Guidelines to the Practice of Anesthesia: Revised Edition 2023.

OVERVIEW: The Guidelines to the Practice of Anesthesia Revised Edition 2023 (the Guidelines) were prepared by the Canadian Anesthesiologists' Society (CAS), which reserves the right to determine their publication and distribution. The Guidelines are subject to revision and updated versions are published annually. The Guidelines to the Practice of Anesthesia Revised Edition 2023 supersede all previously published versions of this document. Although the CAS encourages Canadian anesthesiologists to adhere to its practice guidelines to ensure high-quality patient care, the CAS cannot guarantee any specific patient outcome. Anesthesiologists should exercise their own professional judgment in determining the proper course of action for any patient's circumstances. The CAS assumes no responsibility or liability for any error or omission arising from the use of any information contained in its Guidelines to the Practice of Anesthesia.

RéSUMé: Le Guide d'exercice de l'anesthésie, version révisée 2023 (le Guide), a été préparé par la Société canadienne des anesthésiologistes (SCA), qui se réserve le droit de décider des termes de sa publication et de sa diffusion. Le Guide est soumis à révision et des versions mises à jour sont publiées chaque année. Le Guide d'exercice de l'anesthésie, version révisée 2023, remplace toutes les versions précédemment publiées de ce document. Bien que la SCA incite les anesthésiologistes du Canada à se conformer à son guide d'exercice pour assurer une grande qualité des soins dispensés aux patients, elle ne peut garantir les résultats d'une intervention spécifique. Les anesthésiologistes doivent exercer leur jugement professionnel pour déterminer la méthode d'intervention la mieux adaptée à l'état de leur patient. La SCA n'accepte aucune responsabilité ou imputabilité de quelque nature que ce soit découlant d'erreurs ou d'omissions ou de l'utilisation des renseignements contenus dans son Guide d'exercice de l'anesthésie.

A retrospective cohort study of pre-hospital agitation management by advanced paramedic practitioners in critical care.

Introduction: Pre-hospital clinicians can expect to encounter patients with agitation, including acute behavioural disturbance (ABD). These situations carry significant risk for patients and emergency medical services. Advanced paramedics within the London Ambulance Service (LAS) are frequently tasked to these incidents. At present, little evidence exists regarding clinical decision-making and management of this patient group. We sought to explore the demographics of patients presenting with potential ABD and quantify the degree of agitation, physical restraint, effectiveness of chemical sedation and any associated complications. Methods: A retrospective analysis of pre-hospital clinical records for patients coded with ABD and attended by LAS advanced paramedics between 1 October 2019 and 30 September 2020. Sedation assessment tool (SAT) scores were used as the primary outcome measure. Results: A total of 237 patient records were identified. Of the patients, 147 (62%) were physically restrained and 104 (44%) were chemically sedated. Sedation was more commonly administered where patients were exposed to physical restraint. High SAT scores were associated with the administration of sedative agents and at higher doses. Of patients undergoing sedation, 89 (85%) had a SAT score reduction of 2 points or a final score ≤ 0. The mean SAT score reduction was 2.72. Three cases of minor injury were reported following physical restraint. Conclusion: Advanced paramedics undertook sedation in less than half the cohort, suggesting that other strategies such as communication and positioning were utilised. Most patients were managed into a state between being restless and rousable, largely negating the need for ongoing physical restraint during hospital transfer. Appropriately trained advanced paramedics can utilise sedation safely and effectively in selected cases.

Guidelines to the Practice of Anesthesia - Revised Edition 2022.

OVERVIEW: The Guidelines to the Practice of Anesthesia Revised Edition 2022 (the Guidelines) were prepared by the Canadian Anesthesiologists' Society (CAS), which reserves the right to determine their publication and distribution. The Guidelines are subject to revision and updated versions are published annually. The Guidelines to the Practice of Anesthesia Revised Edition 2022 supersedes all previously published versions of this document. Although the CAS encourages Canadian anesthesiologists to adhere to its practice guidelines to ensure high-quality patient care, the CAS cannot guarantee any specific patient outcome. Anesthesiologists should exercise their own professional judgement in determining the proper course of action for any patient's circumstances. The CAS assumes no responsibility or liability for any error or omission arising from the use of any information contained in its Guidelines to the Practice of Anesthesia.

