Search PubMed⌕ Search

Biomedical subjects

L Voss

Publications and source records attributed to L Voss.

At least 19 recordsLinked to original sources
PubMed2003

Nociceptive and anaesthetic-induced changes in pulse transit time during general anaesthesia.

BACKGROUND: Pulse transit time (rPTT), the interval between ventricular electrical activity and arrival of a peripheral pulse waveform, has been used to detect changes in autonomic tone. The aim of this observational pilot study was to measure changes in rPTT in response to general anaesthesia and noxious stimuli. METHODS: Thirty-one healthy women undergoing gynaecological surgery were allocated to groups depending on the need for airway management with tracheal intubation (n=9), a laryngeal mask (LMA, n=17) or a facemask (n=5). During general anaesthesia, we measured changes in RR interval (RR-int) and rPTT after (i) induction of anaesthesia, (ii) airway manipulation and (iii) surgical stimulus. rPTT was estimated as the interval from the peak in the R-wave to detection of the pulse oximeter waveform in the periphery. RESULTS: Mean baseline rPTT was 245 (SD 27) ms. Upon induction of anaesthesia, rPTT increased (by 28.2 (20.4) ms, P<0.001) in all but two patients. rPTT decreased in response to endotracheal intubation (by 43.1 (24.6) ms, P=0.001) but did not vary in response to insertion of LMA or surgical stimulus. Mean baseline RR-int was 865 (141) ms. A mean reduction in RR-int after tracheal intubation did not reach statistical significance. RR-int was unchanged with induction of anaesthesia, LMA insertion or surgical stimulus. CONCLUSION: Variation in rPTT reflects autonomic responses to nociceptive stimulation and fluctuations in anaesthetic depth independently of heart rate.

Adult↗
PubMed2003

Implicit memory formation in sedated ICU patients after cardiac surgery.

BACKGROUND: Recent research into memory formation under sedation has generated conflicting results. We investigated explicit and implicit memory in ICU patients during moderate to deep propofol sedation following cardiac surgery. METHODS: Two different methods of memory testing were used; (1). free-association (F-A) word-pair testing (n=33) to test conceptual implicit memory and (2). process dissociation procedure (PDP) (n=26) to detect perceptual implicit and explicit memory. One hour after surgery, whilst sedated, the F-A group received one of two lists of 10 category-exemplar word-pairs through headphones, while the PDP group was presented with one of two lists of 16 five-letter words. When awake and co-operative, the F-A group was tested using F-A testing, and the PDP group was tested using the PDP. RESULTS: The F-A group had a mean (SD) correct response rate of 7 (9)% for the target list, and 9 (8)% for the distractor list. The PDP group had a mean (SD) correct response rate of 11 (14) and 10 (13)% for the inclusion and exclusion lists, respectively, with mean correct response rates of 13 (14)% for both the corresponding distractor lists. Neither group showed any significant differences between their responses and a list of distractor words (Wilcoxon tests). CONCLUSION: We found no evidence for memory formation in post-cardiac surgery patients under moderate to deep propofol sedation.

Adult↗
PubMed2000

A school and community outbreak of tuberculosis in Auckland.

AIM: To describe a school and community outbreak of tuberculosis in South Auckland in 1997/8. METHODS: Cases were diagnosed according to national guidelines at Middlemore, Green Lane and Starship Hospitals. Public health follow-up was conducted by Auckland Healthcare. RESULTS: Twelve cases were diagnosed during the outbreak. Nine cases were from the same South Auckland secondary school; six reported no association outside school. Three cases were in younger children who had close household contact with two of the school cases. Nine cases (including eight from the school) had identical Mycobacterium tuberculosis isolates on restriction fragment length polymorphism testing. No microbiological culture was obtained from the three remaining cases. Contact investigation detected five of the cases. Chemoprophylaxis was prescribed for twenty-six school students, two adult staff, and nine household contacts. CONCLUSION: This is the first published account of a tuberculosis outbreak in a New Zealand school setting for decades. Recognition of the outbreak was delayed. DNA fingerprinting played a valuable role in the investigation. The source case may have been a school student. The social impact of the outbreak and preventability with routine adolescent BCG vaccination are discussed.

Adolescent↗
PubMed2000

Hearing in children after meningococcal meningitis.

