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1.
BMC Pregnancy Childbirth ; 17(1): 282, 2017 Sep 02.
Article in English | MEDLINE | ID: mdl-28865442

ABSTRACT

BACKGROUND: For the past decade, Maternal Mortality Reports, published in the United Kingdom every three years, have consistently raised concerns about maternal observations in maternity care. The reports identify that observations are not being done, not being completed fully, are not recorded on Early Warning Score systems, and/or are not escalated appropriately. This has resulted in delays in referral, intervention and increases the risk of maternal morbidity or mortality. However there has been little exploration of the possible reasons for non-completion of maternal observations. METHODS: The aim of this study was to explore midwives' experiences of performing maternal observations and escalating concerns in rural and urban maternity settings in the West Midlands of England. A qualitative design involving a series of six focus groups with midwives and Supervisors of Midwives was employed to investigate the facilitators of, and barriers to the completion of maternal observations. RESULTS: Eighteen Midwives and 8 Supervisors of Midwives participated in a total of 6 focus groups. Three key themes emerged from the data: (1) Organisation of Maternal Observations (including delegation of tasks to Midwifery Support Workers, variation in their training, the care model used e.g. one to one care, and staffing issues); (2) Prioritisation of Maternal Observations (including the role of professional judgement and concerns expressed by midwives that they did not feel equipped to care for women with complex clinical needs; and (3) Negotiated Escalation (including the inappropriate response from senior staff to use of Modified Early Warning Score systems, and the emotional impact of escalation). CONCLUSIONS: A number of organisational and cultural barriers exist to the completion of maternal observations and the escalation of concerns. In order to address these the following actions are recommended: standardised training for Midwifery Support Workers, review of training of midwives to ensure it addresses the increasing complexity of the maternal population, identification and agreement regarding the organisation of maternal observations among staff, an emphasis on increasing the priority placed on maternal observations in all clinical settings, and clarification and reinforcement of escalation procedures for both midwives and senior clinicians.


Subject(s)
Maternal Health Services , Midwifery/methods , Nurse Midwives/psychology , Professional Role/psychology , Referral and Consultation , Adult , England , Female , Focus Groups , Humans , Maternal Mortality , Middle Aged , Observation , Pregnancy , Rural Health Services , Urban Health Services , Young Adult
2.
Biomaterials ; 33(23): 5659-71, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22594975

ABSTRACT

Functionalised siloxane macromonomers, with properties designed for application as an injectable, in situ curable accommodating intraocular lens (A-IOL), were prepared via re-equilibration of a phenyl group-containing polysiloxane of very high molecular weight with octamethylcyclotetrasiloxane (D4) and 2,4,6,8-tetra(n-propyl-3-methacrylate)-2,4,6,8-tetramethyl-cyclotetrasiloxane (D4(AM)) in toluene using trifluoromethanesulfonic acid as a catalyst. Hexaethyldisiloxane was used as an end group to control the molecular weight of the polymer. The generated polymers had a consistency suitable for injection into the empty lens capsule. The polymers contained a low ratio of polymerisable groups so that, in the presence of a photo-initiator, they could be cured on demand in situ within 5 min under irradiation of blue light to form an intraocular lens within the lens capsule. All resulting polysiloxane soft gels had a low elastic modulus and thus should be able to restore accommodation. The pre-cure viscosity and post-cure modulus of the generated polysiloxanes were controlled by the end group and D4(AM) concentrations respectively in the re-equilibration reactions. The refractive index could be precisely controlled by adjusting the aromatic ratio in the polymer to suit such application as an artificial lens. Lens stretching experiments with both human and non-human primate cadaver lenses of different ages refilled with polysiloxane polymers provided a significant increase in amplitude of accommodation (up to 4 D more than that of the respective natural lens). Both in vitro cytotoxicity study using L929 cell lines and in vivo biocompatibility study in rabbit models demonstrated the non-cytotoxicity and ocular biocompatibility of the polymer.


