Quantified Ataxic Breathing Can Detect Opioid-Induced Respiratory Depression Earlier in Normal Volunteers Infused with Remifentanil.

BACKGROUND: Ataxic breathing (AB) is a well-known manifestation of opioid effects in animals and humans, but is not routinely included in monitoring for opioid-induced respiratory depression (OIRD). We quantified AB in normal volunteers receiving increasing doses of remifentanil. We used a support vector machine (SVM) learning approach with features derived from a modified Poincaré plot. We tested the hypothesis that AB may be found when bradypnea and reduced mental status are not present. METHODS: Twenty-six healthy volunteers (13 female) received escalating target effect-site concentrations of remifentanil with a low baseline dose of propofol to simulate typical breathing patterns in drowsy patients who had received parenteral opioids. We derived respiratory rate (RR) from respiratory inductance plethysmography, mental alertness from the Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S), and AB severity on a 0 to 4 scale (categories ranging from none to severe) from the SVM. The primary outcome measure was sensitivity and specificity for AB to detect OIRD. RESULTS: All respiratory measurements were obtained from unperturbed subjects during steady state in 121 assessments with complete data. The sensitivity of AB for detecting OIRD by the conventional method was 92% and specificity was 28%. As expected, 69 (72%) of the instances not diagnosed as OIRD using conventional measures were observed to have at least moderate AB. CONCLUSIONS: AB was frequently present in the absence of traditionally detected OIRD as defined by reduced mental alertness (MOAA/S score of <4) and bradypnea (RR <8 breaths/min). These results justify the need for future trials to explore replicability with other opioids and clinical utility of AB as an add-on measure in recognizing OIRD.

Clarifying the grey space of sugammadex induced bradycardia.

PURPOSE OF REVIEW: This review describes recent prospective and retrospective work exploring the incidence and clinical consequence of sugammadex-induced bradycardia and an update of recent evidence and adverse event reports to the United States Food and Drug Administration regarding the incidence of sugammadex induced bradycardia. RECENT FINDINGS: This work suggests that the incidence of sugammadex-induced bradycardia can range from 1 to 7% depending on the definition to reverse moderate to deep neuromuscular blockade. For most instances, the bradycardia is inconsequential. For those instances that have hemodynamic instability, the adverse physiology is easily treated with appropriate vasoactive agents. One study demonstrated that the incidence of bradycardia from sugammadex is less than with neostigmine. There are several case reports that describe marked bradycardia with cardiac arrest from reversal with sugammadex. The incidence of this type of reaction to sugammadex appears to be very rare. Data from the United States Food and Drug Administration's Adverse Event Reporting System public dashboard corroborates this presence of this rare finding. SUMMARY: Sugammadex-induced bradycardia is common and, in most instances, of minimal clinical consequence. Nevertheless, anesthesia providers should maintain proper monitoring and vigilance to treat hemodynamical instability with each administration of sugammadex.

Genetic variations that influence paclitaxel pharmacokinetics and intracellular effects that may contribute to chemotherapy-induced neuropathy: A narrative review.

Taxanes, particularly paclitaxel and docetaxel, are chemotherapeutic agents commonly used to treat breast cancers. A frequent side effect is chemotherapy-induced peripheral neuropathy (CIPN) that occurs in up to 70% of all treated patients and impacts the quality of life during and after treatment. CIPN presents as glove and stocking sensory deficits and diminished motor and autonomic function. Nerves with longer axons are at higher risk of developing CIPN. The causes of CIPN are multifactorial and poorly understood, limiting treatment options. Pathophysiologic mechanisms can include: (i) disruptions of mitochondrial and intracellular microtubule functions, (ii) disruption of axon morphology, and (iii) activation of microglial and other immune cell responses, among others. Recent work has explored the contribution of genetic variation and selected epigenetic changes in response to taxanes for any insights into their relation to pathophysiologic mechanisms of CIPN20, with the hope of identifying predictive and targetable biomarkers. Although promising, many genetic studies of CIPN are inconsistent making it difficult to develop reliable biomarkers of CIPN. The aims of this narrative review are to benchmark available evidence and identify gaps in the understanding of the role genetic variation has in influencing paclitaxel's pharmacokinetics and cellular membrane transport potentially related to the development of CIPN.

Prolonged Opioid Use and Pain Outcome and Associated Factors after Surgery under General Anesthesia: A Prospective Cohort Association Multicenter Study.

