgesia/anaesthesia]] is used in patient to desensitise a particular region of the body using techniques such as local infiltration, epidural, paravertebral and specific nerve blocks, and intravenous regional anaesthesia

← Older revision		Revision as of 08:43, 8 September 2010
Line 54:		Line 54:

	When assessing pain in animals, it is useful to assume that humans an animals are closely related in terms of pain perception and anticipation in order to provide the correct management. Subtle as well as obvious indicators of pain should also be considered, particularly in obtunded animals as invasive procedures, trauma and many medical illnesses may render the animal unable to demonstrate explicit pain behaviour. However, the best diagnostic indicator for pain is response to appropriate [[Analgesic Drugs\|analgesia]].		When assessing pain in animals, it is useful to assume that humans an animals are closely related in terms of pain perception and anticipation in order to provide the correct management. Subtle as well as obvious indicators of pain should also be considered, particularly in obtunded animals as invasive procedures, trauma and many medical illnesses may render the animal unable to demonstrate explicit pain behaviour. However, the best diagnostic indicator for pain is response to appropriate [[Analgesic Drugs\|analgesia]].
		+
		+	==Analgesics==
		+	[[Systemic Analgesia\|Systemic analgesia]] refers to the use of certain analgesic drugs that act at the appropriate receptor that can be found across the body. Classes of drugs includes opioids, non-steroidal anti-inflammatories (NSAIDS), as well as ketamine and gabapentin.

@@ Line 7: / Line 7: @@
 |pagetype=Clinical
 }}
 ==What is Pain?==