Pharmacokinetics of propofol in severely obese surgical patients.

BACKGROUND: Existing PK models of propofol include sparse data from very obese patients. The aim of this study was to develop a PK model based on standardised surgical conditions and spanning from normal-weight up to, and including, a high number of very obese patients. METHODS: Adult patients scheduled for laparoscopic cholecystectomy or bariatric surgery were studied. Anaesthesia was induced with propofol 2 mg/kg adjusted body weight over 2 min followed by 6 mg/kg/h adjusted body weight over 30 min. For the remainder of the operation anaesthesia was maintained with sevoflurane. Remifentanil was dosed according to clinical need. Eight arterial samples were drawn in a randomised block sampling regimen over a span of 24 h. Time-concentration data were analysed by population PK modelling using non-linear mixed-effects modelling. RESULTS: Four hundred and seventy four serum propofol concentrations were collected from 69 patients aged 19-60 years with a BMI 21.6-67.3 kg/m2. Twenty one patients had a BMI above 50 kg/m2. A 3-compartment PK model was produced wherein three different body weight descriptors and sex were included as covariates in the final model. Total body weight was found to be a covariate for clearance and Q3; lean body weight for V1, V2 and Q2; predicted normal weight for V3 and sex for V1. The fixed allometric exponent of 0.75 applied to all clearance parameters improved the performance of the model. Accuracy and precision were 1.4% and 21.7% respectively in post-hoc performance evaluation. CONCLUSION: We have developed a new PK model of propofol that is suitable for all adult weight classes. Specifically, it is based on data from an unprecedented number of individuals with very high BMI.

Inhalational volatile anaesthetic agents: the atmospheric scientists' viewpoint.

All sectors of society must reduce their carbon footprint to mitigate climate change, and the healthcare community is no exception. This narrative review focuses on the environmental concerns associated with the emissions of volatile anaesthetic agents, some of which are potent greenhouse gases. This review provides an understanding of the global warming potential metric, as well as the concepts of atmospheric lifetime and radiative efficiency. The state of knowledge of the environmental impact and possible climate forcing of emitted volatile anaesthetic agents are reviewed. Additionally, the review discusses how climate metrics can guide mitigation strategies to reduce emissions and suggests present and future options for mitigating the climate impact.

Incidence and factors associated with failed spinal anaesthesia among patients undergoing surgery: a multi- center prospective observational study.

BACKGROUND: Failed spinal anaesthesia causes prolonging of operation time, insufficient analgesia for surgery and needs repeating spinal anaesthesia which in turn causes local anaesthesia toxicity, high spinal and total spinal, and conversion to general anaesthesia. However, the problem remains unexplored in Amhara regional state comprehensive specialized hospitals. OBJECTIVE: To determine incidence and factors associated with failed spinal anaesthesia among patients undergoing surgery in selected Amhara National Regional State comprehensive specialized hospitals, Northwest Ethiopia, 2023. METHODS: Multi-center prospective observational study was conducted. Data was collected using questionnaire and checklist. All consecutive scheduled emergency and elective patients were included in the study. Data was transformed from Epi data to SPSS and logistic regression analysis was done. Both crude and adjusted odds ratio were used to assess the strength of association. Variables with a p-value of less than 0.05 were considered as statistically significant. RESULTS: A total of 532 patients were included in this study with a response rate of 98%. Incidence of failed spinal anaesthesia was 22.4% (CI = 19-25.9). Emergency surgery (AOR = 7.01, CI = 4.5-12.7), dose of bupivacaine of ≤ 10 mg (AOR = 3.02, CI = 1.3-10.2), work experience of anaesthetist < 2 years (AOR = 3.1, CI = 1.7-5.72), bloody CSF (AOR = 8.5, CI = 2.53-18.5), hyperbaric local anaesthetic drug (AOR = 3.3, 95% CI = 3.2-8.2) and local anaesthetist without adjuvants (AOR = 5.25, CI = 2.62-14.2) were associated failed spinal anaesthesia. CONCLUSION AND RECOMMENDATION: The incidence of failed spinal anaesthesia was high in Amhara Region comprehensive specialized hospitals. We suggest that anaesthesia providers should minimize failure by using adjuvants and appropriate dose of local anaesthetic. Additionally, simulation training should be given for anaesthesia trainees to improve their skills and to produce competent professionals.

