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Biomedical subjects

K Wareham

Publications and source records attributed to K Wareham.

17 recordsLinked to original sources

Intra-operative blood salvage in abdominal trauma: a review of 5 years' experience.

We performed a retrospective audit of 1235 patients presenting between 1992 and 1997, following the introduction of intra-operative blood salvage at our hospital. Twenty-two cases of severe abdominal trauma requiring emergency laparotomy and intra-operative blood salvage were identified. The impact of intra-operative blood salvage in aiding resuscitation and reducing demand on allogeneic blood supplies is discussed.

Abdominal Injuries↗

Autologous blood transfusion in total knee replacement surgery.

We compared allogeneic blood usage for two groups of patients undergoing total knee replacement surgery (TKR). Patients were randomized to receive either their post-operative wound drainage as an autotransfusion (n=115) after processing or to have this wound drainage discarded (n=116). Allogeneic blood was transfused in patients of either group whose haemoglobin fell below 9 g dl(-1). Only 7% of patients in the autotransfusion group required an allogeneic transfusion compared with 28% in the control group (P<0.001). There was no hospital mortality and only 3% mortality from all causes at the study completion, which spanned 6 months to 3 yr. There was a higher incidence of infection requiring intervention in the allogeneic group (P<0.036). Total patient costs were Pound Sterling 113 greater in the autotransfusion group. We conclude that in this type of surgery post-operative cell salvage is a safe and effective method for reducing allogeneic blood use.

Adult↗

Population requirement for adult critical-care beds: a prospective quantitative and qualitative study.

BACKGROUND: The provision of adult critical-care facilities is not based on a rational or scientific assessment of need. We aimed to define the numbers of adult critical-care beds required for a population of 500000. METHODS: In five hospitals in Wales, UK, we classified patients who might be suitable for critical care in intensive-care or high-dependency units. On every 12th day for 1 calendar year, we counted the numbers of such patients admitted in a defined geographical population. A panel of ten intensivists made consensus decisions about whether individual patients were in the appropriate unit. The data were used to predict the numbers of beds and units required for the population. FINDINGS: 4058 patients were suitable for critical care, of whom 3028 lived in the study area. 56.4% were in general wards, 22.3% in high-dependency units, and 21.3% in intensive-care units. The mean risk of death was 22.0% and the in-hospital death rate 17.3%. According to the masked consensus, 41.3% of patients required high-dependency beds and 21.5% intensive-care beds. Mean risk of death increased from general wards (14.7%) to high-dependency units (19.2%) to intensive care (37.0%). Based on the consensus decisions, the average daily requirement of intensive-care beds was 21 and of high-dependency beds 43; to meet needs 95% of times required 30 and 55 beds, respectively, in a single critical-care unit. INTERPRETATION: We estimated, scientifically, numbers of adult critical-care beds required to meet population needs. Studies are necessary periodically to track changes in admissions requiring critical care.

APACHE↗

SF-36 scores vary by method of administration: implications for study design.

BACKGROUND: Previous research suggests that people respond differently to health status measures when data are collected by interview or self completion of a questionnaire. The objective of this study was to determine whether SF-36 health status scores differ systematically by method of administration. METHOD: A randomized cross-over study was carried out on 210 new attenders at general medicine, endocrinology, gastroenterology and urological out-patient departments. The outcome was the difference in SF-36 profiles comparing clinic based interviews with self completion at home by the same subjects. RESULTS: For seven of the eight variables of the SF-36 scores were lower in the self assessment, the differences being statistically significant in four of the eight comparisons. The largest differences were in role limitations due to emotional problems (difference 14.74, 95 per cent confidence interval (CI) 7.76-21.7) and social function (difference 7.21, 95 per cent CI 3.19-11.23). CONCLUSIONS: Clinic based interviews systematically exaggerate health status compared with self assessment. The difference is sufficiently large to underestimate the effectiveness of health service interventions when a clinic based pre-intervention and postal self completed follow-up design is used, unless adjustment is made for this systematic bias.

Analysis of Variance↗

Universal prophylaxis for Chlamydia trachomatis and anaerobic vaginosis in women attending for suction termination of pregnancy: an audit of short-term health gains.

