Peripheral nerve blocks for analgesia following cesarean delivery A narrative review.

Spinal and epidural blocks are commonly employed for pain relief during and following cesarean section. Intrathecal morphine (ITM) has been the gold standard for the same for many years. In recent times, many peripheral nerve blocks (PNBs) have been tried for postoperative analgesia following cesarean delivery (PACD). This article has reviewed the common PNBs used for PACD. The role of PNBs along with ITM has been studied and the current best strategy for PACD has also been explored. Currently, Ilio-inguinal nerve and anterior transversus abdominis plane block in conjunction with intrathecal morphine have been found to be the most effective strategy, providing lower rest pain at 6 hours as compared to ITM alone. In patients not receiving intrathecal morphine, recommended PNBs are lateral transversus abdominis plane block, single shot local anesthetic wound infiltration, or continuous wound infiltration with catheter below rectus fascia. PNBs are recommended for PACD. They have an opioid-sparing effect and are devoid of adverse effects associated with central neuraxial blocks such as hypotension, bradycardia, and urine retention. However, caution must be observed with PNBs for possible local anesthetic toxicity due to the large volumes of drug required.

Paediatric patients in mass casualty incidents: a comprehensive review and call to action.

The paediatric population is disproportionately affected during mass casualty incidents (MCIs). Several unique characteristics of children merit special attention during natural and man-made disasters because of their age, physiology, and vulnerability. Paediatric anaesthesiologists play a critical part of MCI care for this population, yet there is a deficit of publications within the anaesthesia literature addressing paediatric-specific MCI concerns. This narrative review article analyses paediatric MCI considerations and compares differing aspects between care provision in Australia, the UK, and the USA. We integrate some of the potential roles for anaesthesiologists with paediatric experience, which include preparation, command consultation, in-field care, pre-hospital transport duties, and emergency department, operating theatre, and ICU opportunities. Finally, we propose several methods by which anaesthesiologists can improve their contribution to paediatric MCI care through personal education, training, and institutional involvement.

Computer-Generated Three-Dimensional Airway Models as a Decision-Support Tool for Preoperative Evaluation and Procedure-Planning in Pediatric Anesthesiology.

Technology improvements have rapidly advanced medicine over the last few decades. New approaches are constantly being developed and utilized. Anesthesiology strongly relies on technology for resuscitation, life-support, monitoring, safety, clinical care, and education. This manuscript describes a reverse engineering process to confirm the fit of a medical device in a pediatric patient. The method uses virtual reality and three-dimensional printing technologies to evaluate the feasibility of a complex procedure requiring one-lung isolation and one-lung ventilation. Based on the results of the device fit analysis, the anesthesiology team confidently proceeded with the operation. The approach used and described serves as an example of the advantages available when coupling new technologies to visualize patient anatomy during the procedural planning process.

Fourth Consensus Guidelines for the Management of Postoperative Nausea and Vomiting.

This consensus statement presents a comprehensive and evidence-based set of guidelines for the care of postoperative nausea and vomiting (PONV) in both adult and pediatric populations. The guidelines are established by an international panel of experts under the auspices of the American Society of Enhanced Recovery and Society for Ambulatory Anesthesia based on a comprehensive search and review of literature up to September 2019. The guidelines provide recommendation on identifying high-risk patients, managing baseline PONV risks, choices for prophylaxis, and rescue treatment of PONV as well as recommendations for the institutional implementation of a PONV protocol. In addition, the current guidelines focus on the evidence for newer drugs (eg, second-generation 5-hydroxytryptamine 3 [5-HT3] receptor antagonists, neurokinin 1 (NK1) receptor antagonists, and dopamine antagonists), discussion regarding the use of general multimodal PONV prophylaxis, and PONV management as part of enhanced recovery pathways. This set of guidelines have been endorsed by 23 professional societies and organizations from different disciplines (Appendix 1).Guidelines currently available include the 3 iterations of the consensus guideline we previously published, which was last updated 6 years ago; a guideline published by American Society of Health System Pharmacists in 1999; a brief discussion on PONV management as part of a comprehensive postoperative care guidelines; focused guidelines published by the Society of Obstetricians and Gynecologists of Canada, the Association of Paediatric Anaesthetists of Great Britain & Ireland and the Association of Perianesthesia Nursing; and several guidelines published in other languages.The current guideline was developed to provide perioperative practitioners with a comprehensive and up-to-date, evidence-based guidance on the risk stratification, prevention, and treatment of PONV in both adults and children. The guideline also provides guidance on the management of PONV within enhanced recovery pathways.The previous consensus guideline was published 6 years ago with a literature search updated to October 2011. Several guidelines, which have been published since, are either limited to a specific populations or do not address all aspects of PONV management. The current guideline was developed based on a systematic review of the literature published up through September 2019. This includes recent studies of newer pharmacological agents such as the second-generation 5-hydroxytryptamine 3 (5-HT3) receptor antagonists, a dopamine antagonist, neurokinin 1 (NK1) receptor antagonists as well as several novel combination therapies. In addition, it also contains an evidence-based discussion on the management of PONV in enhanced recovery pathways. We have also discussed the implementation of a general multimodal PONV prophylaxis in all at-risk surgical patients based on the consensus of the expert panel.

