Population Pharmacokinetics of Intravenous Lidocaine in Adults: A Systematic Review

BACKGROUND

The establishment of optimal dosing regimens for intravenous (IV) lidocaine in the perioperative setting, aiming to balance effective pain relief with minimisation of potential side effects, is a topic of ongoing debate. This discussion stems from the significant variability in lidocaine's pharmacokinetic (PK) parameters and its relatively narrow safety margin. Population pharmacokinetic (popPK) modelling has emerged as a valuable tool for understanding the factors contributing to this observed variability in drug kinetics.

OBJECTIVES

This systematic review compiles the existing knowledge on lidocaine's PK properties and published popPK models, with a focus on significant covariates.

METHODS

A systematic search on Cochrane CENTRAL, Medline, and EMBASE was performed from inception to June 2023. Original clinical studies that administered IV lidocaine to adults and performed PK analyses using a nonlinear mixed effects modelling approach were included. The quality of the included studies was assessed by compliance with the Clinical Pharmacokinetics (ClinPK) statement checklist.

RESULTS

Seven studies were included, which involved a diverse adult population, including both volunteers and patients with various comorbidities. Lidocaine PK was primarily characterised by a two- or three-compartment model. The volume of distribution at steady state ranged from 66 to 194 L, and the total clearance ranged from 22 to 49 L/h. Despite adjusting for significant covariates like heart failure status, alpha-1-acid glycoprotein, duration of lidocaine infusion, and body weight, each study revealed substantial variability in PK parameters. The potential impact of hepatic or renal function biomarkers on these PK parameters calls for further investigation. Incomplete reporting of key aspects of developed models may hinder the models' reliability and clinical application.

CONCLUSION

The findings emphasise the importance of tailoring drug dosage to ensure the safe and effective use of intravenous lidocaine. Optimal design methodologies may be incorporated for a more efficient identification of important covariates. Utilising contemporary model evaluation methods like visual predictive checks and bootstrapping would enhance the robustness of popPK models and the reliability of their predictions. This comprehensive review advances our understanding of lidocaine's pharmacokinetics and lays the groundwork for further research in this critical area of perioperative pain management. Review protocol registered on 25 August 2023 in PROSPERO (CRD42023441113). This work was supported by the Fundamental Research Grant Scheme, the Ministry of Higher Education, Malaysia (FRGS/1/2020/SKK01/UM/02/2).

Partial vs full glottic view with CMACTM D blade intubation of airway with simulated cervical spine injury: a randomized controlled trial

PURPOSE

A previous study reported a shorter time to tracheal intubation by reducing percentage of glottic opening (POGO) view to <50% when intubating a normal adult airway using the Glidescope^TM blade. We evaluate the efficacy of reducing POGO to <50% when intubating patients with rigid cervical immobilization using CMAC^TM D blade.

METHODS

One hundred and four adult patients were randomized to group POGO 100% or POGO <50% . Laryngoscopy was performed by advancing tip of the D blade at vallecula. POGO 100% was achieved by exerting upward force to displace epiglottis until glottic opening from the anterior commissure to inter arytenoid notch. POGO < 50% was acquired by withdrawing the D blade tip dorsally from vallecula. The primary outcome was time to intubation.

RESULTS

The median time (IQR) to successful intubation was 29 (25-35) seconds for group POGO < 50% and 34 (28-40) seconds for group with POGO 100% (difference in medians, 5 seconds; 95% confidence interval, 2 to 8, p = 0.003). Complications were minor.

CONCLUSION

Using the CMAC^TM D blade with a reduced POGO in patients with cervical spine immobilization resulted in faster tracheal intubation.

TRIAL REGISTRATION

The trial is registered at ClinicalTrial.gov (CT.gov identifier: NCT04833166).

Population Pharmacokinetics and Dosing Simulations of Intravenous Oxycodone for Perioperative Pain Relief in Adult Surgical Patients with Obesity

BACKGROUND AND OBJECTIVE

Oxycodone, a semisynthetic thebaine derivative µ-opioid (MOP) receptor agonist, is effective for treating moderate and severe pain in different clinical conditions. The pharmacokinetics of intravenous oxycodone in the obese population has not been studied. This study aims to characterize the pharmacokinetic profile of oxycodone after intravenous administration and to simulate an appropriate dosage for analgesic efficacy in obese patients.

METHODS

We recruited 33 (age range from 21 to 72 years) adult patients with a body mass index of 30 kg/m² and above, who were scheduled for non-cardiac surgeries. Intravenous oxycodone was administered after induction of general anesthesia and blood samples were collected up to 24 h after oxycodone administration. Plasma concentrations of oxycodone were assayed using liquid chromatography-tandem mass spectrometry and 253 concentration-time points were used for pharmacokinetic analysis using nonlinear mixed-effects modeling.

