Comparison of high- and low-dose intrathecal morphine for spinal fusion in children

Nausea and Vomiting After Posterior Spinal Fusion in Adolescent Idiopathic Scoliosis: A Systematic and Critical Analysis Review

BACKGROUND

Postoperative nausea and vomiting (PONV) affects patient satisfaction, health care costs, and hospital stay by complicating the postoperative recovery period after adolescent idiopathic scoliosis (AIS) spinal fusion surgery. Our goal was to identify recommendations for optimal management of PONV in AIS patients undergoing posterior spinal fusion (PSF).

METHODS

We performed a systematic review in June 2022, searching the PubMed and Embase electronic databases using search terms "(Adolescent idiopathic scoliosis) AND (Postoperative) AND (Nausea) AND (Vomiting)." Three authors reviewed the 402 abstracts identified from January 1991 to June 2022. Studies that included adolescents or young adults (<21 years) with AIS undergoing PSF were selected for full-text review by consensus. We identified 34 studies reporting on incidence of PONV. Only 6 studies examined PONV as the primary outcome, whereas remaining were reported PONV as a secondary outcome. Journal of Bone and Joint Surgery Grades of recommendation were assigned to potential interventions or clinical practice influencing incidence of PONV with respect to operative period (preoperative, intraoperative, and postoperative period) on the basis that potential guidelines/interventions for PONV can be targeted at those periods.

RESULTS

A total of 11 factors were graded, 5 of which were related to intervention and 6 were clinical practice-related. Eight factors could be classified into the operative period-1 in the intraoperative period and 7 in the postoperative period, whereas the remaining 3 recommendations had overlapping periods. The majority of grades of recommendations given were inconclusive or conflicting. The statement that neuraxial and postoperative systemic-only opioid therapy have a similar incidence of PONV was supported by good (Grade A) evidence. There was fair (Grade B) and poor evidence (Grade C) to avoid opioid antagonists and nonopioid local analgesia using wound catheters as PONV-reducing measures.

CONCLUSION

Although outcomes after spinal fusion for AIS have been studied extensively, the literature on PONV outcomes is scarce and incomplete. PONV is most commonly included as a secondary outcome in studies related to pain management. This study is the first to specifically identify evidence and recommendations for interventions or clinical practice that influence PONV in AIS patients undergoing PSF. Most interventions and clinical practices have conflicting or limited data to support them, whereas others have low-level evidence as to whether the intervention/clinical practice influences the incidence of PONV. We have identified the need for expanded research using PONV as a primary outcome in patients with AIS undergoing spinal fusion surgery.

Effectiveness and Safety of Intrathecal Morphine for Pediatric Patients Undergoing Scoliosis Surgery: A Systematic Review and Meta-Analysis

Adolescent idiopathic scoliosis (AIS) often necessitates spinal fusion surgery in pediatric patients, posing significant challenges in postoperative pain management. Standard care involves the administration of intravenous opioids perioperatively, often requiring high doses to achieve adequate analgesia following an operation. This increases the risk of adverse events, may delay recovery and prolong hospital stay, and increases the likelihood of future abuse and dependence. In this systematic review and meta-analysis, we assess the safety and effectiveness of intrathecal morphine (ITM) in pediatric patients undergoing posterior spinal fusion. Ovid Embase and MEDLINE were searched in October 2023 for articles that directly compared ITM use with standard pain management approaches for pediatric patients undergoing posterior spinal fusion. Our primary outcome was postoperative pain scores. Secondary outcomes included opioid usage details, adverse events, and blood loss. Of the 384 unique studies identified, nine studies (one randomized control trial, one prospective review, and seven retrospective reviews) met the inclusion criteria. The total number of patients within the ITM and control groups were 1384 and 676, respectively. Meta-analysis revealed significantly lower pain scores in the ITM group (standardized mean difference (SMD): -1.30 (-2.29, -0.31); p = 0.01). Similarly, ITM patients had significantly lower opioid usage, both intraoperatively (mean difference (MD): -0.71 mg/kg (-0.99, -0.44); p < 0.00001) as well as postoperatively (SMD: -2.10 (-3.48, -0.73); p = 0.003), and significantly lower blood loss (MD: -0.88 L (-1.34, -0.43); p = 0.0001). The occurrence of adverse events was similar across both groups. Our analysis of the available data demonstrates that a low to moderate dose of ITM is a safe and effective adjunct to improve standard postoperative care without increasing the risk of respiratory depression. When compared to control, ITM patients had superior analgesia while using fewer opioids had significantly reduced intraoperative blood loss when ITM was administered before spinal fusion, and had a similar complication profile. While further studies are warranted to establish optimal dosing, these findings underscore the potential of ITM as a valuable addition to multimodal pain management.

