Sedation and pain relief in neonatal care PERINATOLOGI KURS 2010, KI Marco Bartocci, MD, PhD Neonatal Intensive Care Unit Neonatal Research Unit Karolinska University Hospital Karolinska Institutet Stockholm contents • Physiologic background of supraspinal pain perception • Clinical approach • Pain scales • Pain drugs in NICU Supraspinal pain processing • The pain system is a dynamic interactive system creating an interoceptive view (relating to stimuli arising within the body) of the body integrity (Price, Science 2000) • Pain perception involves multilayered networks of nociception, nerves, neurons and glia, distributed in multiple spinal and supraspinal areas. (Woolf, Science 2000) What is pain? Pain is a subjective sensory and emotional experience that requires the presence of consciousness to permit recognition of a stimulus as unpleasant. Next questions •Is the brain of the newborn ready (mature enough) to process painful stimuli? •When do we become conscious of ourselves? •How can a newborn communicate his/her pain? Development of pain •Sensory receptors in the moth already at 7 wks •Peri-oral cutaneuos 77,5 wks • Palmar cutaneuos 1010,5 wks (Humphrey, 1964) •Abdominal cutaneuos around 15 wks •Spinal reflex arc in response to noxious stimulus from 8 wks (Okado & Kojma 1984) •Neuron for nociception in the dorsal root ganglion from 19 wks (Kostantinidou 1995) •Receptors on the skin from week 20 •Synapses develop around week 20 •Thalamic afferents reach the subplate zone 20 wks (Rakic, Kostovich, Hevner 1984) • Thalamic afferents reach the cortical plate (Rakic, Kostovich, Golman 1984) •Myelinisering till brainstem, thalamus at week 30 NICU •Endorfins present at week 20 •Nociceptive connections develop between week 22 and 24 •Somatosensory evoked potential with distinct constant component 29 wks (Klimach ‘88) •EEG denoting clear shifting wakefulness-sleeping differences 30 wks Clancy 2003 Why pain perception is potentially possible already in early of development 1. Number of nociceptive nerve fibers in the skin of the neonate is similar to and possibly even greater than the number found in the adult. 2. Despite the incomplete myelination of pain fibers, pain transmission is preserved. The short distances in the immature brain compensate any slowing of velocity that may be caused by the lack of myelinisation. 3. There is abundance of pain neurotransmitters in the newborn brain and in the fetal brain. 4. There are receptive fields of neurons in the somatosensory cortex. Why newborn infants may potentially feel more pain than adults? Pain transmission and neurotransmitters are extremely well developed at birth as well as in the premature, but modulatory and inhibitory circuits are still immature and partially lacking (physiological imbalance excitatory vs. inhibitory fibres) Physiological background: 1. There is a delay in the maturation of descending inhibitory pathways from supraspinal areas 2. There is a delayed maturation of interneurons in the “substantia gelatinosa” 3. There is a deficiency of inhibitory neurotransmitters Development of pain response Lower gestational age may be associated to lower pain thresholds in early development (Anand 1998; Fitzgerald et al. 1988), eventually resulting in greater cortical responses in the more immature preterm neonates following pain stimuli Which cortical areas are involved in pain processing? How nociceptive/painful stimuli arrive at the cortical level in preterm newborn infants? Other areas: Hypothalamus, anterior cyngulate gyrus, amygdala, hyppocampus, nucleus accumbens, cerebellum Inhibitory and facilitatory effects amygdala basal ganglia (etc.) The newborn is not “a little adult” • The structures and mechanisms involved in pain processing during early development are unique and different from those of the adult. • Many of these structures and mechanisms are not maintained beyond specific periods of early development Narsinghani & Anand 2000 Fitzgerald 2005 Pain processing in the brainstem Medulla • 5-10 wks development of medullary nuclei – Formation