Effect of intraoperative infusion of low-dose ketamine on management of postoperative analgesia

Effect of Low-dose Ketamine Infusion on Opioid Consumption in Children Undergoing Open Cardiac Surgery: A Randomized Controlled Double-Blind Study

OBJECTIVE

This study was designed to evaluate the effect of low-dose ketamine infusion on the perioperative consumption of opioids in pediatric open cardiac surgery.

DESIGN

A randomized, controlled, double-blinded single-center study was conducted.

SETTING

The study took place in a tertiary care children's hospital.

PARTICIPANTS

Patients of both sexes aged 2-12 years who underwent cardiac surgery were included.

INTERVENTIONS

Patients in the ketamine group received a bolus of 0.3 mg/kg of ketamine before skin incision followed by continuous intraoperative infusion of 0.25 mg/kg/h and postoperative infusion of 0.1 mg/kg/h for 24 h. Patients in the control groups received volumes of normal saline either bolus or continuous infusion like that of the ketamine group.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the total dose of fentanyl consumed over the first 24 hours postoperatively. Secondary outcomes were intraoperative fentanyl consumption, time to extubation, modified objective pain score, and incidence of vomiting, pruritus, diplopia, or hallucinations. A total of 80 patients were recruited but the final analysis was done on 35 patients in the ketamine group and 34 in the control group. Fentanyl consumption during surgery and in the first 24 hours postoperatively was significantly lower in the ketamine than the control group. Patients in both the ketamine and control groups had similar times to extubation. Modified objective pain scores were significantly lower in the ketamine group than the control group. None of the patients in either group had diplopia or hallucinations.

CONCLUSIONS

Low-dose ketamine infusion in children undergoing open cardiac surgery reduced intra- and postoperative opioid consumption and postoperative pain scores. Moreover, ketamine did not cause diplopia or hallucinations.

Incidence and Associated Factors of Postoperative Undesirable Anesthetic Outcomes Among Surgical Patients at Referral Hospitals in Amhara Region, Ethiopia: A Multi-Center Study

Background

Patients undergoing surgery frequently experience unfavorable anesthetic outcomes. They may have an impact on body systems and result in more serious postoperative morbidities. This study was conducted to determine the incidence of postoperative undesirable anesthetic outcomes among surgical patients at referral hospitals in Amhara region, Ethiopia.

Methods

A total of 412 patients, who underwent surgical procedures between August 1 and October 30 of 2022, were included in this study. The Leiden Perioperative Care Patient Satisfaction Questionnaire's (LPPSq) dimension "discomfort and needs" was used to collect data on the first postoperative day. Data entry and analysis were performed using SPSS version 20. To assess how risk factors affected the outcome variable, logistic regression analysis was utilized. In multivariable logistic regression analysis, a variable with a P-value of less than 0.05 was statistically considered as significant.

Results

The proportion of those who had "at least a little bit" of unfavorable outcomes was calculated to estimate their overall prevalence, and the prevalence of those who had "more than moderate" levels of unfavorable outcomes was determined to appreciate how severe these outcomes were. The percentages of postoperative pain, the most common undesired result, for "at least a little bit" and "more than moderate" were 87.7% and 32.3%, respectively. In this study, postoperative cold was the least prevalent (51.4%) undesirable anesthetic outcome. The remaining undesirable postoperative outcomes were reported less frequently.

Conclusion and Recommendation

Undesirable postoperative anesthetic outcomes were still common. The most frequent unfavorable result was postoperative pain. Adequate postoperative patient follow-up and quality service are paramount.

The Role of Maximal Locoregional Block in Autologous Breast Reconstruction

BACKGROUND

Enhanced Recovery After Surgery (ERAS) has become the standard of care in microsurgical breast reconstruction. The current literature provides overwhelming evidence of the benefit of ERAS pathways in improving quality of recovery, decreasing length of hospital stay, and minimizing the amount of postoperative narcotic use in these patients. However, there are limited data on the role of using maximal locoregional anesthetic blocks targeting both the abdomen and chest as an integral part of an ERAS protocol in abdominally based autologous breast reconstruction. The aim of this study is to compare the outcomes of implementing a comprehensive ERAS protocol with and without maximal locoregional nerve blocks to determine any added benefit of these blocks to the standard ERAS pathway.

