Carbon Footprint of Total Intravenous and Inhalation Anesthesia in the Transcatheter Aortic Valve Replacement Procedure

OBJECTIVES

To quantify and compare the emissions for deep sedation with total intravenous anesthesia (TIVA) and general anesthesia with inhaled agents during the transcatheter aortic valve replacement procedure.

DESIGN

A retrospective study.

SETTING

A tertiary hospital in Boston, Massachusetts.

PARTICIPANTS

The anesthesia records of 604 consecutive patients who underwent the transcatheter aortic valve replacement procedure between January 1, 2018, and March 31, 2022, were reviewed and analyzed.

INTERVENTIONS

Data were examined and compared in the following 2 groups: general anesthesia with inhaled agents and deep sedation with TIVA.

MEASUREMENTS AND MAIN RESULTS

The gases, drugs, airway management devices, and anesthesia machine electricity were collected and converted into carbon dioxide emissions (CO2e). The carbon emissions of intravenous medications were converted with the CO2e data for anesthetic pharmaceuticals from the Parvatker et al. study. For inhaled agents, inhaled anesthetics and oxygen/air flow rate were collected at 15-minute intervals and calculated using the anesthetic gases calculator provided by the Association of Anesthetists. The airway management devices were converted based on life-cycle assessments. The electricity consumed by the anesthesia machine during general anesthesia was estimated from the manufacturer's data (Dräger, GE) and local Energy Information Administration data. The data were analyzed in the chi-squared test or Wilcoxon rank-sum test. There were no significant differences in the patients' demographic characteristics, such as age, sex, weight, height, and body mass index. The patients who received general anesthesia with inhaled agents had statistically higher total CO2e per case than deep sedation with TIVA (16.188 v 1.518 kg CO2e; p < 0.001), primarily due to the inhaled agents and secondarily to airway management devices. For deep sedation with TIVA, the major contributors were intravenous medications (71.02%) and airway management devices (16.58%). A subgroup study of patients who received sevoflurane only showed the same trend with less variation.

CONCLUSIONS

The patients who received volatile anesthesia were found to have a higher CO2e per case. This difference remained after a subgroup analysis evaluating those patients only receiving sevoflurane and after accounting for the differences in the duration of anesthesia. Data from this study and others should be collectively considered as the healthcare profession aims to provide the best care possible for their patients while limiting the harm caused to the environment.

Balancing Patient Needs With Environmental Impacts for Best Practices in General Anesthesia: Narrative Review and Clinical Perspective

Discussions of the environmental impacts of general anesthetics have focused on greenhouse gas (GHG) emissions from inhaled agents, with those of total intravenous anesthesia (TIVA) recently coming to the forefront. Clinical experts are calling for the expansion of research toward life cycle assessment (LCA) to comprehensively study the impact of general anesthetics. We provide an overview of proposed environmental risks, including direct GHG emissions from inhaled anesthetics and non-GHG impacts and indirect GHG emissions from propofol. A practical description of LCA methodology is also provided, as well as how it applies to the study of general anesthesia. We describe available LCA studies comparing the environmental impacts of a lower carbon footprint inhaled anesthetic, sevoflurane, to TIVA/propofol and discuss their life cycle steps: manufacturing, transport, clinical use, and disposal. Significant hotspots of GHG emission were identified as the manufacturing and disposal of sevoflurane and use (attributed to the manufacture of the required syringes and syringe pumps) for propofol. However, the focus of these studies was solely on GHG emissions, excluding other environmental impacts of wasted propofol, such as water/soil toxicity. Other LCA gaps included a lack of comprehensive GHG emission estimates related to the manufacturing of TIVA plastic components, high-temperature incineration of propofol, and gas capture technologies for inhaled anesthetics. Considering that scarce LCA evidence does not allow for a definite conclusion to be drawn regarding the overall environmental impacts of sevoflurane and TIVA, we conclude that current anesthetic practice involving these agents should focus on patient needs and established best practices as more LCA research is accumulated.

Postoperative nausea and vomiting at Landspitali: A prospective study

BACKGROUND

In the last decade, anaesthesia practice has changed at Landspitali, where the majority of patients now receive antiemetic prophylaxis, and the use of total intravenous anaesthesia is the dominant mode for maintenance of anaesthesia. The aim of this study was to assess the incidence of postoperative nausea and vomiting (PONV) in a prospective way, the use of PONV prophylaxis, and clinical risk factors associated with PONV during this era.

METHODS

A prospective cohort study using a convenience sample of 438 patients ≥18 years old admitted to the postoperative care unit (PACU) after elective or emergency operations in May-July 2022 at Landspitali University Hospital in Iceland. Patients answered questionnaires in the PACU and 24 h after discharge from PACU.

RESULTS

The incidence of self-reported moderate/severe nausea (5/10 or higher on NRS) in PACU was 4% and 3% on postoperative day 1. A total of 91% of delivered anaesthetics were with intravenous medications only, and 82% of patients received at least one prophylactic medication for PONV. When asked to rate the worst nausea experienced, this was described as moderate/severe by 7% in PACU and 17% on postoperative day 1. Risk factors associated with PONV were female gender (OR 1.90, 95% CI 1.04-3.53) and a history of motion sickness or PONV (2.74, 1.51-4.94), but increasing age was protective (0.83 per decade, 0.71-0.98). Despite a more liberal administration of antiemetics, patients with more risk factors per Apfel PONV risk classification had a higher incidence of PONV.

CONCLUSION

The incidence of PONV is generally low in this diverse surgical population where anaesthesia is mostly maintained with total intravenous anaesthesia and PONV prophylaxis is common. PONV remains a predictable complication following anaesthesia, suggesting further improvement in its prevention is possible.

Comparison of combined intravenous and inhalation anesthesia and total intravenous anesthesia in laparoscopic surgery and the identification of predictive factors influencing the delayed recovery of neurocognitive function

Background

Compare the anesthesia effects of combined intravenous and inhalation anesthesia (CIVIA) and total intravenous anesthesia (TIVA) in laparoscopic surgery. Furthermore, our objective is to examine the elements that contribute to the delay in postoperative recovery of neurocognitive function and anticipate the manifestation of delayed recovery by analyzing serum cytokines.

Methods

The CIVIA group and the TIVA group both consisted of 130 patients who were scheduled to have elective major abdominal surgery through laparoscopy. The criteria taken into account by the observational and record-keeping study were the patients' ages, sexes, body masses, heights, and the presence or absence of any preexisting problems. Both groups also had their anesthetic depth, duration, and per-unit-of-time muscle relaxant and analgesic dosages recorded. Finally, the length of each patient's stay in the hospital as well as their overall length of stay were tracked. By using the Mini-Mental State Examination (MMSE) to measure cognitive function, we assessed the mental states of the subjects. Additionally, we wanted to identify any biomarkers that could be linked to postoperative cognitive decline or delays in neurocognitive recovery.

Results

A total of 51 participants from the CIVIA group and 53 participants from the TIVA group satisfactorily completed the necessary neuropsychological exam for identifying delayed neurocognitive recovery at the study's completion. In the initial data of the two groups, no significant discrepancies were found (p > 0.05). The CIVIA group exhibited noteworthy reductions in the quantity of administered analgesics and muscle relaxants per unit of time in comparison to the TIVA group (p < 0.05). In addition to this, the duration from the sevoflurane tank being closed to the extubation period demonstrated a significant reduction in the CIVIA group compared to the TIVA group (p < 0.05). Moreover, no statistically notable distinction was observed in terms of postoperative hospitalization duration and overall hospitalization duration among both groups (p > 0.05). According to the study, both the CIVIA group and the TIVA group had a total of 7 (13.72%) and 17 (32.07%) individuals, respectively, who met the criteria for neurocognitive delayed recovery (Odds Ratio: 0.336; 95% CI: 0.134-0.864; p = 0.026). According to the research findings, it is indicated that there is a possibility for an increased presence of IL-6 in the bloodstream within 60 min following the incision made on the skin. This occurrence subsequently leads to the prolonged restoration of neurocognitive capabilities.

Conclusion

The CIVIA technique outperforms the TIVA method in terms of overall assessment in the setting of laparoscopic surgery. It's also important to remember that an increased blood IL-6 level during laparoscopy may operate as a separate risk factor for a delay in the restoration of neurocognitive function.

Reducing the carbon footprint of general anaesthesia: a comparison of total intravenous anaesthesia vs. a mixed anaesthetic strategy in 47,157 adult patients

Global warming is a major public health concern. Volatile anaesthetics are greenhouse gases that increase the carbon footprint of healthcare. Modelling studies indicate that total intravenous anaesthesia is less carbon intensive than volatile anaesthesia, with equivalent quality of care. In this observational study, we aimed to apply the findings of previous modelling studies to compare the carbon footprint per general anaesthetic of an exclusive TIVA strategy vs. a mixed TIVA-volatile strategy. This comparative retrospective study was conducted over 2 years in two French hospitals, one using total intravenous anaesthesia only and one using a mixed strategy including both intravenous and inhalation anaesthetic techniques. Based on pharmacy procurement records, the quantity of anaesthetic sedative drugs was converted to carbon dioxide equivalents. The primary outcome was the difference in carbon footprint of hypnotic drugs per intervention between the two strategies. From 1 January 2021 to 31 December 2022, 25,137 patients received general anaesthesia in the hospital using the total intravenous anaesthesia strategy and 22,020 in the hospital using the mixed strategy. The carbon dioxide equivalent footprint of hypnotic drugs per intervention in the hospital using the total intravenous anaesthesia strategy was 20 times lower than in the hospital using the mixed strategy (emissions of 2.42 kg vs. 48.85 kg carbon dioxide equivalent per intervention, respectively). The total intravenous anaesthesia strategy significantly reduces the carbon footprint of hypnotic drugs in general anaesthesia in adult patients compared with a mixed strategy. Further research is warranted to assess the risk-benefit ratio of the widespread adoption of total intravenous anaesthesia.