of the rhombencephalon (hindbrain) • 10 wks vagal afferents, visceral afferents (nucleus of the solitary tract), general somatic afferent nuclei (trigeminal nuclei) Pain processing in the brainstem Medullary nuclei • Rostral ventromedial medullla (RVM) – Pain modulatory circuitry (especially chronic pain) – Inhibitory and facilitatory effects – Bilateral nociception bladder and colorectal distension (Visceral Sensory Information) (Robbins, Neurosci Lett 2005) – Connections with the Periaqueductal Grey (PAG) and involved in hyperalgesia and allodynia (prostaglandinPGE2 effect) (Heinrecher, Pain 2004, Robbins 2005) – μ-opioid agonists activate neurons in RVM (despite RVM neurons are quite resistant to the development of μ-opioid tolerance) (Mourgan, Pain 2005) Pain processing in the brainstem Medullary nuclei • Dorsal raphe nucleus (DRN) and nucleus raphe magnus (NRM) – They are crucial in opioid induced analgesia (Fields, Nature Review Neurosci 2004) – They are implicated in stress-induced analgesia (Freitas, Exp Neurol 2005) – Intra-oral sucrose activates neurons in the PAG, DRN and NRM modulating the descending pain pathways (Anseloni, Neurosci 2005; Miyase, Neurosci Lett 2005) Pain processing in the brainstem Medullary nuclei • Nucleus tractus solitarius (NTS) – Especially involved in visceral afferent input – Descending inhibitory and facilitatory loops to the spinal cord – Referred pain and viscerotopic specificity (Hua, Am J Phys 2004) – Autonomic response to visceral stimulation (deLange, Neurosci Lett 2005) – Viscerosomatic hyperalgesia (visceral distension) Involved in the “irritable bowel syndrome” (Anand, J Pediatr 2004) Pain processing in the brainstem Medullary nuclei • Trigeminal nuclear complex – 2 distinct nuclei: • interpolaris/caudalis transition zone (Vi/Vc) – Sensory processing deep tissue, somatovisceral, HPA axis and descending modulation of pain • and subnucleus caudalis – Sensory discriminative aspects of pain (Dubner, J Orof Pain 2004) – Focused on oro-facial and dental pain – Crucial importance in the newborn in NICU as 2 of the most common interventions stimulate the trigeminus (intubation and oral suctioning) (Simons, Arch Ped Adol Med 2003) – Possibly involved in the so called mechanism of “Long Term potentiation (LTP) and may contribute to the “Oral aversion syndrome” noted in ex-prematures. (Smith, 2007; Ljang, Pain 2005) Pain processing in the brainstem Pons nuclei • Parabrachialis complex (PBC) – Particularly involved in emotional, autonomic and neuroendocrine features of painful stimulation – Projects to amygdala (emotional affect), hypothalamus and ventrolateral medulla (autonomic adaptation), PAG (emotional behaviour). (Richard, J Comput Neurol 205) Pain processing in the brainstem Pons nuclei • Pontine reticular formation – Particularly involved in somatic motor responses, arousal and emotional feature of pain via medial thalamic and prefrontal cortical connection. (Gauriau, Exp Physiol 2002) Pictures of a neonates showing emotional features just before a venipuncture….. Pain processing in the brainstem Pons nuclei • Locus ceruleus/sub ceruleus (LC/SC) – Neurons in LC are activated by acute and inflammatory pain – Chronic pain suppresses LC activity to produce hyperalgesia (Imbe, Pain 2004; Freitas Exp Neurol 2005) Pain processing in the brainstem Midbrain • It develops from the mesencephalon between the 9th and the 16th gestational week • It consists of: – Periaqueductal grey (PAG) and Ventral tegmental area • Modulatory system of pain • PAG Stress-induced analgesia, sucrose-mediated analgesia, visceral reaction to pain (Cavum, Brain Res 2004; Anseloni Neurosci 2005) • Opioid and non-opioid mechanisms of endogenous analgesia are located in PAG • Different maturational stages of the opioid receptors in PAG may lead to different effects (Rahman, Brain Res Dev Brain Res 1995) Supraspinal Pain processing Thalamus • Relay station conveying sensory, motor and autonomic information. • It is visible at 6 weeks of gestation • Special sensory projection nuclei (lateral geniculate