Observational Pain Scores Research Articles

Skin conductance peaks could result from changes in vital parameters unrelated to pain

Pain is usually assessed by the interpretation of behavior, which can be subjective. Therefore, there is an ongoing search for more objective methods. Performance of skin conductance measurement as a pain assessment tool is variable, as some studies report low specificity and a low predictive value of the method. The aim of this pilot study was to test whether autoregulation of the skin temperature influences the skin conductance of pain-free infants. Skin conductance was highly correlated with skin temperature in all subjects. Moreover, a significant change in all other vital parameters was observed on comparing before- and after-peak data. These results indicate that sympathetic neural activity to maintain homeostasis (such as autoregulation of skin temperature) results in skin conductance peaks. Real-time evaluation of the sympathetic nervous system would be valuable for pain assessment. However, the technique should be better defined to increase both sensitivity and specificity for the measurement of pain before use in daily practice can be advocated. We included 11 infants, median (interquartile range (IQR)) age of 34 (13-76) d, who were admitted to the surgical high-care unit for monitoring after surgery. None was treated with opioids or sedatives, and observational pain scores were low.

Postoperative analgesic efficacy of single high dose and low dose rectal acetaminophen in pediatric ophthalmic surgery

Background:Analgesic efficacy of rectal acetaminophen is variable in different surgical procedures. Little data is available on its efficacy in ophthalmic surgeries. We conducted this prospective, randomized, double blind study to evaluate and compare the efficacy of single high dose and low dose rectal acetaminophen in pediatric ophthalmic surgery over a 24 hour period.Materials and Methods:135 children scheduled for elective ophthalmic surgery were randomly allocated to one of the three groups, high, low, or control (H, L, or N) and received rectal acetaminophen 40 mg/kg, 20 mg/kg or no rectal drug respectively after induction of general anesthesia. Postoperative observations included recovery score, hourly observational pain score (OPS) up to 8 hours, time to first analgesic demand, and requirement of rescue analgesics and antiemetics over a 24 hour period.Results:Nineteen of 30 (63%) of children in group N required postoperative rescue analgesic versus 5/48 (10%) of group H (P <0.0001) and 10/47 (23%) of group L (P =0.0005) during 24 hour period. Mean time to requirement of first analgesic was 206±185 min in group H, 189±203min in group L, and 196 ±170 min in group N (P=0.985). OPS was significantly lower in group H and L compared to group N during first 8 hours. Requirement of rescue antiemetic was 18.7% in group H as compared to 23% each in group L and group N (P >0.5).Conclusions:Single dose rectal acetaminophen can provide effective postoperative analgesia for pediatric ophthalmic surgery at both high dose (40 mg/kg) and low dose (20 mg/kg) both in early postoperative and over a 24 hour period.

Assessing Intravenous Ketamine and Intravenous Dexamethasone Separately and in Combination for Early Oral Intake, Vomiting and Postoperative Pain Relief in Children Following Tonsillectomy

The aim of the present study is to evaluate the effect of preoperative 0.5 mg/kg i.v. dexamethasone in combination with 0.5 mg/kg i.v. ketamine on pain, early oral intake and vomiting in pediatric patients undergoing tonsillectomy during the first 24 hours of the postoperative period. One hundred twenty children who were scheduled for tonsillectomy were randomly assigned to receive a single dose of dexamethasone 0.5 mg/kg i.v. as Group D (n = 30), receive ketamine 0.5 mg/kg i.v. as Group K (n = 30), receive dexamethasone 0.5 mg/kg i.v. and ketamine 0.5 mg/kg i.v. as Group KD (n = 30) and an equivalent volume of saline as Group C (n = 30) 15 minutes before the induction of anesthesia. Post-operative pain was evaluated using an observational pain score (OPS) on arrival to the post-anesthesia care unit (PACU), at 15, 30, 45, and 60 minutes after that and at 1, 2, 4, 6, 12, and 24 hours after arrival to the ward. OPS scores were significantly lower at the time of arrival to the PACU, and at 15, 30, 45, and 60 minutes in the Group KD compared with Group C (p < 0.05). Postoperative OPS scores were significantly lower at 1, 2, 4, 6, 12, and 24 hours after operation in Group KD compared with Group C (p < 0.05). A prophylactic preoperative single dose of i.v. 0.5 mg/kg dexamethasone in combination with a single dose of i.v. 0.5 mg/kg ketamine significantly decreased post-tonsillectomy pain compare with using i.v. ketamine or i.v. dexamehasone separately.

