Pain management after craniotomy

Early Postoperative Opioid Requirement Is Associated With Later Pain Control Needs After Supratentorial Craniotomies

BACKGROUND

Despite a renewed focus in recent years on pain management in the inpatient hospital setting, postoperative pain after elective craniotomy remains under investigated. This study aims to identify which perioperative factors associate most strongly with postoperative pain and opioid medication requirements after inpatient craniotomy.

MATERIALS AND METHODS

Using an existing dataset, we selected a restricted cohort of patients who underwent elective craniotomy surgery requiring an inpatient postoperative stay during a 7-year period at our institution (n=1832). We examined pain scores and opioid medication usage and analyzed the relative contribution of specific perioperative risk factors to postoperative pain and opioid medication intake (morphine milligram equivalents).

RESULTS

Postoperative pain was found to be highest on postoperative day 1 and decreased thereafter (up to day 5). Factors associated with greater postoperative opioid medication requirement were preoperative opioid medication use, duration of anesthesia, degree of pain in the preoperative setting, and patient age. Notably, the most significant factor associated with a higher postoperative pain score and Morphine milligram equivalents requirement was the time elapsed between the end of general anesthesia and a patient's first intravenous opioid medication.

CONCLUSION

Postcraniotomy patients are at higher risk for requiring opioid pain medications if they have a history of preoperative opioid use, are of younger age, or undergo a longer surgery. Moreover, early requirement of intravenous opioid medications in the postoperative period should alert treating physicians that a patient's pain may require additional or alternative methods of pain control than routinely administered, to avoid over-reliance on opioid medications.

Prevention of Post-Operative Pain after Elective Brain Surgery: A Meta-Analysis of Randomized Controlled Trials

Background and Objective: To analyze the effects of several drug for pain prevention in adults undergoing craniotomy for elective brain surgery. Material and Methods: A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The inclusion criteria were limited to randomized controlled trials (RCTs) that evaluated the effectiveness of pharmacological treatments for preventing post-operative pain in adults (aged 18 years or older) undergoing craniotomies. The main outcome measures were represented by the mean differences in validated pain intensity scales administered at 6 h, 12 h, 24 h and 48 h post-operatively. The pooled estimates were calculated using random forest models. The risk of bias was evaluated using the RoB2 revised tool, and the certainty of evidence was assessed according to the GRADE guidelines. Results: In total, 3359 records were identified through databases and registers' searching. After study selection, 29 studies and 2376 patients were included in the meta-analysis. The overall risk of bias was low in 78.5% of the studies included. The pooled estimates of the following drug classes were provided: NSAIDs, acetaminophen, local anesthetics and steroids for scalp infiltration and scalp block, gabapentinoids and agonists of adrenal receptors. Conclusions: High-certainty evidence suggests that NSAIDs and acetaminophen may have a moderate effect on reducing post-craniotomy pain 24 h after surgery compared to control and that ropivacaine scalp block may have a bigger impact on reducing post-craniotomy pain 6 h after surgery compared to control. Moderate-certainty evidence indicates that NSAIDs may have a more remarkable effect on reducing post-craniotomy pain 12 h after surgery compared to control. No moderate-to-high-certainty evidence indicates effective treatments for post-craniotomy pain prevention 48 h after surgery.

The Prevalence and Factors Associated with the Prescription of Opioids for Head/Neck Pain after Elective Craniotomy for Tumor Resection/Vascular Repair: A Retrospective Cohort Study

