[The effects of normal vaginal delivery on oxygen transport to the fetus]. / Ahrif edlilegrar faedingar á súrefnisflutning til fósturs.

OBJECTIVE: To evaluate the effects of normal vaginal delivery (NVD) on oxygen transport to the fetus. Study group and methods: Fifty newborn infants born by NVD and as a control group 50 infants born by elective Cesarean section (ECS) were studied. Factors reflecting oxygen transport to the fetus were measured in venous and arterial cord blood: pH, partial pressure of oxygen (pO2) and carbon dioxide (pCO2), oxygen saturation (SO2), blood oxygen content, base deficit, and lactic acid concentrations, erythropoietin concentrations, number of nucleated red blood cells and haemoglobin concentrations. RESULTS: There was no significant difference in venous blood oxygen content between the two groups of infants. However, arterial blood oxygen content was significanlty lower in the infants born by ECS than in those born by NVD (p<0.001). Infants born by NVD had significantly lower pH (p<0.001), greater base deficit (p<0.001), higher lactic acid (p<0.001) and erythropoietin concentrations (p=0.01), more nucleated red blood cells (p=0.004), and higher hemoglobin concentrations (p=0.002) in venous blood than in the infants born by ECS. pH was lower (p<0.001) and lactic aicid concentrations were higher (p<0.001) in arterial blood than venous blood in both groups of infants. CONCLUSIONS: (1) NVD causes reduction in oxygen transport to the fetus, resulting in acidosis and stimulation of blood forming tissues. (2) ECS is associated with more reduction in umbilical arterial cord blood oxygen content than NVD. (3) When evaluating acidosis in newborns after delivery it is more reliable to measure pH and lactic acid concentrations in arterial rather than venous cord blood.

Severe labetalol overdose in an 8-month-old infant.

We report a case of a large labetalol overdose in an eight-month-old infant that was being treated for hypertension following surgery for coarctation of the aorta. Labetalol, both alpha and beta adrenergic blocking agent was used for treating postoperative hypertension. By mistake, the patient was given an extremely high dose of labetalol intravenously (17.2 mg.kg(-1)). Remarkably, the medication error had a surprisingly limited clinical effect on the infant who survived the incident. We discuss the pharmacokinetic, pharmocodynamic and possible explanations for this fortunate turn of events.

Scopolamine for prevention of postoperative nausea in gynecologic laparoscopy, a randomized trial.

STUDY OBJECTIVE: We sought to estimate effectiveness of transdermal scopolamine to prevent postoperative nausea and vomiting after gynecologic laparoscopy. DESIGN: Patients were randomized to receive preoperative transdermal scopolamine or placebo. Main outcome measure was incidence of nausea during the first 24 hours postoperatively. Wilcoxon rank sum, Student t, chi2, and Fischer exact tests were used for data analysis (Canadian Task Force classification IA). SETTING: Academic teaching hospital. PATIENTS: A total of 48 patients undergoing gynecologic laparoscopy were studied. INTERVENTIONS: Randomized administration of transdermal Scopolamine or placebo in patients having gynecologic laparoscopic surgery. MEASUREMENTS AND MAIN RESULTS: Patients in the scopolamine group had significantly less incidence of nausea (20.8% vs 62.5%, p = .003) and vomiting (8.3% vs 37.5%, p = .016) during the first 24 hours after surgery. Number needed to treat was 3 (95% CI 1.5, 6.1) for nausea and 4 (95% CI 1.9, 14.6) for vomiting. Symptoms of visual disturbance and dry mouth were more common in the scopolamine group. CONCLUSION: Scopolamine patch significantly reduces incidence and severity of nausea and vomiting in the first 24 hours after gynecologic laparoscopic surgery.

Automatic retinal oximetry.

PURPOSE: To measure hemoglobin oxygen saturation (SO(2)) in retinal vessels and to test the reproducibility and sensitivity of an automatic spectrophotometric oximeter. METHODS: Specialized software automatically identifies the retinal blood vessels on fundus images, which are obtained with four different wavelengths of light. The software calculates optical density ratios (ODRs) for each vessel. The reproducibility was evaluated by analyzing five repeated measurements of the same vessels. A linear relationship between SO(2) and ODR was assumed and a linear model derived. After calibration, reproducibility and sensitivity were calculated in terms of SO(2). Systemic hyperoxia (n = 16) was induced in healthy volunteers by changing the O(2) concentration in inhaled air from 21% to 100%. RESULTS: The automatic software enhanced reproducibility, and the mean SD for repeated measurements was 3.7% for arterioles and 5.3% venules, in terms of percentage of SO(2) (five repeats, 10 individuals). The model derived for calibration was SO(2) = 125 - 142 . ODR. The arterial SO(2) measured 96% +/- 9% (mean +/- SD) during normoxia and 101% +/- 8% during hyperoxia (n = 16). The difference between normoxia and hyperoxia was significant (P = 0.0027, paired t-test). Corresponding numbers for venules were 55% +/- 14% and 78% +/- 15% (P < 0.0001). SO(2) is displayed as a pseudocolor map drawn on fundus images. CONCLUSIONS: The retinal oximeter is reliable, easy to use, and sensitive to changes in SO(2) when concentration of O(2) in inhaled air is changed.

Epidemiology and outcome of acute lung injury in European intensive care units. Results from the ALIVE study.

OBJECTIVES: To re-examine the epidemiology of acute lung injury (ALI) in European intensive care units (ICUs). DESIGN AND SETTING: A 2-month inception cohort study in 78 ICUs of 10 European countries. PATIENTS: All patients admitted for more than 4 h were screened for ALI and followed up to 2 months. MEASUREMENTS AND MAIN RESULTS: Acute lung injury occurred in 463 (7.1%) of 6,522 admissions and 16.1% of all mechanically ventilated patients; 65.4% cases occurred on ICU admission. Among 136 patients initially presenting with "mild ALI" (200< PaO2/FiO2 < or =300), 74 (55%) evolved to acute respiratory distress syndrome (ARDS) within 3 days. Sixty-two patients (13.4%) remained with mild ALI and 401 had ARDS. The crude ICU and hospital mortalities were 22.6% and 32.7% (p<0.001), and 49.4% and 57.9% (p=0.0005), respectively, for mild ALI and ARDS. ARDS patients initially received a mean tidal volume of 8.3+/-1.9 ml/kg and a mean PEEP of 7.7+/-3.6 cmH2O; air leaks occurred in 15.9%. After multivariate analysis, mortality was associated with age (odds ratio (OR) =1.2 per 10 years; 95% confidence interval (CI): 1.05-1.36), immuno-incompetence (OR: 2.88; Cl: 1.57-5.28), the severity scores SAPS II (OR: 1.16 per 10% expected mortality; Cl: 1.02-1.31) and logistic organ dysfunction (OR: 1.25 per point; Cl: 1.13-1.37), a pH less than 7.30 (OR: 1.88; Cl: 1.11-3.18) and early air leak (OR: 3.16; Cl: 1.59-6.28). CONCLUSIONS: Acute lung injury was frequent in our sample of European ICUs (7.1%); one third of patients presented with mild ALI, but more than half rapidly evolved to ARDS. While the mortality of ARDS remains high, that of mild ALI is twice as low, confirming the grading of severity between the two forms of the syndrome.