Subject(s)
Accommodation, Ocular/drug effects , Lenses, Intraocular , Siloxanes/chemistry , Siloxanes/pharmacology , Animals , Biocompatible Materials/administration & dosage , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Line , Elastic Modulus , Humans , Injections , Lens, Crystalline/drug effects , Rabbits , Refractometry , Siloxanes/administration & dosage
3.
Biomaterials ; 31(32): 8153-63, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20692702

ABSTRACT

The aged eye's ability to change focus (accommodation) may be restored by replacing the hardened natural lens with a soft gel. Functionalised polysiloxane macromonomers, designed for application as an injectable, in situ curable accommodating intraocular lens (A-IOL), were prepared via a two-step synthesis. Prepolymers were synthesised via ring opening polymerisation (ROP) of octamethylcyclotetrasiloxane (D(4)) and 2,4,6,8-tetramethylcyclotetrasiloxane (D(4)(H)) in toluene using trifluoromethanesulfonic acid (TfOH) as catalyst. Hexaethyldisiloxane (HEDS) was used as the end group to control the molecular weight of the prepolymers, which were then converted to macromonomers by hydrosilylation of the SiH groups with allyl methacrylate (AM) to introduce polymerisable groups. The resulting macromonomers had an injectable consistency and thus, were able to be injected into and refill the empty lens capsular bag. The macromonomers also contained a low ratio of polymerisable groups so that they may be cured on demand, in situ, under irradiation of blue light, in the presence of a photo-initiator, to form a soft polysiloxane gel (an intraocular lens) in the eye. The pre-cure viscosity and post-cure modulus of the polysiloxanes, which are crucial factors for an injectable, in situ curable A-IOL application, were controlled by adjusting the end group and D(4)(H) concentrations, respectively, in the ROP. The macromonomers were fully cured within 5 min under light irradiation, as shown by the rapid change in modulus monitored by photo-rheology. Ex vivo primate lens stretching experiments on an Ex Vivo Accommodation Simulator (EVAS) showed that the polysiloxane gel refilled lenses achieved over 60% of the accommodation amplitude of the natural lens. An in vivo biocompatibility study in rabbits using the lens refilling (Phaco-Ersatz) procedure demonstrated that the soft gels had good biocompatibility with the ocular tissue. The polysiloxane macromonomers meet the targeted optical and mechanical properties of a young natural crystalline lens and show promise as candidate materials for use as injectable, in situ curable A-IOLs for lens refilling procedures.


Subject(s)
Accommodation, Ocular , Biocompatible Materials/chemistry , Lenses, Intraocular , Siloxanes/chemistry , Animals , Cornea/ultrastructure , Injections , Lens, Crystalline/physiology , Macaca fascicularis , Materials Testing , Rabbits
4.
J Antimicrob Chemother ; 65(5): 974-80, 2010 May.
Article in English | MEDLINE | ID: mdl-20233779

ABSTRACT

OBJECTIVES: To assess support discs, comprising polyethylene terephthalate (PET), coated with different polymer/levofloxacin combinations for antimicrobial activity in an animal model of infection, in order to explore the use of specific polymer coatings incorporating levofloxacin as a means of reducing device-related infections. METHODS: Aliphatic polyester-polyurethanes containing different ratios of poly(lactic acid) diol and poly(caprolactone) diol were prepared, blended with levofloxacin and then used to coat support discs. The in vitro levofloxacin release profiles from these discs were measured in aqueous solution. Mice were surgically implanted with the coated discs placed subcutaneously and infection was initiated by injection of 10(6) cfu of Staphylococcus aureus into the subcutaneous pocket containing the implant. After 5, 10, 20 and 30 days, the discs were removed, and the number of bacteria adhering to the implant and the residual antimicrobial activity of the discs were determined. RESULTS: In vitro, the release of levofloxacin from the coated discs occurred at a constant rate and then reached a plateau at different timepoints, depending on the polymer preparation used. In vivo, none of the discs coated with polymer blends containing levofloxacin was colonized by S. aureus, whereas 94% of the discs coated with polymer alone were infected. All discs coated with levofloxacin-blended polymers displayed residual antimicrobial activity for at least 20 days post-implantation. CONCLUSIONS: Bioerodable polyester-polyurethane polymer coatings containing levofloxacin can prevent bacterial colonization of implants in an intra-operative model of device-related infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Levofloxacin , Ofloxacin/pharmacology , Polymers/pharmacology , Prosthesis-Related Infections/prevention & control , Staphylococcal Infections/prevention & control , Animals , Colony Count, Microbial , Disease Models, Animal , Female , Foreign Bodies , Humans , Mice , Mice, Inbred BALB C , Staphylococcus aureus/drug effects
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