METHODS

Forty consecutive patients who underwent abdominally based autologous breast reconstruction in the period between July 2017 and February 2020 were included in this retrospective institutional review board-approved study. The goal was to compare patients who received combined abdominal and thoracic wall locoregional blocks as part of their ERAS pathway (study group) with those who had only transversus abdominis plane blocks. The primary end points were total hospital length of stay, overall opioids consumption, and overall postoperative complications.

RESULTS

The use of supplemental thoracic wall block resulted in a shorter hospital length of stay in the study group of 3.2 days compared with 4.2 days for the control group (P < 0.01). Postoperative total morphine equivalent consumption was lower at 38 mg in the study group compared with 51 mg in the control group (P < 0.01). Complications occurred in 6 cases (15%) in the control group versus one minor complication in the thoracic block group. There was no difference between the 2 groups in demographics, comorbidities, and type of reconstruction.

CONCLUSION

The maximal locoregional nerve block including a complete chest wall block confers added benefits to the standard ERAS protocol in microvascular breast reconstruction.

Opioid use, misuse, and abuse: a narrative review about interventions to reduce opioid consumption and related adverse events in the perioperative setting

Opioids remain the most potent and predictable drug available for perioperative analgesia and moderate-to-severe cancer-related pain. However, their efficacy has been questioned in other clinical settings. Moreover, opioids are associated with a wide variety of dose-dependent adverse events, limiting their use. The indiscriminate prescription of opioids has fueled the so-called "opioid epidemic" in the United States and other developed countries. Thus, there has been a significant effort to develop strategies to curtail their unnecessary prescription. Here, we summarize the history, current trends, and new directions in perioperative opioid prescription in an unbiased manner.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

Perioperative Intravenous Low-Dose Ketamine Infusion to Minimize Pain for Septorhinoplasty: A Prospective, Randomized, Double-Blind Study

OBJECTIVES

Studies investigating the effects of intravenous (IV) ketamine in pain management after septorhinoplasty is limited. This study aims to evaluate the efficacy of low-dose IV infusion of ketamine on pain scores.

METHODS

This randomized, prospective, double-blind study was conducted with 48 patients who underwent septorhinoplasty. Intravenous ketamine bolus (0.5 mg/kg) was administered to the ketamine group (group K, n = 24) at anesthesia induction, and ketamine infusion was continued (0.25 mg/kg/h) during the surgery. In the control group (group C, n = 24), the same protocol was administered using saline instead of ketamine. Furthermore, 50-mg dexketoprofen trometamol was administered to both groups 30 minutes before the end of the surgery. Then it was repeated at the 12th and 24th hours postoperatively. Pain scores were evaluated with the visual analogue scale. Consumptions intraoperative of opioid and sevoflurane, rescue opioid requirement, patient satisfaction, and side effects were recorded.

RESULTS

Pain scores were significantly lower in group K at all postoperative periods (P < .05). There was no significant difference between the groups in terms of intraoperative sevoflurane and remifentanil consumptions (P > .05). Rescue opioid analgesic requirements were significantly lower in group K than group C (0/24 vs 6/24, respectively; P  = .022). Side effects were similar between the groups (P > .05).

CONCLUSION

We recommend the administration of low-dose ketamine infusion during septorhinoplasty surgery because it reduces the requirement for rescue opioid analgesia and postoperative pain scores.

Effect of Perioperative Ketamine on Postoperative Mood and Depression: A Review of the Literature

Introduction: Ketamine is being increasingly utilized in a variety of patient care settings, ranging from high acuity inpatient scenarios to the outpatient management of select mental health diagnoses. Postoperative patients are at an increased risk of developing a depressed state, and though ketamine's ability to improve mood is well documented in the literature, the relationship between perioperative ketamine and postoperative mood has not been fully elucidated. Areas covered: The purpose of this review was to determine ketamine's ability to improve mood and depression scores in the perioperative setting. A comprehensive literature review was conducted using PubMed, MEDLINE, Scopus, ProQuest, Web of Science, and CINAHL using the following search terminology: 'ketamine' AND 'perioperative' OR 'surgery' AND 'mood' OR 'depression.' Seven clinical trials are evaluated in this review. Expert opinion: As the use of ketamine continues to expand, clinicians must be cognizant of the fact that many of its desired effects are likely to overlap. Patients outside of the perioperative setting may benefit from using ketamine as an analgesic or sedative, as appropriate, to mitigate mood and depression. Ketamine, when administered as an anesthetic in the perioperative setting, seemingly has effect on postoperative mood and depression. Further studies that are sufficient.