body – visual; medial geniculate body – auditory) • General sensory projections nuclei (especially involved in pain processing) – ventral posterolateral (VPL) - somatosensory – Ventral posteromedial (VPM) – Posterior nuclear group (Po) and the triangular pain processing Supraspinal Pain processing Sucortical level • Anterior cyngulate gyrus It develops fully at about 24 weeks of gestation – Intensity, sensory-integrative, affective and cognitive modulation – Habituation (Bingel, Pain 2007) Other subcortical areas • Hypothalamus (16-20 weeks of gestation) – Integration discending/ascending information to pain, stress and emotion – Connection with other subcortical areas • Amygdala (12-16 weeks of gestation) – Stress component. Neuroendocrine responses. • Hippocampus (15-16 weeks of gestation) – Anxiety hyperalgesia. Chronic and repetitive pain and stress abundant glucocorticoid receptors • Nucleus accumbens (early in gestation) – Suppression of chronic pain. Antinociception via opioid receptors, dopamine D2 receptors, and calcitonin gene-related receptors Supraspinal Pain processing Cortex • Primary somatosensory cortex (S1) – Somatotopic mapping with narrow receptive fields – Not yet clear its role in conscious experience of pain • Secondary somatosensory cortex (S2) – Large, bilateral receptive fields – More likely directly involved in the processing of the noxious stimulus. Number of patients Mean Median Minimum Maximum SD Gestational age (weeks) 40 32.0 32.0 28.0 36.0 3.0 Postnatal age (hours) 40 30.7 30.0 25.0 42.0 4.8 Weight (grams) 40 1899.5 1772.5 1200.0 3100.0 590.3 Venepuncture duration (seconds) 40 48.3 49.0 35.0 60.0 6.7 Gestational age 20 32.7 33 28.0 36.0 3.0 Postnatal age 20 29.5 28.5 25.0 40.0 4.3 Weight 20 1958.0 2005 1200.0 3010.0 567.0 Venepuncture duration 20 49.8 50 35.0 60.0 6.9 Gestational age 20 31.4 31 28.0 36.0 2.9 Postnatal age 20 32.0 30 25.0 42.0 5.2 Weight 20 1841.0 1595 1200.0 3100.0 621.9 Venepuncture duration 20 46.7 45.5 39.0 59.0 6.2 All subjects Females Males Bartocci et al, Pain 2006 CBV Stimulus Neural response Blood Oxygen level CBF CMRO2 Stimulus Hb O2 Hb H Hb tot Bartocci et al, Pain 2006 primary somatosensory cortex and parts of the secondary somatosensory cortex, insula, cingulate cortex, thalamus, and the amygdala. E E R R Cortical areas illuminated by NIRS Areas of the preterm brain likely to be illuminated by NIRS Bartocci et al, Pain 2006 Figure 1b Near Infrared Spectroscopy NIRS • Photon 1 is scattered and reaches the detector • Photon 2 is absorbed after a number of scattering events • Photon 3 leaves the head without being detected H. Obrig et al. International Journal of Psychophysiology 2000 Venipuncture Tactile stimulus 30 seconds Period: P0 Baseline NIRS recording 60 seconds Period: P1 Tactile NIRS recording 60 seconds Period: P2 Pain NIRS recording 60 seconds 6 Venipuncture 5 [Hb tot] left 4 mmol/L NIRS 3 2 1 [Hb tot] right 0 -1 100 Sat O2 80 % 60 180 HR 160 bpm 140 0 60 s Μmol/L 5 4 3 Hb O2 left 2 Hb O2 right Hb H left 1 Hb H right 0 sec -1 tactile -2 venipuncture 60 sec Bartocci et al Pain 2006 6 A * A. Comparison of the cortical [HbO2] increases between the female (black columns) and male (white columns) neonates following venipuncture. ** 5 microMol/L 4 Females Males 3 2 1 0 [Hb O2 ]diff left hem isphere [Hb O2 ]diff right hem isphere 6 5 B * microMol/L 4 3 2 1 0 [Hb O2 ]diff venipuncture on the left hand [Hb O2 ]diff venipuncture on the right hand B. Differences in cortical [HbO2] changes following venipuncture on the left or the right hand. Black bars denote [HbO2] increases on the left hemisphere and white bars on the right hemisphere. 