Anesthetic management of pediatric patients diagnosed with X-linked adrenoleukodystrophy: A single-center experience.

BACKGROUND: X-linked adrenoleukodystrophy is a progressive demyelinating disease that primarily affects males with an incidence of 1:20 000-30 000. The disease has a wide spectrum of phenotypic expression and may include adrenal insufficiency, cerebral X-linked adrenoleukodystrophy and adrenomyeloneuropathy. The condition has implications for the administration of anesthesia and reports of anesthetic management in those patients are limited at this point. AIM: To review the perioperative care, complications and outcomes of patients diagnosed with X-linked adrenoleukodystrophy at the University of Minnesota Masonic Children's Hospital. METHOD: After obtaining IRB approval, we performed a retrospective chart review of pediatric patients diagnosed with X-linked adrenoleukodystrophy who underwent either surgery or diagnostic/therapeutic procedures that included anesthesia services between January 2014 and December 2016. Data included demographics, American Society of Anesthesiologists classification, preoperative diagnosis, history of hematopoietic stem cell transplant, anesthetic approaches, airway management, medications used, intra- and postoperative complications, and patient disposition. RESULTS: We identified 38 patients who had a total of 166 anesthetic encounters. The majority of patients underwent procedures in the sedation unit (75.9%) and received a total intravenous anesthetic with spontaneous ventilation via a natural airway (86.1%). Preoperative adrenal insufficiency was documented in 87.3% of the encounters. Stress-dose steroids were administered in 70.5% of the performed anesthetics. A variety of anesthetic agents were successfully used including sevoflurane, isoflurane, propofol, midazolam, ketamine, and dexmedetomidine. There were few perioperative complications noted (6.6%) and the majority were of low severity. No anesthesia-related mortality was observed. CONCLUSIONS: With the availability of skilled pediatric anesthesia care, children with X-linked adrenoleukodystrophy can undergo procedures under anesthesia in sedation units and regular operating rooms with low overall anesthesia risk.

Genetics of Malignant Hyperthermia: A Brief Update.

Malignant hyperthermia susceptibility (MHS) and the associated condition malignant hyperthermia (MH) are rare but well-known disorders in the field of anesthesiology. MHS is usually determined by a history of a family member developing a positive episode during general anesthesia and then confirmed by an invasive caffeine halothane contracture test (CHCT). More recently, within the context of MH as a pharmacogenetic disorder, the question of whether or not MHS can be principally genetically determined is of high importance as knowledge of detailed pathogenesis may prevent against its largely invariable lethality if untreated. Thus, in this brief report, genetic terms, as well as updates in the genetics of MHS, will be reviewed in order to better understand both the condition and the current research.

Succinylcholine Use and Dantrolene Availability for Malignant Hyperthermia Treatment: Database Analyses and Systematic Review.