Safety and efficacy of intrathecal morphine in early onset scoliosis surgery

Intrathecal morphine (IM) is a popular adjunct for pain management in spinal deformity surgery for idiopathic scoliosis. It has not been studied in patients with early onset scoliosis (EOS). We retrospectively reviewed EOS patients undergoing growth-friendly surgery who received IM or did not receive IM (non-IM). Data from initial insertion and final fusion procedures were studied. IM was not used for lengthening procedures, short procedures (<3 h), patients with significant underlying respiratory issues, paraplegia, unsuccessful access and anesthesiologist discretion. We assessed pediatric ICU (PICU) admission and IM complications (respiratory depression, pruritus and nausea/vomiting), time to first postoperative opiate, and pain scores. There were 97 patients including 97 initial insertions (26 IM and 71 non-IM) and 74 patients with final fusions (17 IM and 57 non-IM). The first dose of opioids following insertion and final fusion occurred at 16.8 ± 3.8 and 16.8 ± 3.1 h postoperatively in the IM group compared to 5.5 ± 2.8 and 8.3 ± 3.2 h in the non-IM group, respectively ( P  < 0.001). Postoperative pain scores were lower in the IM groups ( P  = 0.001). Two patients with IM developed mild respiratory depression following initial insertion ( P  = 0.01) but did not require PICU admission. The rate of respiratory depression was not different between the final fusion groups. There was no difference between pruritus and nausea/vomiting at the final fusion. Preincision IM can provide well-tolerated and effective initial postoperative analgesia in select children with EOS undergoing spinal deformity surgery.

Effects of 5 µg/kg intrathecal morphine for postoperative analgesia in pediatric patients undergoing major surgery

BACKGROUND

The effects and analgesic adequacy of intrathecal morphine (ITM) administration have been studied less frequently than other regional analgesia techniques in pediatric surgical procedures.

OBJECTIVE

To evaluate the efficacy and adverse event rate of 5 µg/kg ITM administration for postoperative analgesia according to age group.

METHODS

We retrospectively evaluated the medical records of patients who underwent major pediatric surgery and were administered ITM for postoperative analgesia. Patients were divided into three age groups: ≤ 5 years (group I), 5.1-13 years (group II) and > 13 years (group III). All patients received ITM 5 µg/kg (max 300 μg) through the L_4-5 or L₅-S₁ interspace. Postoperative pain (modified pediatric objective pain score > 4), need for rescue analgesics, sleep interruption due to pain, sedation (Ramsay sedation scale score > 3), opioid-related postoperative adverse events (at 0, 4, 8, 12, and 24 h after intervention), hemodynamic data and nurse satisfaction with the analgesic method were compared between groups.

RESULTS

The analysis included 100 children (47 girls, 9 ± 5.4 years). Groups were similar regarding postoperative rescue analgesia consumption and sleep interruption (p = 0.238, p = 0.958), 96% of the children did not require rescue analgesia, and sleep interruption was not observed in 97%. Postoperative adverse events were pruritus in 14 and nausea/vomiting in 9 patients (p = 0.052). Overall, nurses were satisfied or very satisfied in 99% of the cases.

CONCLUSION

Administration of 5 µg/kg ITM can be used for postoperative analgesia in pediatric surgery in all age groups, with no severe adverse events and high nurse satisfaction with analgesic management.

Effects of opioid-reduced anesthesia during scoliosis surgery in children: a prospective observational study

Aims: Opioid-reduced anesthesia (ORA) was suggested to decrease morphine consumption after adolescent idiopathic scoliosis (AIS) surgery and incidence of chronic pain. Materials & methods: A prospective analysis using the ORA in AIS surgery was performed. Two cohorts were compared: a control group (opioid-based anesthesia) and the ORA group. The main outcome was morphine consumption at day 1. Results: 33 patients operated for AIS using ORA were compared with 36 with opioid-based anesthesia. Morphine consumption was decreased in the ORA group (1.1 mg.kg^-1 [0.2-2] vs 0.8 mg.kg^-1 [0.3-2]; p = 0.02) at day 1. Persistent neuropathic pain at 1 year was decreased in the ORA group (p = 0.02). Conclusion: The ORA protocol is efficient to reduce postoperative morphine consumption in AIS surgery and preventing neuropathic pain.

Postoperative Pain Management in Pediatric Spinal Fusion Surgery for Idiopathic Scoliosis

This article reviews and summarizes current evidence and knowledge gaps regarding postoperative analgesia after pediatric posterior spine fusion for adolescent idiopathic scoliosis, a common procedure that results in severe acute postoperative pain. Inadequate analgesia may delay recovery, cause patient dissatisfaction, and increase chronic pain risk. Despite significant adverse effects, opioids are the analgesic mainstay after scoliosis surgery. However, growing emphasis on opioid minimization and enhanced recovery has increased adoption of multimodal analgesia (MMA) regimens. While opioid adverse effects remain a concern, MMA protocols must also consider risks and benefits of adjunct medications. We discuss use of opioids via different administration routes and elaborate on the effect of MMA components on opioid/pain and recovery outcomes including upcoming regional analgesia. We also discuss risk for prolonged opioid use after surgery and chronic post-surgical pain risk in this population. Evidence supports use of neuraxial opioids at safe doses, low-dose ketorolac, and methadone for postoperative analgesia. There may be a role for low-dose ketamine in those who are opioid-tolerant or have chronic pain, but the evidence for preoperative gabapentinoids and intravenous lidocaine is currently insufficient. There is a need for further studies to evaluate pediatric-specific optimal MMA dosing regimens after scoliosis surgery. Questions remain regarding how best to prevent acute opioid tolerance, opioid-induced hyperalgesia, and chronic postsurgical pain. We anticipate that this timely update will enable clinicians to develop efficient pain regimens and provide impetus for future research to optimize recovery outcomes after spine fusion.