BACKGROUND: There is insufficient prospective evidence regarding the relationship between surgical experience and prolonged opioid use and pain. The authors investigated the association of patient characteristics, surgical procedure, and perioperative anesthetic course with postoperative opioid consumption and pain 3 months postsurgery. The authors hypothesized that patient characteristics and intraoperative factors predict opioid consumption and pain 3 months postsurgery. METHODS: Eleven U.S. and one European institution enrolled patients scheduled for spine, open thoracic, knee, hip, or abdominal surgery, or mastectomy, in this multicenter, prospective observational study. Preoperative and postoperative data were collected using patient surveys and electronic medical records. Intraoperative data were collected from the Multicenter Perioperative Outcomes Group database. The association between postoperative opioid consumption and surgical site pain at 3 months, elicited from a telephone survey conducted at 3 months postoperatively, and demographics, psychosocial scores, pain scores, pain management, and case characteristics, was analyzed. RESULTS: Between September and October 2017, 3,505 surgical procedures met inclusion criteria. A total of 1,093 cases were included; 413 patients were lost to follow-up, leaving 680 (64%) for outcome analysis. Preoperatively, 135 (20%) patients were taking opioids. Three months postsurgery, 96 (14%) patients were taking opioids, including 23 patients (4%) who had not taken opioids preoperatively. A total of 177 patients (27%) reported surgical site pain, including 45 (13%) patients who had not reported pain preoperatively. The adjusted odds ratio for 3-month opioid use was 18.6 (credible interval, 10.3 to 34.5) for patients who had taken opioids preoperatively. The adjusted odds ratio for 3-month surgical site pain was 2.58 (1.45 to 4.4), 4.1 (1.73 to 8.9), and 2.75 (1.39 to 5.0) for patients who had site pain preoperatively, knee replacement, or spine surgery, respectively. CONCLUSIONS: Preoperative opioid use was the strongest predictor of opioid use 3 months postsurgery. None of the other variables showed clinically significant association with opioid use at 3 months after surgery.

A Multimodal Approach to Discover Biomarkers for Taxane-Induced Peripheral Neuropathy (TIPN): A Study Protocol.

Introduction: Taxanes are a class of chemotherapeutics commonly used to treat various solid tumors, including breast and ovarian cancers. Taxane-induced peripheral neuropathy (TIPN) occurs in up to 70% of patients, impacting quality of life both during and after treatment. TIPN typically manifests as tingling and numbness in the hands and feet and can cause irreversible loss of function of peripheral nerves. TIPN can be dose-limiting, potentially impacting clinical outcomes. The mechanisms underlying TIPN are poorly understood. As such, there are limited treatment options and no tools to provide early detection of those who will develop TIPN. Although some patients may have a genetic predisposition, genetic biomarkers have been inconsistent in predicting chemotherapy-induced peripheral neuropathy (CIPN). Moreover, other molecular markers (eg, metabolites, mRNA, miRNA, proteins) may be informative for predicting CIPN, but remain largely unexplored. We anticipate that combinations of multiple biomarkers will be required to consistently predict those who will develop TIPN. Methods: To address this clinical gap of identifying patients at risk of TIPN, we initiated the Genetics and Inflammatory Markers for CIPN (GENIE) study. This longitudinal multicenter observational study uses a novel, multimodal approach to evaluate genomic variation, metabolites, DNA methylation, gene expression, and circulating cytokines/chemokines prior to, during, and after taxane treatment in 400 patients with breast cancer. Molecular and patient reported data will be collected prior to, during, and after taxane therapy. Multi-modal data will be used to develop a set of comprehensive predictive biomarker signatures of TIPN. Conclusion: The goal of this study is to enable early detection of patients at risk of developing TIPN, provide a tool to modify taxane treatment to minimize morbidity from TIPN, and improved patient quality of life. Here we provide a brief review of the current state of research into CIPN and TIPN and introduce the GENIE study design.

Pro-Con Debate: Do We Need Quantitative Neuromuscular Monitoring in the Era of Sugammadex?

In this Pro-Con article, we debate the merits of using quantitative neuromuscular blockade monitoring. Consensus guidelines recommend their use to guide the administration of nondepolarizing neuromuscular blockade and reversal agents. A major impediment to this guideline is that until recently, reliable quantitative neuromuscular blockade monitors have not been widely available. Without them, anesthesia providers have been trained with and are adept at using a variety of qualitative neuromuscular blockade monitors otherwise known as peripheral nerve stimulators. Although perhaps less accurate, anesthesia providers find them reliable and easy to use. They have a long track record of using them with the perception that their use leads to effective neuromuscular blockade reversal and minimizes clinically significant adverse events from residual neuromuscular blockade. In the recent past, 2 disruptive developments have called upon anesthesia care providers to reconsider their practice in neuromuscular blockade administration, reversal, and monitoring. These include: (1) commercialization of more reliable quantitative neuromuscular monitors and (2) widespread use of sugammadex, a versatile reversal agent of neuromuscular blockade. Sugammadex appears to be so effective at rapidly and effectively reversing even the deepest of neuromuscular blockades, and it has left anesthesia providers wondering whether quantitative monitoring is indeed necessary or whether conventional, familiar, and less expensive qualitative monitoring will suffice? This Pro-Con debate will contrast anesthesia provider perceptions with evidence surrounding the use of quantitative neuromuscular blockade monitors to explore whether quantitative neuromuscular monitoring (NMM) is just another technology solution looking for a problem or a significant advance in NMM that will improve patient safety and outcomes.