Comparison of Ketamine and Fentanyl for Postoperative Pain Relief in Children Following Adenotonsillectomy

Adenotonsillectomy has a high incidence of postoperative pain. Therefore, the purpose of this study was to evaluate the effectiveness and safety of either ketamine or fentanyl for postoperative pain relief in children following adenotonsillectomy. Sixty children aged 3-12 years, scheduled for adenotonsillectomy, were enrolled in this randomized, double-blind study. Patients were divided into two groups of 30 cases and received intravenous ketamine (0.5 mg kg(-1)) or fentanyl (1 microg kg(-1)). Modified Hannallah pain scale or Observational Pain Scores (OPS), nausea, vomiting, bleeding, rescue analgesia, sedation and post-anesthesia recovery scores were recorded both at first and 15th minute postoperatively. Moreover, patients receiving ketamine (group 1) or fentanyl (group 2) had comparable OPS and sedation score both on arrival and at 15th minute in the recovery room (p > 0.05). Although rescue analgesics were similarly required in both groups (p > 0.05), the time to reach rescue analgesia was shorter in group 1 (p = 0.001). Only one patient in fentanyl group had nausea and vomiting in the first 15 min that needed antiemetic in the recovery room. In conclusion, intravenous fentanyl (1 microg kg(-1)) compared with intravenous ketamine (0.5 mg kg(-1)) might provide extended time to first analgesic in children undergoing adenotonsillectomy. Interestingly, fentanyl and ketamine did not differ in post-operative vomiting.

Oral sucrose as an analgesic drug for procedural pain in newborn infants: a randomised controlled trial

SummaryBackgroundMany infants admitted to hospital undergo repeated invasive procedures. Oral sucrose is frequently given to relieve procedural pain in neonates on the basis of its effect on behavioural and physiological pain scores. We assessed whether sucrose administration reduces pain-specific brain and spinal cord activity after an acute noxious procedure in newborn infants.MethodsIn this double-blind, randomised controlled trial, 59 newborn infants at University College Hospital (London, UK) were randomly assigned to receive 0·5 mL 24% sucrose solution or 0·5 mL sterile water 2 min before undergoing a clinically required heel lance. Randomisation was by a computer-generated randomisation code, and researchers, clinicians, participants, and parents were masked to the identity of the solutions. The primary outcome was pain-specific brain activity evoked by one time-locked heel lance, recorded with electroencephalography and identified by principal component analysis. Secondary measures were baseline behavioural and physiological measures, observational pain scores (PIPP), and spinal nociceptive reflex withdrawal activity. Data were analysed per protocol. This study is registered, number ISRCTN78390996.Findings29 infants were assigned to receive sucrose and 30 to sterilised water; 20 and 24 infants, respectively, were included in the analysis of the primary outcome measure. Nociceptive brain activity after the noxious heel lance did not differ significantly between infants who received sucrose and those who received sterile water (sucrose: mean 0·10, 95% CI 0·04–0·16; sterile water: mean 0·08, 0·04–0·12; p=0·46). No significant difference was recorded between the sucrose and sterile water groups in the magnitude or latency of the spinal nociceptive reflex withdrawal recorded from the biceps femoris of the stimulated leg. The PIPP score was significantly lower in infants given sucrose than in those given sterile water (mean 5·8, 95% CI 3·7–7·8 vs 8·5, 7·3–9·8; p=0·02) and significantly more infants had no change in facial expression after sucrose administration (seven of 20 [35%] vs none of 24; p<0·0001).InterpretationOur data suggest that oral sucrose does not significantly affect activity in neonatal brain or spinal cord nociceptive circuits, and therefore might not be an effective analgesic drug. The ability of sucrose to reduce clinical observational scores after noxious events in newborn infants should not be interpreted as pain relief.FundingMedical Research Council.

