Unravelling the analgesic effects of perioperative magnesium in general abdominal surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Prior research has established the effectiveness of magnesium in relieving postoperative pain. This article aims to evaluate magnesium sulfate for perioperative analgesia in adults undergoing general abdominal surgery under general anesthesia. OBJECTIVE: The primary aim was to assess pain scores at 6 and 24 hours postoperatively in patients receiving magnesium sulfate vs. the control group. Secondary outcomes were postoperative opioid consumption, perioperative complications, and time to rescue analgesia. METHODS: A comprehensive database search identified studies comparing magnesium sulfate with control in adults undergoing general anesthesia for general abdominal surgery. Using random-effects models, data were presented as mean ± Standard Deviation (SD) or Odds Ratios (OR) with corresponding 95% Confidence Intervals (95% CI). A two-sided p-value < 0.05 was considered statistically significant. RESULTS: In total, 31 studies involving 1762 participants met the inclusion criteria. The magnesium group showed significantly lower postoperative pain scores at both early (within six hours) and late (up to 24 hours) time points compared to the control group. The early mean score was 3.1 ± 1.4 vs. 4.2 ± 2.3, and the late mean score was 2.3 ± 1.1 vs. 2.7 ± 1.5, resulting in an overall Mean Difference (MD) of -0.72; 95% CI -0.99, -0.44; p < 0.00001. The magnesium group was associated with lower rates of postoperative opioid consumption and shivering and had a longer time to first analgesia administration compared to the saline control group. CONCLUSION: Magnesium sulfate administration was linked to reduced postoperative pain and opioid consumption following general abdominal surgery.

Comparison of Different Weight Scalars to Dose Sugammadex for the Reversal of Neuromuscular Blockade in Morbidly Obese Patients: A Systematic Review.

This systematic review was conducted to evaluate the optimal weight scalar to dose sugammadex in a morbidly obese (MO) patient population (BMI≥40 kg/m2). The primary outcome was recovery time from moderate neuromuscular blockade (NMB) or deep NMB. Secondary outcomes included time to extubation and incidence of postoperative residual curarization (PORC). Eight randomized controlled trials (RCTs) involving 645 participants were included. The different dose scalars included were total body weight (TBW), ideal body weight (IBW), 20% corrected body weight (CBW) and 40% CBW). A dose of 2 mg/kg of sugammadex based on 40% CBW and a 4 mg/kg dose of sugammadex based on 40% CBW provide a reliable and timely reversal of moderate and deep NMB respectively in the MO patients.

A survey of acute pain service in Canadian teaching hospitals.

BACKGROUND: The first national survey to ascertain the prevalence, structure, and functioning of the APS in Canadian university affiliated hospitals was conducted in 1991. This is a follow-up survey to assess the current status of the APS in Canada. METHODS: We requested completion of a 26-question survey from lead personnel of the APS teams or Anesthesia departments of Canadian teaching hospitals. RESULTS: Among the 32 centers that were contacted, 21 (65.6%) responded. Of these respondents, 18 (85.7%) indicated that they have a structured APS (72.22% adults, 5.56% pediatrics, 22.22% mixed). Among the 18 centers with an APS, 16 of the services are led by an anesthesiologist. Eight centers (44.44%) have a regional anesthesia group, of which five (27.75%) have a regional anesthesia group that is distinct from the APS team. Nine centers (50%) offer ambulatory nerve catheter analgesia after discharge home. Fifteen centers (83.33%) use standardized order sets, and 13 centers (72.22%) use an electronic record for APS. More than 50% of the centers use intravenous lidocaine and ketamine as a part of their multimodal analgesia. CONCLUSION: Most Canadian teaching hospitals do have a functioning APS. This survey has the potential to generate research questions about the availability of standardized and advanced acute pain management in Canada's teaching hospitals.

Methadone for Pain Management: A Pharmacotherapeutic Review.