Effects of Anesthetic Choice on the Incidence of Transcranial-Motor Potential-Induced Oral Trauma

Transcranial motor-evoked potentials (TcMEPs) play an integral role in assessing motor tract function in surgical procedures where motor function is at risk. However, transcranial stimulation creates a risk for oral trauma. Several studies have reported on distinct factors that can influence the rate of TcMEP-induced oral trauma, but little is known about how an anesthetic regimen can influence this rate. In this retrospective review, we investigated the incidence of oral injury under total intravenous anesthesia (TIVA) and balanced anesthesia in 66,166 cases from 2019 to 2021. There were 295 oral injuries in our sample, yielding an incidence of 0.45%, which is in line with ranges reported in the literature. A total of 222 of the injured patients were sedated with balanced anesthesia, while the remaining 73 were under TIVA anesthetics. This difference in distribution was statistically significant (p < 0.0002). Our findings suggest TIVA is associated with lower risk of oral trauma when TcMEPs are monitored, thereby improving patient safety.

On the horns of a dilemma: choosing total intravenous anaesthesia or volatile anaesthesia for cancer surgery, an enduring controversy

Two methods for administering general anaesthesia are widely used: propofol-based total intravenous anaesthesia (propofol-TIVA) and inhalation volatile agent-based anaesthesia. Both modalities, which have been standards of care for several decades, boast a robust safety profile. Nevertheless, the potential differential effects of these anaesthetic techniques on immediate, intermediate, and extended postoperative outcomes remain a subject of inquiry. We discuss a recently published longitudinal analysis stemming from a multicentre randomised controlled trial comparing sevoflurane-based inhalation anaesthesia with propofol-TIVA in older patients with cancer, which showed a reduced incidence of emergence and postoperative delirium, comparable postoperative complication rates within 30 days after surgery, and comparable long-term survival rates. We undertake an assessment of the trial's methodological strengths and limitations, contextualise its results within the broader scientific evidence, and explore avenues for resolving the extant controversies in anaesthetic choice for cancer surgery. We aim to pave the way for the incorporation of precision medicine paradigms into the evolving landscape of perioperative care for patients with cancer.

Total intravenous anesthesia for geriatric hip fracture with severe systemic disease

PURPOSE

Our study aimed to determine the impact of a novel technique of anesthesia administration on the clinical outcomes and complications in geriatric patients with severe systemic disease undergoing hip surgery.

METHODS

We retrospectively identified patients aged > 65 years with severe systemic disease that was a constant of life [American Society of Anesthesiologists (ASA) IV] who underwent surgery for hip fracture between January 2018 and January 2020. The patients were divided into two groups: Group I [fascia iliaca compartment block plus propofol-based total intravenous anesthesia (FICB + TIVA)] and Group II [general anesthesia (GA)]. The primary outcomes were 30-day and 1-year mortality. The secondary outcomes included length of hospital stay, length of intensive care unit (ICU) stay, postoperative morbidity, Visual Analog Scale score, and consumption of analgesics.

RESULTS

There was no significant difference in the 30-day mortality (5 vs. 3.8%, p = 0.85) and 1-year mortality (15 vs. 12%, p = 0.73) between the groups. Group I had significantly lower ICU requirements (p = 0.01) and shorter lengths of ICU stay (p < 0.001) and hospital stay (p < 0.001). Moreover, a smaller proportion of patients in Group I required postoperative morphine or oral opiates.

CONCLUSION

Geriatric patients who underwent hip surgery under FICB + TIVA required fewer ICU admissions, shorter lengths of ICU and hospital stay, and had lesser postoperative opioid consumption than those who were under GA. Hence, we recommend the novel FICB + TIVA technique for hip fracture surgery in geriatric patients with poor general health status and high surgical risks (ASA IV).

Remimazolam Compared to Propofol for Total Intravenous Anesthesia with Remifentanil on the Recovery of Psychomotor Function: A Randomized Controlled Trial

INTRODUCTION

This study aimed to compare remimazolam to propofol in psychomotor recovery after total intravenous anesthesia (TIVA) using the Trieger dot test.

METHODS

Sixty-six patients who were scheduled to undergo endoscopic sinus surgery with American Society of Anesthesiologists (ASA) physical status I or II were randomly allocated to the remimazolam (group R) or propofol group (group P). In group R, all patients received flumazenil postoperatively. After discontinuation of anesthetic agents, the time to eye opening, response to verbal commands, extubation, and discharge from the operation room were measured. Psychomotor recovery was assessed using the Trieger dot test before induction and at 0, 30, 60, 90, 120, 150, and 180 min after anesthesia.

RESULTS

The time to eye opening, response to verbal commands, extubation, and discharge from the operation room were significantly longer in group P compared to group R (group P: 9.8 ± 3.2 min, 11.5 ± 3.4 min, 12.7 ± 3.4 min, 18.1 ± 4.2 min; group R: 6.5 ± 2 min, 7.3 ± 2.6 min, 8.4 ± 2.9 min, 13.2 ± 3.2 min; respectively, p < 0.05). In the Trieger dot test, the number of dots missed was significantly increased in group R compared to group P at 30, 60, 90, and 120 min after discharge from the operation room (group R: 20.5 ± 9.3, 16 ± 8.8, 14.9 ± 11.1, 14.3 ± 10.8; group P: 14.6 ± 7.8, 10 ± 7.1, 8.7 ± 7.3, 7.3 ± 5.7; respectively, p < 0.05). The maximum distance of dots missed was significantly increased in group R compared to group P at 30 min after discharge from the operation room (group R: 3.9 ± 2.8; group P: 2.7 ± 1.6; p < 0.05).

CONCLUSION

Our results suggest that remimazolam with flumazenil leads to rapid recovery following anesthesia; however, it may cause delayed psychomotor decline.

CLINICAL TRIAL REGISTRATION

This trial is registered with the University Hospital Medical Information Network (registration number UMIN000044900).

Outcomes of intravenous and inhalation anesthesia on patients undergoing esophageal cancer surgery: a retrospective observational study

BACKGROUND

Different anesthetics may have opposite effects on the immune system, thus affecting the prognosis of tumor patients. Cell-mediated immunity forms the primary defense against the invasion of tumor cells, so manipulation of the immune system to produce an enhanced anti-tumor response could be utilized as an adjuvant oncological therapy. Sevoflurane has proinflammatory effects, while propofol, has anti-inflammatory and antioxidant effects. Therefore, we compared the overall survival (OS) and disease-free survival (DFS) of patients with esophageal cancer under total intravenous anesthesia and inhalation anesthesia.

METHODS

This study collected the electronic medical records of patients undergoing esophagectomy from January 1, 2014 to December 31, 2016. According to the intraoperative anesthetics, the patients were divided into total intravenous anesthesia (TIVA) group or inhalational anesthesia (INHA) group. Stabilized inverse probability of treatment weighting (SIPTW) was used to minimize differences. Kaplan-Meier survival curve was established to evaluate the correlation between different anesthesia methods in overall survival and disease-free survival of patients undergoing esophageal cancer surgery.

RESULTS

A total of 420 patients with elective esophageal cancer were collected, including 363 patients eligible for study (TIVA, n = 147, INHA, n = 216). After SIPTW there were no significant differences between two groups in overall survival and disease-free survival. However, the adjuvant therapy was statistically significant in improving OS, and the degree of differentiation was correlated with OS and DFS.

CONCLUSIONS

In conclusion, there were no significant difference in overall survival and disease-free survival between total intravenous anesthesia and inhalational anesthesia in patients undergoing esophageal cancer surgery.

Patient characteristics, anaesthetic workload and techniques in the UK: an analysis from the 7th National Audit Project (NAP7) activity survey

Detailed contemporary knowledge of the characteristics of the surgical population, national anaesthetic workload, anaesthetic techniques and behaviours are essential to monitor productivity, inform policy and direct research themes. Every 3-4 years, the Royal College of Anaesthetists, as part of its National Audit Projects (NAP), performs a snapshot activity survey in all UK hospitals delivering anaesthesia, collecting patient-level encounter data from all cases under the care of an anaesthetist. During November 2021, as part of NAP7, anaesthetists recorded details of all cases undertaken over 4 days at their site through an online survey capturing anonymous patient characteristics and anaesthetic details. Of 416 hospital sites invited to participate, 352 (85%) completed the activity survey. From these, 24,177 reports were returned, of which 24,172 (99%) were included in the final dataset. The work patterns by day of the week, time of day and surgical specialty were similar to previous NAP activity surveys. However, in non-obstetric patients, between NAP5 (2013) and NAP7 (2021) activity surveys, the estimated median age of patients increased by 2.3 years from median (IQR) of 50.5 (28.4-69.1) to 52.8 (32.1-69.2) years. The median (IQR) BMI increased from 24.9 (21.5-29.5) to 26.7 (22.3-31.7) kg.m^-2 . The proportion of patients who scored as ASA physical status 1 decreased from 37% in NAP5 to 24% in NAP7. The use of total intravenous anaesthesia increased from 8% of general anaesthesia cases to 26% between NAP5 and NAP7. Some changes may reflect the impact of the COVID-19 pandemic on the anaesthetic population, though patients with confirmed COVID-19 accounted for only 149 (1%) cases. These data show a rising burden of age, obesity and comorbidity in patients requiring anaesthesia care, likely to impact UK peri-operative services significantly.

Ketamine-propofol for total intravenous anaesthesia in rabbits: a comparison of premedication with acepromazine-medetomidine, acepromazine-midazolam or acepromazine-morphine

OBJECTIVE

To describe ketamine-propofol total intravenous anaesthesia (TIVA) following premedication with acepromazine and either medetomidine, midazolam or morphine in rabbits.

STUDY DESIGN

Randomized, crossover experimental study.

ANIMALS

A total of six healthy female New Zealand White rabbits (2.2 ± 0.3 kg).