American Burn Association Guidelines on the Management of Acute Pain in the Adult Burn Patient: A Review of the Literature, a Compilation of Expert Opinion, and Next Steps

The ABA pain guidelines were developed 14 years ago and have not been revised despite evolution in the practice of burn care. A sub-committee of the American Burn Association's Committee on the Organization and Delivery of Burn Care was created to revise the adult pain guidelines. A MEDLINE search of English-language publications from 1968 to 2018 was conducted using the keywords "burn pain," "treatment," and "assessment." Selected references were also used from the greater pain literature. Studies were graded by two members of the committee using Oxford Centre for Evidence-based Medicine-Levels of Evidence. We then met as a group to determine expert consensus on a variety of topics related to treating pain in burn patients. Finally, we assessed gaps in the current knowledge and determined research questions that would aid in providing better recommendations for optimal pain management of the burn patient. The literature search produced 189 papers, 95 were found to be relevant to the assessment and treatment of burn pain. From the greater pain literature 151 references were included, totaling 246 papers being analyzed. Following this literature review, a meeting to establish expert consensus was held and 20 guidelines established in the areas of pain assessment, opioid medications, nonopioid medications, regional anesthesia, and nonpharmacologic treatments. There is increasing research on pain management modalities, but available studies are inadequate to create a true standard of care. We call for more burn specific research into modalities for burn pain control as well as research on multimodal pain control.

Total intravenous anaesthesia with tumescent infiltration anaesthesia without definitive airway for early excision and skin grafting in a major burn - A prospective observational study

Background and Aims:

Patients with major burns posted for early tangential excision and skin grafting pose peculiar challenges for anaesthesiologists. The purpose of the study was to assess safety and efficacy of total intravenous anaesthesia (TIVA) with tumescent infiltration anaesthesia (TIA) for these burn procedures.

Methods:

This observational single-arm study was conducted on 48 cases of a tertiary centre burn unit, requiring early tangential excision and skin grafting between third and fifth days of burn injury. TIVA was administered using a combination of intravenous (iv) infusion of injection dexmedetomidine and iv boluses of fentanyl, ketamine, propofol, midazolam and paracetamol. TIA was administered in burn wounds after aseptic preparation. Spontaneous breathing was maintained with oxygen supplementation. Haemodynamic and respiratory monitoring was done intraoperatively every 15 minutes and for 6 hours postoperatively. Modified Aldrete's score was calculated at 10 minutes after completion of surgery. Statistical analysis was done using statistical package for the social science software (version 16). Descriptive statistics were used for quantitative variables.

Results:

Baseline mean HR was 106.95 ± 11.17 bpm (beats per minute). HR settled at 73.17 ± 6.97 bpm during the intraoperative period. The baseline mean arterial pressure (MAP) of 82.42 ± 10.04 mmHg was maintained at 81 ± 7.32 mmHg during the intraoperative period. In all, 95.8% achieved early recovery with mean modified Aldrete's score of ≥9 at 10 minutes post-surgery. There was no episode of apnoea or desaturation.

Conclusion:

TIVA in combination with TIA minimally interferes with homeostasis and promotes early recovery in patients undergoing early excision and grafting in major burns.

Low-Dose Ketamine for Outpatient Hysteroscopy: A Prospective, Randomised, Double-Blind Study

Objective

Outpatient hysteroscopy is often accompanied by pain and discomfort along with frequent occurrence of bradycardia and hypotension. This study aimed to observe if intravenous low-dose ketamine reduces the pain scores along with lowering the incidence of bradycardia and hypotension during hysteroscopy.

