Tumour excisional surgery, anaesthetic-analgesic techniques, and oncologic outcomes: a narrative review

Cancer is a growing global burden; there were an estimated 18 million new cancer diagnoses worldwide in 2020. Excisional surgery remains one of the main treatments for solid organ tumours in cancer patients and is potentially curative. Cancer- and surgery-induced inflammatory processes can facilitate residual tumour cell survival, growth, and subsequent recurrence. However, it has been hypothesised that anaesthetic and analgesic techniques during surgery might influence the risk of cancer recurrence. This narrative review aims to provide an updated summary of recent observational studies and new randomised controlled clinical trials on whether certain specific anaesthetic and analgesic techniques or perioperative interventions during tumour resection surgery of curative intent materially affect long-term oncologic outcomes.

Using the TI.VA algorithm to titrate the depth of general anaesthesia: a first-in-humans study

Background

The dose of anaesthetic and opioid drugs must be continuously adjusted after the induction of general anaesthesia to maintain an adequate depth of anaesthesia. The TI.VA algorithm is a multiple-input/multiple-output algorithm designed to optimise the balance between anaesthetic and opioid concentrations during general anaesthesia. It applies vector analysis to a two-dimensional matrix to quantify any inadequacy of the depth of anaesthesia at any given moment and determine any drug dose adjustments required to achieve an adequate depth of anaesthesia. This study aimed to capture preliminary data on the performance and safety of the TI.VA algorithm during total i.v. anaesthesia in patients.

Methods

This prospective study enrolled nine patients with breast cancer scheduled to undergo surgery. General anaesthesia was induced under manual control using propofol and remifentanil. Anaesthesia was guided using the TI.VA algorithm from skin incision until surgical resection was completed. The quality of anaesthesia was assessed through an analysis of performance errors. A bispectral index global score (GSBIS) <50 was considered an acceptable target for algorithm performance.

Results

All nine procedures were completed without any adverse events and none of the patients recalled any intraoperative event. Overall, we analysed 3417 monitoring points corresponding to 285 min of surgery. All patients presented a GSBIS below the cut-off value of 50.

Conclusions

The TI.VA algorithm provides adequate control of clinical anaesthesia. A more sophisticated prototype needs to be developed before the trial is expanded to include larger patient populations.

Clinical trial registration

NCT05199883.

Value of enhanced recovery after surgery in patients undergoing endoscopic retrograde cholangiopancreatography with intravenous anaesthesia for choledocholithiasis: a retrospective observational study

Introduction

Enhanced recovery after surgery (ERAS) is rarely used in minimally invasive endoscopic surgery, especially in endoscopic retrograde cholangiopancreatography (ERCP).

Aim

This study evaluated the safety and efficacy of the ERAS protocol in patients undergoing ERCP for choledocholithiasis.

Material and methods

The study had a retrospective design and included patients with biliary tract stones who underwent ERCP between June 2019 and November 2022. Patients who received the ERAS protocol between June 2021 and November 2022 were enrolled as an ERAS group, and those who received traditional perioperative treatment between December 2019 and May 2021 were enrolled as a control group.

Results

A total of 349 patients were enrolled (ERAS group, n = 185; control group, n = 164). The cannulation and stone extraction success rates were significantly higher in the ERAS group than in the control group (p < 0.05). The incidence of postoperative pancreatitis was significantly lower in the ERAS group (p = 0.02), but there were no significant differences in other complications. The postoperative hospital stay was significantly shorter in the ERAS group than in the control group (p < 0.001), with no statistically significant differences in costs according to surgical period, or in total costs, between the 2 groups.

Conclusions

Application of the ERAS protocol is safe and feasible in patients undergoing ERCP for choledocholithiasis. The ERAS protocol can accelerate recovery, reduce postoperative pain, and shorten the hospital stay without increasing the cost of treatment.

Long-term survival in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: follow-up of a multicentre randomised trial

BACKGROUND

Experimental evidence indicates that i.v. anaesthesia might reduce cancer recurrence compared with volatile anaesthesia, but clinical information is observational only. We therefore tested the primary hypothesis that propofol-based anaesthesia improves survival over 3 or more years after potentially curative major cancer surgery.

METHODS

This was a long-term follow-up of a multicentre randomised trial in 14 tertiary hospitals in China. We enrolled 1228 patients aged 65-90 yr who were scheduled for major cancer surgery. They were randomised to either propofol-based i.v. anaesthesia or to sevoflurane-based inhalational anaesthesia. The primary endpoint was overall survival after surgery. Secondary endpoints included recurrence-free and event-free survival.

