Opting off the New South Wales Pap Test Register in a sexual health setting

OBJECTIVES

To determine the proportion of women having a Pap smear at Sydney Sexual Health Centre (SSHC) who opted off the NSW Pap Test Register (PTR) and to establish the characteristics of these women.

DESIGN

Retrospective cross sectional study involving three time periods during 1996 and 1997.

SETTING

A public sexual health centre in Sydney.

PARTICIPANTS

985 women who had a Pap smear at SSHC.

MAIN OUTCOME MEASURES

The participant's decision to opt on or off, and the demographic and behavioural characteristics associated with opting off the PTR.

RESULTS

590 (59.9%) women opted off the PTR. Using logistic regression, young age (p=0.005), birth outside Australia and New Zealand (p=0.0001), not speaking English at home (p=0.005) and being a commercial sex worker (CSW) (p=0.0001) were variables associated with opting off the PTR. Women from countries outside of Australia and New Zealand were more likely to opt off, whether or not they were a CSW and CSWs were more likely to opt off the PTR irrespective of their country of birth (p=0.013).

CONCLUSION

The majority of women (60%) attending the SSHC opted off the PTR. Studies to evaluate culturally appropriate health promotion material particularly for CSWs and women with poor English skills living in Australia are needed and if successful may improve uptake on the PTR.

Tissue-specific and developmental effects of the easily shocked mutation on ethanolamine kinase activity and phospholipid composition in Drosophila melanogaster

The easily shocked (eas) gene of Drosophila melanogaster encodes ethanolamine kinase (EK), the first step in phosphatidylethanolamine (PE) synthesis via the CDP-ethanolamine pathway Flies mutant for eas display a complex neurological phenotype. In this paper we look at the contribution of EK to lipid metabolism during Drosophila development with the goal of linking the eas biochemical defect with the organismal phenotype. Using a chromatography-based assay, EK activity was detected in wild-type flies throughout development. Most of the activity in the adult was present in heads, which is primarily tissue of neural origin. Flies mutant for eas showed severely reduced levels of activity at each stage assayed. Using standard extraction methods and thin layer chromatography, phospholipid composition was assayed in wholeflies and in heads. While PE levels were decreased significantly in both tissues, heads also had significantly less phosphatidylserine (PS). Therefore, decreases in both phospholipids may play a role in producing the aberrant phenotype in eas flies.

Reflective practice in thermoregulatory nursing care

This article demonstrates how the use of a reflective model can aid organisation and rationalisation of thoughts that, in turn, results in improved nursing care of patients with fever.

Selection of cell binding and internalizing epidermal growth factor receptor antibodies from a phage display library

The first step in developing a targeted cancer therapeutic is generating a ligand that binds to a receptor which is either tumor specific or sufficiently overexpressed in tumors to provide targeting specificity. For this work, we generated human monoclonal antibodies to the EGF receptor (EGFR), an antigen overexpressed on many solid tumors. Single chain Fv (scFv) antibody fragments were directly selected by panning a phage display library on tumor cells (A431) overexpressing EGFR or Chinese hamster ovary cells (CHO/EGFR cells) transfected with the EGFR gene and recovering endocytosed phage from within the cell. Three unique scFvs were isolated, two from selections on A431 cells and two from selections on CHO/EGFR cells. All three scFv bound native receptor as expressed on a panel of tumor cells and did not bind EGFR negative cells. Phage antibodies and multivalent immunoliposomes constructed from scFv were endocytosed by EGFR expressing cells as shown by confocal microscopy. Native scFv primarily stained the cell surface, with less staining intracellularly. The results demonstrate how phage antibodies binding native cell surface receptors can be directly selected on overexpressing cell lines or transfected cells. Use of a transfected cell line allows selection of antibodies to native receptors without the need for protein expression and purification, significantly speeding the generation of targeting antibodies to genomic sequences. Depending upon the format used, the antibodies can be used to deliver molecules to the cell surface or intracellularly.