Methods

This prospective, randomised, double-blind trial was conducted in operating rooms in a tertiary care hospital. In this study, we enrolled 72 patients with American Society of Anesthesiologists status I to II undergoing hysteroscopy. We randomised patients into two groups, and both groups received paracervical block. The control group received intravenous pentazocine and promethazine along with saline infusion. The ketamine group received ketamine infusion (0.75 mg kg⁻¹ bolus followed by infusion at the rate of 10 mcg kg⁻¹ min⁻¹). We analysed visual analogue scale (VAS), rescue analgesic consumption, hemodynamic parameters, lowest recorded heart rate, blood pressure, level of sedation, patient’s comfort, surgeon’s satisfaction and nursing staff’s satisfaction.

Results

Analysis of the data revealed that the pain scores were similar in both the groups (p=0.493, p<0.001). Rescue analgesic was required by 47% patients in control group, compared to only 5.6% patients in ketamine group. Episodes of bradycardia and hypotension were more pronounced in the control group than in the ketamine group [77.4±10.9 vs. 78.4±5.5; 67.6±8 vs. 70.1±6 respectively] (p<0.001). Patient comfort and surgeon’s satisfaction were higher in the ketamine group, but nursing satisfaction was higher in the control group. Disorientation was present in 75% patients in the ketamine group as compared to none in the control group.

Conclusion

We concluded that low-dose ketamine in day-care hysteroscopy is an effective and safe agent.

Effect of opioid-free anaesthesia on postoperative epidural ropivacaine requirement after thoracic surgery: A retrospective unmatched case-control study

INTRODUCTION

Patients undergoing thoracic surgery are at risk of severe postoperative pain. Post-thoracotomy pain relief is usually provided with thoracic epidural analgesia (TEA). Intraoperative use of opioids may result in hyperalgesia and increase analgesics consumption. We investigated the effect of opioid-free anaesthesia (OFA) on epidural ropivacaine requirement after thoracotomy.

METHODS

This retrospective study compared postoperative epidural ropivacaine requirement of patients undergoing open thoracotomy and receiving either opioid-based anaesthesia (OBA group) or a non-opioid regimen including clonidine, ketamine and lidocaine (OFA group). All patients received postoperative multimodal analgesia including both epidural analgesia and intravenous analgesics. The primary outcome was the cumulative first 48 postoperative hours epidural ropivacaine consumption. Secondary outcomes included postoperative pain scores, requirement for postoperative morphine titration, total opioid analgesics consumption within the first 48 postoperative hours, incidence of nausea and vomiting, intraoperative haemodynamic.

RESULTS

From January 2015 to February 2018, 50 patients received an OBA and 25 received an OFA. The cumulative first 48 postoperative hours epidural ropivacaine consumption was significantly higher in the OBA-group (919 ± 311 mg versus 693 ± 270 mg, P = 0.002). Numerical Rating Scale at 6 and 24 h were significantly lower in the OFA-group (1[0-2] versus 3 [1-5], P = 0.0005 and 1[0-2] versus 3.5 [1-5], P = 0.001). In post-anaesthesia care unit, the proportion of patients requiring morphine was significantly higher in the OBA-group (42% versus 4%, P < 0.001). During anaesthesia, the OBA-group required more vasopressor support, while there were more hypertensive events in the OFA-group.

CONCLUSION

OFA might reduce ropivacaine consumption, early postoperative pain scores and requirement for morphine titration after thoracotomy.

Pain Management in Trauma in the Age of the Opioid Crisis

It is imperative to find the balance between pain control and addressing the opioid epidemic. Opioids, although effective in the acute pain management, have multiple side effects and can lead to dependence, abuse, overdose, or death. Physicians should identify patients who abuse opioids, using their states' prescription drug-monitoring programs and use screening tools to identify patients at increased risk of developing opioid dependence. Multimodal analgesic plans, incorporating regional techniques, and nonopioid medications should be employed to reduce the amount of opioids received by patients.

Perioperative factors associated with persistent opioid use after extensive abdominal surgery in children and adolescents: A retrospective cohort study

BACKGROUND

In adults, preoperative opioid use and higher perioperative opioid consumption have been associated with higher odds of persistent opioid use after surgery. There are limited data on the prevalence and factors associated with persistent opioid use after major oncologic surgery in children.