5.5 5.0 4.5 4.0 3.5 [Hb O2] left [Hb O2] right * 3.0 2.5 MicroMol/L 2.0 1.5 1.0 * 0.5 0.0 * -0.5 Baseline Tactile Venipuncture Cortical activity in the somatosensory cortex during tactile and painful stimulation (venipunture). Bartocci et al, 2006 7 6 5 * [Hb O2] parietal [Hb O2] occipital 4 3 ] 2microM/L [Hb O * 2 1 0 -1 -2 baseline tactile venipuncture Bartocci et al, Pain 2006 9 8 8 7 7 6 6 5 5 diff right ]2 mmol/L [HbO leftdiff ]2mmol/L [HbO 4 3 3 2 2 1 24 4 26 28 30 32 34 36 38 40 PNA (hours) 42 1 24 44 26 28 30 32 34 36 38 40 PNA (hours) 95% confidence 42 44 95% confidence 9 9 8 8 7 7 6 6 5 5 4 diff right ]2 mmol/L [HbO leftdiff ]2mmol/L [HbO 4 3 2 1 27 3 2 1 0 28 29 30 31 32 GA (weeks) 33 34 35 36 37 95% confidence -1 27 28 29 30 31 32 GA (weeks) 33 34 35 36 37 95% confidence Conclusion from our study • Painful and tactile stimuli elicit specific haemodynamic responses in the somatosensory cortex, implying conscious sensory perception in preterm neonates. • Somatosensory cortical activation occurs bilaterally following unilateral stimulation and these changes are more pronounced in male neonates or preterm neonates at lower gestational ages. Mean PMA at time of study (weeks), 35.0 (5.2); range, 25.7– 45.6 The long latencies of the cortical responses in the youngest infants are likely attributable to the low conduction velocities and slow synaptic responses in the nociceptive circuitry Slater et al. The Journal of Neuroscience, 2006 squeezing 12 10 venipuncture puncture squeezing [HbO2] squeezing microMol/L 8 6 4 2 0 -2 -4 [HbH] -6 time 1 min Effect of squeezing during heel lancing Unpublished data Changes of [HbO2] mMol/L 10 8 Intramuscular injection of vit K 30 min after birth. Injection on the left leg. Recording over the right sensory cortex. 6 4 disinfection 12 2 0 -2 10 sec injection Unpublished data Thanks to Felicia Nordenstam Slater et al, PLoS 2008 Non-noxious touch stimulation Neuroimage 2010 Noxious heel lance stimulation 7 infants; born 24–32 weeks 8 infants; born 37–40 weeks mean PCA at time of heel lance 39.2 ± 1.2 weeks Conclusions – 1 • More and more evidence has been gathered about the anatomical and maturational potentials for supraspinal pain processing in newborn infants, particularly in prematures. • Some of the nociceptive pathways or mechanisms may not be maintained beyond specific periods of early development. This fact has to be taken into account both in research and clinical practice. Conclusions – 2 • There is starting evidence indicating that in newborn infants, especially those born extremely premature, supraspinal pain processing may be not accompanied by corresponding detectable behavioural changes. • Procedures with low pain scores based on behavioural assessment tools alone may not be pain free. • Advances in functional neuroimaging and electrophysiology and molecular neuroscience will provide better understanding of pain processing and therefore increase the possibility of a better pain assessment and treatment. Pain assessment Most neonatal intensive care units rely on subjective assessments made by nursing and medical staff to determine whether a baby requires analgesia or sedation and whether this treatment is effective. Staff perceptions vary considerably, resulting in under-treatment or over-treatment of pain (Lago et al., 2005; Walker, 2005). The “first pain” and the “second pain” The most of the procedures may have a double impact to the discomfort of the baby: acutely during the tissue damaging procedure (‘‘first pain’’) after the procedure (‘‘second pain’’) Boyle et al. Pain 2006 Newborns at 26 (23–31) weeks and birth weight of 845 (500–1935) grams. Pain Scales Commonly used methods for assessment of pain in newborns Premature Infant Pain Profile (PIPP) Neonatal Facial coding scale (NFCS) Neonatal infant Pain scale (NIPS) Cries score Variables assessed GA, Behavioral state, HR, saO2, brow bulge, eye squeeze, nasolabial furrow Brow bulge, eye squeeze, nasolabial furrow, open lips, stretch mouth, lip purse, taut tongue, chin quiver, tongue protrusion Facial expression, cry, breathing patterns, arms, legs, state of arousal Crying, increase saO2, increased vital signs, expression, sleeplessness Reliability Intra and interrater reliability >0.93 Intra and interrater reliability >0.85 Inter-rater reliability >0.92 Inter-rater reliability >0.72 Clinical utility Used at the bedside Used at the bedside Not yet established Preferred by nurses in USA Indicator Description Result Facial activity 1. 