Opioids: A Review of Pharmacokinetics and Pharmacodynamics in Neonates, Infants, and Children

Pain management in the pediatric population is complex for many reasons. Mild pain is usually managed quite well with oral acetaminophen or ibuprofen. Situations involving more severe pain often require the use of an opioid, which may be administered by many different routes, depending on clinical necessity. Acute and chronic disease states, as well as the constantly changing maturational process, produce unique challenges at every level of pediatrics in dosing and management of all medications, especially with regard to high-risk opioids. Although there has been significant progress in the understanding of opioid pharmacokinetics and pharmacodynamics in neonates, infants, children, and adolescents, somewhat limited data exist from which necessary information, concerning the safe and effective use of these agents, may be drawn. The evidence here provided is intended to be helpful in directing the practitioner to patient-specific reasons for preferring one opioid over another. As our knowledge of opioids and their effects has grown, it has become clear that older medications like codeine and meperidine (pethidine) have very limited use in pediatrics. This review provides pharmacokinetic and pharmacodynamic evidence on the currently available opioids: morphine, fentanyl (and derivatives), codeine, meperidine, oxycodone, hydrocodone, hydromorphone, methadone, buprenorphine, butorphanol, nalbuphine, pentazocin, ketobemidone, tramadol, piritramide, naloxone and naltrexone. Morphine, being the most studied opioid analgesic, is the standard against which all others are compared. Pharmacokinetic parameters of morphine that have been found in neonates, i.e., higher volume of distribution, immature metabolic processes that develop at various rates, elimination that is variable based on age and weight, as well as treated and untreated disease processes, are an example of all opioids in the population discussed in this review. Outside the premature and neonatal population, the use of opioids in infants, children, and adolescents quickly begins to resemble the established values found in adults. As such, the concerns (risks) of these medications become comparable to those seen in adults.

Addition of Intrathecal Morphine for Postoperative Pain Management in Pediatric Spine Surgery: A Meta-analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVE

The objective of this study was to determine whether adjunctive intrathecal morphine (ITM) reduces postoperative analgesic consumption following pediatric spine surgery.

SUMMARY OF BACKGROUND DATA

Previous studies that have tested supplemental ITM to manage pain after pediatric spine surgery have been limited by small sample sizes.

METHODS

A comprehensive search of PubMed, Web of Science, Clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials was performed for clinical trials and observational studies. Time to first analgesic demand, postoperative analgesic use, pain scores, and complication data were abstracted from each study. Mean difference (MD) and 95% confidence interval (CI) were used to compare continuous outcomes and odds ratios (OR) and 95% CI were used for dichotomous outcomes.

RESULTS

A total of 5 studies, including 3 randomized controlled trials and 2 retrospective chart reviews, containing 636 subjects, were incorporated into meta-analysis. Subjects that were administered ITM in addition to postoperative analgesics (ITM group) were compared with those receiving postoperative analgesics only (control group). In the ITM group, time to first analgesic demand was longer (MD, 8.79; 95% CI, 4.20-13.37; P<0.001), cumulative analgesic consumption was reduced at 24 hours (MD, -0.40; 95% CI, -0.56 to -0.24; P<0.001), and cumulative analgesic consumption was reduced at 48 hours (MD, -0.43; 95% CI, -0.59 to -0.27; P<0.001). Neither postoperative pain scores at 24 hours (P=0.16) nor 48 hours (P=0.18) were significantly different between ITM and control groups. Rates of respiratory depression, nausea, vomiting, and pruritus were not different between groups (all Ps>0.05).

CONCLUSIONS

Addition of ITM in pediatric spine surgery produced a potent analgesic effect in the immediate postoperative period. Patients administered ITM did not request opiates as early as control and consumed fewer opiates by the second postoperative day. Furthermore, use of ITM did not increase complications such as respiratory depression, nausea, vomiting, or pruritus.

Effects of prophylactic dexamethasone on postoperative nausea and vomiting in scoliosis correction surgery: a double-blind, randomized, placebo-controlled clinical trial

Dexamethasone is widely used for postoperative nausea and vomiting (PONV) prophylaxis, but its effect on PONV prevention in paediatric patients is validated only in short minor surgical procedures. In this study, we aimed to determine whether a single dose of dexamethasone reduces PONV in highly invasive surgeries that require opioid-based postoperative analgesia. One hundred adolescents undergoing scoliosis correction surgery were randomized to receive intravenous dexamethasone 0.15 mg/kg (dexamethasone group) or saline (control group) at induction of anaesthesia. The primary outcome was the incidence of PONV in the 72 h postoperatively. Data for 98 patients were available for analysis. The 72-h incidence of PONV was significantly lower in the dexamethasone group than in the control group (62.5% vs 84.0%; RR 0.74, 95% CI 0.58–0.96, P = 0.02). During the first and second 24-h postoperative intervals, fewer patients in the dexamethasone group received rescue antiemetics. Visual analogue scale scores for nausea and pain were lower in the dexamethasone group than in the control group during the first 24 h postoperatively. Dexamethasone did not increase the number of adverse events. The results of this study showed that a single dose of dexamethasone was effective for reducing PONV after paediatric scoliosis correction surgery.

