Comparison of visual and electromyographic assessments with train-of-four stimulation of the ulnar nerve: a prospective cohort study.

PURPOSE: The use of a peripheral nerve stimulator to assess the level of neuromuscular blockade tasks the anesthesia clinician with subjectively assessing the response to neurostimulation. In contrast, objective neuromuscular monitors provide quantitative information. The purpose of this study was to compare subjective evaluations from a peripheral nerve stimulator with objective measurements of neurostimulation responses from a quantitative monitor. METHODS: Patients were enrolled preoperatively, and intraoperative neuromuscular blockade management was at the discretion of the anesthesiologist. Electromyography electrodes were placed over the dominant or nondominant arm in a randomized fashion. Following onset of nondepolarizing neuromuscular blockade, the ulnar nerve was stimulated, the response was measured with electromyography, and anesthesia clinicians, who were blinded to the objective measurements, subjectively (visually) evaluated the response to neurostimulation. RESULTS: Fifty patients were enrolled and 666 neurostimulations were performed at 333 different time points. Anesthesia clinicians subjectively overestimated the response of the adductor pollicis muscle following neurostimulation of the ulnar nerve 155/333 (47%) of the time when compared with objective electromyographic measurements. When subjective evaluations and objective measurements differed to any degree, subjective evaluations were higher than objective measurements 155/166 (92%) of the time (95% CI, 87 to 95; P < 0.001), representing significant evidence that subjective evaluation overestimates the response to train-of-four stimulation. CONCLUSIONS: Subjective observations of a "twitch" do not consistently correspond to objective measurements of neuromuscular blockade with electromyography. Subjective evaluation overestimates the response to neurostimulation and may be unreliable for determining the depth of block or confirming adequate recovery.

RéSUMé: OBJECTIF: Lors de l'utilisation d'un stimulateur nerveux périphérique pour évaluer le niveau de bloc neuromusculaire, le clinicien en anesthésie doit évaluer de manière subjective la réponse à la neurostimulation. Les moniteurs neuromusculaires objectifs fournissent quant à eux des informations quantitatives. L'objectif de cette étude était de comparer les évaluations subjectives d'un stimulateur nerveux périphérique avec des mesures objectives des réponses de neurostimulation provenant d'un moniteur quantitatif. MéTHODE: Les patients ont été recrutés avant leur opération, et la gestion du bloc neuromusculaire peropératoire était à la discrétion de l'anesthésiologiste. Des électrodes d'électromyographie ont été placées sur le bras dominant ou non dominant de manière aléatoire. Après l'amorce du bloc neuromusculaire non dépolarisant, le nerf cubital a été stimulé, la réponse a été mesurée par électromyographie, et les cliniciens en anesthésie, qui n'avaient pas accès aux mesures objectives, ont évalué subjectivement (visuellement) la réponse à la neurostimulation. RéSULTATS: Cinquante patients ont été recrutés et 666 neurostimulations ont été réalisées à 333 moments différents. Les cliniciens en anesthésie ont subjectivement surestimé la réponse du muscle adducteur du pouce après neurostimulation du nerf cubital 155/333 (47 %) fois par rapport aux mesures électromyographiques objectives. Lorsque les évaluations subjectives et les mesures objectives différaient à quelque degré que ce soit, les évaluations subjectives étaient plus élevées que les mesures objectives 155/166 (92 %) du temps (IC 95 %, 87 à 95; P < 0,001), ce qui représente une preuve significative que l'évaluation subjective surestime la réponse à la stimulation par train-de-quatre. CONCLUSION: Les observations subjectives d'une « contraction ¼ ne correspondent pas systématiquement aux mesures objectives d'un bloc neuromusculaire telles qu'obtenues par électromyographie. L'évaluation subjective surestime la réponse à la neurostimulation et pourrait ne pas être fiable pour déterminer la profondeur du bloc ou confirmer une récupération adéquate.