Assessment of risk for pelvic inflammatory disease in an urban sexual health population

OBJECTIVES

To determine the sexual and demographic risk factors for the acquisition of presumptive pelvic inflammatory disease (PID).

METHODS

A retrospective, case-control study in women, who attended the Sydney Sexual Health Centre (SSHC), between April 1991 and December 1997. Logistic regression analysis was used to adjust for confounding variables.

RESULTS

741 women with PID and an equal number of controls were included. Cases were significantly younger than controls (p < 0.001). 42% of cases were born in north or South East Asia, compared with 12% of the controls (p < 0.001). The adjusted odds ratio for being born in north or South East Asia was 2.8 (95% CI 1.70-4.46), for not speaking English at home was 1.6 (95% CI 1.02-2.55), for having had previous PID was 5.9 (95% CI 3.59-9.73), and for being employed in the commercial sex industry and being born in north or South East Asia was 2.8 (95% CI 1.22-6.22). Women aged 15-19 were at considerable risk of developing PID (OR 5.3 (95% CI 2.76-10.11)). Women with previous human papillomavirus infection were significantly less likely to develop PID (OR 0.6 (95% CI 0.42-0.79)). The use of IUCDs (OR 4.5 (95% CI 2.14-9.39)), condoms (OR 1.4 (95% CI 1.03-1.87)), and not using contraception (OR 1.8 (95% CI 1.20-2.76)) was each associated with an increased risk.

CONCLUSIONS

Several measures may help to reduce the burden of PID. Women should be encouraged to delay the onset of sexual activity and IUCDs should not be used in young women. Sexual health services for women whose home language is not English, and for commercial sex workers born in north or South East Asia should be improved.

Sexually transmitted infections and risk behaviours in women who have sex with women

OBJECTIVES

To assess the prevalence of sexually transmitted infections (STIs) and blood borne viruses, risk behaviours, and demographics in women who have sex with women (WSW).

METHODS

Retrospective cross sectional study using a multivariate model. Demographic, behavioural, and morbidity data were analysed from standardised medical records of patients attending a public STI and HIV service in Sydney between March 1991 and December 1998. All women with any history of sex with a woman were compared with women who denied ever having sex with another woman (controls).

RESULTS

1408 WSW and 1423 controls were included in the study. Bacterial vaginosis (BV) was significantly more common among WSW (OR 1.7, p < 0.001). Abnormalities on cervical cytology were equally prevalent in both groups, except for the higher cytological BV detection rate in WSW (OR 5.3, p = 0.003). Genital herpes and genital warts were common in both groups, although warts were significantly less common in WSW (OR 0.7, p = 0.001). Prevalence of gonorrhoea and chlamydia were low and there were no differences between the groups. The prevalence of hepatitis C was significantly greater in WSW (OR 7.7, p < 0.001), consistent with the more frequent history of injecting drug use in this group (OR 8.0, p < 0.001). WSW were more likely to report previous sexual contact with a homo/bisexual man (OR 3.4, p < 0.001), or with an injecting drug user (OR 4.2, p < 0.001). Only 7% of the WSW reported never having had sexual contact with a male.

CONCLUSION

We demonstrated a higher prevalence of BV, hepatitis C, and HIV risk behaviours in WSW compared with controls. A similar prevalence of cervical cytology abnormalities was found in both groups. Measures are required to improve our understanding of STI/HIV transmission dynamics in WSW, to facilitate better health service provision and targeted education initiatives.