Adverse drug reactions in paediatric surgery: prospective study on frequency and risk related factors.

BACKGROUND: Paediatric patients are especially prone to experiencing adverse drug reactions (ADRs), and the surgical environment gathers many conditions for such reactions to occur. Additionally, little information exists in the literature on ADRs in the paediatric surgical population. We aimed to quantify the ADR frequency in this population, and to investigate the characteristics and risk factors associated with ADR development. METHODS: A prospective observational study was conducted in a cohort of 311 paediatric patients, aged 1-16 years, admitted for surgery at a tertiary referral hospital in Spain (2019-2021). Incidence rates were used to assess ADR frequency. Odds ratios (ORs) were calculated to evaluate the influence of potential risk factors on ADR development. RESULTS: Distinct ADRs (103) were detected in 80 patients (25.7%). The most frequent being hypotension (N = 32; 35%), nausea (N = 16; 15.5%), and emergence delirium (N = 16; 15.5%). Most ADRs occurred because of drug-drug interactions. The combination of sevoflurane and fentanyl was responsible for most of these events (N = 32; 31.1%). The variable most robustly associated to ADR development, was the number of off-label drugs prescribed per patient (OR = 2.99; 95% CI 1.73 to 5.16), followed by the number of drugs prescribed per patient (OR = 1.26, 95% CI 1.13 to 1.41), and older age (OR = 1.26, 95% CI 1.07 to 1.49). The severity of ADRs was assessed according to the criteria of Venulet and the Spanish Pharmacovigilance System. According to both methods, only four ADRs (3.9%) were considered serious. CONCLUSIONS: ADRs have a high incidence rate in the paediatric surgical population. The off-label use of drugs is a key risk factor for ADRs development.

Utilizing generative conversational artificial intelligence to create simulated patient encounters: a pilot study for anaesthesia training.

PURPOSE OF THE STUDY: Generative conversational artificial intelligence (AI) has huge potential to improve medical education. This pilot study evaluated the possibility of using a 'no-code' generative AI solution to create 2D and 3D virtual avatars, that trainee doctors can interact with to simulate patient encounters. METHODS: The platform 'Convai' was used to create a virtual patient avatar, with a custom backstory, to test the feasibility of this technique. The virtual patient model was set up to allow trainee anaesthetists to practice answering questions that patients' may have about interscalene nerve blocks for open reduction and internal fixation surgery. This tool was provided to anaesthetists to receive their feedback and evaluate the feasibility of this approach. RESULTS: Fifteen anaesthetists were surveyed after using the tool. The tool had a median score [interquartile range (IQR)] of 9 [7-10] in terms of how intuitive and user-friendly it was, and 8 [7-10] in terms of accuracy in simulating patient responses and behaviour. Eighty-seven percent of respondents felt comfortable using the model. CONCLUSIONS: By providing trainees with realistic scenarios, this technology allows trainees to practice answering patient questions regardless of actor availability, and indeed from home. Furthermore, the use of a 'no-code' platform allows clinicians to create customized training tools tailored to their medical specialties. While overall successful, this pilot study highlighted some of the current drawbacks and limitations of generative conversational AI, including the risk of outputting false information. Additional research and fine-tuning are required before generative conversational AI tools can act as a substitute for actors and peers.

Twelve tips for developing and implementing an effective critical care simulation programme.

Simulation training in healthcare settings has become a valuable training tool. It provides an ideal formative assessment for interdisciplinary teaching. It provides a high fidelity and highly immersive environment where healthcare staff and students can practice developing their skills in a safe and controlled manner. Simulation training allows staff to practice skills that better prepare them for clinical emergencies, therefore possibly optimising clinical care. While the benefits of simulation education are well understood, establishing a programme for use by critical care staff is complex. Complexities include the highly specialised scenarios that are not typically encountered in non-critical care areas, as well as the need for advanced monitoring equipment, ventilation equipment etc. These 12 tips are intended to assist healthcare educators in navigating the complexities in the establishment of a critical care simulation programme, providing advice on selecting target audiences, learning outcomes, creating a critical care simulation environment and recommendations on evaluation and development of the programme.

