Malignant hyperthermia as a rare complication of local lidocaine injection: A case report

BACKGROUND

Malignant hyperthermia (MH) is a hypermetabolic disorder of skeletal muscles triggered by exposure to volatile anesthetics and depolarizing muscular relaxants. It manifests with clinical presentations such as tachycardia, muscle rigidity, hyperpyrexia, and rhabdomyolysis in genetically predisposed individuals with ryanodine receptor or calcium voltage-gated channel subunit alpha1 S mutations. Local anesthetics, such as lidocaine, are generally considered safe; however, complications can arise, albeit rarely. Lidocaine administration has been reported to induce hypermetabolic reactions resembling MH in susceptible individuals. The exact mechanism by which lidocaine might trigger MH is not fully understood. Although some mechanisms are postulated, further research is needed for a better understanding of this.

CASE SUMMARY

We present the case of MH in a 43-year-old male patient with an unknown genetic predisposition following a lidocaine injection during a dental procedure. This case serves as a reminder that while the occurrence of lidocaine-induced MH is rare, lidocaine can still trigger this life-threatening condition. Therefore, caution should be exercised when administering lidocaine to individuals who may be susceptible to MH. It is important to note that prompt intervention played a crucial role in managing the patient’s symptoms. Upon recognizing the early signs of MH, aggressive measures were initiated, including vigorous intravenous normal saline administration and lorazepam. Due to the effectiveness of these interventions, the administration of dantrolene sodium, a specific antidote for MH, was deferred.

CONCLUSION

This case highlighted the significance of vigilant monitoring and swift action in mitigating the detrimental effects of lidocaine-induced MH. Caution should be exercised when administering lidocaine to individuals who may be predisposed to MH. It is very important to be aware and vigilant of the signs and symptoms of MH as early recognition and treatment intervention are important to prevent serious complications to decrease mortality.

Anesthesia management of a patient undergoing implantation of a left ventricular assist system: A case report

BACKGROUND

Heart failure is generally regarded as a progressive and irreversible medical condition. The EVAHEART is an implantable left ventricular assist system.

CASE SUMMARY

We report the anesthesia management of a 56-year-old male patient with dilated cardiomyopathy undergoing an EVAHEART implantation. Transesophageal echocardiography is crucial to ensure the correct positioning of the device and the proper aortic valve outflow. Because the continuous blood flow device functions best under low systemic and pulmonary vascular resistance, milrinone is the preferred drug. Our patient was accompanied by pulmonary hypertension, so during the operation, nitric oxide was used to reduce pulmonary artery pressure.

CONCLUSION

The cardiac output achieved by the patient with the assistance of EVAHEART can reach 4 L/min, which of course depends on the front load, rear load, and pump speed.

Pre-formed endotracheal tube and stepwise insertion for more successful intubation with video laryngoscopy

BACKGROUND

In anesthesia practice, orotracheal intubation remains the primary concern of the anesthesiologist. The introduction of video laryngoscopy (VL) has increased the success rate of orotracheal intubation; however, conflicting results have been reported regarding the usefulness of the current technique with VL in clinical practice.

AIM

To describe a modification to improve intubation with VL, followed by evaluation of the practice in vivo.

METHODS

First, a mannequin trial was conducted with operators having different experience and background. Then, a retrospective analysis was performed for an > 1-year period with patients who underwent general anesthesia with orotracheal intubation. The endotracheal tube used had been pre-formed with two curves. Stepwise intubation had been performed with direct eye vision, followed by screen assistance and rotation of the tube as needed to direct it toward the glottis. In the mannequin trial, the outcome measures were quantification of torque (force with angular acceleration during levering), need for external maneuvers, and time to intubate. In the clinical experience, orotracheal intubation used VL (pre-formed tube) or direct laryngoscopy (DL) at the anesthetist’s discretion and throat discomfort was reported by the patient.

RESULTS

In the mannequin trials using VL, there was less torque with the pre-formed tube than with a regular tube (8% and 65%, respectively). The first-pass rate was higher with the pre-formed tube (95%) than with a regular tube (81%). However, the time to intubate was longer with the pre-formed tube than with a regular tube (22 s and 12 s, respectively). In clinical practice, 562 patients underwent surgery under general anesthesia with orotracheal intubation using either VL (n = 244) or DL (n = 318) at the discretion of the attending anesthetist. VL was specifically planned in 62 of the patients, due to anticipated difficulty. Second attempts by readjustment of the curve of the tube were significantly fewer with VL than with DL (10% vs 18%). Throat discomfort was reported by fewer patients who underwent VL than those who underwent DL (6% vs 24%).

CONCLUSION

Pre-formed endotracheal tube with stepwise insertion produces less torque, fewer external maneuvers and higher first-pass success rate during VL intubation. Further, prospective studies are warranted.

Intraoperative management of liver transplant in a patient with an undiagnosed ventricular septal defect: A case report

BACKGROUND

The intraoperative management of patients undergoing orthotopic liver transplantation (OLT) frequently encounters hemodynamic instability after reperfusion of the new liver graft. The resulting post-reperfusion syndrome is characterized by an increase in pulmonary vascular resistance and decrease in systemic vascular resistance. In the presence of a left to right intracardiac shunt, this hemodynamic perturbance can lead to shunt reversal followed by hypoxemia and embolization of air and debris into the systemic circulatory system.

CASE SUMMARY

A 43 years-old male with end-stage liver disease due to primary sclerosing cholangitis complicated by portal hypertension and hepatocellular carcinoma presented for an OLT. A bedside transthoracic echocardiography (TTE) was performed immediately before the procedure and unexpectedly identified a ventricular septal defect (VSD). The patient and the surgical team agreed to proceed with the surgery as it was a time critical donation after circulatory organ death. We developed an intraoperative plan to optimize pulmonary and systemic pressures using vasoactive support, optimized mechanical ventilation, and used transesophageal echocardiography (TEE) for intraoperative monitoring. During reperfusion, considerable turbulent flows with air were noted in the right ventricle, but no air was visualized in the left ventricle. Color flow Doppler showed no reversal flow in the VSD. At the end of the procedure, the patient was extubated in the operating room without complication and was transferred to the transplant unit for recovery.

CONCLUSION

Our case highlights the importance of echocardiography in the perioperative assessment of patients undergoing liver transplantation. The TTE findings obtained immediately before the procedure and the real-time use of intraoperative TEE to modify our management during the critical phases of the transplant resulted in continuity of care and a good surgical outcome for this patient.

Low dose corticosteroids in COVID-19 with refractory shock: We are not sure?

Low dose corticosteroids to adult patients with coronavirus disease 2019 (COVID-19) and refractory shock was given some evidence, the evidence was of low quality given particularly for shock-reversal. Evidence. However bacterial sepsis may not provide a similar evidence like in a viral related one. We think that suggesting steroids for COVID-19 may not be adequate in the current time and future data analysis should be directed to find possible evidence in a matched population

Cement-related embolism after lumbar vertebroplasty: A case report

BACKGROUND

Cement-related embolism is a rare but potentially fatal complication in spinal surgery. Cardiac echocardiography can provide valuable information for the early identification.