METHODS

Rabbits were anaesthetized on four occasions, each separated by 7 days: an intramuscular injection of saline alone (treatment Saline) or acepromazine (0.5 mg kg^-1) in combination with medetomidine (0.1 mg kg^-1), midazolam (1 mg kg^-1) or morphine (1 mg kg^-1), treatments AME, AMI or AMO, respectively, in random order. Anaesthesia was induced and maintained with a mixture containing ketamine (5 mg mL^-1) and propofol (5 mg mL^-1) (ketofol). Each trachea was intubated and the rabbit administered oxygen during spontaneous ventilation. Ketofol infusion rate was initially 0.4 mg kg^-1 minute^-1 (0.2 mg kg^-1 minute^-1 of each drug) and was adjusted to maintain adequate anaesthetic depth based on clinical assessment. Ketofol dose and physiological variables were recorded every 5 minutes. Quality of sedation, intubation and recovery times were recorded.

RESULTS

Ketofol induction doses decreased significantly in treatments AME (7.9 ± 2.3) and AMI (8.9 ± 4.0) compared with treatment Saline (16.8 ± 3.2 mg kg^-1) (p < 0.05). The total ketofol dose to maintain anaesthesia was significantly lower in treatments AME, AMI and AMO (0.6 ± 0.1, 0.6 ± 0.2 and 0.6 ± 0.1 mg kg^-1 minute^-1, respectively) than in treatment Saline (1.2 ± 0.2 mg kg^-1 minute^-1) (p < 0.05). Cardiovascular variables remained at clinically acceptable values, but all treatments caused some degree of hypoventilation.

CONCLUSIONS AND CLINICAL RELEVANCE

Premedication with AME, AMI and AMO, at the doses studied, significantly decreased the maintenance dose of ketofol infusion in rabbits. Ketofol was determined to be a clinically acceptable combination for TIVA in premedicated rabbits.

Alternatives to remifentanil for the analgesic component of total intravenous anaesthesia: a narrative review

Propfol-remifentanil-based total intravenous anaesthesia has dominated recent clinical practice due to its favourable pharmacokinetic profile. Interruption in remifentanil supply has presented an opportunity to diversify or even avoid the use of opioids and consider adjuncts to propofol-based total intravenous anaesthesia. Propofol, while a potent hypnotic, is not an effective analgesic. The administration of opioids, along with other adjuncts such as α-2 adrenoceptor agonists, magnesium, lidocaine, ketamine and nitrous oxide provide surgical anaesthesia and avoids large doses of propofol being required. We provide an overview of both target-control and manual infusion regimes for the alternative opioids: alfentanil, sufentanil and fentanyl. The optimal combination of hypnotic-opioid dose, titration sequence and anticipated additional postoperative analgesia required depend on the chosen combination. In addition, we include a brief discussion on the role of non-opioid adjuncts in total intravenous anaesthesia, suggested doses and expected reduction in propofol dose.

Effect of anesthetics on postoperative nausea and vomiting after peripheral vascular surgery in end-stage renal disease patients: A retrospective observational study

Background

Propofol-based total intravenous anesthesia (TIVA) is considered a prophylactic approach to decrease postoperative nausea and vomiting (PONV). Despite general anesthesia commonly being performed in end-stage renal disease (ESRD) patients, PONV in ESRD patients has not been well-described. We investigated PONV in peripheral vascular surgery under general anesthesia in ESRD patients.

Methods

To compare PONV between propofol-based TIVA and anesthesia with volatile anesthetics, we collected retrospective data from patients who underwent peripheral vascular surgery under general anesthesia from July 2018 to April 2020. We performed univariable and multivariable analyses, including factors that could be associated with PONV and those previously shown to affect PONV.

Result

A total of 1,699 peripheral vascular surgeries under general anesthesia in ESRD patients were eligible for analysis. Based on the multivariable analysis, TIVA (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.35-0.60; P < 0.001) significantly decreased PONV. Female sex (OR, 1.85; 95% CI, 1.44-2.38; P < 0.001) and anesthetic duration (OR, 1.01; 95% CI, 1.00-1.01; P < 0.001) were associated with increased PONV.

Conclusion

Propofol-based TIVA is the most influential factor decreasing PONV after peripheral vascular surgery in ESRD patients. Anesthesiologists can apply propofol-based TIVA as an alternative to anesthesia with volatile anesthetics.

The Effect of Propofol versus Inhalation Anesthetics on Survival after Oncological Surgery

Every year, 19.3 million patients worldwide are diagnosed with cancer. Surgical resection represents a major therapeutical option and the vast majority of these patients receive anesthesia. However, despite surgical resection, almost one third of these patients develop local recurrence or distant metastases. Perioperative factors, such as surgical stress and anesthesia technique, have been suggested to play a role to a greater or lesser extent in the development of recurrences, but oncology encompasses a complicated tumor biology of which much is still unknown. The effect of total intravenous anesthesia (TIVA) or volatile anesthesia (VA) on survival after oncological surgery has become a popular topic in recent years. Multiple studies conclude in favor of propofol. Despite the a priori probability that relevant differences in postoperative outcomes are due to the anesthesia technique employed, TIVA or VA, is extremely small. The existing literature includes mainly hypothesis-forming retrospective studies and small randomized trials with many methodological limitations. To date, it is unlikely that use of TIVA or VA affect cancer-free survival days to a clinically relevant extent. This review addresses all relevant studies in the field and provides a substantiated different view on this deeply controversial research topic.

Evaluation of penehyclidine for prevention of post operative nausea and vomitting in patients undergoing total thyroidectomy under total intravenous anaesthesia with propofol-remifentanil

Backgroud

Postoperative nausea and vomiting (PONV) is one of the most common complications after total thyroidectomy under general anesthesia. Total intravenous anesthesia (TIVA) has been documented to prevent PONV in patients undergoing total thyroidectomy. Penehyclidine, an anticholinergic agent with an elimination half-life of over 10 h, is widely used as premedication to reduce glandular secretion. This study aimed to explore the preventative effects of penehyclidine with propofol-remifentanil-TIVA to single-TIVA on PONV in patients undergoing total thyroidectomy.

Methods

A total of 100 patients scheduled for total thyroidectomy were randomly assigned to either the penehyclidine group (n = 50) or TIVA group (n = 50). Propofol and remifentanil were was used for TIVA in all patients. No patients who received premedication. Patients were administrated with either 5 ml of normal saline or 0.5 mg of penehyclidine soon after anesthesia induction. The incidence of nausea and vomiting, the severity of nausea, the requirement of rescue antiemetics, and adverse effects were investigated during the first 24 h in two time periods (0–2 h and 2–24 h).

Results

The overall PONV incidence during the 24 h after surgery was significantly lower in the penehyclidine group compared with the TIVA group (12% vs 36%, P < 0.005). Besides, the incidence of nausea and the incidence of vomiting were significantly lower in the penehyclidine group compared with the TIVA group at 2–24 h after surgery. However, there was no significant difference between the two groups at 0–2 h after surgery.

Conclusions

Administration of penehyclidine under TIVA with propofol-remifentanil is more effective for prevention of PONV than TIVA alone, especially 2–24 h after total thyroidectomy.

Trial registration

https://www.chictr.org.cn/edit.aspx?pid=132463&htm=4 (Ref: ChiCTR2100050278, the full date of first registration: 25/08/2021).

On the horns of a dilemma: choosing total intravenous anaesthesia or volatile anaesthesia

There are two established techniques of delivering general anaesthesia: propofol-based total intravenous anaesthesia (TIVA) and volatile agent-based inhaled anaesthesia. Both techniques are offered as standard of care and have an established safety track record lasting more than 30 years. However, it is not currently known whether the choice of anaesthetic technique results in a fundamentally different patient experience or affects early, intermediate-term, and longer-term postoperative outcomes. This editorial comments on a recently published study that suggests that inhaled volatile anaesthesia might be associated with fewer postoperative surgical complications than propofol-based TIVA for patients undergoing colorectal cancer surgery. We consider the strengths and limitations of the study, place these findings in the context of the broader evidence, and discuss how the current controversies regarding anaesthetic technique can be resolved, thereby helping to bring precision medicine into the modern practice of perioperative care.

Expert Multinational Consensus Statement for Total Intravenous Anaesthesia (TIVA) Using the Delphi Method

Introduction: The use of total intravenous anaesthesia (TIVA) has been well established as an anaesthetic technique over the last few decades. Significant variation in practice exists however, and volatile agents are still commonly used. This study aims to determine the motivations and barriers for using TIVA over the use of volatile agents by analysing the opinion of several international anaesthetists with specific expertise or interests. Methods and participants: The Delphi method was used to gain the opinions of expert panellists with a range of anaesthetic subspecialty expertise. Twenty-nine panellists were invited to complete three survey rounds containing statements regarding the use of TIVA. Anonymised data were captured through the software REDCap and analysed for consensus and prioritisation across statements. Starting with 12 statements, strong consensus was defined as ≥75% agreement. Stability was assessed between rounds. Results: Strong consensus was achieved for four statements regarding considerations for the use of TIVA. These statements addressed whether TIVA is useful in paediatric anaesthesia, the importance of TIVA in reducing the incidence of postoperative nausea and vomiting, its positive impact on the environment and effect on patient physiology, such as airway and haemodynamic control. Conclusions: Using the Delphi method, this international consensus showed that cost, lack of familiarity or training and the risk of delayed emergence are not considered obstacles to TIVA use. It appears, instead, that the primary motivations for its adoption are the impact of TIVA on patient experience, especially in paediatrics, and the benefit to the overall procedure outcome. The effect of TIVA on postoperative nausea and vomiting and patient physiology, as well as improving its availability in paediatrics were considered as priorities. We also identified areas where the debate remains open, generating new research questions on geographical variation and the potential impact of local availability of monitoring equipment.

Consistency of remifentanil concentrations in propofol-Remifentanil infusions. A laboratory-based study

BACKGROUND

There is increasing interest in two-agent single-pump intravenous infusions for anesthesia and sedation in pediatric patients. Propofol-remifentanil is one such mixture. The poor miscibility of such admixtures when remifentanil is added in very high concentrations and when the admixtures are maintained in static conditions has been demonstrated; however, these physiochemical properties have not been examined in clinically relevant concentrations or settings.

AIM

To examine if propofol-remifentanil admixtures maintain consistent remifentanil delivery when mixed in clinically relevant remifentanil concentrations and subjected to the physical effects of an actively infusing, directly-engaged syringe driver system with an extension line, as occurs when propofol-remifentanil is administered to a patient.