Methadone is increasingly being used for its analgesic properties. Despite the increasing popularity, many healthcare providers are not familiar with methadone's complex pharmacology and best practices surrounding its use. The purpose of this narrative review article is to discuss the pharmacology of methadone, the evidence surrounding methadone's use in acute pain management and both chronic cancer and non-cancer pain settings, as well as highlight pertinent safety, monitoring, and opioid rotation considerations. Methadone has a unique mechanism of action when compared with all other opioids and for this reason methadone has come to hold a niche role in the management of opioid-induced hyperalgesia and central sensitization. Understanding of the mechanisms of variability in methadone disposition and drug interactions has evolved over the years, with the latest evidence revealing that CYP 2B6 is the major determinant of methadone elimination and plays a key role in methadone-related drug interactions. From an acute pain perspective, most studies evaluating the use of intraoperative intravenous methadone have reported lower pain scores and post-operative opioid requirements. Oral methadone is predominantly used as a second-line opioid treatment for select chronic pain conditions. As a result, several oral morphine to oral methadone conversion ratios have been proposed, as have methods in which to rotate to methadone. From an efficacy standpoint, limited literature exists regarding the effectiveness of methadone in the chronic pain setting with most of the available efficacy data pertaining to methadone's use in the treatment of cancer pain. Many of the prospective studies that exist feature low participant numbers. Few clinical trials investigating the role of methadone as an analgesic treatment are currently underway. The complicated pharmacokinetic properties of methadone and risks of harm associated with this drug highlight how critically important it is that healthcare providers understand these features before prescribing/dispensing methadone. Particular caution is required when converting patients from other opioids to methadone and for this reason only experienced healthcare providers should undertake such a task. Further randomized trials with larger sample sizes are needed to better define the effective and safe use of methadone for pain management.

Expanding Role of NMDA Receptor Antagonists in the Management of Pain.

Pain management is complex regardless of whether the pain is acute or chronic in nature or non-cancer or cancer related. In addition, relatively few pain pharmacotherapy options with adequate efficacy and safety data currently exist. Consequently, interest in the role of NMDA receptor antagonists as a pharmacological pain management strategy has surfaced. This narrative review provides an overview of the NMDA receptor and elaborates on the pharmacotherapeutic profile and pain management literature findings for the following NMDA receptor antagonists: ketamine, memantine, dextromethorphan, and magnesium. The literature on this topic is characterized by small studies, many of which exhibit methodological flaws. To date, ketamine is the most studied NMDA receptor antagonist for both acute and chronic pain management. Although further research about NMDA receptor antagonists for analgesia is needed and the optimal dosage/administration regimens for these drugs have yet to be determined, ketamine appears to hold the most promise and may be of particular value in the perioperative pain management realm.

Pain and Surgical Outcomes Reporting After Laparoscopic Ventral Hernia Repair in Relation to Mesh Fixation Technique: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

OBJECTIVES: The aim of this meta-analysis was to examine postoperative pain and surgical outcomes (operative time, hospital stay, the incidence of seroma and recurrence) with different mesh fixation methods following laparoscopic ventral hernia repair (LVHR). METHODS: Randomized clinical trials compared different methods of mesh fixation in LVHR and reported on pain outcome measures analyzed. The results were expressed as odds ratio (OR) for combined dichotomous and mean difference (MD) for continuous data. RESULTS: Five randomized controlled trials (RCTs) with a total of 466 patients comparing tack mesh fixation to suture mesh fixation technique in LVHR were identified, all were published after 2005. A meta-analysis gave statistically similar odds of postoperative chronic pain (OR, 1.24; 95% CI, 0.65-2.38; z = 0.65; P = .51). No difference in pain intensity (PI) scores was found at 4-6 weeks (MD, 0.18;% CI, -0.48 to 0.85; z = 0.54; P = .59) and at 3-6 months postoperatively (MD, 0.10; 95% CI, -0.21 to 0.42; z = 0.64; P = .52). There was no difference in the pooled analysis of seroma/hematoma formation (OR, 0.60; 95% CI, 0.29-1.26; z = 1.35; P = .18), recurrence (OR, 1.11; 95% CI, 0.34-3.62; z = 0.18; P = .86), and hospital stay (MD, -0.06; 95% CI, -0.19 to 0.08; z = 0.83; P = .40). Operative time was significantly lower with tack fixation (MD, -19.25; 95% CI, -27.98 to -10.51; z = 4.32; P < .05). CONCLUSIONS: Meta-analysis of RCTs comparing tacks to suture fixation in LVHR showed comparable results with regard to postoperative chronic pain incidence and PI, and hernia recurrence. However, the operative time is shorter with tacks compared to suture fixation technique.

Prevention of chronic post-surgical pain: the importance of early identification of risk factors.

Chronic post-surgical pain (CPSP) is currently an inevitable surgical complication. Despite the advances in surgical techniques and the development of new modalities for pain management, CPSP can affect 15-60% of all surgical patients. The development of chronic pain represents a burden to both the patient and to the community. In order to have a meaningful impact on this debilitating condition it is essential to identify those at risk. Early identification of patients at risk will help to reduce the percentage of patients who go on to develop CPSP. Unfortunately, evidence about any effective actions to reduce this condition is limited. This review will focus on providing context to the challenging problem of CPSP. The possible role of both the surgeon and anesthesiologist in reducing the incidence of this problem will be explored.