Background and objective: There is no report of the rate of opioid prescription at the time of hospital discharge, which may be associated with various patient and procedure-related factors. This study examined the prevalence and factors associated with prescribing opioids for head/neck pain after elective craniotomy for tumor resection/vascular repair. Methods: We performed a retrospective cohort study on adults undergoing elective craniotomy for tumor resection/vascular repair at a large quaternary-care hospital. We used univariable and multivariable analysis to examine the prevalence and factors (pre-operative, intraoperative, and postoperative) associated with prescribing opioids at the time of hospital discharge. We also examined the factors associated with discharge oral morphine equivalent use. Results: The study sample comprised 273 patients with a median age of 54 years [IQR 41,65], 173 females (63%), 174 (63.7%) tumor resections, and 99 (36.2%) vascular repairs. The majority (n = 264, 96.7%) received opioids postoperatively. The opiate prescription rates were 72% (n = 196/273) at hospital discharge, 23% (19/83) at neurosurgical clinical visits within 30 days of the procedure, and 2.4% (2/83) after 30 days from the procedure. The median oral morphine equivalent (OME) at discharge use was 300 [IQR 175,600]. Patients were discharged with a median supply of 5 days [IQR 3,7]. On multivariable analysis, opioid prescription at hospital discharge was associated with pre-existent chronic pain (adjusted odds ratio, aOR 1.87 [1.06,3.29], p = 0.03) and time from surgery to hospital discharge (compared to patients discharged within days 1−4 postoperatively, patients discharged between days 5−12 (aOR 0.3, 95% CI [0.15; 0.59], p = 0.0005), discharged at 12 days and later (aOR 0.17, 95% CI [0.07; 0.39], p < 0.001)). There was a linear relationship between the first 24 h OME (p < 0.001), daily OME (p < 0.001), hospital OME (p < 0.001), and discharge OME. Conclusions: This single-center study finds that at the time of hospital discharge, opioids are prescribed for head/neck pain in as many as seven out of ten patients after elective craniotomy. A history of chronic pain and time from surgery to discharge may be associated with opiate prescriptions. Discharge OME may be associated with first 24-h, daily OME, and hospital OME use. Findings need further evaluation in a large multicenter sample. The findings are important to consider as there is growing interest in an early discharge after elective craniotomy.

Preoperative anxiety on postoperative pain in craniotomy patients

Aim: This study aimed to determine preoperative anxiety and pain levels in patients who underwent craniotomy and investigate the effects on the development of postoperative acute-chronic pain. Materials and Methods: In this prospective, observational study, STAI-I (State-Trait Anxiety Inventory) and STAI-II were used to measure preoperative anxiety levels in a total of 104 patients who underwent craniotomy, and a visual analog score (VAS) was used to determine pain. Demographic data of the patients, ASA (American Society of Anesthesiologists) scores, comorbidities, preoperative and postoperative VAS scores, cause of preoperative anxiety, type, and duration of operation were recorded. Results: The mean values of STAI tests showed that 31.3% of our patients had mild preoperative anxiety, 58.7% had moderate and 10% had severe preoperative anxiety. In the STAI tests we performed before the operation, the mean values were 44 ± 11.2 for STAI-I and 44.5 ± 9.4 for STAI-II. The causes of preoperative anxiety in patients were determined as surgical operation (35.6%), anesthesia applications (17.3%), insufficient information (11.5%), and the possibility of postoperative pain (3.8%). It was observed that 60.6% of our patients had pain in the preoperative period, 51.9% of patients had acute pain in postoperative the 0th minute, 69.2% in 30th minute, 54.8% in 1st hour, 44.2% in 2nd hour, 34.6% in 24th hour, 22.1% in 48th hour, and 51% of patients had chronic pain in postoperative 6th month. We found a significant relationship between STAI-I and VAS scores at the 48th hour and, between STAI-II and VAS scores at the 2nd, 24th hour, and 6th month (p&lt;0.05). Conclusion: It was observed that craniotomy patients mostly had moderate anxiety and moderate to severe pain before the operation, and moderate-severe acute and chronic pain developed after the operation. A significant correlation was found between preoperative anxiety and postoperative pain.

Preoperative Versus Postoperative Scalp Block Combined With Incision Line Infiltration for Pain Control After Supratentorial Craniotomy

OBJECTIVE

Postoperative pain after craniotomy is a significant clinical problem that is sometimes underestimated, although moderate or severe pain in early postoperative period complicates up to 60% of cases. The purpose of this prospective randomized multicenter trial was to determine the optimal timing for selective scalp block in patients undergoing general anesthesia for supratentorial craniotomy.

MATERIALS AND METHODS

After ethics committee approval and informed consent, 56 adult patients were enrolled, and randomly assigned to receive a selective scalp block combined with incision line infiltration preoperatively or postoperatively.