A previous study of infection and morbidity in 400 women attending for termination of pregnancy (TOP) had shown that 32 (8%) harboured cervical Chlamydia trachomatis and 112 (28%) had anaerobic (bacterial) vaginosis (AV). Fifty-three per cent of the women with preoperative C. trachomatis had AV. Thirty of the 32 women with chlamydial infection were followed up and 19 (63%) of these developed post-abortion upper genital tract infection, 7 of whom needed re-admission. In view of the high morbidity in women with chlamydial infection attending for TOP, anti-bacterial prophylaxis with metronidazole suppositories and oral oxytetracycline was introduced for women attending for suction termination of pregnancy (STOP). An audit of the clinical and financial benefits and/or losses was carried out. The audit of 1951 consecutive patients attending for STOP revealed that 132 (6.8%) had chlamydial infection with equivocal results reported in a further 2 patients. One hundred and eight of the 134 women responded to recall. Full genital tract infection screening was carried out in 105 of the 108 recalled patients of whom 5 had repeat positive cervical swabs for C. trachomatis, one had Trichomonas vaginalis, 24 had candidiasis and 17 had anaerobic vaginosis, none had gonorrhoea. Thirteen (12%) of the 108 women had pelvic infection as previously defined, none of whom required re-admission. At least pound sterling 20,000 has been saved each year in our Trust following the introduction of pre-abortion chlamydial screening and universal antichlamydial and anti-anaerobe prophylaxis. The introduction of universal prophylaxis against C. trachomatis and AV has profoundly reduced morbidity in patients attending for TOP and has also resulted in substantial financial savings.

Abortion, Induced↗

Sildenafil: study of a novel oral treatment for erectile dysfunction in diabetic men.

The efficacy and safety of oral sildenafil, a potent inhibitor of phosphodiesterase type 5, were evaluated in men with diabetes mellitus and erectile dysfunction (ED). Twenty-one men (aged 42-65 years) were enrolled in a double-blind, placebo-controlled, three-way crossover study conducted in two parts. In part I, the effect of a single dose (25 mg or 50 mg) of sildenafil or placebo on penile rigidity was assessed by penile plethysmography during visual sexual stimulation. In part II, daily diary records of erectile activity and a global efficacy question were used to evaluate once-daily dosing with 25 mg or 50 mg of sildenafil or placebo for 10 days. After a single 50 mg dose of sildenafil, the adjusted geometric mean duration (min) of penile rigidity >60% at the base of the penis during visual sexual stimulation was significantly increased (10.1 min) compared with placebo (2.8 min; p = 0.0053). In part II, sildenafil significantly increased the number of erections considered sufficiently hard for vaginal penetration compared with placebo (p = 0.0005). Improved erections were reported by 50% and 52% of patients treated with 25 mg and 50 mg of sildenafil, respectively, compared with 10% of those receiving placebo (p values < 0.05). Adverse events were mostly mild or moderate in nature and included muscular pains, headache, and dyspepsia. Sildenafil is a well-tolerated and potentially efficacious oral treatment for ED in men with diabetes mellitus.

3',5'-Cyclic-GMP Phosphodiesterases↗

Timing of removal of the laryngeal mask airway.

Previous studies reported that complications associated with removal of the laryngeal mask were more frequent in awake patients than in anaesthetised patients; however, these studies did not comply with the method described in the manufacturer's instruction manual. The reported incidences of regurgitation during the use of the laryngeal mask also differ considerably between studies. We studied these factors in 66 patients in whom the method described in the manual was used. After induction of anaesthesia, the laryngeal mask and a pH probe were inserted and the cuff of the mask was inflated with a minimum volume of air. Anaesthesia was maintained with nitrous oxide and isoflurane in oxygen. At the end of the operation, we randomly allocated patients to one of two groups and the laryngeal mask was removed either while they were still deeply anaesthetised or after they had regained consciousness. No apparent regurgitation occurred in any patient during operation, but one patient in the anaesthetised group regurgitated immediately after removal of the mask. The incidence of complications during or after removal of the laryngeal mask was significantly greater in the anaesthetised group than that in the awake group (p << 0.001; difference [95% CI]: 48.5 [30.5-66.5]%). Therefore, the laryngeal mask can be safely left in place until the patient has regained consciousness after emergence from anaesthesia.

Adolescent↗

Cell salvage auto transfusion in total knee replacement surgery.