Diagnosing PID--getting the balance right

The objective of the study was to determine the clinical manifestations and diagnostic criteria used to diagnose presumptive pelvic inflammatory disease (PID) at the Sydney Sexual Health Centre (SSHC). The study was a retrospective, case-note review of all women diagnosed with presumptive PID between April 1991 and December 1997. Seven hundred and thirteen women were included. The commonest recorded symptoms were vaginal discharge (68%), lower abdominal pain (65%) and dyspareunia (57%), while adnexal tenderness (83%), cervical motion tenderness (75%) and cervicitis (56%) were the most frequently recorded examination findings. Sixty-two per cent were prescribed doxycycline and metronidazole. The recording of signs and symptoms in women with presumptive PID was poor and only 22% met the current Centers for Disease Control (CDC) diagnostic criteria. It is likely that PID is over diagnosed in this group of women. This may lead to under diagnosis of other conditions causing pelvic pain and may be detrimental to reproductive health.

Neonatal herpes prevention: a minor public health problem in some communities

BACKGROUND

Neonatal herpes is a condition with high morbidity and mortality. The greatest risk occurs when the mother acquires herpes simplex virus (HSV) towards the end of pregnancy. A study from Seattle has suggested that the risk of acquisition of HSV during pregnancy was 3.7%. In Australia, HSV-2 infection is less common in pregnant women than in the United States. Consequently we conducted a study to establish HSV seroprevalence and the rate of HSV seroconversion in this population.

METHODS

The study was conducted at Westmead Hospital, Sydney, between June 1995 and April 1998. Women completed a questionnaire covering risk factors for the acquisition of genital herpes. A serum sample during pregnancy and a specimen of cord blood were obtained and tested for antibodies to HSV-2 using a type specific indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. A subset of the paired sera was tested for antibodies to HSV-1. The data were analysed using SPSS.

RESULTS

326 of the 2616 (12.5%) women were HSV-2 seropositive. Three women (0.15%) acquired HSV-2 infection during pregnancy. None of the three babies of these mothers developed neonatal herpes. 416 maternal cord pairs were tested for HSV-1 antibodies and 330 (79.3%) were positive. No HSV-1 seroconversions occurred.

CONCLUSIONS

In this population, HSV acquisition was uncommon (0.34% per year) and neonatal herpes was rare. A cost effective analysis suggested that type specific serology to screen pregnant women and their partners in low prevalence communities was not cost effective.

HIV, sexually transmitted infections, and risk behaviours in male commercial sex workers in Sydney

OBJECTIVES

To assess prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, and demographics in male commercial sex workers (CSWs)/prostitutes in Sydney.

METHODS

Retrospective, cross sectional study with two comparison groups. Demographic, behavioural, and morbidity data were analysed from standardised medical records of patients attending a public STI and HIV service in Sydney between January 1991 and March 1998. Two comparison groups were used: female CSWs and non-CSW working homosexual men who attended over the same time.

RESULTS

94 male CSWs, 1671 female CSWs, and 3541 non-CSW working homosexual men were included. The prevalence of HIV in male CSWs tested (6.5%) was significantly greater than in female CSWs (0.4%, p = 0.0001), but less than in non-CSW homosexual men (23.9%, p < 0.0001). Genital warts occurred significantly more frequently in male CSWs than in comparison groups. Prevalence of other STIs was similar in all groups. Male CSWs saw significantly fewer clients per week than female CSWs and male and female CSWs used condoms with almost all clients. Male CSWs reported significantly more non-work sexual partners than female CSWs and non-CSW homosexual men and were significantly more likely to have unprotected penetrative sex with their non-work partners than non-CSW homosexual men. Injecting drug use was significantly more frequent in male CSWs than in both comparison groups.

CONCLUSIONS

Although male CSWs use condoms with clients, they are more likely to practise unsafe sex with non-work partners (especially women) and inject drugs than female CSWs and non-CSW homosexual men. Some men with HIV are working within the commercial sex industry. Targeted health education to encourage safer drug use and safer sex outside work is needed.

Management of women with recurrent genital herpes in pregnancy in Australia

OBJECTIVE

To document clinical practice for the management of recurrent genital herpes in pregnant women in Australia.

DESIGN AND PARTICIPANTS

A questionnaire to all doctors associated with the Royal Australian College of Obstetricians and Gynaecologists.