CASE SUMMARY

A 66-year-old woman who underwent lumbar vertebroplasty and internal fixation under general anesthesia experienced an episode of supraventricular tachycardia and ventricular tachycardia at the end of surgery. Point-of-care echocardiogram revealed a foreign body in the right heart. After conservative treatment in the intensive care unit, her family decided on comfort care and she expired.

CONCLUSION

Transthoracic echocardiography may provide early valuable information in patients undergoing vertebroplasty, and mild-moderate pericardial effusion may be a significant sign of a poor outcome.

Unusual bronchoscopic value in percutaneous dilatational tracheostomy: A case report

BACKGROUND

The usage of bronchoscopy during percutaneous dilatational tracheostomy remains under debate. The proponents of bronchoscopy advocating safety of the procedure, whereas the critics raising the concerns about the cost, possible delay in the procedure, and waiting for the device.

CASE SUMMARY

We are highlighting a case of percutaneous dilatational tracheostomy where bronchoscopy aided in diagnosing a rare situation of wire entrapment within the endotracheal tube, treated by withdrawing the wire from the endotracheal tube with good outcome.

CONCLUSION

The bronchoscopy guided approach permitted early diagnosis and helped to end the procedure without complication or possible major surgery in a case of accidental wire puncture of the endotracheal tube.

Healthcare delivery cost and anesthesiologists: Time to have a greater role and responsibility

With the advancement of technology and health sciences, health care delivery costs are steadily increasing. This affects both households and governments. Unfortunately, the present truth is that health has become an essential but unaffordable commodity. This is very concerning. Quality, up-to-date, cost-effective health care delivery is one of the prime objectives, and focuses on administration and health care authority. As the per capita spent on health from public/government funds is very poor in developing countries, the responsibility of cost-effective health care delivery falls primarily on the shoulder of the treating physicians. Anesthesiologists are becoming an indispensable part of health care delivery, having a diverse role in the emergency, critical care, pain, and perioperative care of patients. As the population ages, the need for surgical care is also increasing. Therefore, the anesthesiologist can also play a more significant role in delivering cost-effective health care, and minimize the cost without affecting the quality. This brief narrative review analyzes the current practice of anesthesiologists in two prime areas in the context of cost-savings: Preoperative investigation and low/minimal flow anesthesia.

Enhanced recovery after surgery pathway: The use of fascia iliaca blocks causes delayed ambulation after total hip arthroplasty

BACKGROUND

Fascia iliaca compartment blocks (FIBs) have been used to provide postoperative analgesia after total hip arthroplasty (THA). However, evidence of their efficacy remains limited. While pain control appears to be satisfactory, quadriceps weakness may be an untoward consequence of the block. Prior studies have shown femoral nerve blocks and fascia iliaca blocks as being superior for pain control and ambulation following THA when compared to standard therapy of parenteral pain control. However, most studies allowed patients to ambulate on post-operative day (POD) 2-3, whereas new guidelines suggest ambulation on POD 0 is beneficial.

AIM

To determine the effect of FIB after THA in patients participating in an enhanced recovery after surgery (ERAS) program.

METHODS

We conducted a retrospective analysis of patients undergoing THA with or without FICBs and their ability to ambulate on POD 0 in accordance with ERAS protocol. Perioperative data was collected on 39 patients who underwent THA. Demographic data, anesthesia data, and ambulatory outcomes were compared.

RESULTS

Twenty patients had FIBs placed at the conclusion of the procedure, while 19 did not receive a block. Of the 20 patients with FIB, only 1 patient was able to ambulate. Of the 19 patients without FIB blocks, 17 were able to ambulate. All patients worked with physical therapy 2 h after arriving in the post-anesthesia care unit on POD 0.

CONCLUSION

Our data suggests an association between FIB and delayed ambulation in the immediate post-operative period.

Post-operative urinary retention: Review of literature

Postoperative urinary retention (POUR) is one of the postoperative complications which is often underestimated and often gets missed and causes lot of discomfort to the patient. POUR is essentially the inability to void despite a full bladder in the postoperative period. The reported incidence varies for the wide range of 5%-70%. Multiple factors and etiology have been reported for occurrence of POUR and these depend on the type of anaesthesia, type and duration of surgery, underlying comorbidities, and drugs used in perioperative period. Untreated POUR can lead to significant morbidities such as prolongation of the hospital stay, urinary tract infection, detrusor muscle dysfunction, delirium, cardiac arrhythmias etc. This has led to an increasing focus on early detection of POUR. This review of literature aims at understanding the normal physiology of micturition, POUR and its predisposing factors, complications, diagnosis and management with special emphasis on the role of ultrasound in POUR.

Current challenges in diagnosis of lumbar radiculopathy

Lumbar radiculopathy (LR) is a term used to describe a pain syndrome caused by compression or irritation of nerve roots in the lower back. The surgery cost for LR increased by 23% annually during 1992-2003 in the developed country. Although it is one of most common complaints in clinical practice, the diagnosis for LR is still very challenging. Here we discuss the current tools of LR diagnosis and highlight the needs to develop new diagnosis tools for LR.

Targeting tumor necrosis factor in the brain relieves neuropathic pain

Neuropathic pain is a chronic syndrome caused by direct damage to or disease of the somatosensory nervous system. The lack of safe, adequate and sustained pain relief offered by present analgesic treatments is most alarming. While many treatment options are available to manage chronic pain, such as antidepressants, non-steroidal anti-inflammatory agents, opioids, and anticonvulsants, chronic neuropathic pain remains largely unmanaged. Compounding the dilemma of ineffective chronic pain treatments is the need to provide relief from suffering and yet not contribute to the scourge of drug abuse. A recent epidemic of addiction and accidental drug prescription overdoses parallel the increased use of opioid treatment, even though opioids are rarely an effective treatment of relieving chronic pain. To make matters worse, opioids may contribute to exacerbating pain, and side-effects such as cognitive impairment, nausea, constipation, development of tolerance, as well as their potential for addiction and overdose deaths exist. Clearly, there is an urgent need for alternative, non-opiate treatment of chronic pain. Innovative discoveries of pertinent brain mechanisms and functions are key to developing effective, safe treatments. Pioneering work has revealed the essential effects of the pleiotropic mediator tumor necrosis factor (TNF) on brain functioning. These studies establish that TNF inhibits norepinephrine release from hippocampal neurons, and show that excess TNF production within the hippocampus occurs during neuropathic pain, which mobilizes additional mechanisms that further inhibit norepinephrine release. Significantly, it has been verified that elevated levels of TNF in the brain are actually required for neuropathic pain development. Since TNF decreases norepinephrine release in the brain, enhanced TNF levels would prevent engagement of the norepinephrine descending inhibitory neuronal pain pathways. Increased levels of TNF in the brain are therefore critical to the development of neuropathic pain. Therefore, strategies that decrease this enhanced TNF expression in the brain will have superior analgesic efficacy. We propose this novel approach of targeting the pathologically high levels of brain TNF as an effective strategy in the treatment of the devastating syndrome of chronic pain.