2. 3. 4. Relaxed facial activity Frequent grimaces, lasting grimaces Permanent grimaces resembling crying or blank face Transient grimaces with frowning, lip purse and chin quiver or tautness Body movements 1. 2. 3. 4. Relaxed body movements Transient agitation, often quiet Frequent agitation but can be calmed down Permanent agitation with contraction of fingers and toes and hypertonia of limbs or infrequent, slow movements and prostration Quality of sleep 1. 2. 3. 4. Falls asleep easily Falls asleep with difficulty Frequent, spontaneous arousals, independent of nursing, restless sleep Sleepless Quality of contact with nurses 1. 2. 3. Smiles, attentive to voice Transient apprehension during interactions with nurses Difficulty communicating with nurses. Cries in response to minor stimulation Consolability 1. 2. 3. 4. Quiet, total relaxation Calms down quickly in response to stroking or voice, or with sucking Disconsolate. Sucks desperately Calms down with difficulty EDIN Scale TOTAL SCORE: FLACC Assessment Sedation Normal -2 -1 0 1 2 No cry with painful stimuli Moans or cries minimally with painful stimuli Appropriate crying Not irritable Irritable or crying at intervals Consolable High-pitched or silentcontinuous cry Inconsolable No arousal to any stimuli No spontaneous movement Arouses minimally to stimuli Little spontaneous movement Appropriate for gestational age Restless, squirming Awakens frequently Arching, kicking Constantly awake or Arouses minimally / no movement (not sedated) Mouth is lax No expression Minimal expression with stimuli Relaxed Appropriate Any pain expression intermittent Any pain expression continual Extremities Tone No grasp reflex Flaccid tone Weak grasp reflex muscle tone Relaxed hands and feet Normal tone Intermittent clenched toes, fists or finger splay Body is not tense Continual clenched toes, fists, or finger splay Body is tense Vital Signs HR, RR, BP, SaO2 No variability with stimuli Hypoventilation or apnea < 10% variability from baseline with stimuli Within baseline or normal for gestational age 10-20% from baseline SaO2 76-85% with stimulation – quick > 20% from baseline SaO2 75% with stimulation – slow Out of sync with vent Criteria Crying Irritabili ty Behavior State Facial Expressio n If the newborn is premature: +3 if < 28 weeks gestation / corrected age. +2 if 28 - 31 weeks gestation / corrected age. +1 if 32 - 35 weeks gestation / corrected age. Pain / Agitation N-PASS = Neonatal Pain Agitation Scale By Hummel and Puchaski, 2000 Film “good sedation” • Born at 25 week • NEC operation at 28 weeks • 1st day post-operation – Morphine infusion 10 microg/kg/h – Clonidine infusion 7,5 microg/kg/d – L-bupivacaine: 0,2 mg/kg/h in the wound catheter FANS Faceless Acute Neonatal pain Scale • Heart rate variation 0: < 10% • 1: > 10% • 2: > 50% • Acute discomfort 1: Bradycardia (FC< 100/bpm) or desaturation SpO2< 85% • Limb movements • • • • • 0: Calm, slight 1: Mild intermittent with return to calm 2: Moderate 3: Marked, continuous 4: Global hypotonia • Vocal expression • • • • 0: Absent 1: Brief moaning, anxious 2: Intermittent screaming 3: Constant screaming Milesi et al, 2009 ALPS 1 Pain Assessment Scale for Term Neonates By B. Larsson 0 1 2 Avslappnat Relaxed Spänt uttryck Tense expression Spänt uttryck/Gråtgrimas Tense/grimacing Respiratory pattern Avslappnat Regular Förändrat Changed EXTREMITETS TONUS Avslappnad Relaxed Ökad tonus Increased tonus Stel/Slapp Rigid/hypotoni HAND/FOT Avslappnad Relaxed Lätt knuten Moderately closed Knuten näve, vita knogar Kniper med tår Fisting/white knuckle AKTIVITET Avslappnad Vaken/sover lugnt Normal sleep Orolig Agitated Hyperaktiv/Apatisk Hyperactivity/ apatic ANSIKTSUTTRYCK Face expression ANDNINGSMÖNSTER Ansträngd andning/Gruntar Respiratory efforts/Retractions ALPS 0 (suggestion) <28 weeks 0 1 2 ANSIKTSUTTRYCK Avslappnat Spänt uttryck Sträcker ut tungan Spänt uttryck/Gråtgrimas Tappar hakan ANDNINGSMÖNSTER Avslappnat Ökad andn.frekv, lätt ansträngd Mer oregelbunden Korta andn.pauser < 2 sek Ansträngd andning