MAIN OUTCOME MEASURES

Policies for antenatal herpes screening, circumstances in which delivery by caesarean section was considered appropriate, and the use of aciclovir during pregnancy. The results were analysed by college status, sex, and whether the doctor worked in a public or private facility.

RESULTS

2855 (67.3%) obstetricians returned questionnaires. 696 (34.3%) stated that their hospital had a policy for managing recurrent genital herpes in pregnancy: 44.5% examined the genitalia and 33.8% took cultures during pregnancy. Fellows were more likely to examine the genitalia (87% v 37%, p < 0.001), and more likely to perform antenatal viral cultures than members (75% v 30%, p < 0.001). Doctors working at private hospitals were significantly more likely to take viral cultures than doctors in public hospitals (39% v 33% p < 0.05). Doctors were asked to consider five scenarios and judge whether caesarean section would be appropriate. 96% considered that a caesarean section was appropriate in women with active herpes at the onset of labour. In the case of a recurrence of genital HSV at the time of presentation with ruptured membranes longer than 4 hours, diplomats (79%) were significantly more likely to recommend a caesarean section than fellows (64%), members (63%), or trainees (49%) (all p < or = 0.001). Where there were positive viral cultures before the onset of labour fellows (45%) were more likely than members (29%) (p = 0.005), males (62%) were more likely than females (55%) (p = 0.03), and doctors working in private hospitals (69%) were more likely than those in the public sector (54%) (p < 0.001) to recommend caesarean section.

CONCLUSION

There is considerable divergence of opinion regarding the appropriate management of recurrent genital herpes in pregnancy. The implementation of management guidelines would provide consistency of care.

Effect of maternal diabetes on the fetal exocrine pancreas

To test the hypothesis that fetal pancreatic exocrine and endocrine function are stimulated in parallel in the diabetic pregnancy, 68 mothers with gestational and pregestational diabetes who underwent amniocenteses after 34 weeks' for the evaluation of fetal lung maturity were enrolled. Amniotic fluid specimens were analyzed for C-peptide and trypsin content. Amniotic fluid specimens were obtained from 92 non-diabetic women undergoing amniocenteses for lung maturity, preterm labor, or premature rupture of membranes. Groups were compared using the Wilcoxon rank-sum test, Kruskal Wallis rank sum test, and Spearman's rank correlation test. C-peptide amniotic fluid concentrations were significantly greater in diabetics (median 0.6 ng/ml) than non-diabetics (median 0.4 ng/ml, P= 0.0001), in pregestational (median 0.6 ng/ml) vs. gestational diabetics (median 0.4 ng/ml, P = 0.006), and greater in proportion to severity of disease according to diabetic class (A1 = 0.4 ng/ml, A2 = 0.55 ng/ml, B = 0.6 ng/ml, C = 0.7 ng/ml, D = 0.85 ng/ml, P = 0.04). No significant differences were detected in amniotic fluid trypsin between the diabetic and non-diabetic or the gestational and non-gestational diabetic groups. There was no correlation between C-peptide and trypsin within the diabetic groups. Stimulation of the exocrine and endocrine pancreas does not occur in parallel in the fetus of the diabetic mother. Although originating as a single organ, pancreatic exocrine and endocrine functions are distinct in both physiologic and pathologic conditions.

Feelings and attitudes of gifted students

Differences between the self-perceptions of gifted high school freshmen (n = 62) and nongifted peers (n = 162) were assessed regarding intimacy with family and peers, social support, family responsibilities, self-esteem, depression, and risk-taking behavior. Gifted students perceived themselves as being more intimate with friends, assuming fewer family responsibilities, and taking more risks (both sports- and danger-related risks). Contrary to the literature suggesting delays in the social development of gifted students, these data indicate that gifted students may be socially precocious when compared with their nongifted peers. Gifted students and their teachers were also administered the Perceptions about Giftedness Scale. Gifted students reported feeling the same as, or better than, their peers about their academic and social skills, and their teachers closely agreed. However, the teachers rated the gifted students as being less happy than the students rated themselves.