AIMS

In this study, we sought to determine the prevalence and factors associated with the development of persistent opioid use in a group of children and adolescents who had undergone cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

METHODS

A retrospective study of patients ≤19 years of age was performed. Univariable logistic regression was used to assess factors associated with a postdischarge persistent opioid use of up to 6 months.

RESULTS

Eighty-six children were identified. The median age was 12 years, and 43% were female. The proportion of patients with persistent opioid use over the immediate 3, 6, 12 and 24 postdischarge months was 54/77 (70%), 18/51 (35%), 13/45 (29%), and 3/24 (13%), respectively. The daily average in-patient pain scores were higher in the group of children who subsequently developed persistent opioid use of up to 6 months (estimated difference 0.5, 95% confidence interval [CI]: 0.3, 0.8, P < .01). Furthermore, higher postoperative opioid consumption was associated with greater odds of a subsequent persistent opioid use of up to 6 months (odds ratio 1.03, 95% CI: 1.00, 1.07, P = .05).

CONCLUSION

In this retrospective study of children and adolescents who had undergone a major oncologic surgery, higher in-patient pain scores and higher postoperative opioid consumption were associated with a persistent opioid use of up to 6 months.

Role of Multimodal Analgesia in the Evolving Enhanced Recovery after Surgery Pathways

Enhanced recovery after surgery (ERAS) are specially designed multimodal perioperative care pathways which are intended to attain and improve rapid recovery after surgical interventions by supporting preoperative organ function and attenuating the stress response caused by surgical trauma, allowing patients to get back to normal activities as soon as possible. Evidence-based protocols are prepared and published to implement the conception of ERAS. Although they vary amongst health care institutions, the main three elements (preoperative, perioperative, and postoperative components) remain the cornerstones. Postoperative pain influences the quality and length of the postoperative recovery period, and later, the quality of life. Therefore, the optimal postoperative pain management (PPM) applying multimodal analgesia (MA) is one of the most important components of ERAS. The main purpose of this article is to discuss the concept of MA in PPM, particularly reviewing the use of opioid-sparing measures such as paracetamol, nonsteroid anti-inflammatory drugs (NSAIDs), other adjuvants, and regional techniques.

Endogenous Opiates and Behavior: 2016

This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Opioid-free anaesthesia in three dogs

Opioid-free anaesthesia (OFA) is a relatively new and growing field in human medicine. There are multiple motivations behind this emerging practice with the recognition of several serious potential opioid-related adverse effects including opioid induced hyperalgesia, opioid tolerance and immunomodulatory effects of opioids. Opioids have long been the mainstay of veterinary anaesthesia and pain management practice. The feasibility of OFA in veterinary patients is presented here. A case series of three dogs that underwent OFA for canine ovariohysterectomy is reported. The authors conclude OFA is possible in veterinary medicine; however the move away from the familiar effects of opioids perioperatively is challenging. Gaining experience with these types of protocols for standard procedures in healthy animals, such as neutering, will provide the anaesthetist with the building blocks for more invasive surgeries.

Multimodal Analgesia, Current Concepts, and Acute Pain Considerations

PURPOSE OF REVIEW

Management of acute pain following surgery using a multimodal approach is recommended by the American Society of Anesthesiologists whenever possible. In addition to opioids, drugs with differing mechanisms of actions target pain pathways resulting in additive and/or synergistic effects. Some of these agents include alpha 2 agonists, NMDA receptor antagonists, gabapentinoids, dexamethasone, NSAIDs, acetaminophen, and duloxetine.

RECENT FINDINGS

Alpha 2 agonists have been shown to have opioid-sparing effects, but can cause hypotension and bradycardia and must be taken into consideration when administered. Acetaminophen is commonly used in a multimodal approach, with recent evidence lacking for the use of IV over oral formulations in patients able to take medications by mouth. Studies involving gabapentinoids have been mixed with some showing benefit; however, future large randomized controlled trials are needed. Ketamine is known to have powerful analgesic effects and, when combined with magnesium and other agents, may have a synergistic effect. Dexamethasone reduces postoperative nausea and vomiting and has been demonstrated to be an effective adjunct in multimodal analgesia. The serotonin-norepinephrine reuptake inhibitor, duloxetine, is a novel agent, but studies are limited and further evidence is needed. Overall, a multimodal analgesic approach should be used when treating postoperative pain, as it can potentially reduce side effects and provide the benefit of treating pain through different cellular pathways.