Omväxlande djup och ytlig andning Andningspauser EXTREMITETSTONUS Avslappnad Växlar i balans/slapp i balans/spänd Spänd/Slapp HAND/FOT Avslappnad Lätt knuten Knuten näve, kniper med tår Spretar med fingrar eller tår Slapp AKTIVITET Avslappnad Vaken/sover lugnt Lätt motorisk oro Ihållande motorisk oro Drar sig bakåt Apatisk x x x x x x 7 3 •No intervention • eventuellt NPI ALPS ≤ 3 ALPS >5 NP I ALPS >5 ALPS 4 eller 5 1. ALPS ≤3 NP I Increase MO inf 2,5microg/kg/t (max 40mikrog/kg/hour) a) b) 2. When MO 15microg/kg/h start Klonidine infusion 0,4mikrog/kg/h When MO 20-25-30 microg/kg/h increase Catapresan inf 0,1mikrog/kg/h (max dos 0,7mikrog/kg/h) If MO inf and Clonidine inf are max dos start Ketanest inf. 0,05mg/kg/h ALPS >5 •If MO inf 2,5microg/kg/h(max 40 mikrog/kg/h) •Start Fentanyl 1 mikrog/kg ALPS >5 ALPS ≤3 ALPS 4 eller 5 •Give Fentanyl 1 mikrog/kg ALPS >5 NPI=non pharmacological interventions (dvs. Non nutrive sucking, repositioning, etc.) Pain assessment every 30 min Pain assessment before procedures Pain assessment 10min after procedures Pain assessment 10 min after bolusdos narcotics ALPS >5 ALPS 4 eller 5 ALPS ≤3 •Give Ketanest 0,2mg/kg bolus •Increase MO inf 2,5microg/kg/timme (max 40 mikrog/kg/h) •Increase Clonidine infusion 0,1 mikrog/kg/t up to max 0,7 mikrog/kg/t •If MO inf and Clonidine inf max dos give Ketanest inf. 0,05mg/kg/h ALPS ≤3 •Give Clonidine 2 mikrog/kg (CAVE side effects!) •Increase MO inf 2,5microg/kg/timme (max 40 mikrog/kg/timme) •Start Clonidine infusion 0,4mikrog/kg/h (if no significant side effects) if MO inf 15 mikro/kg/h ALPS 4 eller 5 ALPS ≤3 Weaning from the postoperative pain treatment during the first 24 hours ALPS ≤ 3 for 6 timmar •Take out Ketanest inf. •Reduce MO inf 2,5mikrog/kg/h •If the baby is on both MO and Clonidine, start reducing MO 2,5mikrog/kg/h and after Clonidine 0,1mikrog/kg/h when MO is at 10 and 5 mikrog/kg/h •Stop MO when at 5-2,5 mikrog/kg/h •Stop Clonidine when at 0,2 mikrog/kg/h Weaning from the postoperative pain treatment after the first 24 hours ALPS ≤ 3 for 4 timmar •Take out Ketanest inf. •Reduce MO inf 2,5mikrog/kg/h •If the baby is on both MO and Clonidine, start reducing MO 2,5mikrog/kg/h and after Clonidine 0,1mikrog/kg/h when MO is at 10 and 5 mikrog/kg/h •Stop MO when at 5-2,5 mikrog/kg/h •Stop Clonidine when at 0,2 mikrog/kg/h •Keep assessing pain Pain assessment in the “at risk” newborn Infants at risk for neurological impairment may suffer more pain than healthy infants due to discounting or denial of signals of acute distress by health professionals and parents (Walco et al., 1994) misconceptions about the capacity and sensitivity for pain (Stevens et al., 2007) effects of underlying disease on the nociceptive system inadequate knowledge to systematically study the problem (Oberlander et al., 1999; Oberlander and O’Donnell, 2001) the inability to use analgesic methods used in other infants (e.g., non-nutritive sucking) (Stevens et al., 2007) Higfh risk for NI Moderate risk for NI Low risk for NI Stevens et al., Pain 2007 IVH and pain processing in preterm non-noxious touch Similarity between evoked potentials in preterm infant with and without IVH. noxious heel lance Neuroimage 2010 Contents • Pain development – Pain vs. Nociception • Pain assessment – Importance of pain assessment – Pain scales – Examples • Pain treatment –Painful procedures – NIDCAP – Drugs Hpothesis • More attention should be paid to small procedures. In a recent study about 45% of small painful/discomfort procedures are not adequately treated. (Simons et al 2003, Arch Pediatr Adolesc Med) • We should reconsider treating pain during and after emergency procedures When we should measure pain •Diagnostic •Therapeutic •Clinical Diagnostic – Arterial puncture, venipuncture, heel puncture – Bronscopy – Endoscopy – Lumbar puncture – ROP examination – Suprapubic bladder tap – X-ray (particular cases) Therapeutic – – – – – – – – – – – – – – – – Bladder catheterization Chest tube insertion/removal Oro/naso gastric tube insertion Intramuscular injection Peripheral