Intrathecal Morphine Following Lumbar Fusion: A Randomized, Placebo-Controlled Trial

BACKGROUND

Despite the potential for faster postoperative recovery and the ease of direct intraoperative injection, intrathecal morphine is rarely provided in lumbar spine surgery.

OBJECTIVE

To evaluate the safety and efficacy of intrathecal morphine following lumbar fusion.

METHODS

We randomly assigned 150 patients undergoing elective instrumented lumbar fusion to receive a single intrathecal injection of morphine (0.2 mg) or placebo (normal saline) immediately prior to wound closure. The primary outcome was pain on the visual-analogue scale during the first 24 h after surgery. Secondary outcomes included respiratory depression, treatment-related side effects, postoperative opioid requirements, and length of hospital stay. An intention-to-treat, repeated-measures analysis was used to estimate outcomes according to treatment in the primary analysis.

RESULTS

The baseline characteristics of the 2 groups were similar. Intrathecal morphine reduced pain both at rest (32% area under the curves [AUCs] difference, P < .01) and with movement (22% AUCs difference, P < .02) during the initial 24 h after surgery. The risk of respiratory depression was not increased by intrathecal morphine (hazard ratio, 0.86; 95% confidence interval, 0.44 to 1.68; P = .66). Although postoperative opioid requirements were reduced with intrathecal morphine (P < .03), lengths of hospital stay were similar (P = .32). Other than a trend towards increased intermittent catheterization among patients assigned to intrathecal morphine (P = .09), treatment-related side effects did not significantly differ. The early benefits of intrathecal morphine on postoperative pain were no longer apparent after 48 h.

CONCLUSION

A single intrathecal injection of 0.2 mg of morphine safely reduces postoperative pain following lumbar fusion.

Postoperative pain management in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis: a narrative review

Posterior spinal fusion for adolescent idiopathic scoliosis is one of the most invasive surgical procedures performed in children and adolescents. Because of the extensive surgical incision and massive tissue trauma, posterior spinal fusion causes severe postoperative pain. Intravenous patient-controlled analgesia with opioids has been the mainstay of postoperative pain management in these patients. However, the use of systemic opioids is sometimes limited by opioid-related side effects, resulting in poor analgesia. To improve pain management while reducing opioid consumption and opioid-related complications, concurrent use of analgesics and analgesic modalities with different mechanisms of action seems to be rational. The efficacy of intrathecal opioids and nonsteroidal anti-inflammatory drugs as components of multimodal analgesia in scoliosis surgery has been well established. However, there is either controversy or insufficient evidence regarding the use of other analgesic methods, such as continuous ketamine infusion, perioperative oral gabapentin, acetaminophen, continuous wound infiltration of local anesthetics, a single dose of systemic dexamethasone, and lidocaine infusion in this patient population. Moreover, appropriate combinations of analgesics have not been established. The aim of this literature review is to provide detailed information of each analgesic technique so that clinicians can make appropriate choices regarding pain management in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion.

Perioperative Pain Management in Pediatric Spine Surgery

Pain management after spinal deformity correction surgery for scoliosis in the pediatric population can be difficult. Deformity correction with posterior spinal fusion causes significant tissue trauma. Historically, pain control has been achieved with intravenous opiates. Opiates provide excellent analgesic effect; however, they have serious consequences when used alone. In adult total joint arthroplasty, multimodal pain control has become an increasingly common method to achieve pain control without these sequelae. Recently, the same techniques have been studied in pediatric spinal deformity correction surgery. This article outlines the state of pain management in pediatric spine patients.

Pediatric Perioperative Pain Management

Effective perioperative pain control in pediatric patients undergoing orthopedic surgery remains a challenge. Developing a successful pain control regimen begins preoperatively with assessment of the patient and discussion with the patient and family regarding expectations. Perioperative pain control regimens are customized based on the type of surgery, patient characteristics, and anticipated severity and duration of the postoperative pain. Recent study focuses on multimodal strategies and regional anesthesia options, allowing for decreased opioid use. This article provides an evidence-based overview of preoperative, intraoperative, and postoperative pain control for the pediatric orthopedic patient.

Intrathecal Morphine Versus Extended-Release Epidural Morphine for Postoperative Pain Control in Pediatric Patients Undergoing Posterior Spinal Fusion

BACKGROUND

Posterior spinal fusion for scoliosis is one of the most painful elective pediatric surgeries. Good postoperative pain control allows early ambulation and return of ability to tolerate oral intake. Options for analgesia in this patient population are suboptimal. We hypothesized that extended-release epidural morphine (EREM) would provide better pain control and less adverse effects compared to intrathecal (IT) morphine.

METHODS

The primary outcome was total IV morphine consumption during 0-48 hours postoperatively. Secondary outcomes included time until first patient-controlled analgesia (PCA) demand, pain scores, and adverse opioid effects. After institutional review board approval, 71 subjects undergoing posterior spinal fusion for idiopathic scoliosis completed the study. The subjects were randomly allocated to 7.5 μg/kg IT morphine or 150 μg/kg EREM. The final IT morphine and EREM groups contained 37 and 34 subjects, respectively. Postoperative pain was treated with morphine PCA, ketorolac, oral oxycodone, and acetaminophen. Morphine consumption, pain scores, nausea and vomiting, pruritus, and respiratory depression were measured every 4 hours. Parents completed a caregiver questionnaire about their child's pain control regimen after the first postoperative day.

