Ten-year territory-wide trends in the utilisation and clinical outcomes of extracorporeal membrane oxygenation in Hong Kong.

INTRODUCTION: The utilisation of extracorporeal membrane oxygenation (ECMO) has been rapidly increasing in Hong Kong. This study examined 10-year trends in the utilisation and clinical outcomes of ECMO in Hong Kong. METHODS: We retrospectively reviewed the records of all adult patients receiving ECMO who were admitted to the intensive care units (ICUs) of public hospitals in Hong Kong between 2010 and 2019. Temporal trends across years were assessed using the Mann-Kendall test. Observed hospital mortality was compared with the Acute Physiology and Chronic Health Evaluation (APACHE) IV-predicted mortality. RESULTS: The annual number of patients receiving ECMO increased from 18 to 171 over 10 years. In total, 911 patients received ECMO during the study period: 297 (32.6%) received veno-arterial ECMO, 450 (49.4%) received veno-venous ECMO, and 164 (18.0%) received extracorporeal cardiopulmonary resuscitation. The annual number of patients aged ≥65 years increased from 0 to 47 (27.5%) [P for trend=0.001]. The median (interquartile range) Charlson Comorbidity Index increased from 1 (0-1) to 2 (1-3) [P for trend<0.001] while the median (interquartile range) APACHE IV score increased from 90 (57-112) to 105 (77-137) [P for trend=0.003]. The overall standardised mortality ratio comparing hospital mortality with APACHE IV-predicted mortality was 1.11 (95% confidence interval=1.01-1.22). Hospital and ICU length of stay both significantly decreased (P for trend=0.011 and <0.001, respectively). CONCLUSION: As ECMO utilisation increased in Hong Kong, patients put on ECMO were older, more critically ill, and had more co-morbidities. It is important to combine service expansion with adequate resource allocation and training to maintain quality of care.

Evaluation of learning and exposure in the undergraduate interventional radiology curriculum (ELIXIR).

AIM: To gauge current final year medical students' exposure to interventional radiology (IR)and assess their perceptions of IR as a prospective career option. MATERIALS AND METHODS: An online questionnaire comprising of questions that gauge final-year medical students' understanding of and exposure to IR based on the recommendations set out by the British Society of Interventional Radiology (BSIR), was sent out to final-year students across 34 UK medical schools. RESULTS: Five hundred and ten responses were collected from 33 out of 34 eligible medical schools. Sixty-four per cent of respondents rated their own IR knowledge as inadequate. On average, only 50% of all subtopics proposed in the BSIR undergraduate curriculum was covered during medical school and 32.7% of respondents were not exposed to any fundamental IR principles and techniques recommended by the BSIR during medical school. Regarding careers, 2.7% of respondents reported a definite interest in pursuing a career in IR. Most respondents (89.8%) felt that there was insufficient undergraduate teaching on IR and that they lacked information to consider pursuing a career in IR (87.5%). CONCLUSION: Insufficient exposure and teaching on IR throughout medical schools have led to a lack of awareness and consideration of IR as a future career choice amongst UK medical students. The re-evaluation of IR teaching in the medical school curricula is needed. In the long-term, such recommendations could provide the much-needed solution to the workforce shortages seen in IR.

Systematic review and meta-analysis of ketamine-associated uropathy.