RéSUMé: Le Guide d'exercice de l'anesthésie, version révisée 2022 (le Guide), a été préparé par la Société canadienne des anesthésiologistes (SCA), qui se réserve le droit de décider des termes de sa publication et de sa diffusion. Le Guide est soumis à révision et des versions mises à jour sont publiées chaque année. Le Guide d'exercice de l'anesthésie, version révisée 2022, remplace toutes les versions précédemment publiées de ce document. Bien que la SCA incite les anesthésiologistes du Canada à se conformer à son guide d'exercice pour assurer une grande qualité des soins dispensés aux patients, elle ne peut garantir les résultats d'une intervention spécifique. Les anesthésiologistes doivent exercer leur jugement professionnel pour déterminer la méthode d'intervention la mieux adaptée à l'état de leur patient. La SCA n'accepte aucune responsabilité ou imputabilité de quelque nature que ce soit découlant d'erreurs ou d'omissions ou de l'utilisation des renseignements contenus dans son Guide d'exercice de l'anesthésie.

Guidelines to the Practice of Anesthesia - Revised Edition 2021.

OVERVIEW: The Guidelines to the Practice of Anesthesia Revised Edition 2021 (the Guidelines) were prepared by the Canadian Anesthesiologists' Society (CAS), which reserves the right to determine their publication and distribution. The Guidelines are subject to revision and updated versions are published annually. The Guidelines to the Practice of Anesthesia Revised Edition 2021 supersedes all previously published versions of this document. Although the CAS encourages Canadian anesthesiologists to adhere to its practice guidelines to ensure high-quality patient care, the CAS cannot guarantee any specific patient outcome. Anesthesiologists should exercise their own professional judgement in determining the proper course of action for any patient's circumstances. The CAS assumes no responsibility or liability for any error or omission arising from the use of any information contained in its Guidelines to the Practice of Anesthesia.

RéSUMé: Le Guide d'exercice de l'anesthésie, version révisée 2021 (le Guide), a été préparé par la Société canadienne des anesthésiologistes (SCA), qui se réserve le droit de décider des termes de sa publication et de sa diffusion. Le Guide est soumis à révision et des versions mises à jour sont publiées chaque année. Le Guide d'exercice de l'anesthésie, version révisée 2021, remplace toutes les versions précédemment publiées de ce document. Bien que la SCA incite les anesthésiologistes du Canada à se conformer à son guide d'exercice pour assurer une grande qualité des soins dispensés aux patients, elle ne peut garantir les résultats d'une intervention spécifique. Les anesthésiologistes doivent exercer leur jugement professionnel pour déterminer la méthode d'intervention la mieux adaptée à l'état de leur patient. La SCA n'accepte aucune responsabilité ou imputabilité de quelque nature que ce soit découlant d'erreurs ou d'omissions ou de l'utilisation des renseignements contenus dans son Guide d'exercice de l'anesthésie.

Transcranial Motor-Evoked Potentials Are More Readily Acquired Than Somatosensory-Evoked Potentials in Children Younger Than 6 Years.

BACKGROUND: There is a general belief that somatosensory-evoked potentials (SSEPs) are more easily obtained than transcranial motor-evoked potentials (TcMEPs) in children younger than 6 years. We tested this assumption and the assumption that motor-evoked potentials are rarely obtained in children younger than 2 years. METHODS: The records of all patients who were monitored during surgical procedures between April 1, 2010, and June 30, 2013, were reviewed and those who were younger than 72 months at the time of surgery were identified and analyzed for the rate of obtaining clinically useful SSEPs and motor-evoked potentials. Subgroup analysis was performed by age. RESULTS: A total of 146 patients were identified, 9 had SSEPs without TcMEPs monitored, 117 had both TcMEPs and SSEPs monitored, and the remainder had only electromyographic monitoring. All patients who were to have TcMEPs recorded received a total IV anesthetic. Among the 117 patients who had both SSEPs and TcMEPs monitored, clinically relevant TcMEPs were obtained more frequently than SSEPs (110/117 vs 89/117; χ = 14.82; P = 0.00012). There were significant differences between the rates of obtaining SSEPs and TcMEPs in the 0- to 23-month (P = 0.0038) and 24- to 47-month (P = 0.0056) age groups. Utilization of a double-train stimulation technique facilitated obtaining TcMEPs in the youngest patients. CONCLUSIONS: TcMEPs can be obtained more easily than SSEPs in patients younger than 72 months if a permissive anesthetic technique is used. The success rate for obtaining TcMEPs can be further enhanced by the use of a temporal facilitation (double-train) stimulation technique.