Learning strategies for the advanced trainee in specialist training.

BACKGROUND: A significant factor of clinicians' learning is based on their ability to effectively transfer acquired knowledge, skills, and attitudes from specialty-specific clinical courses to their working environment. MATERIAL AND METHOD: We conducted semi-structured interviews with 20 anaesthesiologist trainees (i.e. residents) in four group and five individual interviews using SRL principles as sensitizing concepts. Data were collected and analyzed iteratively using thematic analysis. RESULTS: Advanced trainees are highly motivated to explore what they have learned in specialty-specific courses, but they often face several barriers in implementing their learning in the workplace environment. Four themes emerged from the interview data: 'Be ready to learn', "Take the 'take-home-messages' home', "Be ready to create your own opportunities', and "Face it, it's not entirely up to you'. Understanding the challenges regarding transferring knowledge from courses to the working environment is an important lesson for assisting trainees set their learning goals, monitor their progress, and re-evaluate their SRL processes. CONCLUSION: Even for advanced trainees, successfully transferring knowledge from specialty-specific courses often requires adequate commitment and support. Medical supervisors and other relevant stakeholders must be aware of their shared responsibility for creating individual environments that support opportunities for trainees to self-regulate their learning.

The Anaesthetic Efficacy of Tetracaine and Oxymetazoline Compared With Co-Phenylcaine in Healthy Individuals.

OBJECTIVES: Nasal anaesthetic-decongestant sprays are commonly used prior to nasal instrumentation, such as flexible and rigid nasal endoscopy. Co-phenylcaine (lignocaine 5%, phenylephrine 0.5%, ENT Technologies Pty Ltd., Melbourne, VIC, Australia) is a combination spray commonly used for this purpose. However, lignocaine is less potent than other local anaesthetics, and both active constituents of Co-phenylcaine have a bitter taste. It was hypothesised that a combination spray containing tetracaine and oxymetazoline would both offer more potent topical anaesthesia and have a better taste. METHODS: Four anaesthetic-decongestant nasal sprays were tested in 10 healthy participants (Co-phenylcaine, and tetracaine 0.5%, 1% and 2% with oxymetazoline 0.05%). Sensory thresholds were sequentially measured at the head of the inferior turbinate using Semmes-Weinstein monofilaments over the following hour. Participants also rated taste on a Likert-style scale, and reported whether they experienced subjective numbness of the maxillary teeth. RESULTS: A median peak sensory threshold of 60 g (the maximum tested) was observed with Co-phenylcaine, but this threshold was exceeded by all the tetracaine-based sprays. Tetracaine 2% with oxymetazoline 0.05% had a significantly more rapid onset than Co-phenylcaine (4 min vs. 6 min, p < 0.05) and a longer duration of action. Eight participants reported dental numbness after administration of tetracaine 2% with oxymetazoline 0.05%, but only one participant after Co-phenylcaine. Tetracaine-based sprays were generally perceived to taste less unpleasant than Co-phenylcaine. CONCLUSION: Tetracaine 2% with oxymetazoline 0.05% is a more potent and rapidly acting anaesthetic-decongestant spray than Co-phenylcaine, with a longer duration of action.

Assessing knowledge of dental house officers regarding dosage calculation and complications of local anaesthesia, in three tertiary care dental hospitals of DUHS, Karachi.

Objectives: To assess the knowledge and awareness of dental house officers regarding calculation of local anaesthesia dosage, and to evaluate differences in practices at various tertiary care facilities. METHODS: The cross-sectional study was conducted at three dental hospitals affiliated with Dow University of Health Sciences, Karachi from July to December 2022, and comprised house officers of either gender currently enrolled at the participating centres. Data was collected using a self-administered questionnaire to assess knowledge and awareness of local anaesthesia dosage calculation, administration methods, and common complications. Data was analysed using SPSS 26. RESULTS: Of the 200 subjects approached, 136(68%) responded, and 89(65.4%) of them were females. Knowledge regarding the meaning of 2% lidocaine solution was low 45(33%), and 68(50%) subjects were knowledgeable about the maximum dosage of lidocaine with epinephrine. In terms of practice, lidocaine was the most commonly administered local anaesthetic 115(85%), followed by bupivacaine 15(11%). The majority of subjects administered local anaesthesia with vasoconstrictor 127(94%), but only 36(27%) performed aspiration during administration. Syncope 71(52%) was the most commonly reported complication, followed by lip/cheek/tongue biting by 35(26%). CONCLUSIONS: House officers' knowledge level of local anaesthesia administration indicated the need for adequate training.