BACKGROUND: Although dantrolene effectively treats malignant hyperthermia (MH), discrepant recommendations exist concerning dantrolene availability. Whereas Malignant Hyperthermia Association of the United States guidelines state dantrolene must be available within 10 min of the decision to treat MH wherever volatile anesthetics or succinylcholine are administered, a Society for Ambulatory Anesthesia protocol permits Class B ambulatory facilities to stock succinylcholine for airway rescue without dantrolene. The authors investigated (1) succinylcholine use rates, including for airway rescue, in anesthetizing/sedating locations; (2) whether succinylcholine without volatile anesthetics triggers MH warranting dantrolene; and (3) the relationship between dantrolene administration and MH morbidity/mortality. METHODS: The authors performed focused analyses of the Multicenter Perioperative Outcomes Group (2005 through 2016), North American MH Registry (2013 through 2016), and Anesthesia Closed Claims Project (1970 through 2014) databases, as well as a systematic literature review (1987 through 2017). The authors used difficult mask ventilation (grades III and IV) as a surrogate for airway rescue. MH experts judged dantrolene treatment. For MH morbidity/mortality analyses, the authors included U.S. and Canadian cases that were fulminant or scored 20 or higher on the clinical grading scale and in which volatile anesthetics or succinylcholine were given. RESULTS: Among 6,368,356 queried outcomes cases, 246,904 (3.9%) received succinylcholine without volatile agents. Succinylcholine was used in 46% (n = 710) of grade IV mask ventilation cases (median dose, 100 mg, 1.2 mg/kg). Succinylcholine without volatile anesthetics triggered 24 MH cases, 13 requiring dantrolene. Among 310 anesthetic-triggered MH cases, morbidity was 20 to 37%. Treatment delay increased complications every 10 min, reaching 100% with a 50-min delay. Overall mortality was 1 to 10%; 15 U.S. patients died, including 4 after anesthetics in freestanding facilities. CONCLUSIONS: Providers use succinylcholine commonly, including during difficult mask ventilation. Succinylcholine administered without volatile anesthetics may trigger MH events requiring dantrolene. Delayed dantrolene treatment increases the likelihood of MH complications. The data reported herein support stocking dantrolene wherever succinylcholine or volatile anesthetics may be used.

Malignant Hyperthermia-Susceptible Adult Patient and Ambulatory Surgery Center: Society for Ambulatory Anesthesia and Ambulatory Surgical Care Committee of the American Society of Anesthesiologists Position Statement.

This document represents a joint effort of the Society for Ambulatory Anesthesia (SAMBA) and the Ambulatory Surgical Care Committee of the American Society of Anesthesiologists (ASA) concerning the safe anesthetic care of adult malignant hyperthermia (MH)-susceptible patients in a free-standing ambulatory surgery center (ASC). Adult MH-susceptible patients can safely undergo a procedure in a free-standing ASC assuming that proper precautions for preventing, identifying, and managing MH are taken. The administration of preoperative prophylaxis with dantrolene is not indicated in MH-susceptible patients scheduled for elective surgery. There is no evidence to recommend an extended stay in the ASC, and the patient may be discharged when the usual discharge criteria for outpatient surgery are met. Survival from an MH crisis in an ASC setting requires early recognition, prompt treatment, and timely transfer to a center with critical care capabilities.

Implementing enhanced recovery pathways to improve surgical outcomes.

An enhanced recovery pathway is a structured perioperative healthcare program that incorporates evidence-based interventions including protocols and guidelines with the aim of providing standardized care. Enhanced recovery pathways can help maintain operating room safety and efficiency, improve postoperative recovery and a variety of important patient outcomes, and reduce overall costs of patient care following major surgery. Postoperative complications are minimized, which, in part, are attributed to adjustments in fasting and postoperative nutrition, interventions aimed at improving early mobilization, and careful selection of pharmacological agents for anesthesia and analgesia. Major surgery can lead to a variety of physiological stressors including organ dysfunction, and hormonal and neurological disturbances. The current notion of fast-tracking (bypassing phase I recovery level of care) differs from enhanced recovery pathways as the principles of enhanced recovery pathways are often applied to inpatient and complex procedures and span the entire spectrum of patient care. Also, enhanced recovery pathways programs are being used for pediatric patients especially with the hope of minimizing opioid exposure and the quality of recovery. A PubMed literature search was performed for articles that included the terms enhanced recovery pathways to improve surgical outcomes. In this article, we summarized the clinical application of enhanced recovery pathways and highlighted the key elements that characterize implementing an enhanced recovery pathway in surgery.

Goal-directed fluid therapy in the perioperative setting.

Improvement in patient outcomes has become a significant consideration with our limited resources in the surgical setting. The implementation of enhanced recovery pathway protocols has resulted in significant benefits to both the patients and hospitals, such as shorter length of hospital stays, reduction in the rate of complications, and fewer hospital readmissions. An emerging component and a key element for the success of Enhanced Recovery After Surgery (ERAS) protocols has been the concept of goal-directed fluid therapy (GDT). GDT related to ERAS protocols attempts to minimize complications associated with fluid imbalance during surgery. We performed a literature search for articles that included the terms enhanced recovery and GDT. We evaluated methods for appropriate volume status assessment, such as heart rate, blood pressure, end-tidal CO2, central venous pressure, urine output, stroke volume, cardiac output, and their derivatives. Some invasive, minimally invasive, and non-invasive monitors of hemodynamic evaluation are now being used to assess volume status and predict fluid responsiveness and fluid need during various surgical procedures. Regardless of monitoring technique, it is important for the clinician to effectively plan and implement preoperative and intraoperative fluid goals. Excess crystalloid fluid should be avoided. In some low-risk patients undergoing low-risk surgery, a "zero-balance" approach is encouraged. For the majority of patients undergoing major surgery, GDT is recommended. Optimal perioperative fluid management is an important component of the ERAS pathways and it can reduce postoperative complications.