METHODS

A propofol 10 mg.ml^-1 combined with remifentanil 5 mcg.ml^-1 solution was run using a Paedfusor^® propofol target-controlled infusion model for 10 kg and 20 kg children for 57 min at a target plasma concentration of 3 mcg.ml^-1 through a 30 ml syringe, 180 cm minimum volume extension line, lever lock cannula, interlink injection site, and 22 g intravenous cannula into sample pots. Samples were taken at the completion of the loading bolus, 1 and 2 min postcompletion of loading bolus, and every 5 min thereafter. The remifentanil concentration in these samples was then assayed using chromatography.

RESULTS

There was no difference in the concentration of remifentanil in the samples based on the duration of infusion to the endpoint of 1 h, or on the patient weight model used. The concentration remained 5 mcg.ml^-1 +/- 0.5 mcg.ml^-1 per sample. The measurement uncertainty for the assay at 0.5 mcg.ml^-1 is +/- 0.2 mcg.ml^-1 .

CONCLUSION

The concentration of remifentanil was 5 mcg.ml^-1 +/- 0.5 mcg.ml^-1 and was consistent across 57 min of infusion, and two different pediatric weight profiles.

The outcome of intravenous and inhalation anesthesia after pancreatic cancer resection: a retrospective study

BACKGROUND

Different types of anesthesia may affect cancer patient's outcomes, we compared the overall survival (OS) and disease-free survival (DFS) of patients with pancreatic cancer under total intravenous and inhalation anesthesia.

METHODS

The authors collected the electronic medical records of patients who had accepted at a pancreatectomy from January 1, 2010 to December 31, 2016. Patients respectively received total intravenous anesthesia (TIVA) or inhalational anesthesia (INHA). Stabilized inverse probability of treatment weighting (SIPTW)was used to minimize differences. Kaplan-Meier survival was established to analyze the influence of sort of anesthesia on disease-free and overall survival. We compare the effects of each sort of anesthesia on cancer recurrence or metastasis and all-cause mortality.

RESULTS

A total of 463 patients who had undergone pancreatic cancer resection were collected in this study, of which 421 patients were available (TIVA group, n = 114 INHA group, n = 307). After SIPTW there were no significant differences between the two groups in disease-free survival (hazard ratio, 1.01, 95%CI, 0.78 to 1.29, P = 0.959) or overall survival (hazard ratio, 1.11, 95%CI, 0.87 to 1.42, P = 0.405).

CONCLUSIONS

In conclusion, the present study showed no significant difference in overall survival and disease-free survival between total intravenous anesthesia and volatile anesthesia.

Pharmacokinetic Pharmacodynamic Modelling Contributions to Improve Paediatric Anaesthesia Practice

The use of pharmacokinetic-pharmacodynamic models has improved anaesthesia practice in children through a better understanding of dose-concentration-response relationships, developmental pharmacokinetic changes, quantification of drug interactions and insights into how covariates (e.g., age, size, organ dysfunction, pharmacogenomics) impact drug prescription. Simulation using information from these models has enabled the prediction and learning of beneficial and adverse effects and decision-making around clinical scenarios. Covariate information, including the use of allometric size scaling, age and consideration of fat mass, has reduced population parameter variability. The target concentration approach has rationalised dose calculation. Paediatric pharmacokinetic-pharmacodynamic insights have led to better drug delivery systems for total intravenous anaesthesia and an expectation about drug offset when delivery is stopped. Understanding concentration-dependent adverse effects have tempered dose regimens. Quantification of drug interactions has improved the understanding of the effects of drug combinations. Repurposed drugs (e.g., antiviral drugs used for COVID-19) within the community can have important effects on drugs used in paediatric anaesthesia, and the use of simulation educates about these drug vagaries.

Total Intravenous Anesthesia with Ketofol versus Combination of Ketofol and Lidocaine for Short-Term Anesthesia in Pediatric Patients; Double Blind, Randomized Clinical Trial of Effects on Recovery

Background: Ketofol admixture has been proposed to be useful for sedation and general anesthesia. The beneficial effect of the combination of ketofol with lidocaine may be a shortened time of anesthesia and recovery period. This study aimed to establish the effect of total intravenous anesthesia (TIVA) with ketofol and ketofol with lidocaine on recovery in children. Methods: Two hundred children from the ages of 1–12 years who underwent short surgical procedures were randomly allocated into two groups. Propofol mixtures (ketofol) were prepared for group l. A ratio of 1:4 of ketofol was used for induction and for the maintenance of anesthesia a ratio of was used 1:7. For the induction and maintenance of anesthesia ketofol with lidocaine (lidoketofol) was used in group II. The McFarlan infusion regimen was used with reduction. The extubating time, anesthesia duration and the length of stay in the post-anesthesia care unit (PACU) were recorded. Results: Extubation time showed to be considerably shorter in the lidoketofol group than in the ketofol group (120 s versus 240 s; p < 0.00001). The anesthesia duration was also significantly shorter in the lidoketofol group (35 min vs. 50 min; p < 0.00001). The lidoketofol group showed to have a lower length of stay in the post-anesthesia care unit (PACU) than the ketofol group (20 min vs. 35 min; p < 0.00001). The lidoketofol group showed lower fentanyl consumption per kg (2.1 µg per kg vs. 2.3 µg per kg; p < 0.056) and lower propofol consumption (6.6 mg per kg vs. 7.6 mg per kg; p < 0.032). Conclusion: The recovery in pediatric anesthesia can improve with usage of TIVA with ketofol plus lidocaine admixture with a reduced McFarlan dose regimen.

Incidence of Postoperative Cognitive Dysfunction Following Inhalational vs Total Intravenous General Anesthesia: A Systematic Review and Meta-Analysis

Postoperative cognitive dysfunction (POCD) has been increasingly recognized as a contributor to postoperative complications. A consensus-working group recommended that POCD should be distinguished between delayed cognitive recovery, ie, evaluations up to 30 days postoperative, and neurocognitive disorder, ie, assessments performed between 30 days and 12 months after surgery. Additionally, the choice of the anesthetic, either inhalational or total intravenous anesthesia (TIVA) and its effect on the incidence of POCD, has become a focus of research. Our primary objective was to search the literature and conduct a meta-analysis to verify whether the choice of general anesthesia may impact the incidence of POCD in the first 30 days postoperatively. As a secondary objective, a systematic review of the literature was conducted to estimate the effects of the anesthetic on POCD between 30 days and 12 months postoperative. For the primary objective, an initial review of 1913 articles yielded ten studies with a total of 3390 individuals. For the secondary objective, four studies with a total of 480 patients were selected. In the first 30 days postoperative, the odds-ratio for POCD in TIVA group was 0.46 (95% CI = 0.26-0.81; p = 0.01), compared to the inhalational group. TIVA was associated with a lower incidence of POCD in the first 30 days postoperatively. Regarding the secondary objective, due to the small number of selected articles and its high heterogeneity, a metanalysis was not conducted. Given the heterogeneity of criteria for POCD, future prospective studies with more robust designs should be performed to fully address this question.

Intraoperative effect of low doses of ketamine or dexmedetomidine continuous rate infusions in healthy dogs receiving propofol total intravenous anaesthesia and epidural anaesthesia: A prospective, randomised clinical study

The present study aimed to determine the effect of either ketamine or dexmedetomidine constant rate infusion (CRI) on intraoperative propofol anaesthetic requirements during total intravenous anaesthesia (TIVA) in healthy dogs undergoing hindlimbs orthopaedic procedures receiving epidural anaesthesia. In this randomised, blinded clinical study, thirty-nine healthy client-owned dogs were premedicated intramuscularly (dexmedetomidine 4 μg/kg and methadone 0.3 mg/kg). General anaesthesia was induced to effect with propofol administered as intravenous bolus, and maintained with propofol TIVA (18 mg/kg/h), adjusted to meet the suitable clinical anaesthetic depth (indicatively±20%) based on clinical judgement. Lumbosacral epidural anaesthesia was performed using bupivacaine (1 mg/kg) and morphine preservative free (0.1 mg/kg). Dogs randomly received either saline (SP; loading dose 1 mL/kg, CRI 1 mL/kg/h), or ketamine (KP; loading dose 1.5 mg/kg, CRI 1.5 mg/kg/h), or dexmedetomidine (DP; loading dose 1 μg/kg/, CRI 1 μg/kg/h). Physiological variables were recorded intraoperatively at 5-min intervals using standard-of-care monitoring. Recovery quality and duration were recorded. Treatment groups were compared with parametric and non-parametric tests as appropriate, p < 0.05. Propofol rates and recovery scores were similar between groups. Overall mean and diastolic blood pressures were higher in group DP compared to group KP (12-14 mmHg, p = 0.016 and p = 0.015, respectively). More dogs required mechanical ventilation in group KP (12 dogs) than in either group SP or DP (7 dogs per group, p = 0.037). Ketamine or dexmedetomidine CRIs, at the studied rates, did not reduce propofol TIVA requirements in dogs undergoing orthopaedic surgery with epidural anaesthesia.

Sleeping Beauty: Anesthesia May Promote Relapse in Dogs With Diffuse Large B-Cell Lymphoma in Complete Remission After Chemo-Immunotherapy

Surgery-induced stress and anesthesia-related immunosuppression are believed to play a critical role in human oncology patients. Studies have hypothesized that anesthesia influences patients' outcome, promoting tumor recurrence and metastasis. Aim of the study was to investigate whether anesthesia promoted relapse in dogs with diffuse large B-cell lymphoma (DLBCL). Medical records were searched for dogs with DLBCL, that were in complete remission (CR) after the same chemo-immunotherapy protocol. Dogs receiving anesthesia were included if the procedure was performed while in CR. Time to relapse (TTR) was obtained via Kaplan–Meier method. Association between anesthesia and relapse was assessed using a nested case-control design and estimated using conditional logistic regression. Sixty-one dogs with DLBCL were included. Overall median TTR was 329 days (95% CI, 281–377). Forty-eight (79%) dogs relapsed during the study period, while 13 (21%) were still in CR at data analysis closure. Eighteen (30%) dogs received anesthesia with opioids, propofol, and isoflurane or sevoflurane. The relative risk of lymphoma relapse for dogs undergoing anesthesia was significantly higher compared with dogs not undergoing anesthesia, with an odds ratio of 3.09 (P = 0.019) on multivariable analysis. Anesthesia may promote relapse in dogs with DLBCL treated with chemo-immunotherapy, although a role of perioperative stress cannot be ultimately excluded. Considering the high frequency of anesthetic procedures required for diagnostic and therapeutic protocols among oncology patients, it is of utmost interest to characterize the effects of single anesthetic agents on the immune system. Further prospective studies are needed to better define the impact of anesthesia on patients' outcome.