Perioperative anaphylactic reactions to central venous and pulmonary artery catheters containing chlorhexidine, sulfadiazine, or latex: a historical cohort study.

PURPOSE: Central venous catheters (CVCs) and pulmonary artery catheters (PACs) containing chlorhexidine, silver sulfadiazine, or latex can cause perioperative anaphylaxis. We examined the incidence of and outcomes associated with anaphylaxis caused by CVCs/PACs. METHODS: In a historical cohort study, we retrospectively identified adult patients fitted with CVCs/PACs at the Mayo Clinics in Minnesota, Arizona, and Florida from 1 January 2008 to 1 March 2018. Potential and confirmed cases of perioperative anaphylactic reactions were individually reviewed and classified. RESULTS: During the study period, 39,505 procedures were performed during which CVCs/PACs were inserted. Of these, 2,937 patients with pre-existing chlorhexidine, sulfonamide (sulfa), and/or latex allergies had CVCs/PACs inserted that contained these substances. Perioperative anaphylaxis, in which CVCs/PACs were the confirmed or potential causative agent, occurred during 53 procedures. Seven patients had a preoperatively reported sulfa or latex allergy; no patients had a preoperative chlorhexidine allergy. Six of the seven patients with reported allergies to sulfa or latex had a CVC/PAC inserted that contained these substances. Twenty-four patients with anaphylaxis had postoperative allergic disease consultation; ten of these (42%) underwent skin testing. CONCLUSION: Perioperative anaphylactic reactions related to CVCs/PACs containing chlorhexidine, silver sulfadiazine, or latex were rare in this large historical cohort study. We identified 2,937 patients with pre-existing chlorhexidine, sulfa, and/or latex allergies and had CVCs/PACs inserted that contained these substances. Although few cases of perioperative anaphylaxis attributable to these substances were observed in patients with corresponding allergies, the potential for substantial complication exists. Providers should be aware of the potential for these hidden exposures.

RéSUMé: OBJECTIF: Les cathéters veineux centraux (CVC) et les cathéters artériels pulmonaires (CAP) contenant de la chlorhexidine, de la sulfadiazine argentique ou du latex peuvent provoquer une anaphylaxie périopératoire. Nous avons examiné l'incidence et les devenirs associés à l'anaphylaxie causée par les CVC/CAP. MéTHODE: Dans une étude de cohorte historique, nous avons identifié rétrospectivement des patients adultes chez lesquels un CVC/CAP avait été installé aux cliniques Mayo du Minnesota, de l'Arizona et de la Floride du 1er janvier 2008 au 1er mars 2018. Les cas potentiels et confirmés de réactions anaphylactiques périopératoires ont été examinés et classés individuellement. RéSULTATS: Au cours de la période à l'étude, 39 505 interventions ont été réalisées au cours desquelles des CVC/CAP ont été insérés. Parmi celles-ci, des CVC/CAP contenant de la chlorhexidine, des sulfamides et/ou du latex ont été insérés chez 2937 patients présentant des allergies préexistantes à ces substances. Une anaphylaxie périopératoire, dont l'agent causal confirmé ou potentiel était le CVC/CAP, s'est produite dans 53 interventions. Sept patients présentaient une allergie aux sulfamides ou au latex signalée avant l'opération; aucun patient n'a eu d'allergie préopératoire à la chlorhexidine. Un CVC/CAP contenant des sulfamides ou du latex a été inséré chez six des sept patients ayant signalé des allergies à ces substances. Vingt-quatre patients atteints d'anaphylaxie ont eu une consultation postopératoire pour une maladie allergique; dix d'entre eux (42 %) ont subi des tests cutanés. CONCLUSION: Les réactions anaphylactiques périopératoires liées aux CVC/CAP contenant de la chlorhexidine, de la sulfadiazine argentique ou du latex étaient rares dans cette vaste étude de cohorte historique. Nous avons identifié 2937 patients présentant des allergies préexistantes à la chlorhexidine, aux sulfamides et/ou au latex chez lesquels des CVC/CAP contenant ces substances ont été insérés. Bien que peu de cas d'anaphylaxie périopératoire attribuable à ces substances aient été observés chez des patients présentant des allergies correspondantes, il existe un risque de complication importante. Les fournisseurs doivent être conscients du potentiel de ces expositions cachées.