RESULTS

Postoperative pain at 24 hours after the procedure was recorded in all 56 enrolled patients. In patients assigned to receive a scalp block preoperatively, median VAS score at 24 hours after surgery was 0 (0 to 2), and in patients assigned to receive a scalp block postoperatively it was 0 (0 to 3) (P>0.05). There was no difference in severity of pain at 24, 12, 6, and 2 hours after surgery between the 2 study groups, but the amount of fentanyl administered intraoperatively was lower in patients assigned to the preoperative scalp block group (1.6±0.7 vs. 2.4±0.7 mkg/kg/h, P=0.01).

DISCUSSION

This study confirms and extends available clinical evidence on the safety and efficacy of selective scalp blocks for the prevention of postoperative pain. Recorded data suggest that there is no difference in terms of occurrence and severity of postoperative pain regardless of whether the scalp block is performed preoperatively (after general anesthesia induction) or postoperatively (before extubation). Patients assigned to receive a scalp block combined with incision line infiltration preoperatively needed less intraoperative opioids than those assigned to postoperative scalp block.

Pain Management Experiences Among Hospitalized Postcraniotomy Brain Tumor Patients

BACKGROUND

Brain tumors account for the majority of central nervous system tumors, and most are removed by craniotomies. Many postcraniotomy patients experience moderate or severe pain after surgery, but patient perspectives on their experiences with pain management in the hospital have not been well described.

OBJECTIVE

The aim of this study was to describe how patients who have undergone a craniotomy for brain tumor removal experience pain management while hospitalized.

METHODS

Qualitative descriptive methods using semistructured interviews were conducted with patients on a neurological step-down unit in an urban teaching hospital in the Midwest United States. Interviews focused on how patients experienced postcraniotomy pain and how it was managed. Narratives were analyzed with standard content analytic procedures.

RESULTS

Twenty-seven participants (median age, 58.5 years; interquartile range, 26-41 years; range, 21-83 years) were interviewed. The majority were white (n = 25) and female (n = 15) and had an anterior craniotomy (n = 25) with sedation (n = 17). Their pain experiences varied on 2 dimensions: salience of pain during recovery and complexity of pain management. Based on these dimensions, 3 distinct types of pain management experiences were identified: (1) pain-as-nonsalient, routine pain management experience; (2) pain-as-salient, routine pain management experience; and (3) pain-as-salient, complex pain management experience.

CONCLUSIONS

Many postcraniotomy patients experience their pain as tolerable and/or pain management as satisfying and effective; others experience pain and pain management as challenging.

IMPLICATIONS FOR PRACTICE

Clinicians should be attuned to needs of patients with complex pain management experiences and should incorporate good patient/clinician communication.

Prevention and treatment of postoperative pain in pediatric patients undergone craniotomy: Systematic review of clinical evidence

BACKGROUND

Prevention and treatment of postoperative pain after craniotomy in pediatric patients is an open and challenging clinical problem due to limited epidemiological data and significant concerns on safety of the most common analgesics in neurosurgical patients. We reviewed the literature to evaluate the possible available strategies in pain management in pediatric patients.

METHODS

The systematic review was performed in accordance with PRISMA statement recommendations. PUBMED, EMBASE and Scopus databases were queried. Inclusion criteria were: randomized controlled trials, prospective and retrospective observational studies published before 2020 and reported postoperative pain management after craniotomy (i.e. including studies accomplished after craniotomy, craniectomy and reconstructive surgery) in children population (neonates to 18 years old).

RESULTS

A total of 11 studies - 4 randomized controlled, 5 prospective observational and 2 retrospective met criteria for inclusion. The selected studies reported data from a total of 1077 patients, with age ranging between neonates to 18 years, 52% male and 48% female. Opioids are still the most commonly used drugs. Paracetamol and NSAIDs are frequently used as adjuvants to reduce postoperative opioid requirements. Data on potential hypocoagulation due to the antiplatelet effect of NSAIDs are lacking. Selective scalp block provides lower pain scores in early postoperative period.

CONCLUSION

Clinical evidence on prevention and treatment of postoperative pain in pediatric patients undergone craniotomy is still sparse. Available data prove that a multimodal approach, realized as the use a combination of opioids, paracetamol/NSAIDs and regional anesthesia, is effective and rarely associate with complications.