INTRODUCTION: This systematic review and meta-analysis focused on the literature regarding ketamine-associated uropathy to summarise its clinical manifestations, the results of urological assessments, and current management. METHODS: A literature search was conducted using keywords and MeSH terms related to ketamine abuse, urinary tracts, and urological examinations. Databases including Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched up to 26 June 2020. RESULTS: In total, 1365 articles were retrieved; 45 articles (4921 patients) were included in the analysis of patient demographics, clinical manifestations, examination results, and treatments. Frequency was the most common manifestation (pooled prevalence 77.1%, 95% confidence interval [CI]=56.9%-92.2%), followed by urgency (69.9%, 95% CI=48.8%-87.3%) and suprapubic pain (60.4%, 95% CI=35.3%-82.9%). Upper urinary tract involvement was less common; the pooled prevalence of hydronephrosis was 30.2% (95% CI=22.0%-39.2%). Further workup revealed a pooled functional bladder capacity of 95.23 mL (95% CI=63.57-126.88 mL), pooled voided volume of 113.31 mL (95% CI=59.44- 167.19 mL), and pooled maximum urine flow rate of 8.69 mL/s (95% CI=5.54-11.83 mL/s). Cystoscopic examinations and bladder biopsy revealed frequent urothelial denudation, inflammatory changes, and inflammatory cell infiltration. Treatments included oral medications for symptomatic relief, intravesical therapy, and surgery (eg, hydrodistension and bladder reconstruction), but ketamine abstinence was necessary for improvement. CONCLUSION: Ketamine-associated uropathy frequently involves frequency, urgency, and suprapubic pain; upper urinary tract involvement is less common. Affected patients showed reductions in bladder capacity and urine flow rate. Endoscopic and histological analyses often revealed cystitis. Despite variations in treatment, ketamine abstinence is important for all patients with ketamine-associated uropathy.

Effects of acute controlled changes in end-tidal carbon dioxide on the diameter of the optic nerve sheath: a transorbital ultrasonographic study in healthy volunteers.

Transorbital ultrasonographic measurement of the diameter of the optic nerve sheath is a non-invasive, bed-side examination for detecting raised intracranial pressure. However, the ability of the optic nerve sheath diameter to predict acute changes in intracranial pressures remains unknown. The aim of this study was to examine the dynamic changes of the optic nerve sheath diameter in response to mild fluctuations in cerebral blood volume induced by changes in end-tidal carbon dioxide. We studied 11 healthy volunteers. End-tidal carbon dioxide was controlled by a model-based prospective end-tidal targeting system (RespirAct™). The volunteers' end-tidal carbon dioxide was targeted and maintained for 10 min each at normocapnia (baseline); hypercapnia (6.5 kPa); normocapnia (baseline 1); hypocapnia (3.9 kPa) and on return to normocapnia (baseline 2). A single investigator repeatedly measured the optic nerve sheath diameter for 10 min at each level of carbon dioxide. With hypercapnia, there was a significant increase in optic nerve sheath diameter, with a mean (SD) increase from baseline 4.2 (0.7) mm to 4.8 (0.8) mm; p < 0.001. On return to normocapnia, the optic nerve sheath diameter rapidly reverted back to baseline values. This study confirms dynamic changes in the optic nerve sheath diameter with corresponding changes in carbon dioxide, and their reversibly with normocapnia.

Effect of different surgical positions on the cerebral venous drainage: a pilot study using healthy volunteers.

Excessive neck flexion and rotation in certain surgical positions may cause kinking of the internal jugular vein that obstructs cerebral venous blood flow and results in elevated intracranial pressure. The objective of this study was to measure internal jugular vein flow and identify potential impediments to venous flow in supine, prone, and park bench positions using non-anaesthetised volunteers. Twenty-seven volunteers were recruited. Venous flow rate was derived from ultrasound measurements of the vessel cross-sectional area and flow velocity. Change from supine to prone position produced a significant increase in both jugular vein cross-sectional areas without affecting venous flows. In the right park bench position, the right internal jugular vein cross-sectional area decreased from 1.2 to 0.9 cm(2) (p = 0.027) without substantive changes in mean venous flow rate (p = 0.91) when compared with supine. In summary, the internal jugular vein flow was not compromised by either prone or park bench positions in non-anaesthetised volunteers, and careful positioning may prevent kinking of the jugular vein. Further studies in anaesthetised and ventilated patients are needed to validate these results for clinical practice.

Real-time ultrasound-guided spinal anesthesia in patients with a challenging spinal anatomy: two case reports.