Mycobacterium infection from a cardiopulmonary bypass heater-cooler unit in a patient with steroid-induced immunosuppression.

PURPOSE: To present a case of mycobacterium infection transmitted through a heater-cooler unit during cardiac bypass surgery. CLINICAL FEATURES: A 63-yr-old woman with a past medical history of aortic coarctation repair in 1963 and a mechanical aortic valve replacement in 2010 was prescribed antibiotics and steroids at an outpatient care facility in September 2015 for symptoms of an upper respiratory tract infection. Four months later, she developed malaise and intermittent fever with anemia and acute kidney dysfunction. Extensive evaluation revealed negative blood cultures but was suggestive of amyloidosis. The patient was therefore started on systemic steroids prior to being referred to us.At our institution, transesophageal echocardiography and cardiac magnetic resonance imaging revealed a normal mechanical aortic prosthesis with an aortic root abscess. The patient was started on empiric antibiotics for endocarditis. Renal biopsy revealed interstitial nephritis with one granuloma for which she was again started on high-dose steroids. The patient continued to deteriorate, with worsening renal function and pancytopenia that required daily red blood cell and platelet transfusions.Three weeks into this hospitalization, her blood cultures were reported to be positive for Mycobacterium chimera, and she was started on a four-drug regimen of rifampin, rifabutin, ethambutol, and clarithromycin, with dramatic clinical improvement. CONCLUSION: Heater-cooler units manufactured by LivaNova prior to September 2014 and used during cardiopulmonary bypass have been linked to M. chimera, which causes a latent infection that may be activated and become disseminated in cases of immunosuppression related to steroid use.

A simple protocol to improve safety and reduce cost in hemodialysis patients undergoing elective surgery.

BACKGROUND: When patients with end-stage renal disease (ESRD) miss their routine intermittent hemodialysis (IHD), electrolyte abnormalities and volume overload often occur. An institutional protocol to ensure that patients receiving IHD have elective surgeries scheduled within 24 hours after their dialysis may reduce procedural delays or cancellations caused by hyperkalemia and hypervolemia after a missed IHD session. The effect of this protocol was evaluated. METHODS: A retrospective chart review was performed for ESRD patients receiving IHD who underwent surgery from 6 months before to 6 months after the institutional protocol was implemented. Preoperative potassium values, timing of IHD relative to surgery, and the nature of surgery (elective or emergent) were documented. The percentage of patients having IHD more than 24 hours before their elective surgery was compared before and after protocol implementation. Average potassium values were compared when IHD occurred within 24 hours vs. more than 24 hours, using t test analysis. Cost associated with delay and cancellation for IHD was also explored. RESULTS: Of the 15,799 cases performed, 190 involved ESRD patients receiving IHD. Before the protocol, 32.1% of elective cases (n = 17) involved patients scheduled for surgery more than 24 hours after IHD vs. 12.0% (n = 6) after the protocol. Preoperative potassium values were less when patients underwent IHD within 24 hours than at more than 24 hours (mean [SD], 4.32 [0.6] mEq/L vs 4.63 [0.8] mEq/L; P = .03). CONCLUSIONS: The simple scheduling policy is effective at reducing both cost and unnecessary perioperative risks for patients.

The impact of sugammadex dosing and administration practices on potential cost savings for pharmacy departments.