Effect of Scalp Nerve Block with Ropivacaine on Postoperative Pain in Patients Undergoing Craniotomy: A Randomized, Double Blinded Study

Scalp nerve block with ropivacaine has been shown to provide perioperative analgesia. However, the best concentration of ropivacaine is still unknown for optimal analgesic effects. We performed a prospective study to evaluate the effects of scalp nerve block with varied concentration of ropivacaine on postoperative pain and intraoperative hemodynamic variables in patients undergoing craniotomy under general anesthesia. Eighty-five patients were randomly assigned to receive scalp block with either 0.2% ropivacaine, 0.33% ropivacaine, 0.5% ropivacaine, or normal saline. Intraoperative hemodynamics and post-operative pain scores at 2, 4, 6, 24 hours postoperatively were recorded. We found that scalp blockage with 0.2% and 0.33% ropivacaine provided adequate postoperative pain relief up to 2 h, while administration of 0.5% ropivacaine had a longer duration of action (up to 4 hour after craniotomy). Scalp nerve block with varied concentration of ropivacaine blunted the increase of mean arterial pressure in response to noxious stimuli during incision, drilling, and sawing skull bone. 0.2% and 0.5% ropivacaine decreased heart rate response to incision and drilling. We concluded that scalp block using 0.5% ropivacaine obtain preferable postoperative analgesia compared to lower concentrations. And scalp block with ropivacaine also reduced hemodynamic fluctuations in craniotomy operations.

Narrative review of acute post-craniotomy pain. Concept and strategies for prevention and treatment of pain

The aim of this narrative review is to confirm that acute pain after craniotomy is frequent and presents with moderate to severe intensity. We also highlight the importance of not only treating post-craniotomy pain, but also of preventing it in order to reduce the incidence of chronic pain. Physicians should be aware that conventional postoperative analgesics (non-steroidal anti-inflammatory, paracetamol, cyclooxygenase inhibitors 2, opioids) are not the only options available. Performing a scalp block prior to surgical incision or after surgery, the use of intraoperative dexmedetomidine, and the perioperative administration of pregabalin are just some alternatives that are gaining ground. The management of post-craniotomy pain should be based on perioperative multimodal analgesia in the framework of an "enhaced recovery after surgery" (ERAS) approach.

Assessing the effectiveness of perioperative s-ketamine on new-onset headache after resective epilepsy surgery (ESPAIN-trial): protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Effective treatment of new-onset headache after craniotomy, especially anterior temporal lobectomy (ATL) and amygdalohippocampectomy for drug-resistant temporal lobe epilepsy, is a challenge. The current practice, acetaminophen combined with opioids is often reported by patients as insufficient and sometimes accompanied by opioid-related adverse effects. Based on expert opinion, anaesthesiologists therefore frequently consider s-ketamine as add-on therapy. This randomised parallel group design trial compares s-ketamine with a placebo as add on medication to a multimodal pain approach.

METHODS AND ANALYSIS

In total 62 adult participants, undergoing ATL for drug resistant epilepsy under general anaesthesia, will be randomised to either receive a 0.25 mg/kg bolus followed by a continuous infusion of 0.1 mg/kg/hour of s-ketamine or placebo (0.9% NaCl) starting before incision and continued for 48 hours as an addition to acetaminophen and opioids administered in a patient-controlled analgesia pump. The primary outcome measure is the cumulative postoperative opioid consumption. Patient recruitment started August 2018 and will end in 2021. Secondary outcome measures are postoperative pain intensity scores, psychological parameters, length of hospital stay and adverse events and will be reassessed at 3 and 6 months after surgery, with a baseline measurement preoperatively. All data are collected by researchers who are blinded to the treatment. The data will be analysed by multivariable linear mixed-effects regression.

ETHICS AND DISSEMINATION

Ethical approval has been given by the local medical ethical committee (NL61666.068.17). This study will be conducted in accordance with the Dutch Medical Research Involving Human Subjects Act and the Declaration of Helsinki. The results of this trial will be publicly disclosed and submitted for publication in an international peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NTR6480.