RESULTS

Amongst subjects randomised, 1195 (mean age 72 yr; 773 [65%] male) were included in the modified intention-to-treat analysis. At the end of follow-up (median 43 months), there were 188 deaths amongst 598 patients (31%) assigned to propofol-based anaesthesia compared with 175 deaths amongst 597 patients (29%) assigned to sevoflurane-based anaesthesia; adjusted hazard ratio 1.02; 95% confidence interval (CI): 0.83-1.26; P=0.834. Recurrence-free survival was 223/598 (37%) in patients given propofol anaesthesia vs 206/597 (35%) given sevoflurane anaesthesia; adjusted hazard ratio 1.07; 95% CI: 0.89-1.30; P=0.465. Event-free survival was 294/598 (49%) in patients given propofol anaesthesia vs 274/597 (46%) given sevoflurane anaesthesia; adjusted hazard ratio 1.09; 95% CI 0.93 to 1.29; P=0.298.

CONCLUSIONS

Long-term survival after major cancer surgery was similar with i.v. and volatile anaesthesia. Propofol-based iv. anaesthesia should not be used for cancer surgery with the expectation that it will improve overall or cancer-specific survival.

CLINICAL TRIAL REGISTRATIONS

ChiCTR-IPR-15006209; NCT02660411.

Carbon footprint of inhalational and total intravenous anaesthesia for paediatric anaesthesia: a modelling study

BACKGROUND

Tackling the climate emergency is now a key target for the healthcare sector. Avoiding inhalational anaesthesia is often cited as an important element of reducing anaesthesia-related emissions. However, evidence supporting this is based on adult practice. The aim of this study was to identify the difference in carbon footprint of inhalational and i.v. anaesthesia when used in children.

METHODS

We used mathematical simulation models to compare general anaesthetic techniques in children weighing 5-50 kg for TIVA, i.v. induction then inhalational maintenance, inhalational induction then i.v. maintenance, and inhalational induction and maintenance. We simulated inhalational induction with sevoflurane alone, and co-induction with sevoflurane and nitrous oxide, and both remifentanil-propofol and propofol-only i.v. anaesthesia. For each technique, we drew on previously published life-cycle data to calculate carbon dioxide equivalents for anaesthetic durations up to 480 min.

RESULTS

TIVA with propofol and remifentanil had a smaller carbon footprint over a typical anaesthetic duration of 60 min (1.26 kg carbon dioxide equivalents [CO₂e] for a 20 kg child) than i.v. induction followed by inhalational maintenance (2.58 kg CO₂e) or inhalational induction and maintenance (2.98 kg CO₂e). Inhalational induction followed by i.v. maintenance only had a lower carbon footprint than inhalational induction and maintenance when used in longer procedures (>77 min for children 5-20 kg; >105 min for children 30-50 kg).

CONCLUSIONS

In a simulation study, i.v. anaesthesia had climate benefits in paediatric anaesthesia. However, when used after inhalational induction, benefits were only achieved in longer procedures. These findings provide evidence-based guidance for reducing the environmental impact of paediatric anaesthesia, but these will require confirmation using real-world data.

The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients

It is generally accepted that geriatric patients are more sensitive to propofol than adults; thus, a dose-adjusted propofol is recommended for these patients during the induction of anesthesia. However, for patients aged 75 years and over, established guidelines for propofol induction doses do not provide dose references. To this end, we observed 80 surgical patients (female 39, male 41, American Society of Anesthesiologists physical status score I ∼ II) to access the appropriate dose of propofol for inducing loss of consciousness (LOC). Accordingly, patients were subdivided into group A (20 patients, 45–64 years), group B (20 patients, 65–74 years), group C (20 patients, 75–84 years), and group D (20 patients, ≥ 85 years). All patients received propofol (at a rate of 0.3 mg/kg/min) alone for inducing LOC, which was defined by loss of both eyelash reflex and verbal response. Compared with group A, the propofol requirement for LOC in Group B, C and D decreased by 14.8, 25.2 and 38.5%, respectively. Bivariate linear correlation analysis showed that propofol requirement was negatively correlated with age. After adjusting for potential confounders, age was still an independent factor affecting propofol requirement. In conclusion, the propofol requirement for inducing LOC decreased significantly in elderly patients. We demonstrated that age was an independent factor impacting propofol requirement for LOC during the induction of general anesthesia, implying that the propofol dose for anesthesia induction should be further reduced in elderly surgical patients, especially those aged 75 years and over.

