Prevention and management of internal cerebrospinal fluid shunt infections.

Cerebrospinal fluid (CSF) shunt infection is a serious and potentially devastating complication of CSF shunt placement. Younger age, previous CSF shunt infection or revision, and the type of the shunt are important risk factors for shunt infection. More than half of the cases are caused by Staphylococcus aureus and coagulase-negative staphylococci. The biofilm plays a central role in its pathogenesis. CSF cultures remain the gold standard for diagnosis of CSF shunt infection. The most effective way to prevent CSF shunt infection is optimization of sterile protocols and use of proper and timely antibiotic prophylaxis. Management of CSF shunt infection frequently requires removal of all shunt components, placement of a temporary external device, and administration of intravenous antibiotics, followed by reshunting at a later time. This review summarizes and analyses the results of previous reports of CSF shunt infection and assesses the prevention and management of this important entity.

Effects of propylene glycol powder on productive performance of lactating cows.

An experiment was conducted by eight lactating Holstein cows with an average milk production of 32.75 kg day(-1) and body weight of 643.6 kg to evaluate the effects of propylene glycol (PG) on productive performance, blood metabolites and nutrients digestibilities. In this experiment a balanced change-over design with four treatments and four periods with 21 days were employed. Treatments included: (1) Control (without PG), (2) 250 g PG/cow/day, (3) 500 g PG/cow/day and (4) 750 g PG/cow/day. Daily milk yield recorded and milk samples were taken during seven and two last days of each period. The results show that dry matter intake, milk yield, fat corrected milk yield, milk compositions were not affected (p > 0.05) by different levels of PG. Supplementing diets with 500 and 750 g PG/cow/day, significantly increased plasma glucose (p < 0.05) but other blood metabolites such as blood urea nitrogen, triglyceride and cholesterol were not affected (p > 0.05) by PG. Apparent digestibility of dry matter and organic matte was not affected (p > 0.05) by PG administration. In conclusion, plasma glucose was increased by using 500 and 750 g PG/cow/day (as powder) in the first and mid lactation stage, but the levels of 250 g PG/cow/day did not have any significant effect on dry matter intake, milk yield, milk compositions and other blood metabolites.

Efficacy of oral naltrexone on pruritus in atopic eczema: a double-blind, placebo-controlled study.

AIM: The intent of our study was to determine the efficacy of oral naltrexone, an opioid antagonist, in the treatment of pruritus in patients with chronic eczema. METHODS: This double-blind, placebo-controlled study recruited 38 patients with eczema complaining from pruritus. Pruritus scores were evaluated. Patients were given placebo (n = 20) or naltrexone 50 mg (n = 18) for 2 weeks period. During the study, pruritus scores based on visual analogue scale system (VAS) were assessed three times: at the start of study, after 1 week, and after 2 weeks. RESULTS: In both groups, decreased VAS scores were observed, but naltrexone showed to be significantly more effective than placebo in decreasing VAS score after 1 week (P < 0.005) and 2 weeks (P < 0.001). CONCLUSION: Naltrexone is more effective than placebo in the treatment of pruritus in patient with eczema. Naltrexone might be considered as an adjunct treatment in the treatment of pruritus. However, further studies in this aspect are highly fostered.

The Stolzalpe technique: a modified Watson-Jones approach.

We report our experiences with minimally invasive total hip replacement performed via a modified Watson-Jones approach with a special positioning technique (the "Stolzalpe technique"). With the patient placed in the conventional supine position, the contralateral leg is held in a gynaecological footrest to allow hyperextension, adduction and external rotation of the leg during femoral preparation. The first 117 patients operated with this technique were compared with a conventionally operated group. The patients operated with the Stolzalpe technique had superior results for nearly all study criteria, including time of operation, time of postoperative intensive care, blood loss, complications and Harris Hip Score. The Stolzalpe technique appears to be the best possible compromise between patient comfort and the surgical demands of proper implant positioning, minimization of anaesthetic risk, and reducing the time required for draping and positioning.

The potential impact of PR interval analysis of the fetal electrocardiogram (FECG) on intrapartum fetal monitoring.

