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.

Ultrasonographic visualization of anatomical variations of the supraclavicular nerves.

Typical anatomy of the supraclavicular nerve (SCN) is described as originating from the cervical plexus and dividing into medial, intermediate, and lateral branches. The SCN is vulnerable to injury during clavicular surgery, leading to altered sensation post-operatively. There is also increasing interest in anesthetizing the SCN in shoulder or clavicular surgery. Utilizing a high-frequency (20 MHz) ultrasound probe, 20 healthy volunteers were scanned, giving data for 40 SCNs. For each nerve, anatomical course and branches were graphically plotted using a custom Python 3.8.12 program and Microsoft Excel. Of 40 nerves, only 19 (47.5%) demonstrated a typical course, with the rest showing considerable variability of branching patterns. Crossing branches (CBs) were found in 24 (60%) with a total of 54. Just over half (29, 54.7%) of these crossed the clavicle lateral to its midpoint, with 32 (59.6%) CBs having a diameter of ≥25% compared to that of the SCN main trunk. The distance from the mid-clavicular point at which the branches crossed the clavicle was recorded. This study demonstrated that over half the SCNs had atypical branching patterns with intra-volunteer variability. Preoperative mapping may be useful in preventing injury and subsequent numbness.

Temporomandibular joint anatomy: Ultrasonographic appearances and sexual dimorphism.

INTRODUCTION: Temporomandibular joint (TMJ) dysfunction is common, with a greater prevalence in females. While magnetic resonance imaging (MRI) is commonly used for clinical investigation, ultrasonography represents a potential alternative in some clinical scenarios. We designed a protocol for ultrasonographic evaluation of the TMJ and assessed its reliability. Presentation was compared between the sexes to establish whether an anatomical dichotomy underlies the female preponderance of TMJ dysfunction. MATERIALS AND METHODS: Ultrasound imaging of the TMJ was carried out in the longitudinal and oblique planes. Standard images were produced using model skulls and healthy volunteers. Measurements were made between the temporal bone, mandibular condyle, joint capsule and overlying skin, as well as of condylar translation during mouth opening. Both joints were scanned in 50 healthy volunteers. Measurements were repeated to evaluate reliability. A novel classification system was used to assess lateral condylar morphology. RESULTS: The protocol facilitated reliable visualization of key anatomical features of the TMJ (average intraclass correlation coefficient = 0.75, p ¯  = 5.4E-03). Distribution of condylar morphology differed between the sexes. The capsular-cutaneous distance ('joint depth') and condylar-temporal bone distance ('interarticular distance') were significantly greater in males than in females. CONCLUSIONS: Ultrasonography provides reliable views of the TMJ in two planes: longitudinal and oblique. Observed sexual dimorphism in TMJ anatomy might be associated with the female preponderance of dysfunction. With a standardized scanning protocol, ultrasound could provide a rapid, cost-effective alternative to MRI as a point-of-care imaging tool in TMJ clinics.

Incidence of hypothermia and factors affecting variation in core body temperature in patients undergoing arthroscopic surgery of the hip.

Perioperative hypothermia (below 36°C) has been associated with post-operative morbidity. The aim of this study was to determine the incidence of post-operative hypothermia in hip arthroscopy patients and factors affecting perioperative body temperature variation. A prospective audit of 50 consecutive patients undergoing hip arthroscopy for a variety of pathologies was carried out. The final sample size was 46 due to missing data in 4 patients. Core body temperature was measured with a nasopharyngeal temperature probe at the induction of anaesthesia and at the end of the procedure. Other recorded variables were type of warming blanket, ambient theatre temperature and duration of surgery. It was noted whether the patient was shivering immediately post-operatively. The following demographic details were recorded : age, sex, body mass index and the American Society of Anaesthesiologists physical status score. The statistical analysis was performed with Stata® 12 (StataCorp LP, College Station, Texas) by use of a conditional regression model to calculate associations between post-operative body temperature and other variables. The series included 30 female and 16 male patients aged 18 to 57 years (mean 35), with a mean BMI of 26.4 (standard deviation 4.2). Overall incidence of hypothermia below 36°C was 61%. Results of the conditional regression analysis suggested a positive association between post-operative body temperature and pre-operative body temperature (P< .001). Incidence of hypothermia in hip arthroscopy patients is high (61%). We recommend warming patients pre-operatively with forced air warming devices to reduce this incidence. Level of evidence : IV.

A Prospective Randomized Controlled Trial Comparing the Efficacy of Fascia Iliaca Compartment Block Versus Local Anesthetic Infiltration After Hip Arthroscopic Surgery.

PURPOSE: To compare the efficacy of fascia iliaca compartment block (FICB) with local anesthetic infiltration (LAI) of the arthroscopy portals for pain control after hip arthroscopy. METHODS: A prospective single-blinded randomized controlled trial that involved patients who underwent hip arthroscopy was performed. Participants were randomized to receiving either FICB or LAI of the portal tracts with local anesthetic. Supplemental analgesia was also used in both groups on an on-demand basis. The primary outcome measure was the postoperative level of pain as assessed by numeric pain score at 1, 3, 6, and 24 hours after the procedure in both groups. Secondary outcome measures were the frequency and the dose of morphine and other medications consumed at 1 and 24 hours after surgery as well as any other adverse events relating to pain or medications used for pain relief in both the groups. RESULTS: The study had to be terminated early because there was a significant statistical difference in the primary outcome measure after the recruitment of 46 patients: 20 in the LAI group and 26 in the FICB group. Severity of pain in the FICB group was higher especially during the first hour postoperatively (P = .02). This was associated with a higher consumption of opioids and other analgesics, which resulted in more side effects such as nausea and vomiting. CONCLUSIONS: LAI provided a better analgesia after arthroscopic surgery of the hip in comparison with FICB and was also associated with reduced consumption of opioids and a lower rate of side effects. LEVEL OF EVIDENCE: Level I, single-blinded randomized controlled study.