The use of Virtual Reality for needle-related procedural pain and distress in children and adolescents in a paediatric oncology unit

Aim It is essential to minimize pain and distress during painful procedures in children. This study examined the effect of using non-immersive Virtual Reality (VR) during a needle-related procedure on reported pain or distress of children and adolescents in a paediatric oncology unit and surveyed their response to the use of VR-equipment during the procedure. Method Twenty-one children and adolescents were included in an intervention group with non-immersive VR and another 21 children and adolescents in a control group where they underwent either venous punctures or subcutaneous venous port devices. Self-reported pain and distress, heart rate and observational pain scores were collected before, during and after the procedures. Semi-structured qualitative interviews were conducted in conjunction with the completed intervention. Results Self-reported and observed pain and distress scores were low and few significant differences of quantitative data between the groups were found. Two themes emerged in the analysis of the interviews; the VR game should correspond to the child and the medical procedure and children enjoyed the VR game and found that it did distract them during the procedure. Conclusion The interviews showed that non-immersive VR is a positive experience for children undergoing a minor procedure such as venous puncture or a subcutaneous venous port access.

A Comparison of Single-Dose Caudal Clonidine, Morphine, or Hydromorphone Combined with Ropivacaine in Pediatric Patients Undergoing Ureteral Reimplantation

Caudal blockade is a common technique for pediatric postoperative analgesia. While safe and effective, caudal opioids are associated with troublesome side effects. Caudal clonidine may offer significant analgesic benefits. We prospectively compared the analgesic, side effect, and rehabilitation profiles of caudal clonidine, hydromorphone, or morphine in a group of 60 pediatric patients undergoing ureteral reimplantation. Patients aged 6 mo to 6 yr were evenly and randomly enrolled in a double-blind manner. Patients received a single caudal dose of 2 mcg/kg of clonidine, 10 mcg/kg of hydromorphone, or 50 mcg/kg of morphine, combined with 1.0 mL/kg of 0.2% ropivacaine with epinephrine. After sevoflurane in oxygen/air anesthesia, all subjects received proxy nurse-controlled analgesia with morphine. Postoperative pain intensity, use of IV morphine, and side effects were assessed during the first 24 h. Oral intake and discharge home were recorded. Caudal clonidine resulted in less postoperative nausea and vomiting (P = 0.01) and pruritus (P = 0.007) than did caudal hydromorphone or caudal morphine. Caudal morphine produced more sustained initial analgesia than did caudal clonidine (P = 0.02). No difference was observed in pain scores, total morphine use, time to first oral intake or discharge home. No postoperative respiratory depression, excessive sedation, hypotension, or bradycardia was identified. Although caudal morphine may result in more sustained initial analgesia, caudal clonidine combined with nurse-controlled analgesia appears to provide comparable analgesia with fewer side effects. Based on these results, the use of caudal clonidine may be superior to caudal opioids after pediatric ureteral reimplantation.

The efficacy of intravenous or peritonsillar infiltration of ketamine for postoperative pain relief in children following adenotonsillectomy1

A few previous studies have suggested the efficacy of i.v. ketamine for postoperative pain relief in children after adenotonsillectomy, but none has investigated the efficacy of peritonsillar infiltration of ketamine in these children. This randomized, placebo-controlled study evaluated the effects of peritonsillar infiltration of ketamine in children undergoing adenotonsillectomy. Ninety ASA I-II children were randomized three groups of 30 each. Group I received: 2 ml i.v. saline, group II received i.v. ketamine (0.5 mgxkg(-1)) and group III received a local peritonsillar infiltration of ketamine (0.5 mgxkg(-1)). All medications were 2 ml in volume which was applied 1 ml per tonsil 3 min prior to tonsillectomy. Modified Hannallah pain scale [observational pain scores (OPS)], nausea, vomiting, bleeding, rescue analgesia, sedation and Aldrete scores were recorded at first, 15th, 30th and 60th min postoperatively. Patients were interviewed on the day after surgery to assess the postoperative pain, nightmares, hallucinations, vomiting and bleeding. Group I had higher OPS scores than group II and group III. Group II and group III had comparable scores, which were not statistically significant (P > 0.05). Group II had higher sedation score at 15th min (P = 0.015). Thirty-two children, 19 of whom were in group I had rescue analgesia in postanesthesia care unit (P < 0.05) and the time to first analgesic requirement was significantly shorter in group I than the other groups (P = 0.006). Group II and group III also had less pain than group I at home (P = 0.023). Low dose ketamine given i.v. or by peritonsillar infiltration perioperatively provides efficient pain relief without side-effects in children undergoing adenotonsillectomy.