Change in management of predicted difficult airways following introduction of video laryngoscopes

AIM

To determine if video laryngoscopy (VL) has significantly impacted management of difficult airways by decreasing the rate of awake fiberoptic intubation (FOI).

METHODS

Anesthetic records of 3723 patients who underwent general anesthesia at Rush University Medical Center were reviewed over a 2-mo period prior to the introduction of VLs in 2009 (“pre-VL” group) and over the same 2-mo period after the introduction of VLs in 2012 (“post-VL” group). Patient records with predicted difficult airways based on pre-operative airway examination were analyzed. The primary outcome was rate of awake FOI.

RESULTS

To control for possible factors that may influence the FOI rate, a logistic regression was performed with these factors included as covariates. The rate of awake FOI was 13.1% in pre-VL group compared to 9.0% in post-VL group. Although this decrease was not statistically significant individually (P = 0.1768), it showed a trend toward significance when covariates were accounted for (P = 0.0910). Several factors predicting a higher likelihood of awake FOI were found to be statistically significant: Morbid obesity (larger BMI P = 0.0154, OR = 1.5 per 10 point BMI increase), male gender (P = 0.0026, OR = 3.0) and a higher el-Ganzouri airway score (P = 0.0007, OR = 1.5). Although VLs were seen to be used to intubate 51% of predicted difficult airways, the rate of awake FOI has not significantly changed.

CONCLUSION

Although VL may continue to grow in popularity, the most difficult airways are still managed using awake FOI.

Hypnosis for burn-related pain: Case studies and a review of the literature

Burn injuries create severe pain and psychological distress that are highly variable between patients. Distinct types of pain during various stages of injury and recovery make treatment complex. Standard pharmacological treatment of pain can have adverse effects and is not effective in treating anxiety and other psychological issues. Researchers have proposed that integrating clinical hypnosis as a complementary therapy can be highly beneficial to burn patients and their healthcare providers. The existing literature is reviewed and specific hypnosis techniques are discussed. Evidence exists indicating that adjunctive hypnosis is effective at reducing pain and procedural anxiety. Implementing a multidisciplinary burn care team that includes clinical hypnosis and focuses on the patients’ psychological health as well as pain reduction is likely to result in faster healing and reduced distress for patients and caregivers alike.

Massive transfusion: An update for the anesthesiologist

Exsanguination from trauma, gastrointestinal bleeding, and obstetric hemorrhage remains a major source of mortality across the planet. Continued research into resuscitation strategies and evolving technology and blood product storage has allowed for patient to undergo very large volume transfusions, even to the point of replacing a patient’s blood volume several times over. As massive transfusions have become more common, more studies have been performed delineating the exact patient population that would benefit, start- and stop-points of transfusions, complications and avoidance of the same. We discuss these points and provide information and strategies for massive transfusion.

Awareness during anesthesia: Current status in Japan

Intraoperative awareness is the explicit recall of sensory perceptions during general anesthesia. I presume the epidemiology and characteristics of intraoperative awareness from these surveys in Japan. A questionnaire survey was conducted via the Internet. The first survey was conducted in 2008. Our survey showed 17% of anesthesiologists experienced definite or possible awareness. The second survey was conducted to evaluate the first survey in detail in 2008. A total of 172 anesthesiologists answered. The total number of reported anesthetic cases was 85156. Twenty-four cases of definite or possible awareness were reported by 21 anesthesiologists. The most surprising finding was total intravenous anesthesia (TIVA) was used in 21 of the 24 cases. The third survey was conducted in 2011 as a continuous survey. Six cases of definite or possible awareness were reported by six anesthesiologists (7%). Two cases were maintained by TIVA, and 2 cases were sevoflurane. The survey showed 76% anesthesiologists routinely use bispectral index (BIS) for TIVA, but for sevoflurane only 27% anesthesiologists routinely use BIS. The incidence of intraoperative awareness decreased in the third survey. The continuous survey revealed the current status of daily anesthesia and the results might be used to prevent the awareness during general anesthesia.

Anaesthesia for patients with arrhythmogenic right ventricular dysplasia

Arrhythmogenic right ventricular dysplasia (ARVD) is an inherited heart muscle disease. Myocyte apoptosis and fibro-fatty scar tissue predisposes patients to malignant ventricular arrhythmias. Patients may present to variety of surgical procedures with diagnosed ARVD. Surgical insult, catecholamine surge and physiological disturbance can be hazardous on the vulnerable myocardium and may result in life-threatening ventricular tachycardia or sudden cardiac death in the perioperative period. Anaesthetists have particular role in perioperative management of this patient population, meticulous perioperative planning, close haemodynamic monitoring and maintenance of physiological stability throughout helps to avoid devastating perioperative loss.

Anesthetic considerations for liver diseases unique to pregnancy

Liver diseases that are most unique to pregnancy consist of hyperemesis gravidarum, acute fatty liver of pregnancy, intrahepatic cholestasis of pregnancy, and hemolysis, elevated liver enzymes and low platelets syndrome. In this review, risk factors, etiology, symptoms, diagnosis, prognosis and treatment of each entity followed by principles of anesthetic management based on the case reports or retrospective records will be addressed.

Intrathecal morphine vs femoral nerve block for postoperative-analgesia after total knee arthroplasty: A two-year retrospective analysis

AIM

To compare the efficacy of intrathecal morphine and single shot femoral nerve block for patients undergoing primary total knee arthroplasty.

METHODS

Data was extracted from electronic medical records and case-paper record files of patients who underwent unilateral primary total knee arthroplasty under spinal anesthesia using bupivacaine 12.5 mg with intrathecal morphine (ITM) 0.2 mg and under general anesthesia (GA) with single shot femoral nerve block (FNB) using 20 mL 0.5% bupivacaine at our hospital in 2013 and 2014. All patients had received peri-articular infiltration as per the hospital protocol. Data for gender, age, weight, American Society of Anesthesiologists status, total surgical time, postoperative pain score using visual analogue scale (VAS) from 1 to 10 at 6 h, 12 h and 24 h postoperatively, 24 h opioid consumption, use of oral multimodal analgesia, postoperative high dependency unit (HDU) admission and the time to discharge from the hospital was collected. The data was analyzed using Mann-Whitney U test for continuous variables and Fischer’s exact-t-test for categorical variables.

RESULTS

Twenty-two patients in ITM group and 32 patients in FNB group were analyzed. Median pain scores using VAS in ITM group were significantly lower at 6 h (0.0 vs 2.0, P < 0.001), 12 h (0.0 vs 2.0, P < 0.001) and 24 h (0.0 vs 2.0, P < 0.001) postoperatively. Also, postoperative morphine consumption in ITM group was significantly lower (P < 0.001). However, median of non-steroid anti-inflammatory drug unit requirement in 24 h postoperatively was statistically significant higher in ITM compared to FNB group (2.0 vs 1.0, P = 0.025). The difference in postoperative paracetamol consumption in 24 h was not statistically significant (P = 0.147). There was no significant difference in the postoperative HDU admission or time to discharge from the hospital. No respiratory depression in either group was noticed.