We conducted a prospective, randomized study to assess the impact of cell salvage, auto transfusion on the requirements for allogeneic blood for patients undergoing a total knee replacement (TKR). One hundred consecutive TKR patients were randomly allocated to receive either autologous blood (using cell salvage) or an allogeneic blood transfusion as necessary. Patients allocated to the autologous group were rescued with allogeneic blood if the postoperative haemoglobin fell below 9 g dL-1. Forty-two (84%) of 50 patients in the autologous group required no supplementary blood transfusion. Forty (80%) of 50 patients allocated to receive allogeneic blood required transfusion. There were no detrimental effects of autologous blood transfusion. We conclude that autologous blood transfusion, using the cell saver system, is a safe and effective method of reducing the need for allogeneic blood transfusion and, in doing so, reduces the risk of transmission of infections associated with allogeneic blood transfusion, whilst decreasing demand on precious allogeneic blood reserves.

Aged↗

Intra-ocular pressure changes in patients with glaucoma. Comparison between the laryngeal mask airway and tracheal tube.

We performed a randomised prospective study in 20 patients with glaucoma to examine the effects of tracheal intubation and laryngeal mask insertion on intra-ocular pressure, mean arterial blood pressure and heart rate. After induction of anaesthesia with propofol, intra-ocular pressure decreased significantly below baseline values in both the laryngeal mask and tracheal tube groups. After insertion of the laryngeal mask, intra-ocular pressure remained significantly below baseline values in all patients. In contrast, tracheal intubation was associated with a significant increase in intra-ocular pressure to above baseline values in three out of eight patients. Insertion of the laryngeal mask had minimal effects on mean arterial blood pressure and heart rate, whereas tracheal intubation significantly increased both factors relative to pre-intubation values.

Adolescent↗

A comparative study of the incidence of sore throat with the laryngeal mask airway.

In a prospective study of 150 patients randomly assigned to three groups, we have compared the incidence and duration of sore throat after a standard anaesthetic regimen using three different methods of airway management: facemask; laryngeal mask, and laryngeal mask with insertion aid. The insertion aid is currently being developed by Portex Ltd and is intended both to facilitate accurate placement of the laryngeal mask and to reduce trauma during insertion. All the patients were women undergoing short operative procedures requiring minimal postoperative analgesia. The incidence of sore throat was significantly less with a facemask (8%) than with the laryngeal mask when used without the insertion aid (28.5%) (p < 0.02). When using the insertion aid the incidence was 18% and this was not statistically different from the facemask. The presence of blood on the laryngeal mask (22%) was less likely when the insertion aid was used (4%) (p < 0.02).

Adult↗

Practice characteristics associated with audit activity: a medical audit advisory group survey.

AIM: A survey of general practices in West Glamorgan was carried out to assess the development of record systems and practice organization and to relate this to audit activity. METHOD: Following mutual agreement practices were visited by two assessors. Visits were conducted using an agreed protocol and practice data were recorded on a semi-structured questionnaire, which had been sent to the practices in advance of the visits. Practices varied from single handed practices to group practices with six partners. RESULTS: Fifty seven of the 63 practices in the county suitable for inclusion were visited (90%). Data were analysed from 54 practices (three visits were regarded as a pilot). The practices more likely to be involved in audit were those with three or more partners and which had modern medical record systems. Audit activity had occurred in 87% of practices who kept clinical summaries in the notes (compared with 38% who did not), in 87% of practices with long-term medication summaries in the notes (compared with 40% with no summaries) and in 85% of practices with a computerized age-sex register (compared with 50% with no register). All training practices had undertaken audit compared with 63% of non-training practices. CONCLUSION: The survey enabled the medical audit advisory group to identify the type and degree of audit undertaken locally and highlighted the characteristics which encourage this activity. As a consequence the group is able to target practices who have limited or no involvement in audit and to offer assistance and advice on record modification likely to enhance audit activity.

England↗

Health gains from screening for infection of the lower genital tract in women attending for termination of pregnancy.