Median Effective Dose of Dexmedetomidine Inducing Bradycardia in Elderly Patients Determined by Up-and-Down Sequential Allocation Method

Purpose: When dexmedetomidine is used in elderly patients, high incidence of bradycardia is reported. Given age-related physiological changes in this population, it is necessary to know the safety margin between the loading dose of dexmedetomidine and bradycardia. Therefore, we conducted this study to investigate the median effective dose (ED50) of dexmedetomidine causing bradycardia in elderly patients. Methods: Thirty patients with ages over 65 years undergoing elective general surgery were enrolled. The Dixon and Massay sequential method were applied to determine the loading dose of dexmedetomidine, starting from 1.0 µg/kg. The dose for the follow-up subjects increased or decreased according to the geometric sequence with the common ratio 1.2, based on the 'negative' or 'positive' response of the previous subject. Positive mean that the subject developed bradycardia during the test. Hemodynamic data including heart rate and systolic blood pressure were recorded. The level of sedation was assessed with the Observer Assessment of Alertness and Sedation Scale (OAA/S). Results: Bradycardia occurred in 13 patients (43.3%). The ED50 of dexmedetomidine causing bradycardia was 1.97 µg/kg (95% CI, 1.53-2.53 µg/kg). OAA/S scores at 10 min after the beginning of the dexmedetomidine infusion and 10 min after the termination of dexmedetomidine administration showed no significant differences between the positive and negative groups (P > 0.05). Conclusion: The ED50 of dexmedetomidine causing bradycardia in our cohort was higher than clinical recommended dose. A higher loading dose appears acceptable for a faster onset of sedation under careful hemodynamic monitoring. Trial registration: ChiCTR 15006368.

Volatile anaesthesia and peri-operative outcomes related to cancer: a feasibility and pilot study for a large randomised control trial

Published data suggest that the type of general anaesthesia used during surgical resection for cancer may impact on patient long-term outcome. However, robust prospective clinical evidence is essential to guide a change in clinical practice. We explored the feasibility of conducting a randomised controlled trial to investigate the impact of total intravenous anaesthesia with propofol vs. inhalational volatile anaesthesia on postoperative outcomes of patients undergoing major cancer surgery. We undertook a randomised, double-blind feasibility and pilot study of propofol total intravenous anaesthesia or volatile-based maintenance anaesthesia during cancer resection surgery at three tertiary hospitals in Australia and the USA. Patients were randomly allocated to receive propofol total intravenous anaesthesia or volatile-based maintenance anaesthesia. Primary outcomes for this study were successful recruitment to the study and successful delivery of the assigned anaesthetic treatment as per randomisation arm. Of the 217 eligible patients approached, 146 were recruited, a recruitment rate of 67.3% (95%CI 60.6-73.5%). One hundred and forty-five patients adhered to the randomised treatment arm, 99.3% (95%CI 96.2-100%). Intra-operative patient characteristics and postoperative complications were comparable between the two intervention groups. This feasibility and pilot study supports the viability of the protocol for a large, randomised controlled trial to investigate the effect of anaesthesia technique on postoperative cancer outcomes. The volatile anaesthesia and peri-operative outcomes related to cancer (VAPOR-C) study that is planned to follow this feasibility study is an international, multicentre trial with the aim of providing evidence-based guidelines for the anaesthetic management of patients undergoing major cancer surgery.

Pharmacokinetics and effects on clinical and physiological parameters following a single bolus dose of propofol in common marmosets (Callithrix jacchus)

The objectives of this study were (a) to establish a population pharmacokinetic model and (b) to investigate the clinical and physiological effects of a single bolus dose of propofol in common marmosets. In Study 1, pharmacokinetic analysis was performed in six marmosets under sevoflurane anaesthesia. 8 mg/kg of propofol was administrated at a rate of 4 mg kg^-1  min^-1 . Blood samples were collected 2, 5, 15, 30, 60, 90, 120 or 180 min after starting propofol administration. Plasma concentration was measured, and population pharmacokinetic modelling was performed. A two-compartment model was selected as the final model. The population pharmacokinetic parameters were as follows: V₁  = 1.14 L, V₂  = 77.6 L, CL₁  = 0.00182 L/min, CL₂  = 0.0461 L/min. In Study 2, clinical and physiological parameters were assessed and recorded every 2 min after 12 mg/kg of propofol was administrated at a rate of 4 mg kg^-1  min^-1 . Immobilization was sustained for 5 min following propofol administration without apparent bradycardia. While combination of propofol and sevoflurane caused apnoea in Study 1, apnoea was not observed following single administration of propofol in Study 2. These data provide bases for further investigation on intravenous anaesthesia using propofol in common marmosets.