CONCLUSION

The ITM group patients had much lower pain scores and morphine requirement in the first 24 hour postoperatively compared to FNB group.

Interventional pain therapy in cervical post-surgery syndrome

Fifteen percent to forty percent of patients present with persistent disabling neck pain or radicular pain after cervical spine surgery. Persistent pain after cervical surgery is called cervical post-surgery syndrome (CPSS). This review investigates the literature about interventional pain therapy for these patients. Because different interventions with different anatomical targets exist, it is important to find the possible pain source. There has to be a distinction between radicular symptoms (radicular pain or radiculopathy) or axial pain (neck pain) and between persistent pain and a new onset of pain after surgery. In the case of radicular symptoms, inadequate decompression or nerve root adherence because of perineural scarring are possible pain causes. Multiple structures in the cervical spine are able to cause neck pain. Hereby, the type of surgery and also the number of segments treated is relevant. After fusion surgery, the so-called adjacent level syndrome is a possible pain source. After arthroplasty, the load of the facet joints in the index segment increases and can cause pain. Further, degenerative alterations progress. In general, two fundamentally different therapeutic approaches for interventional pain therapy for the cervical spine exist: Treatment of facet joint pain with radiofrequency denervation or facet nerve blocks, and epidural injections either via a transforaminal or via an interlaminar approach. The literature about interventions in CPSS is limited to single studies with a small number of patients. However, some evidence exists for these procedures. Interventional pain therapies are eligible as a target-specific therapy option. However, the risk of theses procedures (especially transforaminal epidural injections) must be weighed against the benefit.

Insight into orthodontic appliance induced pain: Mechanism, duration and management

Most of the orthodontic patients experience pain during treatment and this significantly influences their attitudes and the approach towards treatment. A number of factors that influence pain response include age, gender, personal pain threshold, mood and stress level of the person, cultural differences and types of orthodontic treatment. Pain is a often overlooked subject by orthodontists, it is nevertheless important to understand the source and mechanism of the pain that occurs during treatment, as well as the methods for managing and controlling this pain. This review attempts to overview the mechanism, duration and current management strategies of orthodontic treatment.

Transcranial magnetic stimulation as a new tool to control pain perception

Treatment for chronic pain is frequently unsuccessful or characterized by side-effects. The high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been suggested in the management of refractory chronic pain. Various studies have shown that HF-rTMS sessions of long-duration applied at primary motor cortex induce pain relief through mechanisms of plastic changes. Efficacy of rTMS mostly depends on stimulation parameters, but this aspect requires better characterization. A rationale to target other cortical areas exists. Current data are promising, but a careful analysis of stimulation settings and maintenance treatment design are need.

Dexmedetomidine in gastrointestinal endoscopic procedures

Gastrointestinal endoscopy is the gold standard in the examination and the treatment of the diseases of gastrointestinal system, but the disadvantage of being painful process. At this point the sedative and analgesic agents may be important. Dexmedetomidine is a new sedoanalgesic agent which is alternative to benzodiazepines and opioids. It has analgesia, amnesia, sedative and anxiolytic properties. The use of dexmedetomidine as the sole anesthetic agent and as the adjuvant analgesic agent has been published but has not been approved because of the inconsistency of efficacy and safety. The author has been collected the published papers in the literature. This article is aimed to describe the use of dexmedetomidine in various gastrointestinal endoscopic procedures.

Improvised technique for measuring tracheal tube cuff pressure

We agree with the editorial published by Feng et al concerning the insufficient routine monitoring of tracheal tube cuff pressure (TTCP) by anesthesiologists, and propose an improvised technique that can facilitate and promote such routine monitoring by intensive care staff who attend to patients receiving mechanical ventilation. Insufficient monitoring of tracheal cuff pressure has also been documented for intensive care unit nurses. Measurements of cuff pressure are beneficial when used in management of air leakage around an endotracheal tube, and can be easily obtained with the aid of a personalized and simple technique performed using materials that are readily available in all hospitals. Other investigators have previously demonstrated the usefulness of employing an improvised technique. We considered that possible disadvantages are similar to those encountered when using standardized equipment. With our improvised technique, we seek to promote among the nursing staff the determination of the TTCP in intubated patients to reduce the risk of related medical complications.

Zygapophysial joint pain in selected patients

The zygapophysial joints (z-joints), together with the intervertebral disc, form a functional spine unit. The joints are typical synovial joints with an innervation from two medial branches of the dorsal rami. The joint capsule and the surrounding structures have an extensive nerve supply. The stretching of the capsule and loads being transmitted through the joint can cause pain. The importance of the z-joints as a pain generator is often underestimated because the prevalence of z-joint pain (10%-80%) is difficult to specify. Z-joint pain is a somatic referred pain. Morning stiffness and pain when moving from a sitting to a standing position are typical. No historic or physical examination variables exist to identify z-joint pain. Also, radiologic findings do not have a diagnostic value for pain from z-joints. The method with the best acceptance for diagnosing z-joint pain is controlled medial branch blocks (MBBs). They are the most validated of all spinal interventions, although false-positive and false-negative results exist and the degree of pain relief after MBBs remains contentious. The prevalence of z-joint pain increases with age, and it often comes along with other pain sources. Degenerative changes are commonly found. Z-joints are often affected by osteoarthritis and inflammatory processes. Often additional factors including synovial cysts, spondylolisthesis, spinal canal stenosis, and injuries are present. The only truly validated treatment is medial branch neurotomy. The available technique vindicates the use of radiofrequency neurotomy provided that the correct technique is used and patients are selected rigorously using controlled blocks.

Swine model in transplant research: Review of anaesthesia and perioperative management

Pigs are one of most common animal species to be used in biomedical models due to their many anatomical visceral similarities with humans, particularly with regards to transplantation. Despite this use, in many of the researches in which pigs are selected for transplantation, the anaesthesia used is an adaptation of human anaesthesia and presents some limitations such as a reduced analgesia a limited control in perioperative period. In this review we show some of the most important conditions in the preanaesthetic management and of swine as well as we review of anaesthetic protocols for the most common types of swine model of transplantation.