Not everything is as it seems.

We report a case of a patient operated for shoulder rotator cuff injury under interscalene brachial plexus block and general anesthesia, who developed neurological deficit in the nonoperative upper limb in the immediate postoperative period. As our patient developed neurological deficit on the nonoperative side, it was clear from the beginning that neither the nerve block nor the operative procedure was responsible for it. However, had he developed neurological symptoms on the operative side after having a peripheral nerve block, it would have possibly delayed the timely investigation and diagnosis. This case report underlines the need to keep an open mind when investigating neurological symptoms arising in the perioperative period, rather than assuming it to be secondary to either nerve block or as a complication of surgical procedure.

Lower lobe collapse during continuous interscalene brachial plexus local anesthesia at home.

OBJECTIVES: We report a case of pulmonary left lower lobe collapse following an interscalene local anesthetic infusion administered at home. This case highlights the need for patient education and postoperative communication. CASE REPORT: report A 52-year-old male patient presented for a rotator cuff repair. He was a chronic tobacco abuser with a history of occasional chest pain of unexplained cause. An interscalene catheter was placed preoperatively and surgery was performed under a combination of an interscalene block and a general anesthetic. An infusion of 0.2% ropivacaine was started via the interscalene catheter postoperatively and continued at home following his discharge from the hospital on the third postoperative day. Within 24 hours of discharge, he was readmitted to the hospital after complaining of chest pain and dyspnea. The patient was seen in the emergency department by nonanesthesiologists who were not familiar with the potential for interscalene blocks to cause diaphragmatic paresis. CONCLUSIONS: Good communication must be maintained with the patient at all times. Doctors from other specialties may be unaware of the potential complications of an interscalene block.

A study of the characteristics of single-injection insulated block needles in a biologic model.

BACKGROUND AND OBJECTIVES: Single-injection block needles are manufactured in many different lengths, diameters, and tip designs, but the literature contains no reports of methods to assess clinical characteristics of regional-block needles. A novel animal model for the assessment of the characteristics of single-injection regional anesthesia needles is described. METHODS: Nine different needles designed for peripheral nerve blocks that were fitted with identical hubs were used. Pork bellies were used as the biologic model. The bellies were mounted such that the needles passed from inside to outside. The last layer to be penetrated was the skin. Ten experienced and blinded anesthesiologists scored the feel, resistance, and usability of the 9 needles during their passage through similarly prepared pork bellies. Two identical (index) needles were included in the study to assess the internal validity of the study. RESULTS: The overall scoring was acceptably consistent and repeatable and showed statistically significant differences between the needles tested. The needles that were judged the most usable were those with a moderate resistance to passage through the tissue and a high degree of feel, which was defined as the ability to appreciate the passage of the needle through the tissue planes. Needles with very high or very low resistances and those with poor feel scored poorly on the usability scale. Differences in individuals' assessment of the index needles suggested some within-subject variability during the study. CONCLUSIONS: This type of biologic model can be used for the quantifiable and repeatable assessment of different needle tip designs. Needles with moderate resistance and high feel were preferred.

Tourniquet failure during total knee replacement due to arterial calcification: case report and review of the literature.

Use of a tourniquet for performing surgery in order to create a bloodless surgical field and reduce blood loss has been in use for many years. Tourniquets may fail perioperatively for various reasons, leading to ongoing bleeding. An important cause of tourniquet failure is calcification of the underlying artery. A patient undergoing total knee replacement surgery in whom the tourniquet failed, secondary to femoral artery calcification is reported. The implications of tourniquet use in patients with arterial calcification, including acute distal ischaemia, aneurysm formation and vessel fracture will be discussed. Recommendations include: thorough vascular assessment of all patients preoperatively, awareness of the possibility of tourniquet failure particularly in vasculopaths, and the provision of an alternative perioperative management plan such as use of a cell saver device, should the tourniquet fail.

Interscalene brachial plexus block: can the risk of entering the spinal canal be reduced? A study of needle angles in volunteers undergoing magnetic resonance imaging.

BACKGROUND: Spinal cord damage during interscalene brachial plexus block has been attributed to needle entry into the spinal canal. The purpose of this study was to identify the angles and depths of needle insertion that increase the likelihood of such an event, using the traditional classic interscalene approach and two more proximal entry points. METHOD: Magnetic resonance images of the neck from 10 healthy volunteers were used to obtain the three-dimensional spatial coordinates of three skin markers and the right-sided cervical nerves at the exiting neural foramina. The distance of the intervertebral foramina from the skin markers and the angles of the needle vector and the foramina were calculated. RESULTS: The distance from the skin to the intervertebral foramen may be as short as 2.5 cm with the classic approach. A caudal angulation greater than 50 degrees seemed to eliminate the risk of needle entry through the foramen. CONCLUSION: With the classic approach to the interscalene block, there is a greater possibility of the needle passing through the intervertebral foramen if the needle is advanced too deeply. More proximal entry points and techniques that use a more steeply angled needle may reduce the risk of entry into the spinal space.