Scheduled Intravenous Acetaminophen Improves Patient Satisfaction With Postcraniotomy Pain Management: A Prospective, Randomized, Placebo-controlled, Double-blind Study

BACKGROUND

Postcraniotomy pain can be difficult to manage with opioids due to opioid-related side effects, including drowsiness, nausea/vomiting, confusion, and pupillary changes, potentially masking the signs of postoperative neurological deterioration. Intravenous (IV) acetaminophen, a nonopioid analgesic, has been reported to have opioid-sparing effects after abdominal and orthopedic surgeries. This study investigates whether IV acetaminophen has similar effects after craniotomy.

MATERIALS AND METHODS

In this prospective, randomized, placebo-controlled, double-blind clinical trial, 100 adult patients scheduled to undergo supratentorial craniotomy for excision of a brain mass were randomized to receive either IV acetaminophen or placebo preincision and then every 6 hours for a total of 24 hours after surgery. Total 24-hour opioid consumption, pain scores, satisfaction with overall pain management, time to meet postanesthesia care unit discharge criteria, and incidence of opioid-related side effects were compared.

RESULTS

There was no difference in the 24-hour postoperative opioid consumption in morphine equivalents between the IV acetaminophen group (median, 11 mg; n=45) and the placebo group (median, 10.1 mg; n=41). No statistically significant difference of visual analog scale pain score was observed between 2 treatment groups. Patient satisfaction with overall postoperative pain management was significantly higher in the IV acetaminophen group than the placebo group on a 1 to 10 scale (8.1±0.4 vs. 6.9±0.4; P=0.03). There was no significant difference in secondary outcomes, including the incidence of opioid-related side effects.

CONCLUSIONS

IV acetaminophen, as adjunctive therapy for craniotomy procedures, did not show an opioid-sparing effect in patients for the 24 hours after craniotomy; however, it was associated with improved patient satisfaction regarding overall pain control.

Intravenous acetaminophen for postoperative supratentorial craniotomy pain: a prospective, randomized, double-blinded, placebo-controlled trial

OBJECTIVE

Acute pain control after cranial surgery is challenging. Prior research has shown that patients experience inadequate pain control post-craniotomy. The use of oral medications is sometimes delayed because of postoperative nausea, and the use of narcotics can impair the evaluation of brain function and thus are used judiciously. Few nonnarcotic intravenous (IV) analgesics exist. The authors present the results of the first prospective study evaluating the use of IV acetaminophen in patients after elective craniotomy.

METHODS

The authors conducted a randomized, double-blinded, placebo-controlled investigation. Adults undergoing elective, supratentorial craniotomies between September 2013 and June 2015 were randomized into two groups. The experimental group received 1000 mg/100 ml IV acetaminophen every 8 hours for 48 hours. The placebo group received 100 ml of 0.9% normal saline on the same schedule. Both groups were also treated with a standardized pain control algorithm. The study was powered to detect a 30% difference in the primary outcome measures: narcotic consumption (morphine equivalents, ME) at 24 and 48 hours after surgery. Patient-reported pain scores immediately postoperatively and 48 hours after surgery were also recorded.

RESULTS

A total of 204 patients completed the trial. No significant differences were found in narcotic consumption between groups at either time point (in the treatment and placebo groups, respectively, at 24 hours: 84.3 ME [95% CI 70.2–98.4] and 85.5 ME [95% CI 73–97.9]; and at 48 hours: 123.5 ME [95% CI 102.9–144.2] and 134.2 ME [95% CI 112.1–156.3]). The difference in improvement in patient-reported pain scores between the treatment and placebo groups was significant (p < 0.001).

CONCLUSIONS

Patients who received postoperative IV acetaminophen after craniotomy did not have significantly decreased narcotic consumption but did experience significantly lower pain scores after surgery. The drug was well tolerated and safe in this patient population.

Use of Dexmedetomidine for Prophylactic Analgesia and Sedation in Patients With Delayed Extubation After Craniotomy: A Randomized Controlled Trial

Background:

We conducted a randomized trial to evaluate the efficacy and safety of dexmedetomidine for prophylactic analgesia and sedation in patients with delayed extubation after craniotomy.

Methods:

From June 2012 to July 2014, 150 patients with delayed extubation after craniotomy were randomized 1:1 and were assigned to the dexmedetomidine group that received a continuous infusion of 0.6 μg/kg/h (10 μg/mL) or the control group that received a maintenance infusion of 0.9% sodium chloride for injection. The mean percentage of time under optimal sedation (SAS3-4), the percentage of patients who required rescue with propofol/fentanyl, and the total dose of propofol/fentanyl required throughout the course of drug infusion, as well as VAS, HR, MAP, and SpO₂ were recorded.