OBJECTIVE: To review the outcome of sensorineural hearing loss in children who have had confirmed meningococcal meningitis. METHODS: A retrospective audit of children admitted to the Starship Children's Hospital with a confirmed diagnosis of meningococcal meningitis during a 4-year period. RESULTS: Sixty-five children had confirmed meningococcal meningitis. Dexamethasone was administered according to recommended guidelines in 46 children (72%) while 12 children (19%) did not receive steroids at any stage. All children were appropriately referred for hearing assessment. Forty-nine children (75%) had their hearing tested and reliable sensorineural evaluation was obtained in all but one case. Thirty-four children (70%) were seen up to 6 weeks from discharge, 86% by 12 weeks. Sixteen cases (25%) did not attend for audiological assessment. Sensorineural hearing impairment was found in two children (4.2%). CONCLUSIONS: Children with meningococcal meningitis were reliably referred for audiological assessment but 39% either failed to attend for an outpatient hearing evaluation (25%) or had an unacceptable delay between discharge and testing (14%). Of those reliably tested, two children (4.2%) had significant sensorineural hearing loss.

Adolescent↗
PubMed1999

Threats to validity in the longitudinal study of psychological effects: the case of short stature.

In all studies of health-related problems and their effects on well-being, research design issues threaten to compromise the validity of findings. This is particularly so in a longitudinal study, essentially stemming from the tension between maintaining participant compliance and retaining investigator objectivity. Such a tension may be exacerbated where measures of dependent variables such as self-esteem are used alongside the collection of physical data which is essential to the study, as in research into the psychological effects of short stature on children and young people. In this paper one particular project, the Wessex Growth Study, is used to illustrate the common threats to validity, both internal and external, of such research, and to consider future improvements in design. The Wessex Growth Study, set up in 1986, was designed to overcome some of the methodological problems found in earlier research with short stature children. It is following the growth and psychological development through their school years of a cohort of short children (below third centile for height when first identified) and case-matched controls (10th-90th centiles) recruited at school entry (ages 5/6). Findings have generally found only small differences between short and average height children. Though these results so far have mainly been presented cross-sectionally, the young people involved are followed up at 6-monthly intervals for height and other data to be collected, and thus to some extent the study also has the advantages and problems of a longitudinal research design. Using Campbell and Stanley's criteria this article makes clear the strain on both internal and external validity in the study, but argues that these problems are to some extent inherent in all longitudinal psychological research, and are outweighed in the present research by the collection of data on short stature which would not otherwise be available. Future data collection within the study will introduce further improvements in design.

Adolescent↗
PubMed1997

Measles control.

Explore the source record for details and available documents.

Humans↗
PubMed1997

Vertical transmission of hepatitis C virus in New Zealand.

AIMS: To investigate the transmission of hepatitis C virus from viraemic mothers to infants. METHODS: The study group comprised 54 hepatitis C ribonucleic acid (RNA) positive, human immunodeficiency virus (HIV) negative women attending antenatal clinic, their infants when born, 12 previous children and 44 children of 29 additional nonpregnant, viraemic women. During the study period there were 60 live births (1 set of twins, 5 sequential pregnancies). All infants were tested at birth for hepatitis C virus (HCV) RNA. Thirty infants were retested at 6 months or later. Breast milk from 30 mothers was tested for HCV RNA. The 56 other children were tested for antibody to HCV and HCV RNA. RESULTS: Of the 60 infants tested at birth, 30 failed to attend a 6 month or later followup, 2 infants were HCV viraemic by six months of age, 2 infants had one episode of possible HCV RNA positivity followed by loss of detectable HCV RNA and 26 have shown no evidence of HCV infection. Five of the 30 breast milk samples tested were positive for HCV RNA. Four older children of viraemic mothers were HCV RNA positive. CONCLUSIONS: In this study, 2 of 30 (6.6%) of infants born to HIV negative, HCV viraemic mothers acquired HCV infection. Breast milk remains a possible contributory source of infant HCV infection. Management of babies born to HCV viraemic mothers should include retesting of baby for HCV RNA at 3 to 6 months of age.

Adult↗
PubMed1997

Bilateral femoral neck stress fractures in an amenorrheic athlete.

Stress fractures in athletes rarely involve the femoral neck. This report described the diagnosis and treatment of bilateral femoral neck stress fractures in a 30-year-old amenorrheic triathlete who is lactose intolerant and has a low caloric intake. The possibility of fatigue fracture should be considered in patients who have pain in the lower extremities that is exacerbated by activity, especially if they have hormonal or nutritional disorders.

Adult↗
PubMed1996

A new stress-related syndrome of growth failure and hyperphagia in children, associated with reversibility of growth-hormone insufficiency.