Molecular size of recombinant alpha1beta1 and alpha1beta1gamma2 GABAA receptors expressed in Sf9 cells

The present study examines the physical properties of recombinant human GABAA receptors. The baculovirus/Sf9 cell system was used to express combinations of human GABAA receptor subunits: alpha 1 alone, alpha 1 with beta 1, and alpha 1 with beta 1 and gamma 2. Receptors were solubilized using 1% Triton X-100. In sucrose density gradients containing 150mM NaCl, alpha 1 beta 1 receptor-detergent complexes sedimented more slowly than alpha 1 beta 1 gamma 2 constructs (sedimentation coefficient = 7.00 +/- 0.32 and 8.63 +/- 0.48 S, respectively). Stokes' radii for the two receptor-detergent complexes were determined by gel filtration in Sephacryl S-300. These experiments were performed in the presence of 1 M sodium chloride to prevent aggregation. The Stokes' radii for alpha 1 beta 1 and alpha 1 beta 1 gamma 2 receptor-detergent complexes were 9.06 +/- 0.23 and 7.91 +/- 0.19 nm, respectively. Sedimentation experiments in 1 M NaCl revealed similar sedimentation coefficients for alpha 1 beta 1 and alpha 1 beta 1 gamma 2 receptor-detergent complexes (8.79 +/- 0.59 and 8.46 +/- 0.72 S, respectively). The molecular weight of the alpha 1 beta 1 receptor excluding detergent was estimated to be 281 +/- 19 kDa, that of the alpha 1 beta 1 gamma 2 receptor, 247 +/- 21 kDa. This difference is not statistically significant. Given subunit molecular weights which are close to 50 kDa, this suggested a pentameric structure for the majority of alpha 1 beta 1 gamma 2 receptors, and that alpha 1 beta 1 receptors are not"assembly intermediates" with fewer subunits.

Alcoholism and carcinoma change the intracellular pH and activate platelet Na+/H+-exchange in men

The occurrence of carcinoma in chronic alcoholics exceeds that of the general population. Cytoplasmic alkalinization, due to the influence of different factors on the transmembrane Na+/H+ exchange (NHE), has been put forward as a triggering event in cell growth and division. In accordance with these findings, the carcinogenic potential of NHE deficient cell types is reported to be diminished. The aim of this study was to investigate whether the intracellular pH and the NHE activity is altered in chronic alcoholics. Seventy-two Caucasian males were assigned to one of four groups: non-alcoholics without carcinoma, chronic alcoholics without carcinoma, non-alcoholics with carcinoma and chronic alcoholics with carcinoma. Alcoholism was diagnosed according to DSM-III-R. The groups did not differ in relation to basic patient characteristics, such as age and blood pressure. Intracellular calcium, pH and NHE in platelets were determined by spectrofluorometry before and after thrombin stimulation. In chronic alcoholics with carcinoma, the intracellular pH was significantly more alkaline and the NHE activity was elevated. In contrast, a decrease in intracellular pH associated with an increased activity of NHE and a more acidic set point was found in chronic alcoholics without carcinoma. Basal and thrombin stimulated intracellular Ca2+ did not differ between groups except in chronic alcoholics with carcinoma in whom a thrombin-induced increase of Ca2+ due to liberation of Ca2+ from intracellular stores was demonstrated. In chronic alcoholics with carcinoma, cytoplasmic alkalinization was observed and this may be an indication of an increase in cell proliferation. The possibility that the increased incidence of carcinomas in chronic alcoholics is related to the increased activity of NHE and whether this may be prevented by NHE inhibitors requires further investigation.