Consensus document for multimodal intraoperatory neurophisiological monitoring in neurosurgical procedures. Basic fundamentals

The present work aims to establish a guide to action, agreed by anaesthesiologists and neurophysiologists alike, to perform effective intraoperative neurophysiological monitoring for procedures presenting a risk of functional neurological injury, and neurosurgical procedures. The first section discusses the main techniques currently used for intraoperative neurophysiological monitoring. The second exposes the anaesthetic and non-anaesthetic factors that are likely to affect the electrical records of the nervous system structures. This section is followed by an analysis detailing the adverse effects associated with the most common techniques and their use. Finally, the last section describes a series of guidelines to be followed upon the various intraoperative clinical events.

Evaluation of selected parameters of the coagulation system during the perioperative period in patients undergoing endoscopic surgery of the paranasal sinuses

INTRODUCTION

The aim of the study was to evaluate selected parameters of the coagulation system during the perioperative period in patients undergoing endoscopic sinus surgery.

MATERIAL AND METHODS

The study involved 121 patients: group I - 42 patients who did not receive anticoagulatory or antiplatelet medications, qualified for endoscopic sinus surgery under total intravenous anaesthesia (TIVA); group II - 40 patients who received in the perioperative period low-molecular-weight heparins, qualified for endoscopic sinus surgery under TIVA; group III - 39 patients diagnosed according to a schedule, due to vertigo or loss of hearing. All the patients received a full laryngological examination and detailed audiological and otoneurological diagnostics, and examination of selected haemostatic parameters before the surgery/diagnostics.

RESULTS

The analysis of concentrations of coagulation parameters in groups I and II revealed a statistically significantly higher international normalized ratio value before surgery (I - 1.11; II - 1.08) and 48 h following surgery (I - 1.15; II - 1.10) in group I. The concentration of coagulation factor VII in the study patients was considerably higher in group I for all three measurements (481.93; 443.13; 486.02). The concentration of fibrinogen (coagulation factor I) was significantly lower in group I before surgery (3.2) and at 6 h after surgery (2.84). A significantly lower level of von Willebrand factor was found in group I before surgery (2.94). Comparing test results of groups I and III, who did not receive antiaggregants, statistically significant differences were observed in both tests for factors VII and VIII.

CONCLUSIONS

Concentrations of von Willebrand factor and prothrombin revealed statistically significant differences in between groups.

Intravenous versus inhalational anaesthesia and lung ventilation-perfusion matching

Lung gas exchange efficiency deteriorates during general anaesthesia due to ventilation–perfusion ( V/Q) scatter. Propofol total intravenous anaesthesia (TIVA) may preserve V/Q matching better than inhalational agents. We compared V/Q matching in patients randomized to either TIVA or sevoflurane anaesthesia, using deadspace and shunt measurements and the MIGET (Multiple Inert Gas Elimination Technique). Baseline arterial blood and mixed expired gas sampling was done before induction and repeated after one to two hours of relaxant general anaesthesia in 20 patients, supine with controlled ventilation at an FiO2of 0.3 and a target end-tidal PCO2of 30–35 mmHg. Blood samples for MIGET were processed after headspace equilibration by gas chromatography. The primary endpoint was a comparison of the two groups in the change from baseline of absolute difference between log standard deviation of ventilation and blood flow distributions (∂(σV−σQ)). Deadspace fraction increased and PaO2/FiO2ratio decreased across both groups overall with anaesthesia, but change in deadspace was not different between groups (mean (standard deviation, SD) sevoflurane 21.8% (11.7%) versus TIVA 20.5% (10.6%), P = 0.601). Change in PaO2/FiO2ratio was also similar between groups (mean (SD) sevoflurane −51.9 (69.1) mmHg versus TIVA −78.3 (76.9) mmHg, P = 0.43), as was change in shunt fraction (δQs/Qt mean (SD) sevoflurane −5.1% (12.6%) versus TIVA 0.4% (7.7%), P = 0.174). The primary endpoint ∂(σV−σQ) was not different between sevoflurane and propofol TIVA groups (mean (SD) 0.17 (0.81) versus 0.17 (0.29), P = 0.94). TIVA did not better preserve V/Q matching in patients undergoing anaesthesia with controlled ventilation compared with sevoflurane.