BACKGROUND: Growth failure without organic aetiology but associated with behavioural disturbance and psychosocial stress has been termed psychosocial short stature. This condition is not a valid diagnostic entity, but encompasses failure to thrive, stunting secondary to chronic malnutrition, and idiopathic hypopituitarism. Some children show spontaneous catch-up growth when removed from the source of stress, without further treatment, but until now precise definition of this subgroup for the purpose of clinical identification has not been possible. METHODS: Hospital-referred children with growth failure unrelated to organic pathology, who came from stressful homes, were compared with children of short-normal stature identified from an epidemiological survey (n = 31). Growth-hormone dynamics were studied in the hospital group by a combination of diurnal profiles and provocation tests. The tests were repeated after a hospital stay of 3 weeks away from familial stress. Standard behavioural measures were obtained from home and school. FINDINGS: In a distinctive subgroup (n = 29), growth-hormone insufficiency was associated with characteristic behavioural features, especially hyperphagia and polydipsia, and a normal body-mass index. When the children were removed from their stressful home circumstances, growth-hormone insufficiency spontaneously resolved only in formerly hyperphagic subjects. 74% of the non-hyperphagic cases (n = 23) were anorexic, with a low body-mass index and normal growth-hormone responses to provocation tests. INTERPRETATION: We present explicit behavioural and developmental criteria by which the novel syndrome of hyperphagic short stature may be recognised clinically. Such children have a capacity for spontaneous recovery of growth-hormone production on removal from or reduction of stress. Discriminant and predictive validity of the core symptoms are demonstrated. Preliminary familial studies indicate a possible genetic predisposition.

Adolescent↗
PubMed1996

The microbiology of chronic otitis media with effusion in a group of Auckland children.

AIMS: To determine the microbiology of chronic otitis media with effusion in a group of Auckland children. To determine the antimicrobial sensitivities of isolated bacterial pathogens to commonly used antibiotics for this condition. METHODS: A descriptive study recruiting subjects from otherwise well children with chronic otitis media with effusion having insertion of ventilation tubes at Starship Children's Health, Auckland. Tympanocentesis was performed, the middle ear aspirate cultured and antimicrobial sensitivities obtained. RESULTS: Sixty seven children (11mo to 8yr) with chronic otitis media with effusion had tympanocentesis of 105 ears. 38/105 (36%) of the middle ear aspirate cultures were positive. Forty nine organisms were isolated with 10 ears having two or more different bacteria identified. Isolated were 17 Haemophilus influenzae (16 nontype b and 1 type b), 13 Moraxella catarrhalis, nine Streptococcus pneumoniae and 10 'others'. All S pneumoniae(9/9), most H influenzae(14/17) and no M catarrhalis(0/13) were sensitive to amoxycillin. More than 80% of subjects had either a sterile effusion or an organism sensitive to amoxycillin or cotrimoxazole. CONCLUSIONS: Middle ear effusions were culture positive in a third of cases of chronic otitis media with effusion. The commonest organisms were H influenzae nontype b, M catarrhalis and S pneumoniae. This is similar to reports from other countries. Sensitivity data obtained supports the continued recommendation of amoxycillin or cotrimoxazole as first line therapy for the antimicrobial treatment of this condition.

Amoxicillin↗
PubMed1996

Pediatric chance fractures from lapbelts: unique case report of three in one accident.

In 1948, G. Q. Chance described a traumatic spinal injury as a "horizontal splitting of the spine," which has since come to be known as the Chance fracture. In 1965, the first such fracture was described by Howland et al. in a passenger as a result of a lap seatbelt during a motor vehicle accident. Until 1980, there were 36 such injuries reported, but the number of reports has since risen with the advent of mandatory seatbelt laws. We report three cases occurring in a single accident when a popular 4-wheel drive vehicle moving at only approximately 25 mph struck a tree, causing flexion-distraction fractures in all three children wearing lapbelts while seated in the rear seat. All three had a different Chance fracture variant and associated intraabdominal injuries. One child was rendered paraplegic. The purpose of this report is to promote awareness of the associated injuries, and to encourage appropriate use and development of passenger restraints for children.

Abdominal Injuries↗
PubMed1996

Repertoire of transcribed peripheral blood T-cell receptor beta chain variable-region genes in acute rheumatic fever.

Patients with severe group A streptococcal infections have abnormalities in the Vbeta repertoire of peripheral blood T cells that are consistent with superantigen stimulation by cytoplasmic membrane proteins. The purpose of this study was to determine whether similar changes in Vbeta repertoire could be found for patients with acute rheumatic fever (ARF). The mean Vbeta repertoire of peripheral blood T cells in nine hospitalized ARF patients was similar to that of 34 controls and did not change during 6 months of follow-up in 6 of the ARF subjects. We were unable to detect changes in the Vbeta repertoire of peripheral blood T cells from patients with ARF that could be attributed to the influence of a superantigen.

Acute Disease↗