Comparison of two injectable anaesthetic techniques on induction and subsequent anaesthesia in pigs

Pig experiments often require anaesthesia, and a rapid stress-free induction is desired. Induction drugs may alter the subsequent anaesthesia. Therefore, the aim of the present study was to compare, in pigs, the effects of two different injectable anaesthetic techniques on the induction and on the physiological variables in a subsequent eight hours of total intravenous anaesthesia (TIVA). Twelve domestic castrates (Swedish Landrace/Yorkshire) 27‒31 kg were used. The pigs were randomly assigned to different induction drug combinations of zolazepam-tiletamine and medetomidine intramuscularly (ZTMe) or midazolam, ketamine intramuscularly and fentanyl intravenously (MiKF). Time from injection to unconsciousness was recorded and the ease of endotracheal intubation assessed. The TIVA infusion rate was adjusted according to the response exhibited from the nociceptive stimulus delivered by mechanically clamping the dewclaw. The time from injection to unconsciousness was briefer and intubation was easier in the ZTMe group. Results from the recorded heart rate, cardiac index and arterial blood pressure variables were satisfactorily preserved and cardiovascular function was maintained in both groups. Shivering was not observed in the ZTMe group, but was observed in four of the pigs in the MiKF group. The requirement of TIVA was lower in the ZTMe group. In conclusion, ZTMe had better results than MiKF in areas such as shorter induction time, better intubation scoring results and less adjustment and amount of TIVA required up to six hours of anaesthesia. The results may have been due to a greater depth of anaesthesia achieved with the ZTMe combination at the dose used.

Impact of inhalational anesthetic agents on the baseline monitorability of motor evoked potentials during spine surgery: a review of 22,755 cervical and lumbar procedures

BACKGROUND CONTEXT

During spine surgery, motor evoked potentials (MEPs) are often utilized to monitor both spinal cord function and spinal nerve root or plexus function. While there are reports evaluating the impact of anesthesia on the ability of MEPs to monitor spinal cord function, less is known about the impact of anesthesia on the ability of MEPs to monitor spinal nerve root and plexus function.

PURPOSE

To compare the baseline monitorability and amplitude of MEPs during cervical and lumbar procedures between two cohorts based on the maintenance anesthetic regimen: a total intravenous anesthesia (TIVA) versus a regimen balanced with volatile inhalational and intravenous agents.

STUDY DESIGN

Baseline MEP data from a total of 16,559 cervical and 6,196 lumbar extradural spine procedures utilizing multimodality intraoperative neuromonitoring (IONM) including MEPs between January 2017 and March 2020 were obtained from a multi-institutional database. Two cohorts for each region of spine surgery were delineated based on the anesthetic regimen: a TIVA cohort and a Balanced anesthesia cohort.

PATIENT SAMPLE

Age 18 and older. Fellowship support for 65,000 for year 2021.

OUTCOME MEASURES

Percent monitorability and amplitudes of baseline MEPs.

METHODS

The baseline monitorability of each muscle MEP was evaluated by the IONM team in real-time and recorded in the patient's electronic medical record. The relation between anesthetic regimen and baseline monitorability was estimated using mixed effects logistic regression, with distinct models for cervical and lumbar procedures. Subsets of cervical and lumbar procedures from each anesthesia cohort in which all MEPs were deemed monitorable were randomly selected and the average peak-to-trough amplitude of each muscle MEP was retrospectively measured. Mixed-effects linear regression models were estimated (one each for cervical and lumbar procedures) to assess possible differences in average amplitude associated with anesthesia regimen.

RESULTS

At the time of surgery, baseline MEPs were reported monitorable from all targeted muscles in 86.8% and 83.0% of cervical and lumbar procedures, respectively, for the TIVA cohort, but were reported monitorable in just 59.3% and 61.0% of cervical and lumbar procedures, respectively, in the Balanced cohort, yielding disparities of 27.5% and 22.0%, respectively. The model-adjusted monitorability disparity between cohorts for a given muscle MEP ranged from 0.2% to 16.6% but was smallest for distal intrinsic hand and foot muscle MEPs (0.2%-1.1%) and was largest for proximal muscle MEPs (deltoid: 10.8%, biceps brachii: 8.8%, triceps: 13.0%, quadriceps: 16.6%, gastrocnemius: 7.8%, and tibialis anterior: 3.7%) where the monitorability was significantly decreased in the Balanced cohort relative to the TIVA cohort (p<.0001). Relative to the TIVA cohort, the model-adjusted amplitude of an MEP in the Balanced cohort was smaller for all muscles measured, ranging from 27.5% to 78.0% smaller. Relative to the TIVA cohort, the model-adjusted amplitude of an MEP was significantly decreased (p<.01) in the Balanced cohort for the most proximal muscles (Percent smaller: deltoid: 74.3%, biceps: 78.0%, triceps: 54.9%, quadriceps: 54.8%).

CONCLUSIONS

TIVA is the preferred anesthetic regimen for optimizing MEP monitoring during spine surgery. Inhalational agents significantly decrease MEP monitorability and amplitudes for most muscles, and this effect is especially pronounced for proximal limb muscles such as the deltoid, biceps, triceps, and quadriceps.

Pharmacokinetic concepts for dexmedetomidine target-controlled infusion pumps in children

Pharmacokinetic parameter estimates are used in mathematical equations (pharmacokinetic models) to describe concentration changes with time in a population and are specific to that population. Simulation using these models and their parameter estimates can enrich understanding of drug behavior and serve as a basis for study design. Pharmacokinetic concepts are presented pertaining to future designs of dexmedetomidine target-controlled infusion pumps in children. This manuscript provides the pediatric anesthesiologist with an understanding of the nuances that should be considered when using target-controlled infusion pumps; how the central volume may differ between populations, how clearance changes with age, and the impact of adverse effects on dose. In addition, the ideal loading dose and rate of delivery to achieve target concentration without adverse cardiovascular effects are reviewed, and finally, dose considerations for obese children, based on contact-sensitive half-time, are introduced. An understanding of context-sensitive half-time changes with age enables anesthetic practitioners to better estimate duration of effect after cessation of dexmedetomidine infusion. Use of these known pharmacokinetic parameters and covariate information for the pediatric patient could readily be incorporated into commercial target-controlled infusion pumps to allow effective and safe open-loop administration of dexmedetomidine in children.

Effects on Recovery of Pediatric Patients Undergoing Total Intravenous Anesthesia with Propofol versus Ketofol for Short-Lasting Laparoscopic Procedures

BACKGROUND

Combining ketamine and propofol (ketofol) was suggested as a new concept for sedation and general anesthesia in pediatric populations for various conditions. The aim of the present study was to determine the effect of total intravenous anesthesia (TIVA) with propofol and ketofol on recovery after laparoscopic surgery in pediatric patients.

METHODS

Two hundred children with median age of 5 years who underwent laparoscopic surgery were randomized into two groups. Propofol 1% was used for induction and maintenance of anesthesia in group I, while ketamine-propofol combination (ketofol) was used in group II. Ketamine-propofol combination (ketofol) was prepared in the same applicator for group II. Ketofol ratios of 1:4 and 1:7 were used for induction and maintenance of anesthesia, respectively. A reduced McFarlan infusion dose was used in group I (1.2, 1.0, and 0.8 mL/kg/h for 15, 15, and 30 min, respectively), while a McFarlan infusion dose was used in group II (1.5, 1.3, and 1.1 mL/kg/h for 15, 15, and 30 min, respectively). Extubating time, duration of anesthesia, and length of stay in post-anesthesia care unit (PACU) were recorded.

RESULTS

Extubating time was significantly lower in the ketofol group than in the propofol group (240 s vs. 530 s; p < 0.00001). Significantly shorter duration of anesthesia (47 min vs. 60 min; p < 0.00001) as well as length of stay in the PACU (35 min vs. 100 min; p < 0.00001) were recorded in ketofol compared to the propofol group. Total fentanyl (100 µg (interquartile range, IQR 80, 125) vs. 50 µg (IQR 40, 60); p < 0.00001) and propofol (260 mg (IQR 200, 350) vs. 160 mg (IQR 120, 210); p < 0.00001) consumption per body weight were significantly lower in the ketofol group.

CONCLUSIONS

TIVA with ketamine-propofol combination (ketofol) using a reduced McFarlan dose regimen shortened extubating time, duration of anesthesia, as well as length of stay in the PACU in pediatric anesthesia after laparoscopic surgery.

Evaluation of anaesthetic depth and cardiopulmonary effects of propofol infusion rate in Sapajus apella previously chemically contained with dextroketamine-midazolam

BACKGROUND

This study evaluated the cardiopulmonary effects and anaesthetic depth induced by a propofol infusion rate of 0.8 mg/kg/min in monkeys (Sapajus apella).

MATERIALS AND METHODS

Five capuchin monkeys received dextroketamine-midazolam intramuscularly. After a maximum duration of 5 min, the values of the physiological parameters were recorded, and a venous catheter was placed. After recovery from chemical restraint, the animals were anaesthetized with propofol intravenously, which was maintained for 1 h. Physiological parameters, anaesthetic depth, the time and quality of anaesthetic recovery were evaluated.

RESULTS

Heart and respiratory rates, systolic blood pressure and rectal temperature during propofol infusion were lower than those during anaesthesia induction with dextroketamine-midazolam. Unconsciousness, muscle relaxation and lack of response to tail clamping were observed during propofol infusion. No animals showed excitement or vocalization during anaesthetic recovery.