venous catheterization Mechanical ventilation Removal of adhesive tape Suture removal Tracheal intubation All surgical procedures Ventricular tap Central line insertion/removal (?) Tracheal extubation (?) Dressing change (?) Postural drainage (?) Chest physiotherapy (?) Orogastric suctioning • Orogastric suctioning during the neonatal period results in global chronic somatic and visceral hyperalgesia in adult life. Smith et al., 2007 Clinical condition – Mechanical ventilation (especially HFOV) – Chest tube – Post-operative – Fractures – NEC – Plexus injuries – Cephalhematoma – Traumatic deliveries – Skin injuries and infiltration – Pneumothorax (without chest tube) Pain treatment non-pharmacological interventions • • • • Glucose Nutritive and non-nutritive sucking Containment Nidcap Glucose: Analgesic or “just an illusion” • Stress is high even after glucose administration (Ped res 2006) • Oral sucrose does not significantly affect activity in neonatal brain or spinal cord nociceptive circuits, and therefore might not be an effective analgesic drug (Lancet, 2010) Behavioral responses do not match with neurophysiologic signal and stress hormones Glukos • Sucrose on the tongue (not via V-tube) stimulates the release of endogenous opioids. Iof the newborn gets naloxone at the same time, endogenous opioids may be blocked, resulting in loosing the analgesic effect. • The best behavioural response to glucose is observed when in combination pacifier. Containment enhances the effect. • Glucose 30% (300mg/mnl) is a potent solution with a very high osmolality (about 7 times stronger than a normal formula) that can be hazardous to the immature mucosa of the stomach and intestine. Glukos • Extrem prematura barn < v.28 – Ingen peroral Glukos förrän barnets mag- och tarmsystem har tolererat matintag under 1 vecka. • Prematura barn > v.28 – 0,1 – 0,4 ml Glukos per tillfälle. • Vid misstänkt NEC eller efter bukoperation – Ingen Glukos peroralt före påbörjad matupptrappning. • Fullgångna barn – 1,0 ml Glukos, vb kan ytterligare 0,5 + 0,5 ml ges (max 2 ml) per tillfälle. L a n c Suppressing neuronal activity in the surrounding area Inhibitory neurons - - - Other neuron Other neuron Specific neurons (ex. visual, gustatory??) Attention, interest. Taste? Smell? Perception. Macknik, Martinez-Conde, Nature 2007 Macknik, Scientific Am. 2010 Pain treatment • Short term pain (procedural pain) – – – – – – – Fentanyl 0.5-1 microg/kg Remifentanyl 0,1-0,2 microg/kg Ketamine 0,125-0,3mg/kg uo to 3mg/kg Morphine 0.05-0.2 mg/kg Clonidine 3-4microg/kg ggr 3-4/day Propofol 0,5-1,5 mg/kg Ketolarac 1mg/kg (10 min) (very seldom) • Long term pain ( – – – – Morphine, Ketogan 10-50 micro/kg/h Clonidine 9-20microg/day Paracetamol 7,5-15mg/kg x3-4 Gabapentin (neuropatisk smärta) The morphine issue…. • Morphine does not appear to provide adequate analgesia for the acute pain caused by invasive procedures among ventilated preterm neonates. Pediatrics 2005, Carbajal et al. • Morphine does not reduces IVH in ventilated preterm newborn. NEOPAIN study. Lancet 2004, Anand et al. Opioids • Exposure to morphine in early life may affect the development and the expression of pain receptors and thus how pain is going to be perceived in later life (anand 2000) • There is insufficient evidence to recommend routine use of opioids in mechanically ventilated newborns. Opioids should be used selectively, when indicated by clinical judgment and evaluation of pain indicators. (Anand 2006) Our doses…. Namn Conc. (substans) Morfin epidural (morfin hydrochlorh ydrat) 0.4mg/ml injection Dos 0.1-0.2 mg/kg Solut. NaCl 9mg/ml Glu 5%, 0.04mg/ml 5-40 μg/kg/h 10% infusion Other Inj.: Under ca 15min. Inf:: Avoid too quick weaning Effect of oral naloxone hydrochloride on gastrointestinal transit in premature infants treated with morphine p = 0.014 Mean food intake (ml/kg/day) p = 0.183 Perfalgan (Paracetamol iv) Age at operation Below v28 Infusion Perfalgan 7 mg/kg x 3 V. 28-32 7,5 mg/kg x 3 V. 33-36 7,5 mg/kg x 4 Over 37 weeks 10-15 mg/kg x 4 Dosen bör halveras efter ca 4-5 dagar