RESULTS

There was no difference in total morphine consumption over the first 48 hours between subjects in the EREM and IT morphine groups: median (range) 42.2 (5.5-123.0) and 34.0 (4.5-128.8) mg, respectively (P = .27). EREM and IT morphine groups had no difference in time until first PCA demand. Pain scores were no different between the groups from 8 to 24 hours after surgery. Compared to IT morphine, EREM subjects had lower pain scores from 28 to 36 hours after surgery. The reported incidence of pruritus was lower in the EREM subjects.

CONCLUSIONS

There was no difference in total morphine consumption or time until first PCA demand between the EREM and IT morphine groups. EREM provides a longer duration of analgesia after posterior spinal fusion for scoliosis and may be associated with less opioid-induced pruritus.

A retrospective comparison of intrathecal morphine and epidural hydromorphone for analgesia following posterior spinal fusion in adolescents with idiopathic scoliosis

BACKGROUND

Posterior spinal fusion to correct idiopathic scoliosis is associated with severe postoperative pain. Intrathecal morphine is commonly used for analgesia after adolescent posterior spinal fusion; however, anticipating and managing the increase in pain scores after resolution of analgesic effect of intrathecal morphine analgesia is challenging. In 2014, we developed a clinical protocol detailing both the administration of intrathecal morphine intraoperatively and the transition to routine, scheduled oral analgesics at 18 h postoperatively. The goal of our study was to examine the efficacy of our intrathecal morphine protocol vs epidural hydromorphone for postoperative analgesia after posterior spinal fusion.

METHODS

Following IRB approval, we retrospectively identified developmentally intact children of ages 10-20 years in our electronic database with a diagnosis of idiopathic scoliosis who had undergone elective posterior spinal fusion surgery from June 2014 to April 2015. For the intrathecal morphine group, intrathecal morphine was administered in a dose of 12 μg·kg^-1 (max 1000 μg) prior to incision. Postoperatively, all children in the intrathecal morphine group had an order to receive oral oxycodone (0.1 mg·kg^-1 , max 5 mg) starting at 18 h postintrathecal morphine injection. For the epidural hydromorphone group, catheters were placed by the surgeon and bolused with 5 μg·kg^-1 hydromorphone (max 200 μg) and 1 μg·kg^-1 fentanyl (max 50 μg), followed by a continuous infusion of 40-60 μg·h^-1 , and patient-controlled bolus doses of 5 μg with a lockout interval of 30 min. All patients in both groups had postoperative orders for acetaminophen, diazepam, and ketorolac.

RESULTS

During the study time period, 20 patients received intrathecal morphine and were successfully matched with 20 patients who received epidural hydromorphone. All patients in the intrathecal morphine group were transitioned to oral analgesics on the first postoperative day, without need for intravenous opioids after discharge from the postanesthesia care unit. Compared to the epidural hydromorphone group, the intrathecal morphine group reported lower pain scores in the postanesthesia care unit (difference in means -4.26 [95% CI -6.56, -1.96], P = 0.001) and first 8 h after surgery (difference in means -1.88 [95% CI -3.84, 0.082, P = 0.060) and higher pain scores on the 2nd postoperative day (difference in means 1.60 [95% CI 0.10, 3.10], P = 0.037). The documented time to ambulation and time of Foley catheter removal were statistically earlier in the intrathecal morphine group, and the hospital length of stay was significantly shorter (3.0 ± 0.5 days vs 3.5 ± 0.7 days; P = 0.03). Adverse events did not significantly differ between the groups.

CONCLUSION

The efficacy of intraoperative intrathecal morphine for postoperative analgesia in the posterior spinal fusion patient population has been shown previously; however, the pain and analgesic trajectory, including transition to other analgesics, has not previously been studied. Our findings suggest that for many patients, use of intrathecal morphine in addition to routine administration of nonopioid medications facilitates direct transition to oral analgesics in the early postoperative period and earlier routine ambulation and discharge of posterior spinal fusion patients.

Efficacy of intrathecal morphine for postoperative pain management following open nephrectomy

Objective

To evaluate the efficacy and safety of intrathecal morphine (ITM) for postoperative pain control in patients with renal cell carcinoma undergoing open nephrectomy.

Methods

Forty-five patients scheduled for open nephrectomy were randomised to receive 300 µg ITM and intravenous patient-controlled analgesia (IV-PCA) (n = 22) or IV-PCA alone (n = 23) for postoperative analgesia. The numeric pain score (NPS), postoperative IV-PCA requirements and opioid-related complications including nausea, vomiting, dizziness, headache, and pruritus were compared between groups.

Results

NPS was significantly lower in the ITM group up to 24 h postoperatively. Upon coughing, NPS at 24 h postoperatively was 50 (interquartile range (IQR) 30–60) in the ITM group and 60 (45–70) in the IV-PCA group. Cumulative morphine consumption at 72 h postoperatively was significantly lower in the ITM group compared with the IV-PCA group (20 (9–33) mg vs. 31 (21–49) mg, respectively). Opioid-related complications were similar in both groups with the exception of pruritus (ITM, 77% vs. IV-PCA, 26%).