Lactate flux during carotid endarterectomy under general anesthesia: correlation with various point-of-care monitors.

PURPOSE: The ability to assess the brain-at-risk during carotid endarterectomy (CEA) under general anesthesia remains a major clinical problem. Point-of-care monitoring can potentially dictate changes to management intraoperatively. In this observational study, we examined the correlation between a series of point-of-care monitors and lactate flux during CEA. METHODS: Both neurosurgeons and vascular surgeons participated in the study. The patients underwent arterial-jugular venous blood sampling for oxygen, carbon dioxide, glucose, and lactate, n = 26; bispectral index (BIS) monitoring ipsilateral to side of surgery, n = 26; raw and processed electroencephalogram (EEG), n = 22; and bi-frontal cerebral oximetry using the Fore-Sight monitor, n = 20. RESULTS: One patient experienced a new neurological deficit when assessed at 24 hr following surgery. Lactate flux into the brain was correlated with the greatest decrease in cerebral oximetry with carotid cross-clamping; lactate efflux was correlated with the least. The most noticeable changes in processed EEG (density spectral analysis) were also seen with lactate influx, but at a slower time resolution than cerebral oximetry. Loss of autoregulatory behaviour was demonstrated with lactate influx; however, no correlation was seen between lactate flux and BIS monitoring. CONCLUSION: There was a correlation between cerebral oximetry and lactate flux during carotid cross-clamping. The Fore-Sight monitor may be of value as a point-of-care monitor during CEA under general anesthesia. A novel finding of this study is lactate flux into the brain in the presence of a large difference in cerebral oxygenation during cross-clamping of the carotid artery. Registered at clinicaltrials.gov: NCT000737334.

Foot and ankle problems of Aboriginal and non-Aboriginal diabetic patients with end-stage renal disease.

BACKGROUND: There is little information available about the profile of lower extremity morbidity in diabetic patients with end-stage renal disease (ESRD) in the Canadian Aboriginal and non-Aboriginal population. METHOD: A retrospective review of medical records in 127 diabetic patients on hemodialysis at a tertiary health care center was performed. Patient interviews and physical examinations were performed in 77 of these patients (36 Aboriginal, 41 non-Aboriginal), and followup evaluation was done in 39 patients at an average of 1 year later. RESULTS: Aboriginal patients were an average of 7 years younger than non-Aboriginal patients. Comorbidities of diabetes and ESRD were frequent. Peripheral neuropathy and inability to occlude the vessels were present in the majority of feet. Lower extremity complications were frequent, including prior foot ulcer in the majority of patients and an amputation in more than one fourth of the patients. Aboriginal patients had a significantly greater frequency of prior foot ulcer, mean number of foot ulcers per patient, amputation, prior osteomyelitis, and Charcot foot than non-Aboriginal patients. Almost all patients were at risk for future foot ulcer, but many patients did not inspect their feet daily. Home care was significantly less frequently available for Aboriginal than non-Aboriginal patients. The majority of patients had inadequate custom or prefabricated shoes and did not wear insoles on the day of examination. Aboriginal patients cited financial cost, insufficient family support, and language barriers as reasons for inadequate foot care and footwear more frequently than non-Aboriginal subjects. A significantly smaller frequency of Aboriginal patients had good knowledge of footwear or diet than non-Aboriginal patients. CONCLUSIONS: Lower extremity complications were significantly more frequent in Aboriginal than non-Aboriginal diabetic patients with ESRD. Financial cost and knowledge deficit were barriers to adequate foot care and footwear. These findings support the need for a formal foot care and footwear program for this high-risk population.