Multimodal analgesia as an essential part of enhanced recovery protocols in the ambulatory settings.

Enhanced recovery after surgery protocols are multimodal perioperative care pathways designed to achieve early recovery in patients after surgical procedures by defining and maintaining preoperative organ function and minimizing the profound stress response following surgery. Enhanced recovery protocols have primarily been studied for major abdominal surgeries, however, the knowledge acquired from studying these protocols has facilitated treating patients in ambulatory settings. The key components of enhanced recovery protocols include preoperative counseling, preoperative nutrition, altering the standard perioperative fasting guidelines, and the value of carbohydrate loading up to 2 hours preoperatively, standardized analgesic, and anesthetic regimens (epidural and nonopioid analgesia) and early mobilization. A PubMed search was performed with the following key words: multimodal analgesia, enhanced recovery, ambulatory care, pain management, and opioids. We discuss the use of enhanced recovery protocols and multimodal pain care plans in the ambulatory setting.

Research Needs Assessment for Children With Obstructive Sleep Apnea Undergoing Diagnostic or Surgical Procedures.

Recent concerns have been raised about the quality and safety of adenotonsillectomy, a common surgery performed to treat obstructive sleep apnea (OSA) in children. OSA is a risk factor for opioid-related perioperative respiratory complications including those associated with anoxic brain injury or death. Our objective was to identify controversial issues related to the care of children with OSA. A standardized Delphi consensus technique involving an interdisciplinary group of 24 pediatric OSA experts identified 3 key issues: "postoperative disposition, preoperative screening, and pain management." These topics are prime candidates for future systematic reviews and will guide Society of Anesthesia and Sleep Medicine-related research endeavors.

Lifestyle Intervention and Medical Management With vs Without Roux-en-Y Gastric Bypass and Control of Hemoglobin A1c, LDL Cholesterol, and Systolic Blood Pressure at 5 Years in the Diabetes Surgery Study.

Importance: The Roux-en-Y gastric bypass is effective in achieving established diabetes treatment targets, but durability is unknown. Objective: To compare durability of Roux-en-Y gastric bypass added to intensive lifestyle and medical management in achieving diabetes control targets. Design, Setting, and Participants: Observational follow-up of a randomized clinical trial at 4 sites in the United States and Taiwan, involving 120 participants who had a hemoglobin A1c (HbA1c) level of 8.0% or higher and a body mass index between 30.0 and 39.9 (enrolled between April 2008 and December 2011) were followed up for 5 years, ending in November 2016. Interventions: Lifestyle-intensive medical management intervention based on the Diabetes Prevention Program and LookAHEAD trials for 2 years, with and without (60 participants each) Roux-en-Y gastric bypass surgery followed by observation to year 5. Main Outcomes and Measures: The American Diabetes Association composite triple end point of hemoglobin A1c less than 7.0%, low-density lipoprotein cholesterol less than 100 mg/dL, and systolic blood pressure less than 130 mm Hg at 5 years. Results: Of 120 participants who were initially randomized (mean age, 49 years [SD, 8 years], 72 women [60%]), 98 (82%) completed 5 years of follow-up. Baseline characteristics were similar between groups: mean (SD) body mass index 34.4 (3.2) for the lifestyle-medical management group and 34.9 (3.0) for the gastric bypass group and had hemoglobin A1c levels of 9.6% (1.2) and 9.6% (1.0), respectively. At 5 years, 13 participants (23%) in the gastric bypass group and 2 (4%) in the lifestyle-intensive medical management group had achieved the composite triple end point (difference, 19%; 95% CI, 4%-34%; P = .01). In the fifth year, 31 patients (55%) in the gastric bypass group vs 8 (14%) in the lifestyle-medical management group achieved an HbA1c level of less than 7.0% (difference, 41%; 95% CI, 19%-63%; P = .002). Gastric bypass had more serious adverse events than did the lifestyle-medical management intervention, 66 events vs 38 events, most frequently gastrointestinal events and surgical complications such as strictures, small bowel obstructions, and leaks. Gastric bypass had more parathyroid hormone elevation but no difference in B12 deficiency. Conclusions and Relevance: In extended follow-up of obese adults with type 2 diabetes randomized to adding gastric bypass compared with lifestyle and intensive medical management alone, there remained a significantly better composite triple end point in the surgical group at 5 years. However, because the effect size diminished over 5 years, further follow-up is needed to understand the durability of the improvement. Trial Registration: clinicaltrials.gov Identifier: NCT00641251.