Crystal structure of tyrosine hydroxylase at 2.3 A and its implications for inherited neurodegenerative diseases

Tyrosine hydroxylase (TyrOH) catalyzes the conversion of tyrosine to L-DOPA, the rate-limiting step in the biosynthesis of the catecholamines dopamine, adrenaline, and noradrenaline. TyrOH is highly homologous in terms of both protein sequence and catalytic mechanism to phenylalanine hydroxylase (PheOH) and tryptophan hydroxylase (TrpOH). The crystal structure of the catalytic and tetramerization domains of TyrOH reveals a novel alpha-helical basket holding the catalytic iron and a 40 A long anti-parallel coiled coil which forms the core of the tetramer. The catalytic iron is located 10 A below the enzyme surface in a 17 A deep active site pocket and is coordinated by the conserved residues His 331, His 336 and Glu 376. The structure provides a rationale for the effect of point mutations in TyrOH that cause L-DOPA responsive parkinsonism and Segawa's syndrome. The location of 112 different point mutations in PheOH that lead to phenylketonuria (PKU) are predicted based on the TyrOH structure.

Rehabilitation in Franceschetti syndrome: an interdisciplinary approach using bone-anchored hearing aids

The purpose of the study was to determine the effectiveness of a concept of combined interdisciplinary rehabilitation for children with mandibulofacial dysostosis, developed at the Center for Facial Malformations. It consists of binaural implantation of bone-anchored hearing aids and gradual distraction of the mandible. After audiological testing and mandibular distraction on a phantom head designed with data from a spiral CT, the surgery was done in three steps: implanting the fixtures for BAHA and the bone-lengthening device, removing the device after six weeks and completing the BAHA implantation two months later. The distraction procedure and orthodontic treatment were performed on an outpatient basis. The results (six patients, ages 6-19 years) were excellent: after implantation of the BAHA system speech perception increased from approximately 85% with the conventional BCHA to 95-100% with the BAHA. Quality of life was reported to be much better because of the general cosmetic improvement as well as the good acoustic orientation and sound quality with the new hearing devices. We conclude that the interdisciplinary approach provides favorable conditions for rehabilitation in cases of complex malformations of the head and neck.

Evaluation of sexual health services within Australia and New Zealand

OBJECTIVE

To examine and compare specialised services for patients with sexually transmitted diseases (STDs) in Australia and New Zealand.

DESIGN

Postal questionnaire survey.

PARTICIPANTS AND SETTING

All STD facilities in Australia and New Zealand in 1993.

MAIN OUTCOME MEASURES

Patient numbers and demography; staffing levels; the role of nurses; diagnostic and treatment protocols; contact-tracing policies; and the availability of specialist medical services and community and education programs.

RESULTS

83 of 100 clinics responded; 52 were urban, 21 rural, and nine remote. 95% were open to men and women. Staffing levels were similar in Australia and New Zealand and there was considerable consistency in diagnostic techniques and treatment among clinics. Australian clinics more often used ciprofloxacin or ceftriaxone as the treatment of first choice for gonorrhoea; New Zealand clinics were more likely to test for Chlamydia using direct immunofluorescence; and Australian clinics were more likely to test for hepatitis A and offer hepatitis B vaccination to a broader range of patients. 88% of clinics always traced contacts for gonorrhoea, 86% for syphilis and 77% for Chlamydia. 98% of clinics offered HIV test counselling, and 78% STD health education.

CONCLUSIONS

The number of sexual health services has increased over the past decade. Other improvements include most clinics being open to both men and women, and consistency in the diagnosis, treatment and contact tracing of STDs. However, given the lack of adequate comparative data and the variable quality of national surveillance data, it is difficult to determine whether current facilities are meeting service needs.

Human intestinal fatty acid binding protein: report of an assay with studies in normal volunteers and intestinal ischemia

BACKGROUND

Human intestinal fatty acid binding protein (hIFABP) is a cytoplasmic protein of mature small intestinal epithelium. Work with the rat demonstrated that serum levels of IFABP correlated with early phases of intestinal mucosal injury. The aim of this study was to develop an assay for hIFABP and assess its usefulness as a marker for intestinal mucosal injury in human beings.