Tourniquet application during anesthesia: "What we need to know?"

Tourniquets are routinely and safely used in limb surgeries throughout the world. Tourniquet application alters normal physiology. Healthy patients tolerate these physiological changes well, but the physiological changes may not be well-tolerated by patients with poor cardiac function. This review discusses the physiological changes associated with tourniquet use, safe practice and provides the latest updates regarding tourniquet use. A systematic literature search of PubMed, MEDLINE, ScienceDirect, and Google Scholar was done. The search results were limited to the randomized controlled trials and systemic reviews. The papers are summarized in this review.

Postoperative pain management in patients with chronic kidney disease.

Chronic kidney disease (CKD) is a health care problem with increasing prevalence worldwide. Pain management represents one of the challenges in providing perioperative care for this group of patients. Physicians from different specialties may be involved in pain management of CKD patients, especially in advanced stages. It is important to understand the clinical staging of kidney function in CKD patients as the pharmacotherapeutic pain management strategies change as kidney function becomes progressively impaired. Special emphasis should be placed on dose adjustment of certain analgesics as well as prevention of further deterioration of renal function that could be induced by certain classes of analgesics. Chronic pain is a common finding in CKD patients which may be caused by the primary disease that led to kidney damage or can be a direct result of CKD and hemodialysis. The presence of chronic pain in some of the CKD patients makes postoperative pain management in these patients more challenging. This review focuses on the plans and challenges of postoperative pain management for patient at different stages of CKD undergoing surgical intervention to provide optimum pain control for this patient population. Further clinical studies are required to address the optimal medication regimen for postoperative pain management in the different stages of CKD.

Acute pain service: past, present and future.

Post surgical pain is a continuing major medical challenge despite all the advances in understanding acute pain and the development of new modalities of pain management. Since 1985 when the first acute pain service (APS) was started, many organizations initiated APS protocols and guidelines and it became mandatory to have an APS in all major acute care centers. This review focuses on the stages of development of APS and the challenges of postoperative pain management to provide optimal analgesia. Further clinical studies are required to determine best medication regimen for post-operative pain management.

Obstetric anesthesia considerations in Kearns-Sayre syndrome: a case report.

Kearns-Sayre syndrome (KSS) is a rare mitochondrial myopathy that usually develops before 20 years of age. It demonstrates multisystemic involvement with a triad of cardinal features: progressive ophthalmoplegia, pigmentary retinopathy, and cardiac conduction abnormalities. In addition, patients might have cerebellar ataxia, a high content of protein in the cerebrospinal fluid, proximal myopathy, multiple endocrinopathies, and renal tubular acidosis. We herein report the successful obstetric analgesic and anesthetic management of a 28-year-old parturient patient with KSS who required labor analgesia and proceeded to deliver by cesarean section. We extrapolate that regional analgesia/anesthesia might be beneficial for reducing the metabolic demands associated with the stress and pain of labor in patients with KSS. Efficient postoperative analgesia should be provided to decrease oxygen requirements.

The role of a low-dose ketamine-midazolam regimen in the management of severe painful crisis in patients with sickle cell disease.

CONTEXT: Acute pain is one of the main causes of hospital admission in sickle cell disease, with variable intensity and unpredictable onset and duration. OBJECTIVES: We studied the role of a low-dose intravenous (IV) ketamine-midazolam combination in the management of severe painful sickle cell crisis. METHODS: A retrospective analysis was performed with data from nine adult patients who were admitted to the intensive care unit with severe painful sickle cell crises not responding to high doses of IV morphine and other adjuvant analgesics. A ketamine-midazolam regimen was added to the ongoing opioids as an initial bolus of ketamine 0.25mg/kg, followed by infusion of 0.2-0.25mg/kg/h. A midazolam bolus of 1mg followed by infusion of 0.5-1mg/h was added to reduce ketamine emergence reactions. Reduction in morphine daily requirements and improvement in pain scores were the determinants of ketamine-midazolam effect. The t-tests were used for statistical analysis. RESULTS: Nine patients were assessed, with mean age of 27±11 years. Morphine requirement was significantly lower after adding the IV ketamine-midazolam regimen. The mean±SD IV morphine requirement (milligram/day) in the pre-ketamine day (D0) was 145.6±16.5, and it was 112±12.2 on Day 1 (D1) of ketamine treatment (P=0.007). The Numeric Rating Scale scores on D0 ranged from eight to ten (mean 9.1), but improved to range from five to seven (mean 5.7) on D1. There was a significant improvement in pain scores after adding ketamine-midazolam regimen (P=0.01). CONCLUSION: Low-dose ketamine-midazolam IV infusion might be effective in reducing pain and opioid requirements in patients with sickle cell disease with severe painful crisis. Further controlled studies are required to prove this effect.