RESULTS

Intravenous oxycodone pharmacokinetics were well described by a two-compartment open model. The estimated total clearance and central volume of distribution of oxycodone are 28.5 l/h per 70 kg and 56.4 l per 70 kg, respectively. Total body weight was identified as a significant covariate of the clearance and central volume of distribution. Dosing simulations based on the final model demonstrate that a starting dose of 0.10 mg/kg of intravenous oxycodone is adequate to achieve a target plasma concentration and repeated doses of 0.02 mg/kg may be administered at 1.5-h intervals to maintain a plasma concentration within an effective analgesic range.

CONCLUSIONS

A population pharmacokinetic model using total body weight as a covariate supports the administration of 0.10 mg/kg of intravenous oxycodone as a starting dose and repeated doses of 0.02 mg/kg at 1.5-h intervals to maintain targeted plasma concentrations for analgesia in the obese adult population.

Psychological distress among elderly surgical patients who had their surgery postponed during the COVID-19 pandemic

Background

Many institutions withheld elective lists and triaged surgeries during the peak of coronavirus disease 2019 (COVID-19) pandemic. As a result, older surgical patients have had to wait for rescheduled dates in a long waitlist. This study aimed to identify the psychological impact in these patients when they returned for surgery.

Methods

This was a cross-sectional study which included 153 patients aged ≥ 65 years undergoing elective surgery. Trained interviewers recruited and assessed psychological status pre-operatively with two validated questionnaires - Hospital Anxiety and Depression Scale (HADS) and 36-item Short Form Health Survey (SF-36). Specific questions were asked about their postponed surgeries, appetite and fear.

Results

A total of 36 out of 153 (23.5%) patients had their procedures deferred during the first wave of COVID-19 pandemic. Postponed cases were significantly based on the nature of surgery (p = 0.002), cancer diagnosis (p = 0.006) and surgical specialty (p = 0.023). Median HADS scores were higher for patients who were postponed (2.00 versus 4.00 for anxiety, p = 0.180 and 0.00 versus 1.00 for depression, p = 0.424) although no statistical significance was shown. In the whole study population, anxiety was a significant predictor for depression and vice versa (p < 0.001) with other predictive risk factors for anxiety that were age ≥ 85 years old (odds ratio [OR] 6.14, p = 0.018), female (OR 2.41, p = 0.024), cancer (OR 2.19, p = 0.039) and major surgery (OR 2.39, p = 0.023). Similarly, older patients ≥ 85 years old (OR 10.44, p = 0.003) and female (OR 6.07, p = 0.006) had higher risk for depression. Both anxiety and depression were significant risks for loss of appetite (p = 0.005 and 0.001). Lastly, the fear of disease progression due to rescheduling was more frequent in cancer patients (p = 0.035).

Conclusion

The mental health and disease burden of older surgical patients should be taken into careful consideration when cases need to be postponed in our healthcare system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-022-00242-7.

The Use of Cerebral Oximetry in Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The evidence on the use of cerebral oximetry during surgery to minimize postoperative neurologic complications remains uncertain in the literature. The present authors aimed to assess the value of cerebral oximetry in the prevention of postoperative cognitive dysfunction, postoperative delirium, and postoperative stroke in adults undergoing surgery.

DESIGN

A systematic review and meta-analysis.

SETTING

The surgery room.

PARTICIPANTS

Adult patients (ages ≥18 years) undergoing surgery.

INTERVENTIONS

Cerebral oximetry monitoring.

MEASUREMENTS AND MAIN RESULTS

Databases of Ovid MEDLINE, Ovid EMBASE, and CENTRAL were systematically searched from their inception until December 2020 for randomized controlled trials comparing cerebral oximetry monitoring with either blinded or no cerebral oximetry monitoring in adults undergoing surgery. Observational studies, case reports, and case series were excluded. Seventeen studies (n = 2,120 patients) were included for quantitative meta-analysis. Patients who were randomized to cerebral oximetry monitoring had a lower incidence of postoperative cognitive dysfunction (studies = seven, n = 969, odds ratio [OR] 0.23, 95% confidence interval [CI] 0.11-0.48, p = 0.0001; evidence = very low). However, no significant differences were observed in the incidence of postoperative delirium (studies = five, n = 716, OR 0.81, 95% CI 0.53-1.25, p = 0.35; evidence = high), and postoperative stroke (studies = seven, n = 1,087, OR 0.72, 95% CI 0.30-1.69, p = 0.45; evidence = moderate).