Effect of sodium bicarbonate infusion in off-pump coronary artery bypass grafting in patients with renal dysfunction.

BACKGROUND AND AIMS: Acute kidney injury (AKI) following cardiac surgery is a major complication resulting in increased morbidity, mortality and economic burden. This study was designed to determine the benefit of sodium bicarbonate (NaHCO3) supplementation in patients with stable chronic kidney disease (CKD) undergoing off-pump coronary artery bypass grafting (OP-CABG). MATERIAL AND METHODS: We prospectively studied 60 non-dialysis CKD patients with glomerular filtration rate (GFR) ≤60 ml/min/1.73 m2 requiring elective OP-CABG. They were randomly allocatted to one of the two groups. One group received NaHCO3 infusion at 0.5 mmol/kg first hour followed by 0.2 mmol/kg/h till the end of surgery and the other group received 0.9% NaCl. A third group of 30 patients without renal dysfunction undergoing OP-CABG was included. The serum creatinine was estimated prior to surgery, immediately after surgery and on postoperative days 1, 2, 3 and 4. RESULTS: Ten patients (33.3%) in NaCl and 6 (20%) patients each in NaHCO3 and normal groups developed Stage-1 AKI. None of our study patient required renal replacement therapy and no mortality was observed in any of the groups during the perioperative and hospitalization period. CONCLUSION: Perioperative infusion of NaHCO3 in OP-CABG reduced the incidence of Stage-1 AKI by about 40% when compared to NaCl. The incidence of Stage-I AKI in NaHCO3 group was similar to that in patients with normal renal function undergoing OP-CABG. A larger group of patients may be required to suggest a significance of renal protective benefit of NaHCO3 in patients undergoing OP-CABG.

Videolaryngoscopy versus Fiber-optic Intubation through a Supraglottic Airway in Children with a Difficult Airway: An Analysis from the Multicenter Pediatric Difficult Intubation Registry.

BACKGROUND: The success rates and related complications of various techniques for intubation in children with difficult airways remain unknown. The primary aim of this study is to compare the success rates of fiber-optic intubation via supraglottic airway to videolaryngoscopy in children with difficult airways. Our secondary aim is to compare the complication rates of these techniques. METHODS: Observational data were collected from 14 sites after management of difficult pediatric airways. Patient age, intubation technique, success per attempt, use of continuous ventilation, and complications were recorded for each case. First-attempt success and complications were compared in subjects managed with fiber-optic intubation via supraglottic airway and videolaryngoscopy. RESULTS: Fiber-optic intubation via supraglottic airway and videolaryngoscopy had similar first-attempt success rates (67 of 114, 59% vs. 404 of 786, 51%; odds ratio 1.35; 95% CI, 0.91 to 2.00; P = 0.16). In subjects less than 1 yr old, fiber-optic intubation via supraglottic airway was more successful on the first attempt than videolaryngoscopy (19 of 35, 54% vs. 79 of 220, 36%; odds ratio, 2.12; 95% CI, 1.04 to 4.31; P = 0.042). Complication rates were similar in the two groups (20 vs. 13%; P = 0.096). The incidence of hypoxemia was lower when continuous ventilation through the supraglottic airway was used throughout the fiber-optic intubation attempt. CONCLUSIONS: In this nonrandomized study, first-attempt success rates were similar for fiber-optic intubation via supraglottic airway and videolaryngoscopy. Fiber-optic intubation via supraglottic airway is associated with higher first-attempt success than videolaryngoscopy in infants with difficult airways. Continuous ventilation through the supraglottic airway during fiber-optic intubation attempts may lower the incidence of hypoxemia.

Emerging roles of liposomal bupivacaine in anesthesia practice.