Results:

The percentage of time under optimal sedation was significantly higher in the dexmedetomidine group than in the control group (98.4%±6.7% vs. 93.0%±16.2%, P=0.008). The VAS was significantly lower in the dexmedetomidine group than in the control group (1.0 vs. 4.0, P=0.000). The HR and mean BP were significantly lower in the dexmedetomidine group than in the control group at all 3 time points (before endotracheal suctioning, immediately after extubation, and 30 min after extubation). No significant difference in SpO₂ was observed between the 2 groups. For hemodynamic adverse events, patients in the dexmedetomidine group were more likely to develop bradycardia (5.3% vs. 0%, P=0.043) but had a lower likelihood of tachycardia (2.7% vs. 18.7%, P=0.002).

Conclusions:

Dexmedetomidine may be an effective prophylactic agent to induce sedation and analgesia in patients with delayed extubation after craniotomy. The use of dexmedetomidine (0.6 μg/kg/h) infusion does not produce respiratory depression, but may increase the incidence of bradycardia.

Are neuromuscular blocking agents being misused in laboratory pigs?

The literature (2012-4) describing experimental pig surgery was reviewed to estimate the extent to which neuromuscular block (NMB) is used, to examine methods for ensuring unconsciousness, and to identify the rationale for use of NMB and establish the anaesthetist's training. In the first stage of a two-stage review, NMB use was estimated using Web of Knowledge to identify articles describing NMB during pig surgeries. In the second stage, PubMed and Google Scholar were used to increase the number of articles for determining measures taken to prevent accidental awareness during general anaesthesia (AAGA). The corresponding authors of screened articles were emailed four times to establish the reason for using NMB and the anaesthetists' backgrounds (medical, veterinary, or technical). The first search revealed NMB use in 80 of 411 (20%) studies. Of the 153 articles analysed in the second stage, two described strategies to reduce AAGA. Some (6%) papers did not provide information on anaesthetic doses; citations supporting anaesthetic efficacy were found in only 13. Five of 69 papers using inhalation agents measured end-tidal anaesthetic concentrations based on human, not porcine, minimal alveolar concentrations. The methods in 13% of articles reporting anaesthetic depth assessment were incomplete or questionable, or both; four described using somatic motor reflexes. Corresponding authors of 121 articles reported that the principal reason for NMB was improved 'surgical visualization' (26%). Medical or veterinary anaesthetists supervised anaesthesia in 70% of studies; non-anaesthetists provided NMB, unsupervised, in 23. Nine respondents prioritized experimental expediency over pig welfare. In laboratory pig studies, AAGA may be prevalent; reported details of its attempted prevention are woefully inadequate.

Integrative review: postcraniotomy pain in the brain tumour patient

AIM

To conduct an integrative review to examine evidence of pain and associated symptoms in adult (≥21 years of age), postcraniotomy, brain tumour patients hospitalized on intensive care units.

BACKGROUND

Healthcare providers believe craniotomies are less painful than other surgical procedures. Understanding how postcraniotomy pain unfolds over time will help inform patient care and aid in future research and policy development.

DESIGN

Systematic literature search to identify relevant literature. Information abstracted using the Theory of Unpleasant Symptoms' concepts of influencing factors, symptom clusters and patient performance. Inclusion criteria were indexed, peer-reviewed, full-length, English-language articles. Keywords were 'traumatic brain injury', 'pain, post-operative', 'brain injuries', 'postoperative pain', 'craniotomy', 'decompressive craniectomy' and 'trephining'.

DATA SOURCES

Medline, OVID, PubMed and CINAHL databases from 2000-2014.

REVIEW METHOD

Cooper's five-stage integrative review method was used to assess and synthesize literature.

RESULTS

The search yielded 115 manuscripts, with 26 meeting inclusion criteria. Most studies were randomized, controlled trials conducted outside of the United States. All tested pharmacological pain interventions. Postcraniotomy brain tumour pain was well-documented and associated with nausea, vomiting and changes in blood pressure, and it impacted the patient's length of hospital stay, but there was no consensus for how best to treat such pain.