METHODS

Recombinant hIFABP (r-hIFABP) was used to produce rabbit anti-hIFABP. Specificity and avidity of binding were tested with immunoprecipitation and Scatchard analysis. r-hIFABP was labeled with 125I, and a competitive assay was developed. Urine and serum from normal volunteers and from patients with necrotizing enterocolitis (NEC), acute thromboembolic related intestinal ischemia, and systemic inflammatory response syndrome were tested for hIFABP.

RESULTS

Molecular weight was 10(-12) kd, limit of detection was 1.87 ng/ml, and no cross-reactivity occurred when tested against rat IFABP or human heart FABP. Mean levels of hIFABP (ng/ml) were controls (serum less than 1.87, urine less than 1.87), NEC (serum 14.7 ng/ml), intestinal ischemia (serum 50 ng/ml, urine 52.3 ng/ml), systemic inflammatory response syndrome (serum 5.3 ng/ml, urine 13.2 ng/ml).

CONCLUSIONS

This assay is quantitative for hIFABP in serum and urine. Results from both normal persons and those with various causes of intestinal ischemia parallel our previous findings in the rat. Preliminary findings suggest that hIFABP may serve as a diagnostic marker for early intestinal mucosal compromise and, in addition, that it should prove useful as a tool in developing rationale therapeutic regimens to treat these complex clinical problems.

"Tethered cord syndrome"--recent clinical experience

Thirty-three consecutive patients treated surgically for "tethered cord syndrome" over a 3-three year period were reviewed. The main presenting complaints were back and leg pain, progressive lower limb and spinal deformity, and neurological deficits. Untethering of the cord was achieved in 32 patients, in whom the filum terminale was divided in 17. There were no serious complications; one patient had a CSF leak which required surgical repair. The mean postoperative follow-up was 15 months and 20 of the patients reported improvement, the rest were unchanged. There was no neurological deterioration in any of the patients. Our series suggests that cord release in patients with "tethered cord syndrome" improves or arrests the progression of neurological deterioration.

Monitoring of flaps by measurement of intracapillary haemoglobin oxygenation with EMPHO II: experimental and clinical study

OBJECTIVE

To find out whether measurements of intracapillary haemoglobin oxygenation made with the non-invasive Erlangen microlightguide spectrophotometer (EMPHO II) provided accurate data about the oxygen supply as well as the blood flow to free flaps in rats and humans.

DESIGN

Experimental, and prospective open clinical study.

SETTING

University hospital, Germany. ANIMALS and

SUBJECTS

Thirty male Wistar rats and 20 patients who underwent microsurgical transplant of free flaps (radial forearm, n = 8; osteocutaneous fibula, n = 7; and myocutaneous from the lateral thigh, n = 5).

INTERVENTIONS

Measurement of the haemoglobin oxygenation of the skin before, during, and after transfer of the flap.

MAIN OUTCOME MEASURES

Reproducibility and mean curves for haemoglobin oxygenation and haemoglobin concentration.

RESULTS

All values were reproducible, and there were only slight fluctuations. Uninjured skin in rats (baseline value) oxygenation of the total haemoglobin concentration ranged from 15% to 45% (mean 23%). After the flaps were raised there was a slight increase (to a mean of 37%), probably as a result of reactive hyperaemia. There was a rapid decrease within a few minutes of arterial occlusion, and residual oxygenation of up to 20% after perfusion stopped. The flap was totally deoxygenated after 1 h. Venous occlusion caused a similar pattern and all flaps were deoxygenated by 30 min. In the clinical study ligation of the vascular pedicle caused a massive reduction in values but after anastomosis there was significantly higher haemoglobin oxygenation (P = 0.05) and this continued to increase postoperatively. There were no complications and oxygenation gradually and continuously decreased from the base of the flap to the periphery.

CONCLUSION

The non-invasive EMPHO II provides reliable and easily assessable data about the circulation and supply of oxygen to a transplanted free flap.