Conclusions

ITM was associated with greater analgesia without serious complications in patients undergoing open nephrectomy.

Immediate rescue designs in pediatric analgesic trials: a systematic review and meta-analysis

BACKGROUND

Designing analgesic clinical trials in pediatrics requires a balance between scientific, ethical, and practical concerns. A previous consensus group recommended immediate rescue designs using opioid sparing as a surrogate measure of analgesic efficacy. The authors summarize the performance of rescue analgesic designs in pediatric trials of four commonly used classes of analgesics: opioids, nonsteroidal antiinflammatory drugs, acetaminophen, and local anesthetics.

METHODS

MEDLINE, Embase, CINAHL, The Cochrane Library, and Web of science were searched in April 2013. The 85 studies selected were randomized or controlled clinical trials using immediate rescue paradigms in postoperative pain settings. A random-effects meta-analysis was used to synthesize predefined outcomes using Hedges' g. Difference between the means of the treatment arms were also expressed as a percentage of the corresponding value in the placebo group (placebo-treatment/placebo). Distributions of pain scores in study and control groups and relationships between opioid sparing and pain scores were examined.

RESULTS

For each of the four study drug classes, significant opioid sparing was demonstrated in a majority of studies by one or more of the following endpoints: (1) total dose (milligram per kilogram per hour), (2) percentage of children requiring rescue medication, and (3) time to first rescue medication (minutes). Pain scores averaged 2.4/10 in study groups, 3.4/10 in control groups.

CONCLUSIONS

Opioid sparing is a feasible pragmatic endpoint for pediatric pain analgesic trials. This review serves to guide future research in pediatric analgesia trials, which could test whether some specific design features may improve assay sensitivity while minimizing the risk of unrelieved pain.

Intrathecal morphine analgesia after cervical and thoracic spinal cord tumor surgery

Object

The aim of this study was to provide evidence for the effect of intrathecal morphine application after spinal cord tumor resection.

Methods

Twenty patients participated in a prospective open proof-of-concept study. During dural closure, morphine (7 μg/kg) was injected into the subarachnoid space. All patients were monitored in an intensive care setting postoperatively. Pain, additional opioids given, and vital parameters were recorded.

Results

Six patients received a mean morphine dose of 365 μg between C-3 and C-7 and 14 patients received a mean dose of 436 μg between T-2 and T-12. In the cervical and thoracic groups, the mean Numeric Rating Scale score was highest upon intensive care unit admission (1.2 and 2.5, respectively) and declined at 12 hours (0.5 and 0.8, respectively). Minimal extra morphine was required. Minor side effects occurred without consequence.

Conclusions

Intrathecal morphine for postoperative analgesia after resection of cervical and thoracic spinal cord tumors is effective and safe. These preliminary results require confirmation by larger comparative studies and further clinical experience.

Spinal anesthesia in children: A review

Even after a vast safety record, the role of spinal anesthesia (SA) as a primary anesthetic technique in children remains contentious and is mainly limited to specialized pediatric centers. It is usually practiced on moribund former preterm infants (<60 weeks post-conception) to reduce the incidence of post-operative apnea when compared to general anesthesia (GA). However, there is ample literature to suggest its safety and efficacy for suitable procedures in older children as well. SA in children has many advantages as in adults with an added advantage of minimal cardio-respiratory disturbance. Recently, several reports from animal studies have raised serious concerns regarding the harmful effects of GA on young developing brain. This may further increase the utility of SA in children as it provides all components of balanced anesthesia technique. Also, SA can be an economical option for countries with finite resources. Limited duration of surgical anesthesia in children is one of the major deterrents for its widespread use in them. To overcome this, several additives like epinephrine, clonidine, fentanyl, morphine, neostigmine etc. have been used and found to be effective even in neonates. But, the developing spinal cord may also be vulnerable to drug-related toxicity, though this has not been systematically evaluated in children. So, adjuvants and drugs with widest therapeutic index should be preferred in children. Despite its widespread use, incidence of side-effects is low and permanent neurological sequalae have not been reported with SA. Literature yields encouraging results regarding its safety and efficacy. Technical skills and constant vigilance of experienced anesthesia providers is indispensable to achieve good results with this technique.

Postoperative pain management after spinal fusion surgery: an analysis of the efficacy of continuous infusion of local anesthetics

Spinal fusion surgery is a major surgery that results in severe postoperative pain, therefore pain reduction is a primary concern. New strategies for pain management are currently under investigation and include multimodal treatment. A 3-year retrospective analysis of patients with idiopathic scoliosis undergoing spinal fusion surgery was performed at our hospital, assessing patient pain scores, opioid use, and recovery. We evaluated the effect of adding continuous infusion of local anesthetics (CILA) to a postoperative pain management protocol that includes intraoperative intrathecal morphine, as well as postoperative patient-controlled analgesia and oral opioid/acetaminophen combination. The study compared 25 patients treated according to the standard protocol, with 62 patients treated with CILA in addition to the pain management protocol. Patients in the CILA group used nearly 0.5 mg/kg less opioid analgesics during the first 24 hours after surgery.