Sugammadex: Role in current anaesthetic practice and its safety benefits for patients

Sugammadex has revolutionized anaesthetic management of reversal of neuromuscular block (NMB) by way of its unique mechanism of action encapsulating the amino steroid neuromuscular blocking drugs rocuronium and vecuronium. The cholinesterase inhibitors have significant pharmacological and clinical limitations whereas sugammadex allows predictable, safe and rapid reversal from any depth of blockade. The financial cost of sugammadex is significant. Many hospitals in the United Kingdom use clinical guidelines to direct best use of sugammadex in their institutions. Auditing the use of sugammadex provides useful information on which patients are benefiting from sugammadex. The clinical benefits of sugammadex are well understood. No patient should now be subjected to the danger of post-operative residual curarization. Versatility in the ability to reverse NMB has brought opportunities to the anaesthetist in the management of rapid sequence induction using high dose rocuronium with the knowledge that safe reversal of NMB is now possible in the unlikely event of a “can’t intubate can’t ventilate” situation. Do we still need suxamethonium to be available? The nature of surgery continues to evolve with ever-increasing enthusiasm for minimally invasive laparoscopic techniques. There is evidence to support using a deeper level of NMB to improve the working space and operating conditions in laparoscopic surgery. It is now possible to maintain a deep level of NMB right up until the end of surgery with no concerns about the ability to effect safe reversal of NMB. Vigilance about the possibility of allergic sensitivity to sugammadex needs to be maintained. The increased usage of rocuronium has the potential for rocuronium-induced anaphylaxis. Conversely, there is a potential role for sugammadex in the treatment of rocuronium anaphylaxis. Clinicians who have used sugammadex are struck with the quality of recovery seen in their patients. It is important that the economic implications of the use of sugammadex are fully understood. This article considers the current role of sugammadex in clinical practice outside of routine reversal of NMB and discusses how the addition of sugammadex to the anaesthetic armamentarium brings safety benefits for patients.

Update in perioperative anesthetic management of pheochromocytoma

Pheochromocytoma is a tumor that originates from either chromaffincells in adrenal medulla or in other paraganglia tissues of the sympathetic nervous system. The perioperative management is quite challenging especially in view of hemodynamic fluctuations. Pheochromocytoma is challenging in view of the impact of excessive and depleted catecholamines in the perioperative period. It requires a through preoperative evaluation and optimization with meticulous intraoperative management. The postoperative period requires vigilance to prevent any untoward complication. In this review we review these concepts based on recent evidence for an optimal outcome.

Perioperative hypothermia: Causes, consequences and treatment

Perioperative hypothermia, core temperature below 36.0 °C, transpires due to disruption of thermoregulation by anesthesia coupled with cold exposure to procedural surroundings and cleansing agents. Although most publications have focused on thermoregulation disruption with general anesthesia, neuraxial anesthesia may also cause significant hypothermia. The clinical consequences of perioperative hypothermia are multiple and include patient discomfort, shivering, platelet dysfunction, coagulopathy, and increased vasoconstriction associated with a higher risk of wound infection. Furthermore, postoperative cardiac events occur at a higher rate; although it is unclear whether this is due to increased oxygen consumption or norepinephrine levels. Hypothermia may also affect pharmacokinetics and prolong postoperative recovery times and hospital length of stay. In order to combat perioperative hypothermia, many prevention strategies have been examined. Active and passive cutaneous warming are likely the most common and aim to both warm and prevent heat loss; many consider active warming a standard of care for surgeries over one hour. Intravenous nutrients have also been examined to boost metabolic heat production. Additionally, pharmacologic agents that induce vasoconstriction have been studied with the goal of minimizing heat loss. Despite these multiple strategies for prevention and treatment, hypothermia continues to be a problem and a common consequence of the perioperative period. This literature review presents the most recent evidence on the disruption of temperature regulation by anesthesia and perioperative environment, the consequences of hypothermia, and the methods for hypothermia prevention and treatment.

Pharmacokinetics and pharmacodynamics of lignocaine: A review

Lignocaine is an essential drug on World Health Organisation essential drug list, considered efficacious, safe and cost-effective for any health-care system. Despite its ubiquitous use in medicine and surgery, there are few detailed reviews of its pharmacokinetics and pharmacodynamics. Being an amide-type local anesthetic and Class 1b antiarrhythmic, lignocaine is most frequently used clinically for its anesthetic and antiarrhythmic benefits. However, lignocaine has important antinociceptive, immuno-modulating, and anti-inflammatory properties. Information pertaining to the pharmacokinetics and pharmacodynamics of lignocaine was examined by performing a literature search of PubMed, Embase and MEDLINE (via Ovid), pharmacology textbooks and online sources. We present a focused synopsis of lignocaine’s pharmacological composition, indications for use and mechanisms of action, focusing on its anti-inflammatory, immuno-modulating and analgesia effects. In addition we review the dosing regimes and infusion kinetics of lignocaine in the clinical setting. Finally, we review the evidence for ligocaine’s modulation of the inflammatory response during major surgery and its specific effects on cancer recurrence. These indirect effects of local anesthetics in tumor development may stem from the reduction of neuroendocrine responses to the stress response elicited by major surgery and tissue damage, enhanced preservation of immune-competence, in addition to opioid-sparing effects of modulating tumor growth.

Anesthesia for bronchoscopic amniotic membrane grafting to treat non-healing bronchial dehiscence

Airway complications after lung transplantation remain a significant cause of morbidity and mortality. Many of these occur at the anastomotic sites, which are susceptible due to poor collateral circulation. Of the possible complications, bronchial dehiscence is particularly formidable. These cases have been successfully treated bronchoscopically with metallic stents, which likely promote healing through granulation tissue formation. However, limited options exist in cases where the dehiscence fails to heal following stent placement. Here, we present the case report of a 65-year-old male who developed bronchial dehiscence status post bilateral lung transplantation for idiopathic pulmonary fibrosis that failed to heal with simple stent placement. Eventually, the patient underwent amniotic membrane grafting with stenting as a novel therapy for non-healing bronchial dehiscence, for which we describe the anesthetic management. His anesthetic plan included inhalational induction with sevoflurane, propofol infusion for total intravenous anesthesia, rocuronium for muscle relaxation, and closed-circuit assisted ventilation. His existing tracheostomy was used as the airway for oxygenation and induction. In summary, our anesthetic plan for the lung transplant patient was effective; future amniotic membrane grafting for bronchial dehiscence through bronchoscopy may follow a similar technique. Ultimately, the choice of anesthesia in this patient population requires judicious consideration of the requirements of the procedure as well as the pathophysiology of the transplanted lung.

Critical importance of tracheal tube cuff pressure management

The ideal range for tracheal tube cuff pressures is usually taken to be between 20 to 30 cm H₂O. This is easily measured with a cuff pressure manometer and should be measured in each instance. The importance of tracheal tube cuff pressures is highlighted by the spectrum of airway complications that can occur with incorrect cuff pressures. High cuff pressures can result in complications ranging from sore throat and hoarseness to tracheal stenosis, necrosis, and even rupture. In such cases, the postulated causative factor is diminished blood flow to tracheal mucosa due to excessive cuff pressure on the tracheal wall. This hypothesized ischemic injury then produces healing fibrosis months or even years later. On the other hand, cuff pressures that are too low place the patient at risk for aspiration of gastric contents and consequently, aspiration pneumonitis and pneumonia. This is why the authors recommend that cuff pressures be measured following all intubations.