DISCLAIMER: In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. PURPOSE: Neuromuscular blocking agents (NMBAs) are commonly used during surgery, and restoring neuromuscular function at the end of surgery is vital in preventing complications of residual paralysis. Recent guidelines from the American Society of Anesthesiology recommend using sugammadex over neostigmine; however, sugammadex is significantly more expensive than neostigmine and may increase drug expenditure for pharmacy departments. This review summarizes evidence evaluating sugammadex dose adjustments and the potential of these dose adjustments to lead to cost savings for pharmacy departments. SUMMARY: We found evidence suggesting that the manufacturer-recommended sugammadex dose may not be needed in many patients and that dosing based on an adjusted body weight or based on depth of neuromuscular blockade may lead to lower sugammadex usage. Combining sugammadex with neostigmine could also decrease the dose of sugammadex required. We have highlighted the importance of objective neuromuscular monitoring to guide sugammadex dosing and evaluation for residual neuromuscular blockade. Cost savings for pharmacy departments may be realized by these alternative dosing strategies and/or vial-splitting practices. CONCLUSION: Implementing practices related to sugammadex vial splitting and dose adjustment based on body weight and depth of neuromuscular blockade shows potential benefits in terms of sugammadex cost savings.

Area under the curve and amplitude of the compound motor action potential are clinically interchangeable quantitative measures of neuromuscular block: a method comparison study.

Background: Current guidelines recommend quantitative neuromuscular block monitoring during neuromuscular blocking agent administration. Monitors using surface electromyography (EMG) determine compound motor action potential (cMAP) amplitude or area under the curve (AUC). Rigorous evaluation of the interchangeability of these methods is lacking but necessary for clinical and research assurance that EMG interpretations of the depth of neuromuscular block are not affected by the methodology. Methods: Digitised EMG waveforms were studied from 48 patients given rocuronium during two published studies. The EMG amplitudes and AUCs were calculated pairwise from all cMAPs classified as valid by visual inspection. Ratios of the first twitch (T1) to the control T1 before administration of rocuronium (T1c) and train-of-four ratios (TOFRs) were compared using repeated measures Bland-Altman analysis. Results: Among the 2419 paired T1/T1c differences where the average T1/T1c was ≤0.2, eight (0.33%) were outside prespecified clinical limits of agreement (-0.148 to 0.164). Among the 1781 paired TOFR differences where the average TOFR was ≥0.8, 70 (3.93%) were outside the prespecified clinical limits of agreement ((-0.109 to 0.134). Among all 7286 T1/T1c paired differences, the mean bias was 0.32 (95% confidence interval 0.202-0.043), and among all 5559 paired TOFR differences, the mean bias was 0.011 (95% confidence interval 0.0050-0.017). Among paired T1/T1c and TOFR differences, Lin's concordance correlation coefficients were 0.98 and 0.995, respectively. Repeatability coefficients for T1/T1c and TOFR were <0.08, with no differences between methods. Conclusions: Quantitative assessment neuromuscular block depth is clinically interchangeable when calculated using cMAP amplitude or the AUC.

Pharmacology and Perioperative Considerations for Diabetes Mellitus Medications.

BACKGROUND: Given the prevalence of diabetes mellitus in modern society, health care providers are frequently tasked with managing glucose control in the perioperative period. When determining perioperative diabetes management, the clinician must balance the need to maintain relative euglycemia at the time of surgery with preventing hypoglycemia or hyperglycemia in a fasting surgical patient. This balance requires an understanding of the pharmacology of these medications, the type of surgery, and the patient's degree of diabetic control. OBJECTIVE: We discuss the various medications used in the treatment of diabetes mellitus and the current recommendations regarding perioperative care. METHOD: A review of the current literature present on Pubmed and Medline was conducted between the years 2000-2016. The reference lists of each selected article were also reviewed for additional sources of information. CONCLUSION: Perioperative control of blood glucose levels is associated with less morbidity and improved surgical outcomes in patients with and without DM. Preoperatively, clinicians need to thoughtfully adjust diabetic medications on the basis of patient comorbidities, the duration of the fasting period, and the duration of surgery. Intraoperative and postoperative strategies typically use insulin to maintain blood glucose levels in the range of 80 to 180 mg/dL.