Does thrombin play a role in the pathogenesis of brain damage after periventricular hemorrhage?

Neonatal periventricular hemorrhage (PVH) is a devastating complication of prematurity in the human infant. Based upon observations made primarily in adult rodents and the fact that the immature brain uses proteolytic systems for cell migration and growth, we hypothesized that thrombin and plasmin enzyme activities contribute to the brain damage after PVH. The viability of mixed brain cells derived from newborn rat periventricular region was suppressed by whole blood and thrombin, but not plasmin. Following injection of autologous blood into the periventricular region of newborn rat brain, proteolytic activity was detected in a halo around the hematoma using membrane overlays impregnated with thrombin and plasmin fluorogenic substrates. Two-day old rats received periventricular injection of blood, thrombin, and plasminogen. After 2 days, thrombin and blood were associated with significantly greater damage than saline or plasminogen. Two-day old mice received intracerebral injections of blood in combination with saline or the proteolytic inhibitors hirudin, alpha2macroglobulin, or plasminogen activator inhibitor-1. After 2 days, hirudin significantly reduced brain cell death and inflammation. Two-day-old mice then received low and high doses of hirudin mixed with blood after which behavioral testing was conducted repeatedly. At 10 weeks there was no statistically significant evidence for behavioral or structural brain protection. These results indicate that thrombin likely plays a role in neonatal periventricular brain damage following PVH. However, additional factors are likely important in the recovery from this result.

Presidential address from the new president of the British Dental Association.

Professor Ian McIntyre was installed as the new President of the British Dental Association at this year's 2003 National Annual Conference held in Manchester on April 24-26, 2003.

Body oxygen stores, aerobic dive limits and diving behaviour of the star-nosed mole (Condylura cristata) and comparisons with non-aquatic talpids.

The dive performance, oxygen storage capacity and partitioning of body oxygen reserves of one of the world's smallest mammalian divers, the star-nosed mole Condylura cristata, were investigated. On the basis of 722 voluntary dives recorded from 18 captive star-nosed moles, the mean dive duration (9.2+/-0.2 s; mean +/- S.E.M.) and maximum recorded dive time (47 s) of this insectivore were comparable with those of several substantially larger semi-aquatic endotherms. Total body O(2) stores of adult star-nosed moles (34.0 ml kg(-1)) were 16.4 % higher than for similarly sized, strictly fossorial coast moles Scapanus orarius (29.2 ml kg(-1)), with the greatest differences observed in lung and muscle O(2) storage capacity. The mean lung volume of C. cristata (8.09 ml 100 g(-1)) was 1.81 times the predicted allometric value and exceeded that of coast moles by 65.4 % (P=0.0001). The overall mean myoglobin (Mb) concentration of skeletal muscles of adult star-nosed moles (13.57+/-0.40 mg g(-1) wet tissue, N=7) was 19.5 % higher than for coast moles (11.36+/-0.34 mg g(-1) wet tissue, N=10; P=0.0008) and 54.2 % higher than for American shrew-moles Neurotrichus gibbsii (8.8 mg g(-1) wet tissue; N=2). The mean skeletal muscle Mb content of adult star-nosed moles was 91.1 % higher than for juveniles of this species (P<0.0001). On the basis of an average diving metabolic rate of 5.38+/-0.35 ml O(2) g(-1) h(-1) (N=11), the calculated aerobic dive limit (ADL) of star-nosed moles was 22.8 s for adults and 20.7 s for juveniles. Only 2.9 % of voluntary dives by adult and juvenile star-nosed moles exceeded their respective calculated ADLs, suggesting that star-nosed moles rarely exploit anaerobic metabolism while diving, a conclusion supported by the low buffering capacity of their skeletal muscles. We suggest that a high mass-specific O(2) storage capacity and relatively low metabolic cost of submergence are key contributors to the impressive dive performance of these diminutive insectivores.