Infection of the upper genital tract after abortion is well recognised, but routine screening for infection before termination is rare, and few centres are aware of the prevalence of post-abortion complications in their population. We undertook a study to assess the prevalence and sequelae of genital-tract infection in patients undergoing termination of pregnancy and to estimate the costs and potential benefits of introducing screening and prophylaxis for the most commonly found organisms. The study in Swansea, UK, was of 401 consecutive patients attending for termination of pregnancy; only 1 patient refused to take part. Immediately before the termination procedure vaginal and cervical swabs were taken for microscopic examination and culture of Trichomonas vaginalis, Neisseria gonorrhoeae, and candida species. We sought Chlamydia trachomatis by enzyme-linked immunosorbent assay. 112 (28%) women had the typical bacterial flora of anaerobic (bacterial) vaginosis, 95 (24%) had candidal infection, 32 (8%) chlamydial infection, 3 (0.75%) trichomonas infection, and 1 (0.25%) gonorrhoea. Postoperative follow-up of 30 of the women with chlamydial infection showed that pelvic infection developed in 19 (63%), of whom 7 were readmitted to hospital. 9 male partners of women with chlamydial (plus gonococcal in 1 case) infection were examined; 8 were symptom-free, 3 had C trachomatis infection, and 1 N gonorrhoeae. Estimated costs of hospital admissions for complications of chlamydial infection were more than double the costs of providing a routine chlamydia screening programme and prophylactic treatment. Screening for chlamydial infection before termination of pregnancy is essential. Prophylactic treatment for both chlamydial infection and anaerobic vaginosis should also be considered. Male partners of women infected with chlamydia are often symptom-free, but they must be traced to avoid reinfections.

Abortion, Induced↗

Effects of low-dose cimetidine on nocturnal acid secretion in healthy subjects.

The effects of 100 mg and 200 mg bedtime doses of cimetidine on nocturnal gastric acid secretion were examined in nine healthy subjects in a double blind, placebo controlled, randomised three way crossover study. Treatment was given at 23.00 hours and the gastric contents continually aspirated from midnight until 07.00 hours the following morning. Hourly aliquots were analysed for pH and acid output. Relative to placebo the 100 mg and 200 mg doses of cimetidine respectively increased mean pH by 2.22 and 2.63 units/h (P less than 0.001) with mean acid output decreasing by 0.95 and 0.98 mmol/h (P less than 0.001). Whilst mean pH was higher and mean acid output was lower for 200 mg cimetidine compared to 100 mg cimetidine the difference was not statistically significant. Mean hourly pH was consistently above pH 3 for 100% of the time for both doses of cimetidine whereas mean pH failed to reach this value at anytime on placebo. Low doses of cimetidine taken at bedtime effectively reduced nocturnal gastric acid secretion in healthy individuals.

Administration, Oral↗

Reversion of the attenuated and temperature-sensitive phenotypes of the Sabin type 3 strain of poliovirus in vaccinees.

Isolates of type 3 poliovirus from vaccine-recipients were characterized in terms of virulence, sensitivity of growth to high temperatures, and differences in genome structure from the Sabin type 3 vaccine strain. These included point mutations in the region of the genome coding for the structural proteins and in the 5' noncoding region, and the presence of type 1 or type 2 poliovirus genomic sequences resulting from intertypic recombination. Isolates from healthy vaccinees resembled those from vaccine-associated cases of poliomyelitis in all of these properties. Suppression of the temperature-sensitive phenotype was strictly correlated with reversion to virulence in nonrecombinant type 3 strains. Recombinant isolates were more attenuated than expected, even when they had lost all mutations known to attenuate the type 3 vaccine strain.

Base Sequence↗

The temperature sensitivity of the Sabin type 3 vaccine strain of poliovirus: molecular and structural effects of a mutation in the capsid protein VP3.

The growth of the Sabin strain of type 3 poliovirus is reduced at high temperatures compared to that of its virulent precursor strain Leon. Recombinant viruses have been generated from infectious cDNA clones and demonstrate that the temperature-sensitive (ts) phenotype is mainly attributable to a difference in residue 91 of the virion protein VP3. Examination of non-ts mutants derived in vitro or in vivo reveals the existence of second site mutations some of which are clearly able to suppress the ts phenotype. The location of residue 91 of VP3, and of a number of candidate suppressor mutations, in the atomic structure of the virion suggests that the ts phenotype may result in destabilization of the particle and that the suppressors may function by stabilizing specific interfaces. It is not yet clear whether the ts phenotype is expressed at the level of the particle or in the form of defects in assembly or uncoating of the virion, or all three.

Amino Acid Sequence↗