Injury patterns of e-scooter-related orthopaedic trauma in central London: a multicentre study

PURPOSE

Electric scooters (E-Scooters) are being increasingly used in urban areas as a new means of transport. E-scooter sharing schemes have recently been piloted in the United Kingdom; however, there are no published data on orthopaedic injuries and user behaviour patterns in the UK. We aim to identify the patterns and severity of orthopaedic injuries related to e-scooter use.

METHODS

We performed a retrospective review of all orthopaedic referrals relating to e-scooter use from 1 March to 30 November 2020 at three hospitals, including one major trauma centre in central London. Data including patient demographics, mechanism of injury, diagnosis and treatment were collected.

RESULTS

One hundred and five orthopaedic injuries were identified in 83 patients. The median age was 32 years and 83% were male. Seventy-nine (95.2%) patients were riders, four were pedestrians. All e-scooters were privately owned. There were 93 fractures (88.6% of total injuries noted) including 12 (12.9%) open. Fifty-two (56.0%) were upper limb fractures, 39 (41.9%) lower limb and 2 (2.1%) spinal and rib fractures. Twenty-five patients (30.1%) required an operation and 29 (34.9%) required hospital admission. Helmet use was present in 34.1%. The most common place of injury was the road (65.1%) followed by pavement (32.9%).

CONCLUSION

E-scooters can cause serious injury, most commonly in males. There was an equal distribution of upper and lower limb injuries, with many associated with high-energy trauma requiring operative intervention. Helmet use was seen in one third of riders. As e-scooter use continues to increase across the UK, additional steps should be taken to ensure the safety of the riders and public.

1037 Early Detection and Management of Preoperative Anaemia in An Elective Vascular Surgery Cohort

Introduction

Iron deficiency anaemia is the most common cause of anaemia in the surgical population. Patients receiving transfusions during major surgery encounter more adverse outcomes compared to those that do not, indicating the early management of pre-operative anemia is likely to reduce major surgical patient morbidity and mortality. Previous studies have demonstrated that 33% of patients undergoing major vascular surgery operations are anaemic (haemaglobin, Hb, <130g/L).

Aim

We aim to reduce the proportion of anaemic patients undergoing major vascular surgery by 50%.

Method

A point-of-care HemoCue machine was used to measure Hb in patients who were referred for elective major surgery in 11 vascular clinics. Patients with Hb < 130g/L were prescribed a 1-month course of Ferrous Sulfate (200mg TDS), and a letter was sent to their GP requesting iron function tests. Post-intervention Hb levels were rechecked following the preoperative anaesthetics review.

Results

11 patients were referred for major surgery, of which 4 were identified as anaemic (36%). The mean Hb concentration was 121.3g/L, which increased to 137.3g/L following oral iron therapy. The mean duration of follow up was 36 days (range 0-94 days).

Conclusions

The implementation of a HemoCue machine to identify and manage preoperative anaemia was successful in our pilot study. Further work should include full integration of our pathway into current vascular clinics without student support. This will enable evaluation of the impact of our intervention on a wider scale.

Assessment of liquid captopril formulations used in children

OBJECTIVE

Unlicensed liquid captopril formulations are commonly used to treat children with heart disease. This study assessed the bioequivalence of two liquid preparations against a licensed tablet form.

DESIGN

An open label, single dose, three-treatment, three-period, crossover trial.

SETTING

Outpatient.

PATIENTS

Healthy adult volunteers (n=18).

INTERVENTIONS

Each subject was randomly assigned to one of six dosing sequences, and dosed with 25 mg captopril on each of three dosing visits separated by a washout of at least 14 days. Blood samples for pharmacokinetic analysis were taken at regular intervals (0 min to 10 h) post-dose.

MAIN OUTCOME MEASURES

Bioequivalence of the formulations would be concluded if the 90% CI for the estimated ratio of the means of C(max) (maximum plasma concentrations) and area under curve(AUC) (extent of absorption) lay entirely within the range 0.8 to 1.25

RESULTS

Both liquid formulations failed the bioequivalence assessment with respect to C(max) and AUC. The 90% CI of the mean ratios of liquid/licensed tablet for both C(max) and AUC, fell outside the 0.8 to 1.25 limits. There was also considerable within-subject variability in C(max) (97.5%) and AUC (78.5%).

CONCLUSIONS

Unlicensed captopril formulations are not bioequivalent to the licensed tablet form, or to each other, and so cannot be assumed to behave similarly in therapeutic use. Thus formulation substitution must be done with care and may require a period of increased monitoring of the patient. There is also significant within-subject variability in performance which has clinical implications with respect to titrating to an optimum therapeutic dose.