CONCLUSION

Adult patients with cerebral oximetry monitoring were associated with a significant reduction of postoperative cognitive dysfunction. However, given the low certainty of evidence and substantial heterogeneity, more randomized controlled trials using standardized assessment tools for postoperative cognitive dysfunction and interventions of correcting cerebral desaturation are warranted to improve the certainty of evidence and homogeneity.

Evaluate construct validity of the Revised American Pain Society Patient Outcome Questionnaire in gynecological postoperative patients using confirmatory factor analysis

Background

The Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R) evaluates the patient-reported quality of pain management in adults. A validated APS-POQ-R is pivotal to guide effective pain management with better patient satisfaction. Previous studies revealed that subscales of “patients’ perception of pain management” were unstable cross-culturally. This study aims to evaluate the construct validity of the APS-POQ-R in gynecological postoperative patients with a multi-cultural background using confirmatory factor analysis to allow comparisons among different a priori models at the latent factor level.

Methods

Patients aged 18 years old or above and who were scheduled for gynecology surgery were selected. Three different models with a combination of latent factors were based on a priori hypotheses from previous studies. The root-mean-squared error of approximation, comparative fit index, Tucker-Lewis Index, Chi-squared test, and change in Chi-squared statistic given a change in degrees of freedom between models were used to assess the model fit to the present data.

Results

A total of 302 patients completed the questionnaire. The five-factor model which was based on Gordon’s study has an acceptable fit for the data and was superior when compared to the one-factor baseline model. Although the four-factor model, which originated from Botti’s study, also demonstrates a good model fit, the “perception of care” construct was excluded in this model. The “perception of care” construct is conceptually important as patient-centered care has become the focus of quality improvement of pain service.

Conclusions

The APS-POQ-R is easy to administer and is useful for quality evaluation in postoperative pain management. The present study demonstrates that a five-factor structure of the APS-POQ-R is the best fitting model in our patient sample. The results of this study provide further evidence to support the use of APS-POQ-R as a measurement tool for pain management evaluation in acute postoperative patients with a multi-cultural background.

The handling of safety concerns among anaesthetists when restarting full surgical lists during the COVID-19 pandemic

Around June 2020, many institutions restarted full operating schedules to clear the backlog of postponed surgeries because of the first wave in the COVID-19 pandemic. In an online survey distributed among anaesthestists in Asian countries at that time, most of them described their safety concerns and recommendations related to the supply of personal protective equipment and its usage. The second concern was related to pre-operative screening for all elective surgical cases and its related issues. The new norm in practice was found to be non-standardized and involved untested devices or workflow that have since been phased out with growing evidence. Subsequent months after reinstating full elective surgeries tested the ability of many hospitals in handling the workload of non-COVID surgical cases together with rising COVID-19 positive cases in the second and third waves when stay-at-home orders eased.

Baska mask versus endotracheal tube in laparoscopic cholecystectomy surgery: a prospective randomized trial

Background: Supraglottic airway devices have increasingly been used as the airway technique of choice in laparoscopic surgeries. This study compared the efficacy and safety of the Baska Mask with endotracheal tube (ETT) in patients undergoing elective laparoscopic cholecystectomy.Research design and methods: This single-center, prospective, randomized controlled trial recruited 60 patients aged 18-75 years with American Society of Anesthesiologists' classifications I to III. The time taken to achieve effective airway, number of attempts, ease of insertion, ventilation parameters, hemodynamics data, and pharyngolaryngeal complications were recorded.Results: The time taken to achieve effective airway was shorter for the Baska group (26.6 ± 4.7 vs. 47.2 ± 11.8 s; p < 0.001), although the first-time insertion success rate was ≥90% for both groups. The ETT group experienced more pharyngolaryngeal complications, including cough, trauma, spasm, dysphonia, and sore throat, during device insertion and removal and had higher systolic and diastolic blood pressures during intubation (p = 0.001). The Baska Mask achieved significantly lower peak airway pressure (p = 0.024) with stable oropharyngeal leak pressure ≥33 cmH₂O throughout the surgery.Conclusions: The Baska Mask is a suitable alternative to endotracheal intubation in selected patients undergoing laparoscopic cholecystectomy, with shorter insertion times, fewer perioperative complications, and improved ventilatory performance and hemodynamic response.Trial registration: The trial is registered at ClinicalTrials.gov (NCT03045835), 8 February 2017.

Clinical performance of the LMA Protector™ airway in moderately obese patients

Background

The 4th National Audit Project of The Royal College of Anaesthetists and The Difficult Airway Society (NAP4) reported a higher incidence of supraglottic airway device (SAD) related pulmonary aspiration in obese patients especially with the first-generation SADs. The latest single-use SAD, the Protector™ provides a functional separation of the respiratory and digestive tracts and its laryngeal cuff with two ports allowing additional suction in tandem with the insertion of a gastric tube. The laryngeal cuff of LMA Protector™ allows a large catchment reservoir in the event of gastric content aspiration.