eller till barn med nedsatt leverfunktion. PM - Smärtlindring under pleuradrän insättning 1. Optimize the enviroment The operator should have a comfortable work place. The baby should stay in the nest and be held and contained Prepared all the tools to reduce the time of the procedure Evaluation of potential hazardous conditions hypotension, bleeding, etc 2. Morphine 0,4mg/ml 0,1-0,2 mg/kg bolus Catapresan (Clonidine) 15 or 1.5 microg/ml 1-3 microg/kg x3-4 max 9-12 microg/kg/dygn 0,1-0,4 microg/kg/t (inf) Ketanest (Ketamine) 25 or 25 mg/ml 0.01-0.05 mg/kg/t inf 0.125-0.25 mg/kg inj upp till 1-2 mg/kg OBS! Det tar ca 1150 min minst innan morfinet har effekt Glu5% or NaCl CAVE HR, BT! Tar BT before injektion/ infusion startas Glu5% or NaCl Need of sedation? Midazolam 1mg/ml 0,05-0,1 mg/kg bolus 3. Local analgesia Tamponated xylocain 2% (2ml NaHCO3 + 8 ml xylocain) OBS! Observe if the analgesia is enough! OBS! If need give more morphine (0.02-0.03mg/kg) or other drugs Chest tube insertion 4. Continous Morfin inf. (0,04mg/ml) 5-20microg/kg/timme •If the baby is very calm consider nu MO inf. And consider Clonidine if BP is stable. 5. Morfin weaning •Pain assessment is fundamental •About 6-8 hours interval between the dos lowering down to the lower dos •The longer is the infusion the longer is the weaning time •Consider other drugs Clonidine or ketamine during the weaning •Paracetamol should be kept about 1-2 days after morphine is ceased •Naloxon hydrochlorid p.o. Morfin infusion After the chest tube is positioned assess pain and give iv paracetamol (Perfalgan 10mg/ml) 7,5 10mg/kg iv x 4/d. (Better iv than rectally, Alvedon Pain assessment! rekt 30mg/kgx3 first day followed by 10-20mg/kg x3) Pain treatment local anaesthesia • • • • • EMLA LMX Xylocaine Chirocaine (L-bupivacaine) Rupivacaine EMLA – EMLA-krämen innehåller lidokain och prilokain som tränger in i huden och ger en lokal hudanestesi. Prilokainet som finns i krämen kan i kombination med Sulfa, Trimetroprim-Sulfa (Bactrim) eller NO kan öka Met-Hb. Över vecka 30 • Barn > 30 gestationsveckor – 1 månad efter fullgången tid • 0,5 gram (0,5 ml) EMLA högst 1 gång per dygn i högst en timme. Local anesthesia with subcutaneous catheter Levobupivacaine (Chirocaine®) Levobupivacaine is an amide-type local anaesthetic. As with all local anaesthetic agents, levobupivacaine inhibits conduction of the action potential in nerves involved in sensory and motor activity and sympathetic activity Infusionsvätska Chirocaine 1,25mg/ml (L-bupivacaine) Dos: 2 mg/kg x 4 eller som kontinuerlig infusion, 8-15 mg/kg/dygn Group A: Morphine infusion at a starting dose of 10 microg/kg/h + paracetamol (Perfalgan®) 7,5mg/kg 4 times daily Group B: Morphine infusion at a starting dose of 10 microg/kg/h + paracetamol (Perfalgan®) 7,5mg/kg 4 times daily + Chirocaine® (1,25mg/ml) and a dose of 2 mg/kg subcutaneously 4 times daily. Morphine infusion (microg/kg) tot 800 600 400 200 0 p<0.05 w ithout local anaesthesia group A w ith local anaesthesia group B Best Practice & Research Clinical Anaesthesiology, 2010 Local anesthesia for the insertion of naso-gastric tube in premature infants Lidocaine, 5mg/ml 2 puff (0,5mg) lidocaine in the nose/pharynx 1 min before insertion 2.5 ALPS/NIPS score 2 1.5 ALPS diff NIPS diff 1 0.5 0 Placebo Lidocaine Social influences Pain event Familial context Pain experience Child Community context Cultural context Pain expression Assessment of pain Caregiver Intervention from International Association for the Study of Pain Take home message • Newborns at all gestational ages are receptive, more susceptible and vulnerable to both nociception and painful stimuli. • Nociceptive and painful stimuli during the neonatal period might impair the capacity to perceive, express and describe pain later in life. • Adequate pain prevention and treatment are based on pain systematic and standardized assessment pain scale, courses, up-to-date • There is the need to develop new strategies and alternatives to opioid treatment research on pharmacodynamic and pharmacocynetic urges!