Retrospective case-control non-inferiority analysis of intravenous lidocaine in a colorectal surgery enhanced recovery program

BACKGROUND

Enhanced recovery after surgery (ERAS) programs typically utilizes multi-modal analgesia to reduce perioperative opioid consumption. Systemic lidocaine is used in several of these ERAS algorithms and has been shown to reduce opioid use after colorectal surgery. However it is unclear how much the other components of an ERAS protocol contribute to the final outcome. Using a noninferiority analysis we sought to assess the role of perioperative lidocaine in an ERAS program for colorectal surgery, using pain and opioid consumption as outcomes.

METHODS

We conducted a retrospective review of patients who had received intravenous lidocaine perioperatively during colorectal surgery. We matched them with patients who were managed using a multi-component ERAS protocol, which included perioperative lidocaine. We tested a joint hypothesis of noninferiority of lidocaine infusion to ERAS protocol in postoperative pain scores and opioid consumption. We assigned a noninferiority margin of 1 point (on an 11-point numerical rating scale) difference in pain and a ratio [mean (lidocaine) / mean (ERAS)] of 1.2 in opioid consumption, respectively.

RESULTS

Fifty-two patients in the lidocaine group were matched with patients in the ERAS group. With regards to opioid consumption, in the overall [1.68 (1.43-1.98)] [odds ratio (95% confidence interval)] analysis and on postoperative day (POD) 1 [2.38 (1.74-3.31)] lidocaine alone was inferior to multi-modal analgesia. On POD 2 and beyond, although the mean odds ratio for opioid consumption was 1.43 [1.43 (1.17-1.73)], the lower limit extended beyond the pre-defined cut-off of 1.2, rendering the outcome inconclusive. For pain scores lidocaine is non-inferior to ERAS [-0.17 (-1.08-0.74)] on POD 2 and beyond. Pain scores on POD 1 and in the overall cohort were inconclusive based on the noninferiority analysis.

CONCLUSIONS

The addition of a multi-component ERAS protocol to intravenous lidocaine incrementally reduces opioid consumption, most evident on POD 1. For pain scores the data is inconclusive on POD 1, however on POD 2 and beyond lidocaine alone is non-inferior to an ERAS program with lidocaine. Opioid-related complications, including return of bowel function, were not different between the groups despite reduced opioid use in the ERAS group.

[Complex regional pain syndrome: A review]

BACKGROUND

Complex regional pain syndrome is characterized by spontaneous or induced pain disproportionate in relation to the initial event and is accompanied by a variety of regional and motor disturbances, leading to a variety of clinical presentations. It is often associated with surgery and minor trauma.

PATHOPHYSIOLOGY

Three mechanisms are postulated: changes secondary to post traumatic inflammation, peripheral vasomotor dysfunction and structural and functional changes of the central nervous system as a result of maladaptation.

DIAGNOSIS

made based on the criteria of Budapest. The patient must have one symptom and sign of each criterion at diagnosis: Continuing pain, disproportionate to any inciting event. A sensory, vasomotor, oedema and motor/trophic change sign and symptoms that are not explained by another diagnosis or cause.

TREATMENT

Multimodal treatment is suggested. There is no gold standard. In early stage NSAIDs or steroids can be used. Drugs used for neuropathic pain treatment have been suggested, but there is not enough evidence for any of these. There is low evidence that bisphosphonates, calcitonin, ketamine and mirror therapy are effective compared to placebo. Interventional treatment should be stepped from epidural block, neurostimulation, intrathecal pump to experimental therapies in case of intractable pain.

DISCUSSION

Although complex regional pain syndrome has been a recognized entity for over 100 years, no clear evidence exists for first-line treatments; however, new technologies that are applicable in complex regional pain syndrome treatment have been developed.