Intravenous Lipid Emulsion does NOT have a role in severe poisoning: CON.

Intravenous lipid emulsion (ILE) has been suggested as a potential universal antidote for cardiovascular and central nervous system toxicity resulting from a multitude of pharmaceutical and nonpharmaceutical poisonings. While there is some evidence to suggest that ILE may have a positive effect in cardiovascular system toxicity after accidental intravenous lipophilic local anaesthetic overdose, this cannot be extrapolated to cases of severe poisoning resulting from oral drug overdose. Treatment recommendations are based upon variable outcome animal studies and low-level clinical evidence with a significant degree of positive reporting bias. Currently, there is a paucity of controlled clinical data to support ILE use to treat severe drug poisoning after oral overdose. ILE use should be limited to well-designed, ethically approved, controlled clinical trials aimed at determining the true effectiveness of this therapy. This should replace the current scattergun clinical use in a multiplicity of poisoning scenarios and subsequent anecdotal reporting approach.

Distinct pathophysiological characteristics in developing muscle from patients susceptible to malignant hyperthermia.

BACKGROUND: Most patients with malignant hyperthermia susceptibility diagnosed by the in vitro caffeine-halothane contracture test (CHCT) develop excessive force in response to halothane but not caffeine (halothane-hypersensitive). Hallmarks of halothane-hypersensitive patients include high incidence of musculoskeletal symptoms at rest and abnormal calcium events in muscle. By measuring sensitivity to halothane of myotubes and extending clinical observations and cell-level studies to a large group of patients, we reach new insights into the pathological mechanism of malignant hyperthermia susceptibility. METHODS: Patients with malignant hyperthermia susceptibility were classified into subgroups HH and HS (positive to halothane only and positive to both caffeine and halothane). The effects on [Ca2+]cyto of halothane concentrations between 0.5 and 3 % were measured in myotubes and compared with CHCT responses of muscle. A clinical index that summarises patient symptoms was determined for 67 patients, together with a calcium index summarising resting [Ca2+]cyto and spontaneous and electrically evoked Ca2+ events in their primary myotubes. RESULTS: Halothane-hypersensitive myotubes showed a higher response to halothane 0.5% than the caffeine-halothane hypersensitive myotubes (P<0.001), but a lower response to higher concentrations, comparable with that used in the CHCT (P=0.055). The HH group had a higher calcium index (P<0.001), but their clinical index was not significantly elevated vs the HS. Principal component analysis identified electrically evoked Ca2+ spikes and resting [Ca2+]cyto as the strongest variables for separation of subgroups. CONCLUSIONS: Enhanced sensitivity to depolarisation and to halothane appear to be the primary, mutually reinforcing and phenotype-defining defects of halothane-hypersensitive patients with malignant hyperthermia susceptibility.

Evaluation of National Anaesthetics Teaching in Undergraduate Medicine (ENATUM).