A retrospective study was performed at the Queens Medical Centre, Nottingham, UK to evaluate the potential value of PR interval analysis of the FECG compared to conventional intrapartum assessment with fetal heart rate monitoring. Two-hundred sixty-five labours were selected for monitoring. Outcome was assessed by the number of fetal scalp blood samples (FBS) performed and the associated incidence of acidosis in the first stage of labour, the mode of delivery and whether or not this was expedited for fetal heart abnormality or an abnormal scalp pH. The condition of the fetus at delivery was assessed by arterial and venous blood acid-base status, Apgar score and the need for admission to the neonatal intensive care unit. Conventional electronic fetal heart rate monitoring (EFM) was used in all labours. The addition of PR interval assessment would potentially reduce the numbers of normal FBSs being carried out from 85.5% to 26.8% and the proportion of cases of missed acidosis at delivery from 8.5% to 4.5%. These results highlight the potential benefit of PR interval analysis in improving interpretation of the intrapartum cardiotocograph and need to be tested by prospective randomised controlled study.

Antenatal assessment using the FECG obtained via abdominal electrodes.

During the past decade a variety of intrapartum fetal monitors have been constructed that process the entire fetal electrocardiogram (FECG), obtained via a scalp electrode. They therefore differ from conventional monitors in aiming to extract relevant timing and magnitude information from the morphology of the FECG rather than simply the RR interval and hence heart rate. An intrapartum monitor such as this has been successfully developed by ourselves. This paper describes the early results obtained whilst attempting to extend this form of monitoring forward into the antenatal period. In order to achieve this the FECG must be acquired via surface electrodes placed on the maternal abdomen, which yields a signal containing the FECG amidst a number of noise sources. Our investigations into the feasibility of "antenatal abdominal FECG analysis" have been on two fronts. The first has been to produce a bedside monitor similar in function to our intrapartum device, whilst the second has been to address the possibility of performing such monitoring in ambulant subjects. At present the antenatal bedside monitor has successfully extracted and processed the FECG in approximately 75% of the cases studied, with subjects ranging from 20 weeks through to term having been monitored. We also have demonstrated the feasibility of the long term monitoring of maternal and fetal heart rate using a portable instrument.

The prediction of fetal acidosis at birth by computerised analysis of intrapartum cardiotocography.

OBJECTIVE: To assess the capability of a computer software interpretation program, using intrapartum fetal heart rate and intrauterine pressure as recorded in a cardiotocogram to predict fetal acidosis at birth. DESIGN AND SUBJECTS: A retrospective analysis of digitised fetal heart rate and uterine activity values obtained from 73 high risk women in labour. SETTING: Two university teaching hospitals. METHODS: A computer software program was constructed to analyse the digitised data and predict acidosis. The results of the analysis were compared with actual umbilical arterial blood pH and base excess at delivery. RESULTS: The software cardiotocogram interpreter was able to predict a pH of less than 7.15 with an accuracy of 77%, a sensitivity of 88% and specificity of 75% in this set of data. It was able to predict a base excess of less than -8 mmol/l with an accuracy of 81%, a sensitivity of 76% and specificity of 82%. CONCLUSIONS: A computerised method of analysing fetal heart rate and uterine activity using a simple algorithm has demonstrated a capability to predict fetal acidosis at the time of delivery. Further research in this area is warranted.

Computerised fetal heart rate analysis in labour--effect of sampling rate.

OBJECTIVE: To study the effect of sampling rate on the accuracy of fetal heart rate recording in labour. DESIGN: Prospective observational study. METHODS AND SUBJECTS: The fetal heart rate was obtained from 153 fetuses in labour. The heart rate data was sampled at a rate of 0.5 Hz (every 2 s) and the means and standard deviations of 5-min segments compared against the mean and standard deviation for all beats in the same time interval. RESULTS: There was a highly significant correlation between the means (r = 0.994, p < 0.001) and standard deviations (r = 0.957, p < 0.001) of FHR sampled on successive beats compared with 2 s sampling. CONCLUSION: Two second sampling of the fetal heart rate in labour will allow a highly complex analytical algorithm to process the signal in near real time for objective analysis.

Atrioventricular block during fetal heart rate decelerations.

Electrocardiograms (ECG) was examined in 15 fetuses during fetal heart rate decelerations in labour. Sinus bradycardia was demonstrated in six cases and in two cases inversion of the P wave was seen. In seven cases there was complete dissociation of the P wave from the QRS complex, indicating complete atrioventricular heart block. Many decelerations are vagally mediated, but such cases associated with complete atrioventricular heart block may be due to the effect of hypoxia on the bundle of His.

Physical, neuromotor and intellectual impairment in non-cretinous schoolchildren with iodine deficiency.