Intrathecal morphine reduces blood loss during idiopathic scoliosis surgery: retrospective study of 256 pediatric cases

BACKGROUND

This retrospective cohort study was designed to assess the impact of intrathecal morphine compared with no intrathecal morphine on blood loss and on hemodynamic stability during surgery for pediatric idiopathic scoliosis correction.

METHODS

A retrospective review was done of 256 anesthetic charts who underwent scoliosis surgery between January 1993 and February 2012 by the same orthopedic surgeon. 128 patients were operated on before 2003 without intrathecal morphine (NITM group) and 128 were treated later on with intrathecal morphine (ITM group).Primary endpoints were a 20% decrease in blood loss in the ITM group and hemodynamic stability.

RESULTS

Both groups were similar for age, girl/boy ratio, weight and duration of surgery. Blood loss was significantly greater in the NITM group: 1793.1 ± 964.3 ml vs 655.8 ± 323.0 ml (P < 0.0001). Overall mean decrease in blood loss was 63.4% between the NITM group and the ITM group. A significantly (P < 0.0001) greater number of patients from the NITM group (122) received blood transfusions as compared to the ITM group (30). The volume of blood transfused per patient was significantly greater in the NITM group (701.4 ± 492.5 ml) than in the ITM group (293.7 ± 170.9 ml) (P < 0.0001). Heart rate was stable intra-operatively in both groups. Variation in blood pressure >20% of baseline occurred more frequently in the NITM group (28.1%) than in the ITM group (14.8%) (P = 0.01).

CONCLUSIONS

These data demonstrate that intrathecal morphine in pediatric surgical scoliosis correction significantly decreases intra-operative blood loss and transfusions and enhances blood pressure stability.

Pulmonary complications after spine surgery

Spine surgery is one of the fastest growing branches of orthopedic surgery. Patients often present with a relatively high acuity and, depending on surgical approach, morbidity and mortality can be comparatively high. Among the most prevalent and most frequently fatality-bound perioperative complications are those affecting the pulmonary system; evidence of clinical or subclinical lung injury triggered by spine surgical procedures is emerging. Increasing burden of comorbidity among the patient population further increases the likelihood of adverse outcome. This review is intended to give an overview over some of the most important causes of pulmonary complications after spine surgery, their pathophysiology and possible ways to reduce harm associated with those conditions. We discuss factors surrounding surgical trauma, timing of surgery, bone marrow and debris embolization, transfusion associated lung injury, and ventilator associated lung injury.

Beyond opioid patient-controlled analgesia: a systematic review of analgesia after major spine surgery

Postoperative pain control in patients undergoing spine surgery remains a challenge for the anesthesiologist. In addition to incisional pain, these patients experience pain arising from deeper tissues such as bones, ligaments, muscles, intervertebral disks, facet joints, and damaged nerve roots. The pain from these structures may be more severe and can lead to neural sensitization and release of mediators both peripherally and centrally. The problem is compounded by the fact that many of these patients are either opioid dependent or opioid tolerant, making them less responsive to the most commonly used therapy for postoperative pain (opioid-based intermittent or patient-controlled analgesia). The purpose of this review was to compare all published treatment options available that go beyond intravenous opiates and attempt to find the best possible treatment modality.

Reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery

At present, individual techniques, including intraoperative acute normovolemic hemodilution, use of tranexamic acid, use of intrathecal morphine, proper positioning, and modification of operative techniques, seem most promising for reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery. Other techniques including preoperative autologous predonation; mandatory discontinuation of use of antiplatelet agents; intraoperative and postoperative red-blood-cell salvage; use of aprotinin, epsilon-aminocaproic acid, recombinant factor VIIa, or desmopressin; induced hypotension; avoidance of hypothermia; and minimally invasive operative techniques require additional studies to either establish their effectiveness or address safety considerations.

Pharmacotherapy for acute pain in children: current practice and recent advances

INTRODUCTION

Acute pain in children may be undertreated. Improved understanding of developmental neurobiology and paediatric pharmacokinetics should facilitate better management of pharmacotherapy. The objective of this review is to discuss current paediatric practice and recent advances with these analgesic agents by using an evidence-based approach.

AREAS COVERED

Using PubMed an extensive literature review was conducted on the commonly used analgesic agents in children from 2000 to April 2010.

EXPERT OPINION

A multimodal analgesic regimen provides better pain control and functional outcome in children. The choice of pharmacological treatment is determined by the severity and type of pain. However, more research and evidence is required to determine the optimal drug combinations.

[Intrathecal opioid medication for perioperative analgesia in severely handicapped children undergoing spinal operations]

PURPOSE OF THE STUDY

Intrathecal opioids have been shown to be safe and effective for postoperative analgesia in healthy children for spinal surgery. The aim of this study was to evaluate the applicability of intrathecal opioids in severely handicapped children scheduled for spinal surgery.

METHODS

With hospital ethical committee approval, patients with physical states III and IV of the ASA classification requiring spinal surgery were retrospectively studied. In addition to inhalational anesthesia with sevoflurane or intravenous anesthesia using propofol, morphine 20 microg/kgBW and sufentanil 1.5 microg/kgBW were administered intrathecally before surgery. After surgery an infusion of nalbuphine was started. Need for additional intraoperative and postoperative analgesics, time of extubation, postoperative pain scores and p(a)CO2 values as well as adverse effects were recorded.