Covalent coupling of concanavalin A to a Carbopol 934P and 941P carrier in glucose-sensitive gels for delivery of insulin

A novel glucose-sensitive gel formulation, containing concanavalin A and specific polysaccharides, was stabilised via covalent coupling to two structurally different carbomers. The bonding was done to minimise leaching of gel components thereby preventing toxicity and preserving the working mechanism of the gel. Increased gel stability was introduced by covalently bonding amine groups present on the lysine residues of concanavalin A to carboxylic moieties on Carbopol 934P NF and 941P NF using carbodiimide chemistry. The introduction of dextran then produced a glucose-sensitive formulation that transformed from gel to sol in the presence of free glucose. Rheological examination of glucose-sensitive gels stabilised in this way and containing varying concentrations of glucose was conducted with a cone and plate viscometer used in continual rotation mode. A decrease in viscosity over the chosen glucose concentration range was exhibited by both carbomer-stabilised formulations. The subsequent testing of such formulations in in-vitro diffusion experiments revealed that the leaching of concanavalin A from the covalently coupled gels is restricted significantly with respect to non-coupled formulations. In addition, insulin delivery in response to glucose in the physiologically relevant glucose concentration range has been demonstrated using the carbomer-stabilised gels at 37 degrees C. The performance of this self-regulating drug delivery system has been improved in terms of increased gel stability with reduced component leaching.

A covalently stabilised glucose responsive gel formulation with a Carbopol carrier

A novel glucose-responsive gel formulation was stabilised via covalent coupling to a carbomer resin. The gel formed between the plant lectin, concanavalin A and specific polysaccharides was stabilised to minimise leaching of gel components into the surroundings. This was required to prevent toxicity and to preserve the working mechanism of the formulation. Increased gel stability was introduced by covalently bonding amine groups present on the lysine residues of concanavalin A to carboxylic moieties on Carbopol 974P NF using carbodiimide chemistry. The introduction of dextran then produced a glucose-responsive formulation that transformed from gel to sol in the presence of free glucose. The rheological properties and in vitro component and insulin release of the carbomer-stabilised gel were evaluated. A decrease in viscosity over a chosen glucose concentration range was exhibited by the carbomer-based gel. The testing of such a formulation in in vitro diffusion experiments revealed that the leaching of concanavalin A from the covalently coupled gels was restricted significantly with respect to a non-coupled gel. Insulin delivery in response to glucose in the physiologically relevant glucose concentration range was demonstrated using the carbomer-stabilised gel at 37 degrees C. The performance of this novel self-regulating drug delivery system has been improved in terms of increased gel stability with reduced component leaching.

Insulin delivery governed by covalently modified lectin-glycogen gels sensitive to glucose

A glucose-sensitive gel formulation containing concanavalin A and glycogen has been reported previously. Precipitation resulting from the addition of concanavalin A to glycogen has been documented, but the formation of glucose-sensitive gels based on lectin-glycogen interactions is novel and used here in our studies. An improved in-vitro self-regulating drug-delivery system, using covalently modified glucose-sensitive gels based on concanavalin A and a polysaccharide displacement mechanism, is described. The successful use of the covalently modified gels addresses a problem identified previously where significant leaching of the mitogenic lectin from the gel membranes of non-coupled gels was encountered. Concanavalin A was covalently coupled to glycogen by use of derivatives of Schiff's bases. The resulting gels, like the non-coupled gels, were shown to undergo a gel-sol transformation in response to glucose. Insulin delivery was demonstrated using this covalently modified system in conditions of repeated glucose triggering at 20 degrees C and 37 degrees C. The magnitude of the response was less variable than for the dextran-based gels studied previously. The performance of this system has been improved in terms of concanavalin A leaching. This could, therefore, be used as the basis of the design of a self-regulating drug-delivery device for therapeutic agents used to treat diabetes mellitus.

The delivery of insulin from aqueous and non-aqueous reservoirs governed by a glucose sensitive gel membrane

A self regulating delivery device, responsive to glucose, has been shown to operate successfully in vitro. This comprises a gel membrane which determines the delivery rate of insulin from a reservoir. The gel consists of a synthetic polysucrose and the lectin, concanavalin A. The mechanism is one of displacement of the branched polysaccharide from the lectin receptors by incoming glucose. The gel loses its high viscosity as a result but reforms on removal of glucose, thus providing the switch controlling the drug diffusion rate. The drug does not require to be chemically modified and thus the device is adaptable to other anti-hyperglycaemic drugs. However, results here indicate that the molecular weight of the solute may be an important parameter. Others include path length, gel formulation and temperature. It had been hypothesised that the reversal might be improved by the use of a non-aqueous reservoir of insulin. However, with the use of insulin, the switching off was found to be superior to that found with other test solutes used in previous studies, irrespective of the reservoir solvent. The advantages in the use of the non-aqueous system include, however, more reproducibility in the magnitude of response and a reduced temperature sensitivity.