Translating the expression of pain in the face of uncertainty: The importance of human pain experiments for applied and clinical science

This brief commentary attempts to provide a concise synthesis of social psychology experiments that inform an interpretation of clinical pain. From a social perspective the expression of pain is a complex phenomenon that is greater than the patient’s physiology. Numerous experiments show that pain is modulated by social and contextual factors. These experiments point to the role of the listener as a social agent that can modulate the patient’s expression. Within the clinical setting the patient’s pain experience can be understood as the uncertainty of physical damage and their expression as an attempt to reduce that uncertainty. How successfully this occurs is in part dependent on the empathetic reception of the provider. Chronic pain is a state that is challenging to effectively model in humans but may persist in patients due to an inability to receive effective empathetic reception at the critical time of need (at or near onset). Rather than focusing on pain’s alleviation future avenues of pain interventions may do well by turning attention to the most effective ways to impart a message that the patient will be “okay” in a genuinely empathetic manner.

Transthoracic echocardiography assists appropriate pulmonary artery catheter placement: An observational study

AIM: To investigate the utility of transthoracic echocardiography in confirming appropriate pulmonary artery catheter (PAC) placement.

METHODS: Three commonly used transthoracic echocardiography (TTE) views were used to confirm PAC position in 103 patients undergoing elective cardiac surgery - the parasternal short axis right ventricular inflow-outflow view; the subcostal short axis right ventricular inflow-outflow view; and the parasternal short axis ascending aortic view. All PACs were inserted by the managing anesthesiologist under pressure waveform guidance alone, who was blinded to all sonographic information. A sonographer blinded to all pressure waveform information confirmed visualisation of an “empty” PA before PAC insertion, and visualisation of the PAC balloon in the main PA (MPA) or right PA (RPA) after attempts at placement were complete. Agreement, sensitivity and specificity of TTE in confirming appropriate PAC placement was compared against pressure waveform guidance as the “gold standard”. The successful view used was compared against patients’ anthropomorphic indices, presence of lung hyperinflation, and insertion of PAC during positive pressure ventilation. Agreement between TTE and pressure waveform guidance was analysed using Cohen’s Kappa statistic. The relative proportion of total RPA seen by subcostal vs parasternal TTE views was also compared with a further 20 patients’ computed tomography (CT) pulmonary angiograms (CTPA), to determine efficacy in detection of distal RPA PAC placement.

RESULTS: Appropriate positioning of the PAC balloon, and its to-and-fro movement consistent with a non-wedged state, within the MPA or RPA was confirmed by TTE in 98 of the 103 patients [sensitivity 95% (95%CI: 89%-98%)], and absence of the PAC balloon before insertion correctly established in 100 patients [specificity 97% (92%-99%)]. This was in very good agreement with pressure waveform guidance [Cohen’s Kappa 0.92, (0.87-0.98)]. The subcostal view was the best view to visualise the PAC tip when it was placed in the right pulmonary artery (OR 70, P < 0.0001), was more successful in patients with COAD (OR 9.5, P = 0.001), and visualized 61% (vs 44% by parasternal views, P < 0.001) of mean RPA lengths compared with CTPA; however the parasternal views were more successful in patients with higher body mass indexs (OR 0.78 for success with subcostal views, P < 0.001). There was a trend towards insertion during intermittent positive pressure ventilation favoring visualisation by subcostal views (OR 3.9, P = 0.08). The subcostal view visualized a greater length of the RPA than parasternal views (3.9 cm vs 2.9 cm, P < 0.0001). PACs were more often placed in the MPA than RPA (80 vs 18 patients). Three patient’s pulmonary arteries were not visible by any TTE view; in a further 2 patients, despite pre-insertion visualisation of their pulmonary arteries, the PAC balloon was not visible by any view with TTE where correct placement by pressure waveform was unequivocal.

CONCLUSION: TTE can assist appropriate PAC placement by visualization of an unwedged PAC balloon in the PA.

Bradycardia and hypotension during pediatric scoliosis surgery-hypovolemia or spinal shock?

We present the case of a 13-year-old boy undergoing scoliosis repair utilizing skull-femoral traction who developed sudden, sustained bradycardia and hypotension during scoliosis repair, associated with loss of somatosensory evoked potentials and motor evoked potentials to all four limbs. A diagnosis of spinal shock and hypovolemia was made after ruling out primary cardiac causes, sepsis, anaphylaxis and intra-spinal pedicle screw placement. Acute complications of surgical scoliosis repair are reviewed along with anatomy of the sympathetic nervous system. In this case spinal shock may have been due to hypovolemia as well as spinal cord manipulation during T12 vertebral column resection that was needed to effect scoliosis correction. Treatment included volume expansion and inotropic support. Anesthesiologists caring for these patients should be mindful of the possibility of spinal shock during correction of severe scoliosis, particularly when vertebral column resection is undertaken.

Anesthesia and acupuncture

Using acupuncture instead of anesthetics to induce analgesia was performed in China many years ago in surgical anesthetization. Although many medical units in China’s cities and rural areas are applying these techniques in operations, it should be pointed out that acupuncture anesthesia is still in the process of development and is of next to no practical and even less scientific value in the western world. However, acupuncture-assisted anesthesia can be useful also in countries other than China.

Human factors in anaesthetic crisis

This paper discusses some of the key aspects of human factors in anaesthesia for the improvement of patient safety. Medical errors have emerged as a serious issue in healthcare delivery. There has been new interest in human factors as a means of reducing these errors. Human factors are important contributors to critical incidents and crises in anaesthesia. It has been shown that the prevalence of human factors in anaesthesia can be as high as 83%. Cognitive thinking process and biases involved are important in understanding human factors. Errors of cognition linked with human factors lead to anaesthetic errors and crisis. Multiple errors in the cognitive thinking process, known as “Cognitive dispositions to respond” have been identified leading to errors. These errors classified into latent or active can be easily identified in the clinical vignettes of serious medical errors. Application of the knowledge on human factors and use of cognitive de-biasing strategies can avoid human errors. These strategies could involve use of checklists, strategies to cope with stress and fatigue and the use of standard operating procedures. A safety culture and health care model designed to promote patient safety can compliment this further. Incorporation of these strategies strengthens the defence layers against the “Swiss Cheese” models, which exist in the health care industry.

Intrathecal morphine for postoperative analgesia: Current trends

The practice of anesthesiology has always been governed by evidence-based medicine. The quick turnover rate of patients in the operating room and patient safety and satisfaction, have also further changed the way we practice anesthesia. The use of intrathecal (IT) opiates as an effective form of postoperative pain relief has been established for many years. Morphine was the first opioid used by IT route. In clinical practice, morphine is regarded as the gold standard, or benchmark, of analgesics used to relieve intense pain. Perhaps for this reason, IT morphine has been used for over 100 years for pain relief. IT morphine is one of the easiest, cost-effective and reliable techniques for postoperative analgesia and technical failures are rare. And yet there is no consensus amongst anesthesiologists regarding the dose of IT morphine. Like all other methods of pain relief, IT morphine also has some side effects and some of them are serious though not very common. This review article looks into some of the key aspects of the use of IT morphine for post-operative analgesia and various doses for different procedures are discussed. This article also describes the side effects of IT morphine and how to treat and prevent them.