Raw and processed electroencephalography in modern anesthesia practice: a brief primer on select clinical applications.

The evidence supporting the intraoperative use of processed electroencephalography (pEEG) monitoring to guide anesthetic delivery is growing rapidly. This article reviews the key features of electroencephalography (EEG) waveforms and their clinical implications in select patient populations and anesthetic techniques. The first patient topic reviewed is the vulnerable brain. This term has emerged as a description of patients who may exhibit increased sensitivity to anesthetics and/or may develop adverse neurocognitive effects following anesthesia. pEEG monitoring of patients who are known to have or are suspected of having vulnerable brains, with focused attention on the suppression ratio, alpha band power, and pEEG indices, may prove useful. Second, pEEG monitoring along with vigilant attention to anesthetic delivery may minimize the risk of intraoperative awareness when administering a total intravenous anesthesia in combination with a neuromuscular blockade. Third, we suggest that processed EEG monitoring may play a role in anesthetic and resuscitative management when adverse changes in blood pressure occur. Fourth, pEEG monitoring can be used to better identify anesthesia requirements and guide anesthetic titration in patients with known or suspected substance use.

Observation of Complement Protein Gene Expression Before and After Surgery in Opioid-Consuming and Opioid-Naive Patients.

Opioids may influence inflammation. We compared genes associated with pain and inflammation in patients who consumed opioids (3-120 mg of oral morphine equivalents per day) with those who did not for differential expression. White blood cells were assayed in 20 patients presenting for total lower extremity joint replacement. We focused on messenger ribonucleic acid expression of complement proteins. We report that the expression of a complement inhibitor, complement 4 binding protein A, was reduced, and the expression of a complement activator, complement factor D, was increased in opioid-consuming patients. We conclude that opioid consumption may influence expression of complement activators and inhibitors.

The effect of audiovisual distraction on patient-controlled sedation under spinal anesthesia: a prospective, randomized trial.

Audiovisual distraction (AVD) has been used to augment or replace procedural sedation. We investigated whether AVD in patients having total hip (THA) or total knee arthroplasty (TKA) under spinal anesthesia would reduce self-administered propofol consumption during surgery. 50 participants were randomized equally into a patient-controlled sedation (PCS) group or AVD group. All participants were given a spinal block and a propofol PCS device prior to surgery. In addition, Group AVD participants selected and watched a movie or documentary film on a tablet device with noise-cancelling headphones during surgery. The primary outcome of this study was total propofol consumption standardized as mcg/kg/min. Secondary outcomes evaluated increased supplemental oxygen use, rescue airway interventions, hypotension, disruptive movement events during surgery, sedation, and satisfaction with anesthesia scores. Historical clinician-controlled propofol usage at our institution over the previous 2 years were recorded. There was no significant difference in median propofol consumption between Groups PCS and AVD, 8.4 mcg/kg/min (1.6-18.9) vs 4 mcg/kg/min (0-9) (P = 0.29), respectively. Historical clinician-controlled usage of propofol demonstrated a median of 39.3 mcg/kg/min (29.2-51.2). There were few differences in the secondary outcome measures. The use of AVD did not reduce patient-controlled propofol consumption in patients having a THA or TKA surgery under spinal anesthesia.

A pharmacokinetic-pharmacodynamic real-time display may change anesthesiologists' behavior.

We have developed a real-time graphical display that presents anesthetic pharmacology data (drug effect site concentrations (Ce) and probability of anesthetic effects including hypnosis, loss of response to tracheal intubation), improving a previous prototype. We hypothesized that the use of the display alters (1) clinical behavior of anesthesiologists (i.e., Ce of isoflurane and fentanyl at the end of anesthesia), (2) fentanyl dose during the first 30 min of recovery in the post anesthesia care unit (PACU), and that the response of clinicians to the display in terms of workload and utility is favorable. The display was evaluated in a two-group, non-randomized prospective observational study of 30 patients undergoing general anesthesia using isoflurane and fentanyl. The isoflurane-predicted Ce was lower in the display group (without-display: 0.64% ± 0.06%; with-display: 0.42 ± 0.04%; t23.9 = 3.17, P = 0.004 < adjusted alpha 0.05/2). The difference in fentanyl-predicted Ce did not achieve statistical significance (without-display: 1.5 ± 0.1 ng/ml; with-display: 2.0 ± 0.2 ng/ml; t25.5 = 2.26, P = 0.03 > adjusted alpha 0.05/2) (means ± standard error). A joint test of isoflurane and fentanyl Ce with respect to the display condition rejected the null hypothesis of no differences (Hotelling T2, P = 0.01), supporting our primary hypothesis. The total fentanyl per patient during the first 30 min in the PACU with the display was 75.0 ± 62.7 µg and that without the display was 83.0 ± 74.7 µg. There was no significant difference between the groups (means ± standard deviation, P = 0.75). There were no differences in perceived workload. Use of the display does not appear to be cognitively burdensome and may change the anesthesiologist's dosing regimen.