CONCLUSION

The Theory of Unpleasant Symptoms provided structure to the search. Postcraniotomy pain is experienced by patients, but associated symptoms and impact on patient performance remain poorly understood. Further research is needed to improve understanding and management of postcraniotomy pain in this population.

Pain management in pigs undergoing experimental surgery; a literature review (2012-4)

Failure to provide effective analgesia to animals in noxious studies contravenes the obligation to refine animal experimentation and, by increasing 'noise' in physiological data sets, may decrease the scientific validity of results. Pig models of surgical conditions are becoming increasingly important and used for translational work. This review aimed to determine the extent to which the recent biomedical literature describes pain assessment and alleviation in pigs recovering from experimental surgery. Three databases (Medline, Web of Knowledge, and Google Scholar) were searched to find relevant studies published from January 2012 to March 2014. Information on pain assessment and peri- and postoperative analgesia was extracted. The review identified 233 papers meeting selection criteria. Most articles (193/233, 83%) described use of drugs with analgesic properties, but only 87/233 (37%) described postoperative analgesia. No article provided justification for the analgesic chosen, despite the lack of guidelines for analgesia in porcine surgical models and the lack of formal studies on this subject. Postoperative pain assessment was reported in only 23/233 (10%) articles. It was found that the reporting of postoperative pain management in the studies was remarkably low, reflecting either under-reporting or under-use. Analgesic description, when given, was frequently too limited to enable reproducibility. Development of a pain-scoring system in pigs, together with the mandatory description of pain management in submitted articles, would contribute to improved laboratory pig welfare.

Pain following craniotomy: reassessment of the available options

Pain following craniotomy has frequently been neglected because of the notion that postcraniotomy patients do not experience severe pain. However a gradual change in this outlook is observed because of increased sensitivity of neuroanaesthesiologists and neurosurgeons toward acute postcraniotomy pain. Multiple modalities exist for treating this variety of pain each with its own share of advantages and disadvantages. However, individually none of these modalities has been proclaimed as the best and applicable universally. A considerable amount of dispute remains to ascertain the appropriate therapeutic regimen for treating postcraniotomy pain in spite of numerous trials using different drugs and their combinations. This review aims to highlight the genesis, characteristics, and different strategies that are undertaken for management of acute postcraniotomy pain. Chronic postcraniotomy pain which can be debilitating sequelae is also discussed concisely.

Pain Management in Post-Craniotomy Patients: A Survey of Canadian Neurosurgeons

Introduction:

Despite the growing recognition for analgesic needs in post-craniotomy patients, this remains a poorly studied area in neurological surgery. The class and regimen of analgesia that is most suitable for these patients remains controversial. The objective of this study is to examine the current beliefs and practices of Canadian neurosurgeons when managing post-craniotomy pain.

Methods:

A survey was sent to all practicing Canadian neurosurgeons to examine the following aspects of analgesia in craniotomy patients: type of analgesics used, common side effects encountered, satisfaction with current regimen and the rationale for their practice.

Results:

Of 156 potential respondents, 103 neurosurgeons (66%) completed the survey. Codeine (59%) was the most prescribed firstline analgesic followed by morphine (38%). The use of a second-line opioid was significantly higher among codeine prescribers compared to morphine, 53% compared to 28% (p < 0.001). Nausea, constipation and neurologic depression were reported as common side effects by 76%, 66% and 27% of respondents respectively. Of the respondents, 90% reported a high level of satisfaction with their current choice of analgesia; nonetheless, they predominantly described their practice as personal preference or protocol driven rather than evidence-based.

Conclusions:

Codeine - a weak opioid - is the most common first-line analgesic prescribed to craniotomy patients. This practice is associated with substantially increased reliance on potent opioids for rescue analgesia. Whether novel regimens can provide optimal pain control while minimizing neurologic and gastrointestinal side effects remains to be addressed by future trials.

Incidence of pain after craniotomy in children

BACKGROUND

There is very few information regarding pain after craniotomy in children.

OBJECTIVES

This multicentre observational study assessed the incidence of pain after major craniotomy in children.