Age-related impact of neuropathic pain on animal behaviour

The number of old and very old persons is increasing and there is evidence that aging coincides with chronic painful conditions. Pain induces behavioural disorders that have been so far poorly identified in old and even less in very old animals. The aim of this study was to: (1) compare the evolution of pain in senescent animals (37–39 months) to old (20–22 months) and young (4–6 months) Lou/cjall rats after a chronic constriction of the sciatic nerve; (2) evaluate pain during four weeks after surgery with an experimental and an observational approach to determine how the response to noxious stimuli correlates with recorded spontaneous behaviour. Results showed that senescent animals are less sensitive to neuropathic pain than old or young rats while senescent/old rats are more sensitive to acute pain. The correlation between observational and experimental pain scores stresses the reliability of non-invasive measures for pain evaluation in senescent populations. The dichotomy between neuropathic and acute pain perceptions with age needs to be further investigated and would help to better understand the reasons of this uneven pain perception and expression with age.

Usefulness of epidural anesthesia in gynecologic laparoscopic surgery for infertility in comparison to general anesthesia

Although the advantages of epidural anesthesia in open surgery have been established, its usefulness in the setting of laparoscopic surgery remains to be studied. Patients undergoing laparoscopic surgery for infertility were randomly administered epidural anesthesia (group A, n = 11) or general anesthesia (group B, n = 9). The operation was performed under 4 mmHg pneumoperitoneum and in the 20 degrees Trendelenburg position. Respiratory function tests using a spirometer and blood gas analysis were performed during the intra- or perioperative period. Pain status was evaluated with visual analog scale scoring. The number of postoperative recovery days needed to resume daily activities was obtained by a questionnaire. Respiratory rate, minute volume, P(a)CO2, % vital capacity (VC), and forced expiratory volume in 1 s (FEV1) % were virtually constant throughout the study period in group A, whereas %VC was decreased immediately after operation in group B (p < 0.05). Minute volume immediately after operation was significantly increased in group B compared with group A (p < 0.01), suggesting shallow respiration in women undergoing general anesthesia. Observed pain scores on abdominal pain, shoulder pain, and dyspnea were very low during operation in group A. Pain scores immediately and 3 h after operation were also minimal in group A, whereas abdominal pain scores at these points were significantly higher in group B than those in group A (both p < 0.01). The number of days required for a half reduction in wound pain, trotting, and full recuperation for group A were less than those for group B (p < 0.05). Epidural anesthesia, when used in laparoscopic surgery for infertility treatment, has advantages over general anesthesia in terms of analgesic effects, postoperative respiratory function, and a return to preoperative daily activities.

Comparison of continuous infusion of fentanyl to bolus dosing in neonates after surgery

Objective: Concern about respiratory depression may lead to underuse of postoperative narcotic analgesia in neonates. The authors compared continuous infusion of fentanyl with bolus dosing in infants after surgery to determine whether continuous infusion is associated with less respiratory depression. Study Design: In the first phase of the study, 16 patients were randomly assigned to receive fentanyl by continuous infusion (C) or bolus dosing every 2 hours (B) in a double-blinded trial. Respiratory events were recorded. An observational pain score and saliva for cortisol concentration were obtained 2, 8, and 24 hours after beginning treatment to compare efficacy of pain control. In the second phase, 20 additional patients received fentanyl by continuous infusion in an unblinded fashion, with the same data collection, to more accurately determine the incidence of respiratory events. Results: In phase 1, apnea occurred in eight of nine B patients (89%) compared with one of seven C patients (14%; P < .009), prompting termination of the randomized trial. The incidence of apnea or significant respiratory depression in the next 20 patients (phase 2) who received fentanyl by continuous infusion was 25% (5 of 20; P < .01 v B). Episodes of apnea in B patients required significantly more intervention than episodes in C patients ( P < .01). However, in phase 2, more patients remained intubated and ventilated than in phase 1. Pain scores and salivary cortisol concentrations decreased over the 24-hour study period and were similar in B and C patients during both phases of the study. Conclusion: Continuous infusion of fentanyl at the doses studied is associated with pain control similar to that with bolus dosing at regular intervals. Although episodes of respiratory depression were less severe and less frequent for C patients, there may be an increased need for ventilator support with continuous infusion of fentanyl to achieve acceptable pain control. Providing adequate pain control to neonates in the immediate postoperative period remains a challenge.