BACKGROUND: During a global pandemic where anaesthetists play a pertinent role in treating coronavirus 2019 (COVID-19), it is crucial to inspire medical students to consider a career in anaesthetics and perioperative care. Where anaesthetic skills are vital for all surgical foundation doctors, regardless of whether they have a rotation in anaesthetics, this study seeks to establish the current level of exposure to anaesthetics in the UK medical schools' curriculum and evaluate if the current anaesthetic undergraduate curriculum is sufficient to prepare students to pass their exams and perform the duties expected of them as future junior doctors. METHODS: A 35-item structured questionnaire, registered at University College London Hospital Research & Development (R&D), was distributed amongst foundation doctors who had graduated from UK universities within the previous 3 years between August and October 2020. RESULTS: In total, 239 participants completed the questionnaire from 34 UK medical schools. Despite 90.0% of participants being allocated an 'anaesthesia' placement, 54.0% spent <15 hours shadowing an anaesthetist throughout their medical school. Of participants, 38.5% agreed that their anaesthetic teaching was sufficient compared to teaching of other specialities, with 48.6% of students not satisfied with the teaching provided to meet anaesthetic learning outcomes set by The Royal College of Surgeons of England; 72.4% said they would have benefited from additional anaesthetic teaching, with 80.7% stating it would have increased understanding into the speciality; and 71.5% stated a short course in anaesthetics alongside undergraduate training would have been beneficial. CONCLUSIONS: Our results demonstrate that there is a lack of standardization in undergraduate anaesthetics teaching nationally and an additional undergraduate anaesthetic teaching programme is required to increase understanding and provide further insight into anaesthetics. Key messages:  The emergence of the coronavirus 2019 (COVID-19) pandemic has halted undergraduate medical education, in particular perioperative medicine and surgery.Exposure to anaesthesia is already limited in the medical undergraduate curriculum, with a limited number of anaesthesia-themed foundation rotations available for junior doctors.Recent UK graduates feel that undergraduate anaesthetics education is inadequate at medical school, reporting a lack of confidence in applying undergraduate anaesthesia learning outcomes.Additional anaesthetic teaching and online teaching methods are suggested ways of improving the delivery of undergraduate anaesthetic education.Can a national, standardized anaesthetics teaching curriculum improve the undergraduate knowledge base of anaesthesia?

Anaesthetic National Teaching Programme for Students (ANTPS).

The COVID-19 pandemic has significantly undermined undergraduate anaesthetic teaching in spite of the vital role of the specialty against the pandemic. Anaesthetic National Teaching Programme for Students (ANTPS) was designed to meet the evolving needs of undergraduates and tomorrow's doctor by standardising anaesthetic training, preparing for final exams and equipping competencies vital for doctors of all grades and specialties. Our Royal College of Surgeons England-accredited University-College-Hospital-affiliated programme consisted of six-biweekly sessions were delivered online by anaesthetic trainees. Prerandomised and postrandomised session-specific multiple-choice questions (MCQs) assessed students' improvement in knowledge. Anonymous feedback forms were provided to students after each session and 2 months following the programme. 3743 student feedback forms (92.2% of attendees) across 35 medical-schools were recorded. There was a mean improvement in test score (0.94±1.27, p<0.001). 313 students completed all six sessions. Based on 5-point Likert scale, students who completed the programme showed an improvement in their confidence in knowledge and skills to face common foundation challenges (1.59±1.12, p<0.001) and thus felt better prepared for life as junior doctors (1.60±1.14, p<0.001). With an increase in confidence in students to pass their MCQs, Observed Structured Clinical Examinations and case-based discussion assessments, 3525 students stated they would recommend ANTPS to other students. Unprecedented COVID-19 factors impacting training, positive student feedback and extensive recruitment, demonstrate that our programme is an indispensable learning resource which standardises anaesthetic undergraduate education nationally, prepares undergraduates for their anaesthetic and perioperative exams and lays strong foundations for implementation of clinical skills required by all doctors, to optimise training and patient care.

Sevoflurane consumption pattern by individual anaesthesiologists varies widely despite using the same high-end workstations in the same hospital.