CONCLUSION

Propofol infusion rate of 0.8 mg/kg/min promoted surgical general anaesthesia, with transient hypotension, which showed excellent anaesthetic recovery.

Correlation of exhaled propofol with Narcotrend index and calculated propofol plasma levels in children undergoing surgery under total intravenous anesthesia - an observational study

BACKGROUND

Exhaled propofol concentrations correlate with propofol concentrations in adult human blood and the brain tissue of rats, as well as with electroencephalography (EEG) based indices of anesthetic depth. The pharmacokinetics of propofol are however different in children compared to adults. The value of exhaled propofol measurements in pediatric anesthesia has not yet been investigated. Breathing system filters and breathing circuits can also interfere with the measurements. In this study, we investigated correlations between exhaled propofol (exP) concentrations and the Narkotrend Index (NI) as well as calculated propofol plasma concentrations.

METHODS

A multi-capillary-column (MCC) combined with ion mobility spectrometry (IMS) was used to determine exP. Optimal positioning of breathing system filters (near-patient or patient-distant) and sample line (proximal or distal to filter) were investigated. Measurements were taken during induction (I), maintenance (M) and emergence (E) of children under total intravenous anesthesia (TIVA). Correlations between ExP concentrations and NI and predicted plasma propofol concentrations (using pediatric pharmacokinetic models Kataria and Paedfusor) were assessed using Pearson correlation and regression analysis.

RESULTS

Near-patient positioning of breathing system filters led to continuously rising exP values when exP was measured proximal to the filters, and lower concentrations when exP was measured distal to the filters. The breathing system filters were therefore subsequently attached between the breathing system tubes and the inspiratory and expiratory limbs of the anesthetic machine. ExP concentrations significantly correlated with NI and propofol concentrations predicted by pharmacokinetic models during induction and maintenance of anesthesia. During emergence, exP significantly correlated with predicted propofol concentrations, but not with NI.

CONCLUSION

In this study, we demonstrated that exP correlates with calculated propofol concentrations and NI during induction and maintenance in pediatric patients. However, the correlations are highly variable and there are substantial obstacles: Without patient proximal placement of filters, the breathing circuit tubing must be changed after each patient, and furthermore, during ventilation, a considerable additional loss of heat and moisture can occur. Adhesion of propofol to plastic parts (endotracheal tube, breathing circle) may especially be problematic during emergence.

TRIAL REGISTRATION

The study was registered in the German registry of clinical studies (DRKS-ID:  DRKS00015795 ).

Macrocirculatory Parameters and Oxygen Debt Indices in Pigs During Propofol Or Alfaxalone Anesthesia When Subjected to Experimental Stepwise Hemorrhage

Background: Pigs are anesthetized when used for emergency procedures live tissue training (LTT) of civilian and military medical personnel or for experimental purposes, but there is a paucity in the literature regarding anesthesia of pigs for this purpose. Objective(s): The main goals of the study were to compare oxygen debt, macrocirculatory parameters, and time to cardiac arrest between pigs in hemorrhagic shock and anesthetized with propofol-ketamine-dexmedetomidine or alfaxalone-ketamine-dexmedetomidine. Design: A prospective, non-blinded randomized study design was used. Sixteen pigs were randomized in blocks of four to be anesthetized with either propofol-ketamine-dexmedetomidine (n = 8) or alfaxalone-ketamine-dexmedetomidine (n = 8) as a continuous infusion. Interventions: Premedication with ketamine 15 mg kg^-1 and midazolam 1 mg kg^-1 was given i.m. Anesthesia was maintained with propofol 8 mg kg^-1 h^-1 or alfaxalone 5 mg kg^-1 h^-1 combined with ketamine 5 mg kg^-1 h^-1 and dexmedetomidine 4 μg kg^-1 h^-1 i.v. A stepwise, volume-controlled model for hemorrhage was created by exsanguination. Main Outcome Measures: Indices of oxygen debt (lactate, base excess, and oxygen extraction), macrocirculatory (PR, SAP, DAP, MAP, and CI, SVI, and TPR) variables, and time to death was compared between groups. Results: Pigs in the alfaxalone group had significantly higher SAP than pigs given propofol. No difference in other macrocirculatory variables or indices of oxygen debt could be found. A blood loss of 50% of the total blood volume or more was possible in most pigs with both anesthetic regimes. Conclusions: Pigs anesthetized with propofol or alfaxalone combined with ketamine and dexmedetomidine tolerated substantial blood loss.

Why do We Use the Concepts of Adult Anesthesia Pharmacology in Developing Brains? Will It Have an Impact on Outcomes? Challenges in Neuromonitoring and Pharmacology in Pediatric Anesthesia

BACKGROUND

Pediatric sedation and anesthesia techniques have plenty of difficulties and challenges. Data on the pharmacologic, electroencephalographic, and neurologic response to anesthesia at different brain development times are only partially known. New data in neuroscience, pharmacology, and intraoperative neuromonitoring will impact changing concepts and clinical practice. In this article, we develop a conversation to guide the debate and search for a view more attuned to the updated knowledge in neurodevelopment, electroencephalography, and clinical pharmacology for the anesthesiologic practice in the pediatric population.

Seeing White: Management of TIVA during autologous breast reconstruction

Total IntraVenous Anaesthesia is frequently the anaesthetic of choice for enhanced recovery after surgery pathways during breast reconstruction free flap surgery. This relies upon the continuous intravenous infusion of propofol. We describe our experience of two patients where augmentation of a venously congested DIEP flap with a cephalic vein transposition procedure, risked interruption of the intravenous delivery of anaesthesia to the patient. We also share our steps taken to mitigate this risk going forward.

Attitudes of Spanish-speaking veterinarians interested in anaesthesia towards use of total intravenous anaesthesia in dogs: a survey study

OBJECTIVES

To describe Spanish-speaking veterinary anaesthetists' attitudes towards use of total intravenous anaesthesia (TIVA) in dogs.

STUDY DESIGN

Prospective online voluntary survey.

POPULATION

Data from 300 answered surveys.

METHODS

An anonymous questionnaire was sent via e-mail to representatives of the four largest Spanish-speaking veterinary anaesthesia and analgesia associations. It was distributed through mailing lists (Spain, Argentina, Mexico) or social media (Spain, Chile) to gather information on the use, opinions and perceived advantages of TIVA, as well as on preferred alternatives to isoflurane for providing general anaesthesia. Logistic regression was used to test for response associations.

RESULTS

A total of 275 (92%) respondents had used TIVA (24% rarely, 36% sometimes, 40% very often or always). There was an association between a higher rate of TIVA usage and a low specialization level, less clinical experience and unavailability of anaesthetic gas scavenging systems. The main reasons for not using TIVA were lack of familiarity with the technique (92%), unavailability of infusion pumps (32%), established institutional anaesthetic protocol (32%), and technical difficulty (20%). Among frequent TIVA users, a higher proportion reported the greater ease of TIVA use (52%) compared to those that did not perceive such benefit (17%) [odds ratio (OR) = 5.2; 95% confidence interval (CI95), 1.7-16.6; p = 0.004). More respondents did not consider TIVA more expensive (60%) (OR = 2.1; CI95, 1.0-4.3; p = 0.034), more difficult to perform (59%) (OR = 2.5; CI95, 1.3-4.9; p = 0.006) or to manage the equipment (53%) (OR = 3.3; CI95, 1.4-7.8; p = 0.008), than inhalational anaesthetics. During isoflurane shortages, respondents reportedly preferred using an alternative inhalational agent (59%) rather than TIVA (47%).

CONCLUSIONS AND CLINICAL RELEVANCE

TIVA use is widespread among veterinarians within the surveyed associations. Frequent TIVA users reported greater perceived advantages. In situations of isoflurane shortage, an alternative inhalational anaesthetic was preferred over TIVA.

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.

Anaesthesia and multimodality intraoperative neuromonitoring in carotid endarterectomy. Chronological evolution and effects on intraoperative neurophysiology

Contingency data was retrospectively collected to evaluate the historical and current ability to provide multimodality intraoperative neurophysiological monitoring during carotid endarterectomy under two conditions: total intravenous anaesthesia (TIVA) and low dose halogenated anaesthesia (SEVO). 229 patients were monitored during carotid endarterectomy procedures under general anaesthesia between 2012 and 2020. 121 Patients were monitored with SEVO at a minimum alveolar concentration less than 0.7 and 108 were monitored using TIVA, according to common anaesthetic practice standards in our hospital across the years. Multimodality IONM was established with electroencephalography, somatosensory evoked potentials and motor evoked potentials. As compared to TIVA, patients monitored with SEVO showed significantly higher motor evoked potential thresholds (313.52 ± 77.74 SEVO and 218.93 V ± 103.2 V TIVA p < 0.05) and lower reproducibility. Electroencephalography and somatosensory evoked potentials showed no significant differences among the groups. When using SEVO, multimodality intraoperative neurophysiological monitoring during carotid endarterectomy could mask or miss a motor isolated change in patients in spite of low dose minimum alveolar concentration and of apparently adequate electroencephalography and somatosensory evoked potentials for monitoring. Given these difficulties, we believe the chronological transfer to TIVA could have improved our ability to establish multimodality intraoperative neurophysiological monitoring during carotid endarterectomy in recent times.