Ketamine: 50 Years of Modulating the Mind

Ketamine was introduced into clinical practice in the 1960s and continues to be both clinically useful and scientifically fascinating. With considerably diverse molecular targets and neurophysiological properties, ketamine’s effects on the central nervous system remain incompletely understood. Investigators have leveraged the unique characteristics of ketamine to explore the invariant, fundamental mechanisms of anesthetic action. Emerging evidence indicates that ketamine-mediated anesthesia may occur via disruption of corticocortical information transfer in a frontal-to-parietal (“top down”) distribution. This proposed mechanism of general anesthesia has since been demonstrated with anesthetics in other pharmacological classes as well. Ketamine remains invaluable to the fields of anesthesiology and critical care medicine, in large part due to its ability to maintain cardiorespiratory stability while providing effective sedation and analgesia. Furthermore, there may be an emerging role for ketamine in treatment of refractory depression and Post-Traumatic Stress Disorder. In this article, we review the history of ketamine, its pharmacology, putative mechanisms of action and current clinical applications.

Evaluation and Management of Sleep Disorders in the Hand Surgery Patient

Despite posing a significant public health threat, sleep disorders remain poorly understood and often underdiagnosed and mismanaged. Although sleep disorders are seemingly unrelated, hand surgeons should be mindful of these because numerous conditions of the upper extremity have known associations with sleep disturbances that can adversely affect patient function and satisfaction. In addition, patients with sleep disorders are at significantly higher risk for severe, even life-threatening medical comorbidities, further amplifying the role of hand surgeons in the recognition of this condition.

Effects of low-dose ketamine on succinylcholine-induced postoperative myalgia in outpatient surgeries: a randomized, double-blind study

Objective

Despite the many complications of succinylcholine, it is still widely used as a superior muscle relaxant for rapid sequence induction. One of these complications is postoperative myalgia (POM). The aim of this study was to investigate the prophylactic effect of low-dose ketamine on the incidence and severity of POM.

Materials and methods

In this double-blind clinical study, a total of 148 patients scheduled for general anesthesia were randomly divided into two equal groups. Initially, in Group K, 0.5 mg/kg of ketamine was injected intravenously, whereas in Group N, the same volume (5 mL) of normal saline was injected. Thereafter, anesthesia was induced in all patients, by injecting 1.5 mg/kg of fentanyl and 2 mg/kg of propofol intravenously. Following the loss of eyelid reflex, 1.5 mg/kg of succinylcholine was injected intravenously as a muscle relaxant and then the patients were intubated. POM was defined as a pain with no surgical interferences, and its intensity was graded based on a four-point scale. The incidence and severity of myalgia were assessed by a blinded observer 24 hours after surgery.

Results

In terms of demographic data, the results of this study showed that there is no significant difference between patients in both groups (P>0.05). Overall, the incidence of POM in Group K was significantly less, when compared with Group N (P<0.05), but both groups were comparable based on the grade 2 of POM. After the induction of anesthesia, the systolic and diastolic blood pressure values were found to reduce in both groups (P<0.05). However, the changes were somehow similar, and repeated measures of variance analysis showed no significant difference in the two study groups (P>0.05).

Conclusion

The addition of 0.5 mg/kg of ketamine to propofol for the induction of anesthesia can be effective in reducing the incidence of low-grade POM.

Low-Dose Ketamine Pretreatment Reduces the Incidence and Severity of Myoclonus Induced by Etomidate: A Randomized, Double-Blinded, Controlled Clinical Trial

Myoclonic movement induced by etomidate is a common but undesirable problem during general anesthesia induction. To investigate the influence of pretreatment with low-dose ketamine on the incidence and severity of myoclonus induced by etomidate, 104 patients were randomized allocated to 1 of 2 equally sized groups (n = 52) to receive either intravenous low-dose ketamine 0.5 mg/kg (group K) or an equal volume of normal saline (group S) 1 minute before induction of anesthesia with 0.3-mg/kg etomidate. The incidence and severity of myoclonus were assessed for 2 minutes after administration of etomidate. Here, we found that the incidence and intensity of myoclonus were both significantly reduced in low-dose ketamine-treated group compared with saline-treated group. The incidence of adverse effects was low and similar between groups. These results demonstrate that intravenous infusion of low-dose ketamine 0.5 mg/kg 1 minute prior to etomidate administration is effective in relieving etomidate-induced myoclonic movements during general anesthesia induction.