Volatile anaesthetics are potent greenhouse gasses but contemporary workstations enable considerable savings while improving patient safety. Institutions may provide this technology to reduce the ecological footprint but proper training and motivation is required to maximize their ecologic and financial benefit. This study aims to compare the sevoflurane consumption of 22 anaesthesiologists in a medium sized hospital 4 years after flow-i workstations (Getinge, Sweden) entered into service, in three airway approaches: intubated patients, laryngeal mask ventilation, and mask anaesthesia. Typical sevoflurane consumption for each anaesthesiologist was defined as the mean cumulative consumption in the chronologically first 50 cases meeting the inclusion criteria for each airway group in 2019. The potential savings, if everyone were to adopt the approach of the more economical anaesthesiologists (15th percentile), was calculated. The CO2 equivalent emissions were calculated using a GWP20 of 702 and a GWP100 of 195. The median [range] consumption after 45 min was 10.9 [7.5-18.4] ml in intubated patients and 9.0 [7.4-15.3] ml in patients with laryngeal mask, and 9.9 [3.4-20.9] ml after 8 min with mask ventilation. This corresponds to a double to six fold consumption between the least and most wasteful approach. The typical CO2 equivalent emissions (GWP20) per anaesthesiologist varied between 8.0 and 19.6 kg/45 min in intubated airways, between 7.9 and 16.3 kg/45 min in LMA, and between 3.6 and 22.3 kg/8 min in mask ventilation. Despite using the same workstations in the same hospital, the typical sevoflurane consumption differed dramatically between 22 anaesthesiologists. In addition to providing advanced workstations, proper education is required to achieve the behavior change needed to reduce the pollution and financial waste associated with volatile anaesthetics.

The Local Anaesthetic Procaine Prodrugs ProcCluster® and Procaine Hydrochloride Impair SARS-CoV-2 Replication and Egress In Vitro.

As vaccination efforts against SARS-CoV-2 progress in many countries, there is still an urgent need for efficient antiviral treatment strategies for those with severer disease courses, and lately, considerable efforts have been undertaken to repurpose existing drugs as antivirals. The local anaesthetic procaine has been investigated for antiviral properties against several viruses over the past decades. Here, we present data on the inhibitory effect of the procaine prodrugs ProcCluster® and procaine hydrochloride on SARS-CoV-2 infection in vitro. Both procaine prodrugs limit SARS-CoV-2 progeny virus titres as well as reduce interferon and cytokine responses in a proportional manner to the virus load. The addition of procaine during the early stages of the SARS-CoV-2 replication cycle in a cell culture first limits the production of subgenomic RNA transcripts, and later affects the replication of the viral genomic RNA. Interestingly, procaine additionally exerts a prominent effect on SARS-CoV-2 progeny virus release when added late during the replication cycle, when viral RNA production and protein production are already largely completed.

Intraoperative Epidural Analgesia Practices And Their Outcomes In Major Abdominal Surgeries At A Tertiary Care Hospital In Karachi.

OBJECTIVE: To investigate the association involving site, concentrations and dosing of local anaesthetics used intraoperatively on postoperative pain scores, motor block and need for rescue analgesia. METHODS: The observational study was conducted from June 1, 2020, to May 31, 2021, at the Aga Khan University Hospital, Karachi, and comprised patients planned for major abdominal surgeries with epidurals as primary analgesic modality. They were followed prospectively from placement of epidurals to 24h postoperatively. Data was collected from anaesthesia chart and pain management notes. Data was analysed using SPSS 19. RESULTS: Of the 170 patients, 96(56.4%) were females and 74(43.5%) were males. The overall mean age was 54.1±12.6 years and mean body mass index was 26.7±5.5Kg/m2. More than half of the patients 110(64.7%) had thoracic epidural, while 60(35.3%) had lumber epidural. Requirement of opioid co-analgesia intraoperatively was significantly high with higher compared to lower concentration of local anaesthetics (p=0.004). The difference in frequencies of motor block was significantly associated with catheter length (p=0.006). CONCLUSIONS: Intraoperative management of epidurals is an essential but overlooked component of perioperative pain management. Guidelines should be formulated for intraoperative epidural analgesic regimens to improve postoperative outcomes.

Fraud and retraction in perioperative medicine publications: what we learned and what can be implemented to prevent future recurrence.

Fraud in medical publications is an increasing concern. In particular, disciplines related to perioperative medicine-including anaesthesia and critical care-currently hold the highest rankings in terms of retracted papers for research misconduct. The dominance of this dubious achievement is attributable to a limited number of researchers who have repeatedly committed scientific fraud. In the last three decades, six researchers have authored 421 of the 475 papers retracted in perioperative medicine. This narrative review reports on six cases of fabricated publication in perioperative medicine that resulted in the paper's retraction. The process that led to the unveiling of the fraud, the impact on clinical practice, and changes in regulatory mechanisms of scientific companies and governmental agencies' policies are also presented. Fraud in medical publications is a growing concern that affects perioperative medicine requiring a substantial number of papers to be retracted. The continuous control elicited by readers, by local institutional review boards, scientific journal reviewers, scientific societies and government agencies can play an important role in preserving the 'pact of trust' between authors, professionals and ultimately the relationship between doctors and patients.