The anesthetist's choice of inhalational vs. intravenous anesthetics has no impact on survival of glioblastoma patients

Recent data suggest that the type of anesthesia used during the resection of solid tumors impacts the long-term survival of patients favoring total-intravenous-anesthesia (TIVA) over inhalative-anesthesia (INHA). Here we sought to query this impact on survival in patients undergoing resection of glioblastoma (GBM). All patients receiving elective resection of a newly diagnosed, isocitrate-dehydrogenase-1-(IDH1)-wildtype GBM under general anesthesia between January 2010 and June 2017 in the Department of Neurosurgery, Heidelberg University Hospital, were included. Patients were grouped according to the applied anesthetic technique. To adjust for potential prognostic confounders, patients were matched in a 1:2 ratio (TIVA vs. INHA), taking into account the known prognostic factors: age, extent of resection, O-6-methylguanine-DNA-methyltransferase-(MGMT)-promoter-methylation-status, pre-operative Karnofsky-performance-index and adjuvant radio- and chemotherapy. The primary endpoint was progression-free-survival (PFS) and the secondary endpoint was overall-survival (OS). In the study period, 576 patients underwent resection of a newly diagnosed, IDH-wildtype GBM. Patients with incomplete follow-up-data, on palliative treatment, having emergency or awake surgery; 54 patients remained in the TIVA-group and 417 in the INHA-group. After matching, 52 patients remained in the TIVA-group and 92 in the INHA-group. Median PFS was 6 months in both groups. The median OS was 13.5 months in the TIVA-group and 13.0 months in the INHA-group. No significant survival differences associated with the type of anesthesia were found either before or after adjustment for known prognostic factors. This retrospective study supports the notion that the current anesthetic approaches employed during the resection of IDH-wildtype GBM do not impact patient survival.

The Effect of Propofol Versus Volatile Anesthetics on Persistent Pain After Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVES

Sternal incisions can generate persistent and intense post-sternotomy pain. Propofol has been shown to improve postoperative analgesia, but the preventive effect on persistent pain after cardiac surgery is unknown. The hypothesis of the present study was that intraoperative propofol-based anesthesia compared with volatile anesthesia could reduce the risk of chronic pain after cardiac surgery.

DESIGN

A single-center, two-arm, patient-and-evaluator-blinded, randomized controlled trial.

SETTING

A single major urban teaching and university hospital.

PATIENTS

Five-hundred adult patients undergoing cardiac surgery via sternotomy randomly were assigned. With six withdrawals from the study and five from surgery, 244 in the total intravenous anesthesia group and 245 in the volatile group were included in the modified intention-to-treat analysis.

INTERVENTIONS

Patients randomly were assigned to receive either propofol-based total intravenous anesthesia or volatile anesthesia during surgery.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were the incidence of pain at three, six, and 12 months after surgery defined as pain score >0 on the numeric rating scale. The secondary outcomes included acute pain, opioid use during the first 72 hours after surgery, and quality of life. The use of propofol did not significantly affect chronic pain at three months (55.4% v 52.9%, difference 2.5%, 95% confidence interval [CI] -6.6 to 11.6; p = 0.656), six months (35.5% v 37.5%, difference -2.0%, 95% CI -10.9 to 6.9; p = 0.657), or 12 months (18.2% v 20.7%, difference -2.5%, 95% CI -9.8 to 4.8; p = 0.495) compared with volatile anesthetics. Furthermore, there were no differences in acute pain score; morphine-equivalent consumption during the first 72 hours; and quality of life at three, six, and 12 months after surgery.

CONCLUSIONS

Intraoperative administration of propofol did not reduce persistent pain after cardiac surgery compared with volatile anesthetics.

Effect of Patient State Index Monitoring on the Recovery Characteristics in Morbidly Obese Patients: Comparison of Inhalation Anesthesia and Total Intravenous Anesthesia

PURPOSE

Obese patients have a significantly higher risk of adverse effects associated with general anesthesia. The purpose of this study was to evaluate the effects of Patient State Index (PSI) monitoring on recovery from anesthesia and the incidence of any postoperative complications among patients undergoing bariatric surgery with total intravenous anesthesia (TIVA) and inhalational anesthesia.

DESIGN

This prospective, double-blind, and randomized controlled trial was conducted between February 2017 and August 2017 and included 120 morbidly obese patients (body mass index >40 kg/m²).

METHODS

Patients were randomly divided into four groups; group P-PSI (n = 30): TIVA with PSI monitoring; group P (n = 30): TIVA without PSI monitoring; group D-PSI (n = 30): desflurane with PSI monitoring; and group D (n = 30): desflurane without PSI monitoring. The discharge time from the postanesthesia care unit (PACU), postoperative complications, and hemodynamic parameters were recorded and evaluated.

FINDINGS

No significant differences were found in demographic data, duration of anesthesia, admittance to PACU, discharge from PACU, modified Aldrete scores, and perioperative mean blood pressure and heart rate. Nausea and vomiting scores were significantly lower in group P-PSI, group P, and group D-PSI compared with group D.

CONCLUSIONS

Although TIVA and inhalational anesthesia can be safely used for obese patients, intraoperative PSI monitoring may decrease the discharge time from PACU and reduces incidence of postoperative nausea and vomiting caused by inhalation anesthetics.

Preemptive local anesthetic infiltration reduces opioid requirements without attenuation of the intraoperative electrical stapedial reflex threshold in pediatric cochlear implant surgery

Background and Aims:

Total intravenous anesthesia using remifentanil provides good surgical condition without affecting the intraoperative electrical stapedial reflex threshold (ESRT). However, remifentanil results in hyperalgesia and increases postoperative opioid requirements. Local anesthetic infiltration is alternative methods to opioid for providing analgesia. However, otologists avoids its use as it can abolish the ESRT. We investigated the effect of the preemptive local anesthetic infiltration on intraoperative ESRT and opioid requirements in pediatric cochlear implant surgery performed under TIVA.

Material and Methods:

Prospective, randomized, double-blinded, controlled study including 70 child undergoing cochlear implant under TIVA were randomly assigned to a local anesthesia (LA group, n = 35) or control (CT group, N = 35). The primary outcome was the total tramadol consumption during the first 24 h postoperative, and the secondary outcomes were time to first analgesia request, postoperative pain scores, the ESRT and, propofol and remifentanil requirements. The incidence of postoperative vomiting was recorder as well.

Results:

The total tramadol consumption during the first 24 h after surgery was significantly less in the LA group than in CT group (8.25 [4.3] vs. 16.5 [6.57] mg, P < 0.01). The time to first analgesic request was significantly prolonged in the LA group as compared with the CT group [8 [2–12] vs. 3 [0–8] h, P < 0.01). The postoperative Faces, Legs, Activity, Cry Consolability pain scores were significantly lower in the LA group at 15 min, 30 min, 2, 4 and 6 h postoperative. Mean remifentanil infusion rate [mean (standard deviation)] was significantly higher in in the CT group than in the LA group [0.7 (0.3) vs. 0.5 (0.2) μg/kg/min; P = 0.001).The ESRT response, propofol requirements, and the incidence of postoperative vomiting had no significant differences between both groups.

Conclusion:

Preemptive local anesthetic infiltration reduced opioid requirements without attenuation of the ESRT in pediatric cochlear implant surgery performed under TIVA.

Use of dexmedetomidine and opioids as the primary anesthetic in infants and young children: A retrospective cohort study

BACKGROUND

Anesthetic regimens using dexmedetomidine and short-acting opioids have been suggested as potential alternatives to sevoflurane-based anesthesia in children. The primary aim of this study is to compare demographics, intraoperative characteristics, and complications of general anesthetics in which dexmedetomidine and opioids were used without sevoflurane, or in combination with a low sevoflurane concentration, in children 36 months old and younger. The secondary aim is to evaluate intraoperative bispectral index (BIS) values when available in these patients.

METHODS

General anesthetics performed between January 1, 2017, and May 1, 2018, in children 2 years and younger who received dexmedetomidine and remifentanil, with or without sevoflurane, were identified. Additional anesthetics performed during this time in children 36 months and younger who received dexmedetomidine and opioids and had BIS monitoring were also identified. Charts were reviewed for demographic and intraoperative variables, including drug administration and hemodynamic data.

RESULTS

A total of 244 patients were identified. All but 22 patients received remifentanil. Ninety-two patients received sevoflurane with a mean end-tidal concentration of 0.84% (SD 0.43). Compared to the sevoflurane group, the nonsevoflurane group received more remifentanil (median dose 0.4 μg/kg/min vs 0.2 μg/kg/min, difference of 0.1 μg/kg/min, 95% CI 0.1-0.3, P < .001) and more dexmedetomidine (median dose 0.9 μg/kg/h vs 0.3 μg/kg/h, difference of 0.6 μg/kg/h, 95% CI 0.4-0.8, P < .001), and had a higher mean arterial pressure (median 53 mm Hg vs 42 mm Hg, difference of 11 mm Hg, 95% CI 8.1-14.8, P < .001). Complications between the two groups were comparable. The median percent intraoperative time with BIS reading <60 was 71.6% (95% CI: 63.3%-79.8%).

CONCLUSION

Dexmedetomidine and opioids can effectively be used in young children as an alternative total intravenous anesthesia technique with or without <1 minimum alveolar concentration of sevoflurane. Bispectral index monitoring reveals a likely sufficient depth of hypnosis.

Surgical Field Visualization during Functional Endoscopic Sinus Surgery: Comparison of Propofol- vs Desflurane-Based Anesthesia

OBJECTIVE

To assess if the type of general anesthetic affects bleeding and field visualization during endoscopic sinus surgery.

STUDY DESIGN

Prospective, randomized, controlled trial.

SETTING

Academic teaching hospital and Veterans Affairs hospital in the United States.

SUBJECTS AND METHODS

Seventy patients were randomized to 1 of 3 anesthetic regimens: (1) the volatile anesthetic desflurane (n = 22), (2) intravenous anesthesia with propofol (n = 25), or (3) a combination of propofol and desflurane (n = 23). Intravenous remifentanil was titrated to decrease the mean arterial pressure to 60 to 70 mm Hg but not ≥30% from baseline. Surgical bleeding scores were recorded along with bleeding rates and hemodynamic parameters, including cardiac output and systemic vascular resistance through pulse contour analysis from a radial arterial line. Statistics: multiple comparison tests and regression analyses; α = .05.

RESULTS

There were no differences in bleeding rate (median, 0.58, 0.85, 0.57 mL min^-1), bleeding score (2.1, 2.0, 2.0), surgery duration (79, 81, 86 minutes), extubation time (9, 7, 8 minutes), recovery room time (65, 61, 61 minutes), or any hemodynamic parameters among groups 1 through 3, respectively. Group 1 required lower remifentanil infusions than group 2 (0.11 vs 0.26 µg kg^-1 min^-1; P = .01). The bleeding score correlated positively with height (P = .014) and the Lund-MacKay score (P = .013). Bilateral vs unilateral surgery led to longer surgery duration (P = .001) and recovery room time (P = .004).

