Biomedical subjects

Nikos Kametas

Publications and source records attributed to Nikos Kametas.

5 recordsLinked to original sources

PubMed2004

Respiratory function in pregnancy at sea level and at high altitude.

OBJECTIVE: To determine the effect of pregnancy on respiratory function in a non-Caucasian group and determine whether there was an interaction between pregnancy and altitude of residence. DESIGN: Prospective cross sectional study. SETTING: Antenatal clinics in Peru, at sea level in Lima and at high altitude in Cerro de Pasco. SAMPLE: Peruvian women with singleton pregnancies; 122 living at sea level and 192 living at 4300 m altitude in the Peruvian Andes. At each location, 19 non-pregnant women were also studied. METHODS: Respiratory function was measured in pregnant and non-pregnant women living at sea level and at 4300 m. MAIN OUTCOME MEASURES: Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), total lung capacity (TLC), inspiratory capacity (IC), residual volume (RV), expiratory residual volume (ERV) and functional residual capacity (FRC). RESULTS: At sea level, RV and TLC were higher in the third compared with the first trimester (P < 0.05). At high altitude, FEV1 (P < 0.01), ERV (P < 0.01) and FRC (P < 0.01) were lower in the third compared with the first trimester. Pregnant and non-pregnant women at high altitude were 4 cm shorter (P < 0.0001) and had larger lung volumes (P < 0.01); their total lung capacities were approximately 1 L greater than women living at sea level (P < 0.0001). CONCLUSION: These results suggest that the effect of pregnancy on the respiratory function of healthy women is influenced by altitude of residence.

Altitude↗

PubMed2004

Ultrasonographic occiput position in early labour in the prediction of caesarean section.

OBJECTIVE: To investigate the value of ultrasonographically determined occiput position in the early stages of the active phase of labour, in addition to traditional maternal, fetal and labour-related characteristics, in the prediction of the likelihood of caesarean section. DESIGN: Prospective observational study. SETTING: District general hospital in the UK. POPULATION: Six hundred and one singleton pregnancies with cephalic presentation in active labour at term with cervical dilatation of 3-5 cm. METHODS: Transabdominal sonography to determine fetal occiput position was carried out by an appropriately trained sonographer immediately before or after the routine clinical examination by the attending midwife or obstetrician. MAIN OUTCOME MEASURE: Caesarean section. RESULTS: Delivery was vaginal in 514 (86%) cases and by caesarean section in 87 (14%). The fetal occiput position was posterior in 209 (35%) cases and in this group the incidence of caesarean section was 19% (40 cases), compared with 11% (47 of 392) in the non-occiput posterior group. Multiple regression analysis revealed that significant independent contribution in the prediction of caesarean section was provided by maternal age (OR 1.1, 95% CI 1.0-1.2), Afro-Caribbean origin (OR 2.4, 95% CI 1.2-4.6), height (OR 0.93, 95% CI 0.89-0.97), parity (OR 0.2, 95% CI 0.1-0.4), type of labour (OR 2.2, 95% CI 1.3-3.8), gestation (OR 1.4, 95% CI 1.1-1.7), fetal head descent (OR 0.6, 95% CI 0.4-0.9), occiput posterior position (OR 2.2, 95% CI 1.3-3.7) and male gender (OR 2.0, 95% CI 1.2-3.5). CONCLUSIONS: The risk of caesarean section can be estimated during the early stage of active labour by the sonographically determined occiput position, in addition to traditional maternal, fetal and labour-related characteristics.

Adolescent↗

PubMed2003

Pulmonary diffusing capacity in pregnancy at sea level and at high altitude.