METHODS

After IRB approval, 213 infants and children who were <10 years old and undergoing major craniotomy were consecutively enrolled in nine Italian hospitals. Pain intensity, analgesic therapy, and adverse effects were evaluated on the first 2 days after surgery. Moderate to severe pain was defined as a median FLACC or NRS score ≥ 4 points. Severe pain was defined as a median FLACC or NRS score ≥ 7 points.

RESULTS

Data of 206 children were included in the analysis. The overall postoperative median FLACC/NRS scores were 1 (IQR 0 to 2). Twenty-one children (16%) presented moderate to severe pain in the recovery room and 14 (6%) during the first and second day after surgery. Twenty-six children (19%) had severe pain in the recovery room and 4 (2%) during the first and second day after surgery. Rectal codeine was the most common weak opiod used. Remifentanil and morphine were the strong opioids widely used in PICU and in general wards, respectively. Longer procedures were associated with moderate to severe pain (OR 1.30; CI 1.07-1.57) or severe pain (OR 1.41; 1.09-1.84; P < 0.05). There were no significant associations between complications, pain intensity, and analgesic therapy.

CONCLUSION

Children receiving multimodal analgesia experience little or no pain after major craniotomy. Longer surgical procedures correlate with an increased risk of having postoperative pain.

Use of dexmedetomidine for prophylactic analgesia and sedation in delayed extubation patients after craniotomy: a study protocol and statistical analysis plan for a randomized controlled trial

BACKGROUND

Pain and agitation are common in patients after craniotomy. They can result in tachycardia, hypertension, immunosuppression, increased catecholamine production and increased oxygen consumption. Dexmedetomidine, an alpha-2 agonist, provides adequate sedation without respiratory depression, while facilitating frequent neurological evaluation.

METHODS/DESIGN

The study is a prospective, randomized, double-blind, controlled, parallel-group design. Consecutive patients are randomly assigned to one of the two treatment study groups, labeled 'Dex group' or 'Saline group.' Dexmedetomidine group patients receive a continuous infusion of 0.6 μg/kg/h (10 ug/ml). Placebo group patients receive a maintenance infusion of 0.9% sodium chloride for injection at a volume and rate equal to that of dexmedetomidine. The mean percentages of time in optimal sedation, vital signs, various and adverse events, the percentage of patients requiring propofol for rescue to achieve/maintain targeted sedation (Sedation-Agitation Scale, SAS 3 to 4) and total dose of propofol required throughout the study drug infusion are collected. The percentage of patients requiring fentanyl for additional rescue to analgesia and total dose of fentanyl required are recorded. The effects of dexmedetomidine on hemodynamic and recovery responses during extubation are measured. Intensive care unit and hospital length of stay also are collected. Plasma levels of epinephrine, norepinephrine, dopamine, cortisol, neuron-specific enolase and S100-B are measured before infusion (T1), at two hours (T2), four hours (T3) and eight hours (T4) after infusion and at the end of infusion (T5) in 20 patients in each group.

DISCUSSION

The study has been initiated as planned in July 2012. One interim analysis advised continuation of the trial. The study will be completed in July 2013.

TRIAL REGISTRATION

ClinicalTrials (NCT): ChiCTR-PRC-12002903.

Acute and chronic pain following craniotomy

PURPOSE OF REVIEW

The purpose of the review is to describe what is currently known about the mechanisms, incidence and risk factors for acute and chronic postcraniotomy pain. The review will also summarize the evidence supporting the prevention and management of acute and chronic postcraniotomy pain.

RECENT FINDINGS

Current studies suggest acute and chronic pain is common in patients after craniotomy. Surgical and patient factors may influence the incidence and severity of pain and a multimodal approach to acute postcraniotomy pain is recommended. Although codeine and tramadol are frequently used in the postoperative period, research suggests morphine provides superior efficacy with a good safety profile. Local anesthesia with nerve blocks has not been shown to consistently reduce acute postoperative pain, though it has recently been demonstrated to dramatically reduce the incidence of chronic pain. Despite this, little is known about the mechanisms, prevention and treatment of chronic postcraniotomy pain.

SUMMARY

Acute and chronic pain following craniotomy is frequent and underrecognized. Several surgical and patient risk factors predispose patients to pain following neurosurgery. Further research is needed to determine the mechanisms, predictors, prevention and optimal treatment of acute and chronic pain following craniotomy.