Spinal anesthesia may be challenging in patients with poorly palpable surface landmarks or abnormal spinal anatomy. Pre-procedural ultrasound imaging of the lumbar spine can help by providing additional anatomical information, thus permitting a more accurate estimation of the appropriate needle insertion site and trajectory. However, actual needle insertion in the pre-puncture ultrasound-assisted technique remains a 'blind' procedure. We describe two patients with an abnormal spinal anatomy in whom ultrasound-assisted spinal anesthesia was unsuccessful. Successful dural puncture was subsequently achieved using a technique of real-time ultrasound-guided spinal anesthesia. This may be a useful option in patients in whom landmark-guided and ultrasound-assisted techniques have failed.

Does regional anaesthesia improve outcome after total hip arthroplasty? A systematic review.

Total hip arthroplasty (THA) is amenable to a variety of regional anaesthesia (RA) techniques that may improve patient outcome. We sought to answer whether RA decreased mortality, cardiovascular morbidity, deep venous thrombosis (DVT) and pulmonary embolism (PE), blood loss, duration of surgery, pain, opioid-related adverse effects, cognitive defects, and length of stay. We also questioned whether RA improved rehabilitation. To do so, we performed a systematic review of the contemporary literature to compare general anaesthesia (GA) and RA and also systemic and regional analgesia for THA. To reflect contemporary surgical and anaesthetic practice, only randomized controlled trials (RCTs) from 1990 onward were included. We identified 18 studies involving 1239 patients. Only two of the 18 trials were of Level I quality. There is insufficient evidence from RCTs alone to conclude if anaesthetic technique influenced mortality, cardiovascular morbidity, or the incidence of DVT and PE when using thromboprophylaxis. Blood loss may be reduced in patients receiving RA rather than GA for THA. Our review suggests that there is no difference in duration of surgery in patients who receive GA or RA. Compared with systemic analgesia, regional analgesia can reduce postoperative pain, morphine consumption, and nausea and vomiting. Length of stay is not reduced and rehabilitation does not appear to be facilitated by RA or analgesia for THA.

The post-operative analgesic efficacy and tolerability of lumiracoxib compared with placebo and naproxen after total knee or hip arthroplasty.

BACKGROUND: Lumiracoxib is a novel selective cyclooxygenase-2 (COX-2) inhibitor in development for the treatment of chronic and acute pain. METHODS: This randomized, double-blind multicentre study enrolled 180 patients (aged 18-80 years) with moderate-to-severe pain (>or=2 on a 4-point categorical scale) within 48 h of unilateral total knee or total hip arthroplasty. Patients were randomized to receive lumiracoxib 400 mg once daily (n = 60), placebo (n = 60) or naproxen 500 mg twice daily (n = 60). The study consisted of a 12-h single-dose phase followed by a multiple-dose phase (up to 96 h or until discontinuation). The primary efficacy measure was the summed (time-weighted) pain intensity difference over 0-8 h after the first dose (SPID-8). RESULTS: Lumiracoxib and naproxen were comparable and both treatments were superior to placebo for the primary efficacy measure, SPID-8. Both treatments were generally similar and also superior to placebo for the secondary efficacy measures during both the single- and multiple-dose phases for up to 96 h. Both active treatments were well tolerated. CONCLUSION: Lumiracoxib is an effective alternative to traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs) for the treatment of post-operative pain.

Ultrasound guidance for a lateral approach to the sciatic nerve in the popliteal fossa.

Descriptions of the use of ultrasound for nerve location have focused on upper limb blocks. We present a case in which ultrasound imaging was used for a lateral approach to the sciatic nerve in the popliteal fossa. Ultrasound images taken proximal to the popliteal crease showed tibial and common peroneal nerves as round hyperechoic structures superficial and lateral to the tibial artery. Under direct ultrasound guidance, we placed a block needle close to the tibial nerve and confirmed its position with nerve stimulation. Injected local anaesthetic was seen on ultrasound as it spread around both tibial and common peroneal nerves.