Phantom limb pain: A review of evidence-based treatment options

Phantom limb pain (PLP) is not uncommon after amputation. PLP is described as a painful sensation perceived in the missing limb. Despite of its complicated pathophysiology, high prevalence of PLP has been associated with poor health-related quality of life, low daily activity and short walking distances. A prompt and effective management of PLP is essential in caring for the amputee population. Current treatments including physical therapy, psychotherapy, medications, and interventions have been used with limited success. In this review, we provided an updated and evidence-based review of treatment options for PLP.

Lumbar radiculopathy and its neurobiological basis

Lumbar radiculopathy, a group of diseases in which the dorsal root ganglia (DRG) or dorsal roots are adversely affected by herniated discs or spinal stenosis, are clinically characterized by spontaneous and evoked types of pain. The pain is underpinned by various distinct pathophysiological mechanisms in the peripheral and central nervous systems. However, the diagnosis of lumbar radiculopathy is still unsatisfactory, because the association of the pain with the neurobiological basis of radiculopathy is largely unknown. Several animal models used to explore the underlying neurobiological basis of lumbar radiculopathy could be classified as mechanical, chemical, or both based on the component of injury. Mechanical injury elevates the intraneural pressure, reduces blood flow, and eventually establishes ischemia in the dorsal root and the DRG. Ischemia may induce ischemic pain and cause nerve damage or death, and the subsequent nerve damage or death may induce neuropathic pain. Chemical injury predominately induces inflammation surrounding the dorsal roots or DRG and consequent inflammatory mediators cause inflammatory pain. Furthermore, DRG neurons sensitized by inflammatory mediators are hypersensitive to innocuous mechanical force (stretch or compression) and responsible for mechanical allodynia in radiculopathy. As well, central sensitization in the spinal cord may play an important role in pain generation in lumbar radiculopathy. Increasing knowledge of pain-generating mechanisms and their translation into clinical symptoms and signs might allow for dissecting the mechanisms that operate in each patient. With precise clinical phenotypic characterization of lumbar radiculopathy and its connection to a specific underlying mechanism, we should be able to design optimal treatments for individuals. This review discusses the present knowledge of lumbar radiculopathy and proposes a novel mechanism-based classification.

Anesthesia for ambulatory surgery in a child with hyposensitivity to pain

Congenital hyposensitivity to pain is a condition with predisposition to injury. In these patients, knowledge regarding anesthetic requirements and complications derives from individual case reports, or small case series. Different categories have been described. In patients with hyposensitivity to pain, preventing and treating anxiety as well as insuring immobilization, avoidance of triggering of autonomic reflexes, and sedation are integral aspects for a safe and adequate anesthetic management.

Paroxetine vs pregabalin for the management of neuropathic pain in multiple sclerosis

AIM: To compare the effectiveness and tolerability of paroxetine vs pregabalin for the management of multiple sclerosis (MS)-induced neuropathic pain (NPP).

METHODS: A randomized, flexible-dose open-label 8-wk study involving 21 relapsing-remitting MS patients with MS-induced NPP was conducted to evaluate the effectiveness and tolerability of pregabalin versus paroxetine for pain management. The trial included a 3-wk dose titration phase followed by a 5-wk stable dose phase. Primary outcome measures included daily patient-reported pain intensity as measured using a 100 mm visual analogue scale (VAS_pain) and daily impact of pain on daily activities (VAS_impact). Hierarchical regression modeling was conducted on each outcome to determine if within person VAS trajectory for pain and impact differed across study groups, during 56 d follow-up.

RESULTS: Attrition rates were significantly greater (P < 0.001) in the paroxetine versus pregabalin study group (70% vs 18.2%, respectively). Average study duration between study groups also significantly differed (P < 0.001). Paroxetine participants completed an average of 27.3 d of treatment vs 49.5 d in the pregabalin group, with the majority of patients withdrawing due to adverse events. Due to the high attrition rates in the paroxetine study arm, the investigators stopped the study prior to achieving complete recruitment. As such, no significant differences between pregabalin and paroxetine study arms were noted for the primary outcome measures (VAS_pain, VAS_impact). Comparative assessment of baseline patient characteristics also revealed no significant differences between the study arms.

CONCLUSION: High attrition rates associated with paroxetine use suggest that it be used with caution for MS-induced NPP. Efficacy outcomes could not be assessed due to attrition.

Endoscopic removal of a self-expanding metallic airway stent: A case report

Self-expanding metallic stents are sometimes placed for the management of obstructing airway lesions or conditions such as airway wall malacia or tracheal stenosis. However, endoscopic removal of these devices from the airway can pose extreme challenges for both clinical airway management as well as for the administration of general anesthesia. We report on a 61-year-old man with a complex cardiac history presenting for endoscopic stent removal necessitated by the formation of extensive granulation tissue. Comorbidities included a history of myocardial infarction, an ischemic cardiomyopathy with severe left heart failure (ejection fraction of 25%), mild right heart failure, 2+ tricuspid regurgitation status post tricuspid valve repair, and atrial fibrillation. An automatic external (wearable) cardiac defibrillator (Zoll Life Vest) was also in place. Induction of anesthesia was carried out using etomidate, with maintenance of anesthesia carried out with a propofol infusion (total intravenous anesthesia). Rocuronium was used for neuromuscular blockade. A size 4 iGel supraglottic airway and, later, rigid bronchoscopy formed the basis for airway management. Stable conditions were met through the 2-h procedure, and the patient recovered uneventfully. Our successful experience in this case leads us to propose further use of a supraglottic airway in conjunction with total intravenous anesthesia for these procedures.

Comparison of flow rate accuracy and consistency between the on-Q, baxter, and ambu pain infusion devices

AIM: Providing analgesia via peripheral nerve catheters attached to an infusion pump is an effective pain management option in children.

METHODS: Portable infusion pumps are being used with increased frequency in pediatric patients. Because these pumps are infusing potentially toxic doses of medications, the accuracy and consistency of these devices becomes very important in this patient population. This study is a comparison of the actual delivery volume of local anesthetic of three elastomeric infusion devices approved for patient use in the ambulatory setting. Three brands of disposable elastomeric infusion devices were used (Five On-Q, Five Baxter, and Five Ambu pumps). Each was filled with 200 mL of Ropivicaine 0.1% and connected to a single, end hole infusion catheter and set to infuse at 12 mL/h. The devices were run simultaneously. The fluid delivered was measured every hour with a graduated column over a tenhour period. The ambient temperature was also recorded.

RESULTS: There were statistically significant differences in the output from each elastomeric device over the 10 h infusion period when compared to the nominal rate of 12 mL/h. The output from the Ambu and Baxter pumps was less than that set on the regulator, while the output from the On-Q pump was greater than that set on the regulator. The results remained statistically significant after adjusting the nominal rate to correct for differences in temperature. The Ambu infusion device was the most consistent, while the Baxter infusion device was the most accurate. This emphasizes the importance of health care providers understanding the infusion profile of the pump being used for continuous peripheral nerve block, as these alterations in flow could result in inadequate analgesia, early reservoir exhaustion, excessive muscle weakness or potential toxicity, especially when used in pediatric patients.