A review of the use of ketamine in pain management.

Ketamine is a noncompetitive antagonist of N-methyl-d-aspartate receptor. It has been widely used in anesthesia and pain management. Ketamine has been administered via the intravenous, intramuscular, subcutaneous, oral, rectal, topical, intranasal, sublingual, epidural, and caudal routes. Ketamine improves postoperative and posttrauma pain scores and reduces opioid consumption. It has special indication for patients with opioid tolerance, acute hyperalgesia, and neuropathic pain. It also has a role in the management of chronic pain including both cancer and noncancer pain. Recreational use of ketamine is increasing as well through different routes of administration like inhalation, smoking, or intravenous injection. Long-time exposure to ketamine, especially in the abusers, may lead to serious side effects. This review is trying to define the role of ketamine in pain management.

Speechless after general anaesthesia for caesarean section.

'Speechless' patient after general anesthesia may be a real horror for the anaesthetist as well as the patient and his relatives. Whatever the cause "functional or organic" the anaesthetist will be under pressure as his patient is not able to talk. Here we report a 40 years old patient who has no history of medical problems and developed aphemia after general anaesthesia for emergency caesarean section with an uneventful intra-operative course. Clinical examinations and investigations failed to reveal any clear cause and the patient returned her ability to talk and discharged home with normal voice.

Prevention of Intra-operative Cerebral Ischemia during Carotid Endarterectomy, Loco-regional versus General Anesthesia.

Carotid endarterectomy (CEA), as a prophylactic operation is becoming more popular. It is performed in patients who are at risk of stroke from dislodged atheromatous plaque at the carotid bifurcation. The major concern during CEA is the detection of cerebral hypoperfusion or ischemia during carotid cross clamping. Some studies have shown that the introduction of loco-regional anesthesia has lowered the incidence of major complications compared with general anesthesia since ischemia detection is easier in conscious patient.

Adult Sickle Cell Disease: A Five-year Experience of Intensive Care Management in a University Hospital in Oman.

OBJECTIVES: Sickle cell disease (SCD) is an inherited disease caused by an abnormal type of haemoglobin. It is one of the most common genetic blood disorders in the Gulf area, including Oman. It may be associated with complications requiring intensive care unit (ICU) admission. This study investigated the causes of ICU admission for SCD patients. METHODS: This was a retrospective analysis of all adult patients ≥12 years old with SCD admitted to Sultan Qaboos University Hospital (SQUH) ICU between 1st January 2005 and 31st December 2009. RESULTS: A total number of 49 sickle cell patients were admitted 56 times to ICU. The reasons for admission were acute chest syndrome (69.6%), painful crises (16.1%), multi-organ failure (7.1%) and others (7.2%). The mortality for SCD patients in our ICU was 16.1%. The haemoglobin (Hb) and Hb S levels at time of ICU admission were studied as predictors of mortality and neither showed statistical significance by Student's t-test. The odds ratio, with 95% confidence intervals, was used to study other six organ supportive measures as predictors of mortality. The need for inotropic support and mechanical ventilation was a good predictor of mortality. While the need for non-invasive ventilation, haemofiltration, blood transfusions and exchange transfusions were not significant predictors of mortality. CONCLUSION: Acute chest syndrome is the main cause of ICU admission in SCD patient. Unlike other supportive measures, the use of inotropic support and/or mechanical ventilation is an indicator of high mortality rate SCD patient.

Esophageal bezoar formation due to solidification of enteral feed administered through a malpositioned nasogastric tube: case report and review of the literature.

Enteral feeding is now standard and routine practice in intensive care. The use of a nasogastric tube for enteral feeding is generally considered to be safe, but tubes with small bores can sometimes lead to aspiration or passage clogging when malpositioned in sedated patients who are on long-term mechanical ventilation. Thus, accurate confirmation of correct placement is mandatory in such patients. This is not always the case, but this faulty practice can lead to serious complications in the absence of potential bezoar-forming medicines or gastrointestinal pathology. We present here one such interesting case of a patient who developed esophageal bezoar due to a malpositioned nasogastric tube for administering a casein-containing feed. In addition, we present a review of the literature.