Despite advances in drug technology and improvements in technology, including peripheral nerve catheters and ultrasound, postoperative pain is still a significant problem in the clinical setting worldwide. Postoperative pain can have a critical negative impact with regard to physiological consequences to the body and therefore, the role of liposomal bupivacaine as an extended release bupivacaine with approximately 72 h of duration may have far-reaching and significant impact in clinical practice. Liposomal bupivacaine has a DepoFoam multivesicular liposome technology with particle suspension in an isotonic aqueous solution and consists of tiny lipid-based particles, which contain discrete water-filled chambers dispersed through a lipid matrix. Other advantages include a reduction in opioid consumption, while not requiring a catheter or any other device, as well as easy dilution with saline. This review summarizes current research with this novel agent in postsurgical pain, and discusses potential roles in chronic pain states. Further studies are warranted for its use in epidural and intrathecal administration. Moreover, this review will explore the expansion of liposomal bupivacaine's current clinical role.

Novel propofol derivatives and implications for anesthesia practice.

Propofol (2,6-diisopropylphenol) is the most commonly used intravenous agent for induction of anesthesia. It is also used for maintenance of anesthesia and sedation in both Intensive Care Units and outpatient procedural settings. Its success in the clinical setting has been a result of its rapid onset, short duration of action, and minimal side effects despite disadvantages associated with its oil emulsion formulation. Early attempts to alter the standard emulsion or to develop new formulations with cyclodextrins and micelles to resolve issues with pain upon injection, the need for antimicrobial agents, and possible hyperlipidemia have mostly failed. With these challenges in the foreground, attention has now shifted to the use of more prodrugs and exogenous alternatives, the success of which is yet to be determined. These new agents must offer significant clinical advantages over the well-entrenched, generic propofol oil emulsion to justify higher costs and to be well received in the increasingly cost-conscious healthcare marketplace.

Anesthetic care and perioperative complications in children with Sanfilipo Syndrome Type A.

BACKGROUND: Patients with mucopolysaccharidoses (MPS) are generally considered high risk for anesthesia care, owing to disease-related factors. Sanfilippo syndrome type A (MPS IIIA) is the most frequently occurring MPS. Anesthesia-specific information for MPS IIIA is not readily available in the literature. OBJECTIVES: To report post hoc analyses on anesthesia care and outcomes from a 2-year study of the natural history of patients with untreated MPS IIIA (NCT01047306). METHODS: Subjects were ≥1 year of age, developmental age ≥1 year, and without significant central nervous system impairment (other than that due to MPS IIIA) or issues that would preclude study procedures. Procedures requiring general anesthesia included brain/abdominal magnetic resonance imaging, lumbar puncture, and echocardiography. Sedation, intubation, and extubation procedures as well as postoperative airway problems were recorded at baseline and 6, 12, and 24 months of age. RESULTS: Twenty-five patients (baseline age, 13-220 months) received a total of 94 general anesthetics. Patients successfully received oral sedation prior to 76 of 94 anesthetics. No patients required airway intervention or oxygen supplementation during sedation. All anesthesia providers described facemask ventilation and endotracheal intubations as 'easy'. All subjects were successfully extubated after completion of the procedures. No patients required reintubation. Six (24%) patients had episodes of postoperative airway problems: wheezing (7/94, 7.4%), croup (6/94, 6.4%), and laryngospasm (2/94, 2.1%). CONCLUSION: We found no change in the modified Cormack-Lehane intubation grades in 25 Sanfilippo syndrome type A children over the 2-year study period.

Role of ketamine for analgesia in adults and children.

Ketamine an N-methyl-D-aspartate (NMDA) receptor blocking agent and a dissociative anesthetic with neurostimulatory side effects. In recent years, multiple research trials as well as systematic reviews and meta-analyses suggest the usefulness of ketamine as a strong analgesic used in subanesthetic intravenous doses, and also as a sedative. In addition, ketamine was noted to possess properties of anti-tolerance, anti-hyperalgesia and anti-allodynia most likely secondary to inhibition of the NMDA receptors. Tolerance, hyperalgesia and allodynia phenomena are the main components of opioid resistance, and pathological pain is often seen in the clinical conditions involving neuropathic pain, opioid-induced hyperalgesia, and central sensitization with allodynia or hyperalgesia. All these conditions are challenging to treat. In low doses, ketamine does not have major adverse dysphoric effects and also has the favorable effects of reduced incidence of opioid-induced nausea and vomiting. Therefore, ketamine can be a useful adjunct for pain control after surgery. Additional studies are required to determine the role of ketamine in the immediate postoperative period after surgical interventions known to produce severe pain and in the prevention and treatment of chronic pain.