CONCLUSION

When remifentanil is used for controlled hypotension, propofol has no advantage over desflurane to improve surgical field visualization during functional endoscopic sinus surgery.

Evaluation of emergence agitation after general anaesthesia in rhinoplasty patients: Inhalation anaesthesia versus total intravenous anaesthesia

BACKGROUND

Emergence agitation (EA) is a clinical condition that occurs early in recovery from general anaesthesia, and reduces patient comfort. The aim of this study was to compare the effects of low-flow sevoflurane anaesthesia and total intravenous anaesthesia (TIVA) on agitation in rhinoplasty patients, and to determine the frequency of EA in low flow sevoflurane anaesthesia after rhinoplasty.

MATERIAL AND METHODS

A total of 90 rhinoplasty patients, under general anaesthesia were included in this prospective randomised study. After induction of anaesthesia, propofol infusion was initiated in the TIVA group (n = 45), and sevoflurane was administered in the SEVO group with a fresh gas flow of 1 l/min and MAC (minimum alveolar concentration) 1-1.1 (n = 45). Early emergence times, Richmond agitation-sedation scale (RASS), Boezaart scale, Likert scale and incidences of nausea/vomiting were recorded at the end of surgery.

RESULTS

Early emergence time was significantly shorter in the TIVA group, than in the SEVO group (p < 0.001). İntraoperative bleeding was significantly lower in the TIVA group, than in the SEVO group (p = 0.005), and surgical field image quality and surgeon satisfaction were better in the TIVA group (p = 0.016, p < 0.001). The ratio of patients with RASS > +1 for all patients was 35.6% at 0 min, postoperatively. This rate was 12.2% (n = 11) in the TIVA group, and 23.3% (n = 21) in the SEVO group (p = 0.028).

CONCLUSIONS

In rhinoplasty, TIVA caused shorter early emergence times, less bleeding, high surgeon satisfaction, and lower EA scores when compared with low flow sevoflurane anaesthesia.

Anesthetic management of a patient with large atrial septal defect undergoing laparoscopic cholecystectomy: A case report

A 51-year-old woman presented with symptomatic GB stone was planned for elective laparoscopic cholecystectomy. She had known osteum secondum type atrial septal defect, moderate pulmonary hypertension, and atrial fibrillation. We report the case of a patient with a large atrial septal defect (65 mm) and hemodynamic instability who underwent laparoscopic cholecystectomy under total intravenous anesthesia with careful hemodynamic monitoring. Thorough surveillance and effort could help to make the surgery successful.

Effects of ketamine or midazolam continuous rate infusions on alfaxalone total intravenous anaesthesia requirements and recovery quality in healthy dogs: a randomized clinical trial

OBJECTIVE

To determine the alfaxalone dose reduction during total intravenous anaesthesia (TIVA) when combined with ketamine or midazolam constant rate infusions and to assess recovery quality in healthy dogs.

STUDY DESIGN

Prospective, blinded clinical study.

ANIMALS

A group of 33 healthy, client-owned dogs subjected to dental procedures.

METHODS

After premedication with intramuscular acepromazine 0.05 mg kg^-1 and methadone 0.3 mg kg^-1, anaesthetic induction started with intravenous alfaxalone 0.5 mg kg^-1 followed by either lactated Ringer's solution (0.04 mL kg^-1, group A), ketamine (2 mg kg^-1, group AK) or midazolam (0.2 mg kg^-1, group AM) and completed with alfaxalone until endotracheal intubation was achieved. Anaesthesia was maintained with alfaxalone (6 mg kg^-1 hour^-1), adjusted (±20%) every 5 minutes to maintain a suitable level of anaesthesia. Ketamine (0.6 mg kg^-1 hour^-1) or midazolam (0.4 mg kg^-1 hour^-1) were employed for anaesthetic maintenance in groups AK and AM, respectively. Physiological variables were monitored during anaesthesia. Times from alfaxalone discontinuation to extubation, sternal recumbency and standing position were calculated. Recovery quality and incidence of adverse events were recorded. Groups were compared using parametric analysis of variance and nonparametric (Kruskal-Wallis, Chi-square, Fisher's exact) tests as appropriate, p < 0.05.

RESULTS

Midazolam significantly reduced alfaxalone induction and maintenance doses (46%; p = 0.034 and 32%, p = 0.012, respectively), whereas ketamine only reduced the alfaxalone induction dose (30%; p = 0.010). Recovery quality was unacceptable in nine dogs in group A, three dogs in group AK and three dogs in group AM.

CONCLUSIONS AND CLINICAL RELEVANCE

Midazolam, but not ketamine, reduced the alfaxalone infusion rate, and both co-adjuvant drugs reduced the alfaxalone induction dose. Alfaxalone TIVA allowed anaesthetic maintenance for dental procedures in dogs, but the quality of anaesthetic recovery remained unacceptable irrespective of its combination with ketamine or midazolam.

A comparison of respiratory function in pigs anaesthetised by propofol or alfaxalone in combination with dexmedetomidine and ketamine

BACKGROUND

General anaesthesia in pigs maintained with intravenous drugs such as propofol may cause respiratory depression. Alfaxalone gives less respiratory depression than propofol in some species. The aim of the investigation was to compare respiratory effects of propofol-ketamine-dexmedetomidine and alfaxalone-ketamine-dexmedetomidine in pigs. Sixteen pigs premedicated with ketamine 15 mg/kg and midazolam 1 mg/kg intramuscularly were anaesthetised with propofol or alfaxalone to allow endotracheal intubation, followed by propofol 8 mg/kg/h or alfaxalone 5 mg/kg/h in combination with ketamine 5 mg/kg/h and dexmedetomidine 4 µg/kg/h given as a continuous infusion for 60 min. The pigs breathed spontaneously with an FIO₂ of 0.21. Oxygen saturation (SpO₂), end-tidal CO₂ concentration (PE'CO₂), respiratory rate (f_R) and inspired tidal volume (V_T) were measured, and statistically compared between treatments. If the SpO₂ dropped below 80% or if PE'CO₂ increased above 10.0 kPa, the pigs were recorded as failing to complete the study, and time to failure was statistically compared between treatments.

RESULTS

Alfaxalone treated pigs had significantly higher respiratory rates and lower PE'CO₂ than propofol treated pigs, with a f_R being 7.3 /min higher (P = 0.01) and PE'CO₂ 0.8 kPa lower (P = 0.05). SpO₂ decreased by 0.6% and f_R by 1.0 /min per kg increase in body weight in both treatment groups. Three of eight propofol treated and two of eight alfaxalone treated pigs failed to complete the study, and times to failure were not significantly different between treatments (P = 0.75).

CONCLUSIONS

No major differences in respiratory variables were found when comparing treatments. Respiratory supportive measures must be available when using both protocols.

Volatiles or TIVA: Which is the standard of care for pediatric airway procedures? A pro-con discussion

Anesthesia for pediatric airway procedures constitutes a true art form that requires training and experience. Communication between anesthetist and surgeon to establish procedure goals is essential in determining the most appropriate anesthetic management. But does the mode of anesthesia have an impact? Traditionally, inhalational anesthesia was the most common anesthesia technique used during airway surgery. Introduction of agents used for total intravenous anesthesia (TIVA) such as propofol, short-acting opioids, midazolam, and dexmedetomidine has driven change in practice. Ongoing debates abound as to the advantages and disadvantages of volatile-based anesthesia versus TIVA. This pro-con discussion examines both volatiles and TIVA, from the perspective of effectiveness, safety, cost, and environmental impact, in an endeavor to justify which technique is the best specifically for pediatric airway procedures.

Total intravenous anesthesia in domestic chicken (Gallus gallus domesticus) with propofol alone or in combination with methadone, nalbuphine or fentanyl for ulna osteotomy

OBJECTIVE

To compare the propofol infusion rate and cardiopulmonary effects during total intravenous anesthesia with propofol alone and propofol combined with methadone, fentanyl or nalbuphine in domestic chickens undergoing ulna osteotomy.

STUDY DESIGN

Prospective, randomized, experiment trial.

ANIMALS

A total of 59 healthy Hissex Brown chickens weighing 1.5 ± 0.2 kg.

METHODS

Anesthesia was induced with propofol (9 mg kg^-1) administered intravenously (IV) and maintained with propofol (1.2 mg kg^-1 minute^-1) for 30 minutes. Birds were intubated and supplemented with 100% oxygen through a nonrebreathing circuit under spontaneous ventilation. Thereafter, each animal was randomly assigned to one of four groups: group P, no treatment; group PM, methadone (6 mg kg^-1) intramuscularly (IM); group PN, nalbuphine IM (12.5 mg kg^-1); and group PF, fentanyl IV (30 μg kg^-1 loading dose, 30 μg kg^-1 hour^-1 constant rate infusion). During the osteotomy surgery, the propofol infusion rate was adjusted to avoid movement of birds and provide adequate anesthesia. Pulse rate, invasive blood pressure, respiratory frequency, end-tidal carbon dioxide partial pressure (Pe'CO₂) and hemoglobin oxygen saturation (SpO₂) were recorded.

RESULTS

Data were available from 58 chickens. The mean ± standard deviation propofol infusion rate (mg kg^-1 minute^-1) for the duration of anesthesia was: group P, 0.81 ± 0.15; group PM, 0.66 ± 0.11; group PN, 0.60 ± 0.14; and group PF, 0.80 ± 0.07. Significant differences were P versus PM (p = 0.042), P versus PN (p = 0.002) and PF versus PN (p = 0.004). Pulse rate, blood pressure and SpO₂ remained acceptable for anesthetized birds with minor differences among groups. Values of Pe'CO₂ >60 mmHg (8 kPa) were observed in all groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Methadone and nalbuphine, but not fentanyl, decreased the propofol infusion rate required for anesthesia maintenance, but resulted in no obvious benefit in physiological variables.