CONCLUSION: This investigation demonstrates that three modern elastomeric infusion pumps have significantly different output than the nominal rate set on the regulator.

Complex regional pain syndrome: From diagnosis to rehabilitation

Complex regional pain syndrome (CRPS) is a debilitating pathology characterised by intense chronic pain associated with vasomotor, sensory and motor dysfunction of the affected limb. Although the pathophysiology of CRPS is not fully understood, it is recognised that inflammatory processes and autonomic dysfunction are involved. These processes are associated with peripheral and central sensitisation as well as changes in brain structure and function, and are reflected in the clinical presentation of CRPS. CRPS management requires an interdisciplinary team and requires the therapeutic approach to be individualised. With regard to pharmacological treatment, bisphosphonates, corticosteroids, ketamine and anticonvulsants have been demonstrated to be effective for CRPS management. Psychotherapy, including cognitive-behavioural therapy, has produced promising results but more studies are needed to confirm its efficacy. Among rehabilitation interventions, there is evidence of the efficacy of physiotherapy and occupational therapy in diminishing CRPS symptoms and achieving a higher level of functioning. In this regard, the rehabilitation modality that seems the most promising according to the actual literature is graded motor imagery, which can help to reverse the maladaptive neuroplasticity occurring in CRPS.

Molecular mechanism of inflammatory pain

Chronic inflammatory pain resulting from arthritis, nerve injury and tumor growth is a serious public health issue. One of the major challenges in chronic inflammatory pain research is to develop new pharmacologic treatments with long-term efficacy and few side effects. The mediators released from inflamed sites induce complex changes in peripheral and central processing by directly acting on transducer receptors located on primary sensory neurons to transmit pain signals or indirectly modulating pain signals by activating receptors coupled with G-proteins and second messengers. High local proton concentration (acidosis) is thought to be a decisive factor in inflammatory pain and other mediators such as prostaglandin, bradykinin, and serotonin enhance proton-induced pain. Proton-sensing ion channels [transient receptor potential V1 (TRPV1) and the acid-sensing ion channel (ASIC) family] are major receptors for direct excitation of nociceptive sensory neurons in response to acidosis or inflammation. G-protein-coupled receptors activated by prostaglandin, bradykinin, serotonin, and proton modulate functions of TRPV1, ASICs or other ion channels, thus leading to inflammation- or acidosis-linked hyperalgesia. Although detailed mechanisms remain unsolved, clearly different types of pain or hyperalgesia could be due to complex interactions between a distinct subset of inflammatory mediator receptors expressed in a subset of nociceptors. This review describes new directions for the development of novel therapeutic treatments in pain.

Perioperative care and cancer recurrence: Is there a connection?

Cancer is the second most common cause of death in the United States. Metastatic disease is a more important cause of cancer-related death relative to primary tumor progression. Surgical excision is the primary treatment for most malignant tumors. However, surgery itself can inhibit important host defenses and promote the development of metastases. An altered balance between the metastatic potential of the tumor and the anti-metastatic host defenses, including cell-mediated immunity and natural killer cell function, is a plausible mechanism of increased cancer metastasis. This article reviews the increasingly recognized concept of anesthetic technique along with perioperative factors and their potential to affect long-term outcome after cancer surgery. The potential effect of intravenous anesthetics, volatile agents, local anesthetic drugs, opiates, and non-steroidal anti-inflammatory drugs are reviewed along with recent literature and ongoing clinical trials in this area. Regional anesthesia is increasingly emerging as a safer option with less cancer recurrence potential as compared to general anesthesia. Blood transfusion, pain, stress, use of beta-blockers, and hypothermia are other potentially important perioperative factors to consider.

Acute coagulopathy of trauma: Mechanism, monitoring, management

Coagulopathy is a well-known consequence of trauma and is the most common cause of mortality in the young. However, its cause and management is still controversial. A new concept in the understanding of coagulopathy in trauma is the occurrence of Acute coagulopathy of trauma (ACoT). ACoT is associated with hypo perfusion and tissue trauma as seen in massive injury. The incidence of coagulopathy increases with injury scores and is associated with higher number of ventilator days, higher morbidity and mortality. The process of coagulation is better described by the cell based model with a central role for platelets rather than the older plasma based model. This shift in our understanding supports the theory that ACoT results from the endothelial release of thrombomodulin and activated protein C in the presence of hypoperfusion. This in turn leads on to a hyperfibrinolytic and hypocoagulable state. Viscoelastic hemostatic assays are replacing the older tests like prothrombin time in the assessment of coagulopathy. These tests are accurate, determine the need for transfusion and can be performed at the point of care. Damage control resuscitation includes newer concepts like permissive hypotension, increased use of plasma as a part of massive transfusion protocols and damage control surgery.

Opioid misuse in Canada and critical appraisal of aberrant behavior screening tools

The incidence of prescription opioid misuse in Canada is increasing. Initiatives for safe prescribing practices for opioid medications include risk assessment for current and future opioid misuse. A clinical screening tool that can be universally applied to all patient populations is currently not available. Our objective was to provide a brief narrative review on opioid misuse from a Canadian perspective as well as a critical appraisal of the available clinical screening tools for detecting aberrant behaviors associated with opioid misuse. The Drug Abuse Screening Test, Addiction Behaviors Checklist, Diagnosis, Intractability, Risk and Efficacy Inventory, Pain Assessment and Documentation Tool, Prescription Drug Use Questionnaire, Prescription Opioid therapy Questionnaire, Screener and Opioid Assessment for Patients with Pain (SOAPP), Revised SOAPP, Pain Medication Questionnaire, Opioid Risk Tool and Current Opioid Misuse Measure were included in the following review. Overall, a wide variability in quality, sensitivity and specificity was observed between screening tools. There is an overall lack of applicability to diverse patient populations as the majority of screening tools have been validated in pain clinic populations only. To conclude, there is a great need for a validated and convenient aberrant behaviors risk assessment tool that can be applied to a diverse patient population in a clinical setting.

Lung preconditioning in anesthesia: Review of the literature

Lung injury can arise during or after anesthesia and can lead to a complicated postoperative course with great implications for the patient. Unfortunately, treatment of acute lung injury is at the moment mainly supportive and rates of recovery have not really improved in the recent years. In many cases, lung injury can be anticipated and preventive measures seem possible. This represents a unique challenge to the anesthesiologist, as some new opportunities to reduce the frequency and/or severity of lung injury seem now available. These chances may arise from the potency of preconditioning the lungs before the main injury, with smaller injurious insults. Although preconditioning began to be applicated first on the myocardium, experimental studies have shown potentially beneficial results also for the lungs. This review summarizes the main methods of lung preconditioning that have been tried in experimental studies in the literature and the main mechanisms that are perhaps involved. Emphasis is given in the two main methods of preconditioning that seem readily applicable in the clinical praxis, that is ischemic preconditioning, as well as preconditioning with volatile anesthetics. The few, but interesting clinical studies are also summarized and the future research points in this evolving field of anesthesia are stressed.