Thyroid status and neurologic, psychometric and auditory functions were evaluated in presumably normal schoolchildren aged 6 to 16 years from three areas of iodine deficiency in Iran. The subjects from each area were identified as members of groups A, B or C. In group A there were retarded growth, high prevalence of visible goiter (93%), low T4 (39%) and high TSH (70%). In group B 66% had a visible goiter and 7% had high serum TSH. In group C visible goiter was present in 22% of the subjects but they had normal thyroid function. Urinary iodine excretion was low in all three groups. Head circumference was less in groups A and B, as compared to C. Pyramidal signs occurred in over half of the subjects in Group A (hyperreflexia in 39% and crossed adductor reflex in 29%). The glabellar sign was present in 50% of group A and 20% of group B. Forty-four percent of the subjects in group A and 17% in group B had hearing deficits as shown by audiometry. Psychomotor examination was performed using the Bender Gestalt test. A higher number of errors was evident in groups A and B their psychomotor age was below their chronological age. The results of the Raven test showed mild impairment of IQ in group A, with 55% having an IQ below 91 and 15% less than 70. The subjects in group B had lower IQ than group C, but higher than group A. There was a negative correlation between serum TSH and free thyroid indices and a positive correlation between TSH and the number of pyramidal signs. This study demonstrates that mild to moderate growth retardation and neurological, auditory and psychomotor impairments occur in apparently normal subjects residing in areas of iodine deficiency.

A comparative study of the fetal electrocardiogram recorded by the STAN an Nottingham systems.

OBJECTIVE: To compare the T:QRS ratio recorded by the STAN and Nottingham fetal electrocardiogram (FECG) monitors. DESIGN: Prospective observational study. SETTING: London teaching hospital delivery suite and research unit. METHODS AND SUBJECTS: The T:QRS ratios generated by the STAN and Nottingham FECG monitors were simultaneously recorded and compared using signals generated from a computer-produced ECG signal and signals from 11 term fetuses recorded during labour. RESULTS: There was an acceptable level of agreement between the two systems with the computer-generated signals, but it was not clinically acceptable with the signals from the fetuses recorded during labour. Disagreements in the T:QRS values were probably due to differences in the reference points for the measurement of the S-T segment and T-wave height. CONCLUSION: The different points of reference for measurement of S-T segment and T-wave height can explain poor agreement between the two methods of FECG waveform analysis. The suggested adopted points of reference are those corresponding to adult electrocardiographic methodology.

Cumulative changes in the fetal electrocardiogram and biochemical indices of fetal hypoxia.

Previous studies have shown that the relationship between P-R interval of the fetal electrocardiogram (FECG) and the fetal heart rate (FHR) varies according to the acid-base status of the fetus. In the normal fetus there is a negative correlation between these two parameters. However, as acidosis develops, the relationship becomes positive. In order to express this relationship in a quantitative form, an index known as the ratio index (RI) has been derived. This index provides a cumulative time based description of the relationship between the P-R interval and FHR for the whole labour. The aim of this study was to evaluate this derived index and compare it with fetal hypoxia. The FECG was recorded from 132 fetuses during labour using a fetal scalp electrode, and analysed using the Nottingham FECG system. Changes in the nature of this relationship between the P-R interval and heart rate were compared against biochemical markers of asphyxia, namely umbilical artery pH, lactate and umbilical venous norepinephrine and hypoxanthine. Significant correlations were demonstrated between the RI and umbilical arterial pH (r = -0.38, P < 0.01), lactate (r = 0.36, P < 0.01), log10norepinephrine (r = 0.37, P < 0.01), and hypoxanthine (r = 0.28, P < 0.01). The measurement of the ratio index during labour may be a useful method of determining fetal hypoxia during labour.

Diabetic pregnancy 1977-1990: have we reached a plateau?

We have compared 81 pregnancies in women with type 1 (insulin dependent) diabetes in 1984-1990 with 58 in 1977-1983. In 1984-1990, women booked earlier (8 weeks [median] vs 12 weeks), mean haemoglobin A1 was lower in each trimester, and fewer days were spent in hospital before delivery (5.3 days [mean] vs 15). The latter was due to more experience in managing diabetic control as outpatients and fewer admissions for fetal monitoring. Most admissions are now for pre-eclampsia and intercurrent illnesses. The proportion of deliveries by caesarean section has not changed significantly (53% in 1984-1990 vs 66% in 1977-1983), but most are now done as emergencies. The incidence of macrosomia is constant (26% in 1984-1990 vs 21% in 1977-1983). There was one stillbirth, one intra-uterine death (complicating maternal ketoacidosis) and one perinatal death in 1984-1990, compared with no losses in 1977-1983. Two babies had major congenital abnormalities in 1984-1990, compared with one in 1977-1983. These results compare favourably with those from other centres in the United Kingdom. We conclude we have reached a nearly irreducible minimum for hospital days before delivery and congenital abnormalities, but that there is scope for a small reduction in the caesarean section rate.