Methods

We evaluated the performance characteristics of the LMA Protector™ in 30 unparalysed, moderately obese patients. First attempt insertion rate, time for insertion, oropharyngeal leak pressure (OLP), and incidence of complications were recorded.

Results

We found high first and second attempt insertion rates of 28(93%) and 1(33%) respectively, with one failed attempt where no capnography trace could be detected, presumably from a downfolded device tip. The LMA Protector™ was inserted rapidly in 21.0(4.0) seconds and demonstrated high OLP of 31.8(5.4) cmH2O. Fibreoptic assessment showed a clear view of vocal cords in 93%. The incidence of blood staining on removal of device was 48%, postoperative sore throat 27%, dysphagia 10% and dysphonia 20% (all self-limiting, resolving a few hours postoperatively).

Conclusions

We conclude that the LMA Protector™ was associated with easy, expedient first attempt insertion success, demonstrating high oropharyngeal pressures and good anatomical position in the moderately obese population, with relatively low postoperative airway morbidity.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12617001152314. Registered 7 August 2017.

Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

BACKGROUND

Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications.

METHODS

HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896).

FINDINGS

Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4-9) in the accelerated-surgery group and 24 h (10-42) in the standard-care group (p<0·0001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0·91 (95% CI 0·72 to 1·14) and absolute risk reduction (ARR) of 1% (-1 to 3; p=0·40). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0·97 (0·83 to 1·13) and an ARR of 1% (-2 to 4; p=0·71).

INTERPRETATION

Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care.

FUNDING

Canadian Institutes of Health Research.

The hemodynamic and pain impact of peripheral nerve block versus spinal anesthesia in diabetic patients undergoing diabetic foot surgery

PURPOSE

Comparison of hemodynamic profiles and pain scores in diabetic patients undergoing diabetic foot surgery receiving peripheral nerve block (PNB) or spinal anesthesia [subarachnoid block (SAB)].

METHODS

This was a prospective, randomised controlled trial. We recruited diabetic patients aged > 18 years, American Society of Anesthesiologists class II-III, who were scheduled for unilateral diabetic foot surgery below the knee. All patients were assessed for autonomic dysfunction using the Survey of Autonomic Symptoms score. Participants were randomly assigned to receive either PNB or SAB for the surgery. Hemodynamic data, including usage of vasopressors, were recorded at 5-min intervals for up to 1 h after the induction of anesthesia. Pain scores were recorded postoperatively, and follow-up was done via telephone 6 months later.

RESULTS

Compared to the PNB group, the SAB group had a larger number of patients with significant hypotension (14 vs. 1; p = 0.001) and more patients who required vasopressor boluses (6 vs. 0 patients). Compared to SAB group, the patients in the PNB group had a longer postoperative pain-free duration (9 vs. 4.54 h; p = 0.002) and lower pain scores 1 day after surgery (3.63 vs. 4.69; p = 0.01).

CONCLUSION

Peripheral nerve block should be considered, whenever possible, as the first option of anesthesia for lower limb surgery in diabetic patients as it provides hemodynamic stability and superior postoperative pain control compared to SAB.

TRIAL REGISTRATION

Clinical trial registry: ClinicalTrials.gov. ID NCT02727348.

Randomized comparison of the Baska FESS mask and the LMA Supreme in different head and neck positions

BACKGROUND

The Baska functional endoscopic sinus surgery (FESS) mask is a new supraglottic airway designed for head and neck procedures. This prospective, randomized controlled trial compared the oropharyngeal leak pressure (OLP) of the Baska FESS mask with the laryngeal mask airway (LMA) Supreme in different head and neck positions.

METHODS

One hundred patients undergoing elective surgery were recruited. OLP was compared in supine position, 45° lateral rotation, 45° neck extension, and 30° neck flexion. Glottic view, insertion time, ease of insertion, number of attempts, ease and time of insertion of gastric tube, and complications were also compared.

RESULTS

The OLP of the Baska FESS was higher than the LMA Supreme in all head and neck positions studied (p < 0.001). Glottic views were better in the Baska FESS in supine and lateral rotation. LMA Supreme was easier (p = 0.046) and faster (p < 0.001) to insert. First attempt insertion success rates were 91.8% for Baska FESS and 98% for LMA Supreme. Gastric drain was easier and faster to insert (p < 0.001) in the LMA Supreme.

CONCLUSIONS

The Baska FESS provides a superior airway seal with higher mean OLP than the LMA Supreme in all head and neck positions studied. However, LMA Supreme was superior in terms of ease and speed of insertion.