The impact of pregnancy on respiratory function and whether this is influenced by living conditions, such as altitude of residence, must be determined if the management of pregnant women, particularly those with pulmonary disease is to be optimized. Pulmonary diffusing capacity, corrected for haemoglobin concentration (DL(COc)), therefore, was measured in 112 healthy Peruvian women with singleton pregnancies living at sea level and 192 living at 4300 m. At each location, 19 non-pregnant women were studied. The mean DL(COc)s of the pregnant and non-pregnant women studied at sea level were similar but lower than those of their high altitude counterparts (P<0.001, P<0.001). At high altitude, the mean DL(COc)s of women studied in the first and second trimester were similar to that of non-pregnant women, but the mean DL(COc) of pregnant women studied in the third trimester was lower than that of the non-pregnant women (P<0.01). Our results demonstrate that the effect of pregnancy on pulmonary diffusing capacity is influenced by altitude of residence.

Altitude↗

PubMed2003

Maternal electrolyte and liver function changes during pregnancy at high altitude.

BACKGROUND: High-altitude (HA) hypoxia leads to profound cardiovascular, respiratory and electrolyte changes, and pregnancy at HA has been associated with increased incidence of preeclampsia and intrauterine growth restriction. OBJECTIVE: To examine the effect of high altitude on maternal serum electrolytes and liver enzymes. DESIGN: Cross-sectional study of 77 pregnant women at 6-40 weeks of gestation resident at HA (4370 m above sea level) and 80 at sea level (SL) and 13 and 15 nonpregnant women at each altitude, respectively. Serum electrolytes (sodium, potassium, calcium and phosphate), creatinine, bilirubin and liver enzymes (alkaline phosphatase (ALP), aspartate transaminase (AST) and gamma-glutamyl transferase (gamma-GT)) were measured. RESULTS: Pregnancy at HA, compared to SL, was associated with higher serum osmolality (0.4%), sodium (0.7%), creatinine (14%) and phosphate (5%) concentrations and lower potassium (10%) concentration. Calcium and albumin-corrected calcium concentrations were higher at HA compared to SL in nonpregnant women (8%), with no difference in pregnant women. AST, gamma-GT and ALP concentrations were not significantly different between HA and SL, neither in pregnant nor in nonpregnant women. AST and gamma-GT were lower in pregnant compared to nonpregnant women (30%) at HA, whereas the difference was not significant at SL. Total bilirubin concentrations were higher at HA compared to SL by about 25% both in pregnant and in nonpregnant women, the difference reaching statistical significance only in the pregnant group. CONCLUSIONS: Pregnancy at HA is associated with increased osmolality, sodium, creatinine, calcium, phosphate and total bilirubin concentrations. Liver enzyme activities are similar to SL.

Adult↗

PubMed2002

Respiratory function in singleton and twin pregnancy.

OBJECTIVE: Singleton pregnancy causes important changes in respiratory function. The incidence of twin pregnancies is increasing, but it is not known whether affected women suffer greater respiratory compromise. The aim of this study was to determine if changes in respiratory function during pregnancy in healthy women were greater in those with a twin pregnancy compared with those with a singleton pregnancy. DESIGN: Cross sectional study. SETTING: London teaching hospital. POPULATION: Healthy pregnant women attending the antenatal clinic and ultrasound department. METHODS: A cross sectional study of respiratory function was performed in 68 women with twin pregnancies (17 examined in the first trimester, 35 second trimester, 16 third trimester) and 140 women with singleton pregnancies (28, 80, 40, respectively) and 22 non-pregnant women. Women were examined once between 7 and 40 weeks of gestation. Forced vital capacity, relaxed vital capacity, forced expiratory volume in 1 second (FEV1), peak flow, inspiratory capacity, functional residual capacity (FRC), expiratory reserve volume, pulmonary diffusing capacity and minute ventilation were measured. RESULTS: Both in twin and singleton pregnancies, the mean FRC and expiratory reserve ventilation of women studied in the third trimester and minute ventilation of women studied in each trimester differed significantly from that of the non-pregnant women. There were, however, no significant differences demonstrated in respiratory function between healthy women with twin as compared with singleton pregnancies. CONCLUSION: In healthy women, the extra demands of atwin compared with a singleton pregnancy do not compromise further the respiratory system.

Adult↗