Association between anaesthetic technique and unplanned admission to intensive care after thoracic lung resection surgery: the second Association of Cardiothoracic Anaesthesia and Critical Care (ACTACC) National Audit

Unplanned intensive care admission is a devastating complication of lung resection and is associated with significantly increased mortality. We carried out a two-year retrospective national multicentre cohort study to investigate the influence of anaesthetic and analgesic technique on the need for unplanned postoperative intensive care admission. All patients undergoing lung resection surgery in 16 thoracic surgical centres in the UK in the calendar years 2013 and 2014 were included. We defined critical care admission as the unplanned need for either tracheal intubation and mechanical ventilation or renal replacement therapy, and sought an association between mode of anaesthesia (total intravenous anaesthesia vs. volatile) and analgesic technique (epidural vs. paravertebral) and need for intensive care admission. A total of 253 out of 11,208 patients undergoing lung resection in the study period had an unplanned admission to intensive care in the postoperative period, giving an incidence of intensive care unit admission of 2.3% (95%CI 2.0-2.6%). Patients who had an unplanned admission to intensive care unit had a higher mortality (29.00% vs. 0.03%, p < 0.001), and hospital length of stay was increased (26 vs. 6 days, p < 0.001). Across univariate, complete case and multiple imputation (multivariate) models, there was a strong and significant effect of both anaesthetic and analgesic technique on the need for intensive care admission. Patients receiving total intravenous anaesthesia (OR 0.50 (95%CI 0.34-0.70)), and patients receiving epidural analgesia (OR 0.56 (95%CI 0.41-0.78)) were less likely to have an unplanned admission to intensive care after thoracic surgery. This large retrospective study suggests a significant effect of both anaesthetic and analgesic technique on outcome in patients undergoing lung resection. We must emphasise that the observed association does not directly imply causation, and suggest that well-conducted, large-scale randomised controlled trials are required to address these fundamental questions.

The minimum infusion rate of alfaxalone during its co-administration with lidocaine at three different doses by constant rate infusion in goats

OBJECTIVE

To determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement in response to standardized stimulation while co-administered with lidocaine at three different doses by constant infusion rate infusion (CRI) in goats.

STUDY DESIGN

Prospective, blinded, randomized crossover, experimental.

ANIMALS

A total of eight healthy goats: four does and four wethers.

METHODS

Anaesthetic induction was with lidocaine at 1 mg kg^-1 [low dose of lidocaine (L-Lid)], 2 mg kg^-1 [moderate dose (M-Lid)] or 4 mg kg^-1 [high dose (H-Lid)] and alfaxalone at 2 mg kg^-1. Anaesthetic maintenance was with alfaxalone initially at 9.6 mg kg^-1 hour^-1 combined with one of three lidocaine treatments: 3 mg kg^-1 hour^-1 (L-Lid), 6 mg kg^-1 hour^-1 (M-Lid) or 12 mg kg^-1 hour^-1 (H-Lid). The MIR of alfaxalone was determined by testing for responses to a stimulation in the form of clamping on a digit with a Vulsellum forceps every 30 minutes during lidocaine CRI. Basic cardiopulmonary parameters were measured.

RESULTS

The alfaxalone MIRs were 8.64 (6.72-10.56), 6.72 (6.72-8.64) and 6.72 (6.72-6.72) mg kg^-1 hour^-1 during L-Lid, M-Lid and H-Lid, respectively, without any significant differences among treatments. Compared to the initial rate of 9.6 mg kg^-1 hour^-1, these reductions in MIR are equivalent to 10, 30 and 30%, respectively. Significant increases in heart rate (HR) and arterial carbon dioxide partial pressure (PaCO₂) and decreases in arterial haemoglobin saturation (SaO₂), arterial oxygen partial pressure (PaO₂) and respiratory frequency (f_R) immediately after induction were observed during all lidocaine treatments.

CONCLUSIONS AND CLINICAL RELEVANCE

Lidocaine reduces the alfaxalone MIR by up to 30% with a tendency towards a plateauing in this effect at high CRIs. Immediate oxygen supplementation might be required to prevent hypoxaemia.