RESULTS

A total of 28 patients aged from 2.8 to 18.5 years (median 11.6 years) were studied. Immediate tracheal extubation in the operating room was possible in 17 patients and for 11 patients delayed extubation was elected. All patients were extubated within 24 h except for 1 patient who received massive postoperative transfusions. In 26 out of 28 patients (93%) the combination of intrathecal opioids with postoperative nalbuphine provided adequate analgesia. Observed side effects were post-operative nausea and vomiting (PONV), pruritus and moderate hypoventilation. In two patients a change to intravenous morphine therapy was necessary.

CONCLUSION

The use of intrathecal opioids for perioperative pain control from spinal fusion in severely handicapped children is feasible. Intrathecal opioids provide adequate postoperative analgesia and allow early extubation without persisting relevant respiratory compromise in most of these patients.

Validation of a preclinical spinal safety model: effects of intrathecal morphine in the neonatal rat

BACKGROUND

Preclinical studies demonstrate increased neuroapoptosis after general anesthesia in early life. Neuraxial techniques may minimize potential risks, but there has been no systematic evaluation of spinal analgesic safety in developmental models. We aimed to validate a preclinical model for evaluating dose-dependent efficacy, spinal cord toxicity, and long-term function after intrathecal morphine in the neonatal rat.

METHODS

Lumbar intrathecal injections were performed in anesthetized rats aged postnatal day (P) 3, 10, and 21. The relationship between injectate volume and segmental spread was assessed postmortem and by in vivo imaging. To determine the antinociceptive dose, mechanical withdrawal thresholds were measured at baseline and 30 min after intrathecal morphine. To evaluate toxicity, doses up to the maximum tolerated were administered, and spinal cord histopathology, apoptosis, and glial response were evaluated 1 and 7 days after P3 or P21 injection. Sensory thresholds and gait analysis were evaluated at P35.

RESULTS

Intrathecal injection can be reliably performed at all postnatal ages and injectate volume influences segmental spread. Intrathecal morphine produced spinally mediated analgesia at all ages with lower dose requirements in younger pups. High-dose intrathecal morphine did not produce signs of spinal cord toxicity or alter long-term function.

CONCLUSIONS

The therapeutic ratio for intrathecal morphine (toxic dose/antinociceptive dose) was at least 300 at P3 and at least 20 at P21 (latter doses limited by side effects). These data provide relative efficacy and safety for comparison with other analgesic preparations and contribute supporting evidence for the validity of this preclinical neonatal safety model.

Continuous intravenous morphine infusion for postoperative analgesia following posterior spinal fusion for idiopathic scoliosis

STUDY DESIGN

A retrospective study of postoperative pain management.

OBJECTIVE

Evaluate the efficacy and safety of continuous intravenous morphine infusion for postoperative pain management in patients with idiopathic scoliosis (IS) undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI).

SUMMARY OF BACKGROUND DATA

Postoperative pain is a common problem following surgery for IS. There are no published reports regarding the use of a continuous intravenous morphine infusion for this patient population.

METHODS

We retrospectively reviewed data regarding 339 consecutive patients with IS who underwent PSF and SSI between 1992 and 2006. All patients received intrathecal morphine after the induction of general anesthesia. Following surgery, preordered morphine infusion (0.01 mg/kg/h) was started at first reported pain. The infusion rate was titrated based on vital signs, visual analog scale (VAS) pain scores (0-10), and clinical status. It was continued until patients were able to take oral analgesics. We reviewed intrathecal morphine dosage, VAS pain scores through the third postoperative day, interval to start of morphine infusion, total morphine requirements in the first 48 hours, and any adverse reactions (nausea/vomiting, pruritus, respiratory depression, and pediatric intensive care unit admission).

RESULTS

Mean intrathecal morphine dose was 15.5 +/- 3.9 microg/kg and mean interval to start of the intravenous morphine infusion was 17.5 +/- 5 hours. Mean VAS pain scores were 3.1, 4.5, 4.5, and 4.6 at 12 hours, 1, 2, and 3 days after surgery, respectively.The total mean morphine dose in the first 48 hours postoperatively was 0.03 +/- 0.01 mg/kg/h. Total morphine received was 1.44 +/- 0.5 mg/kg. Nausea/vomiting and pruritus, related to the morphine infusion occurred in 45 patients (13.3%) and 14 patients (4.1%), respectively. No patients had respiratory depression or required Pediatric Intensive Care Unit admission.

CONCLUSION

A low frequency of adverse events and a mean postoperative VAS pain score of 5 or less demonstrate that a continuous postoperative morphine infusion is a safe and effective method of pain management in patients with IS following PSF and SSI.

Pharmacologic management of acute pediatric pain

The accurate assessment and effective treatment of acute pain in children in the hospital setting is a high priority. During the past 2 to 3 decades, pediatric pain management has gained tremendous knowledge with respect to the understanding of developmental neurobiology, developmental pharmacology the use of analgesics in children, the use of regional techniques in children, and of the psychological needs of children in pain. A wide range of medications is available to treat a variety of pain types. This article provides an overview of the most common analgesic medications and techniques used to treat acute pain in children.