Pharmacological and clinical implications of local anaesthetic mixtures: a narrative review.

Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long- and short-acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non-steroidal anti-inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non-steroidal anti-inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose-dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required.

Utility of nasal application of lignocaine gel using cotton tip swab versus squirting with slip-tip syringe for transnasal fibreoptic bronchoscopy: a pilot randomised controlled trial.

BACKGROUND: During flexible fibreoptic bronchoscopy through the nasal route, anaesthesia of the nasal passage is achieved by lignocaine gel application by a slip-tip syringe or with the help of a cotton tip swab. No studies in existing literature have compared the two techniques in terms of efficacy. METHODS: 137 consecutive patients undergoing bronchoalveolar lavage (BAL) were recruited over a 2-year period. The patients underwent BAL after nasal anaesthesia-either by slip-tip syringe or by cotton tip swab smeared with 2% lignocaine gel. Patients were monitored for intraprocedural epistaxis, discomfort and improvement in operator visibility of nasal passage. RESULTS: 67 patients were randomised to cotton swab and 70 patients to the gel instillation group. There were no significant differences in terms of epistaxis, 29.9% in the cotton tip swab (95% CI 19.3% to 42.3%) versus 24.3% in the gel instillation group (95% CI 14.8% to 36%) or detection of nasal blocks, 7.5% in the cotton tip swab (95% CI 2.5% to 16.6%) versus 10% in the gel instillation group (95% CI 4.1% to 19.5%) in the two groups, although a significant difference was there in terms of visibility, 73.1% in the cotton tip swab (95% CI 60.9% to 83.2%) versus 42.9% in the gel instillation group (95% CI 31.1% to 55.3%). There was no difference in the mean pain score across the two groups either during the procedure or 1 hour after it. A short systematic review of existing literature on the topic has been provided for comparison. CONCLUSION: Application of 2% lignocaine gel by slip-tip syringe and cotton tip swab are equivalent in terms of observed and narrated pain experienced by patients, frequency of epistaxis and nasal blocks. Vision was better preserved in the cotton tip swab group.

The effect of intraperitoneal ropivacaine on post-operative pain and recovery after diagnostic laparoscopy and hysteroscopy: A randomised double-blind placebo-controlled trial.

BACKGROUND: Intraperitoneal local anaesthetic has shown benefit in operative laparoscopy; however, no randomised controlled trial has been reported with patients having diagnostic laparoscopy. AIMS: To determine the effect of intraperitoneal ropivacaine on post-operative analgesic requirements, pain, nausea scores and recovery following gynaecological diagnostic laparoscopy and hysteroscopy. MATERIALS AND METHODS: Randomised double-blind placebo-controlled trial. Well women aged 18-50 years, undergoing day case hysteroscopy and diagnostic laparoscopy for gynaecological indications were randomised to 20 mL of 150 mg intraperitoneal ropivacaine diluted in saline, or 20 mL normal saline instillation (placebo) at the end of the procedure. Women were followed up until eight hours post-discharge. RESULTS: Slower than anticipated recruitment meant that the study was finished before the sample size of 100 patients was achieved. Fifty-nine patients were included for analysis. Thirty-one patients were randomised to ropivacaine and 28 patients to control. Sixty-one percent of patients in both arms required opioid medication in recovery. The total median equivalent morphine dose was significantly higher in the patients randomised to control (11.7 mg) vs ropivacaine (6.7 mg), P = 0.03. Time to discharge was 20 min faster in patients randomised to ropivacaine, but this finding did not reach significance. Overall pain and nausea scores in the first eight hours showed no significant differences. CONCLUSION: There was significantly reduced opioid use in recovery when using intraperitoneal ropivacaine compared to placebo, in this randomised placebo-controlled trial on women undergoing day case diagnostic laparoscopy and hysteroscopy.