The 30 minutes decision-to-delivery interval for 'urgent' caesarean sections: an elusive target.

The aim of this audit was to evaluate whether the '30 minute decision-to-delivery interval' for 'urgent' caesarean section has shown consistent improvement with repeated audit within this unit. The audit dataset comprised a random sample of all urgent caesarean sections carried out in 2004 classified as 'urgent', i.e. to be completed in 30 min. Nearly one-third of caesarean sections recorded on the delivery suite database as 'urgent' were incorrectly coded. A personal review of case notes was undertaken to ensure accurate data capture. Delivery suite data was analysed by post-hoc modelling of a 'normal' (Gaussian) distribution. The proportion of true 'urgent' caesarean sections completed in 30 min was 50% and some 90% of women were delivered within 40 min. The data were normally distributed, with non-random events, accounted for 25% of the variability. A model for 'urgent' caesarean section, accommodating random and non-random factors closely matched the audit data. We conclude that non-random, institutional, factors reflecting overall delivery suite activity adversely effect the decision-to-delivery interval regardless of the performance of personnel and processes within a delivery suite.

A reproducibility study of technetium-99m macroaggregated albumin foot perfusion imaging in patients with diabetes mellitus.

The reproducibility of Technetium-99m macroaggregated albumin (99mTc-MAA) foot perfusion imaging was assessed in 14 diabetic patients with foot ulcers. Bilateral femoral intra-arterial injections of 99mTc-MAA were administered and the feet imaged with a gamma camera. Patients returned 1 week later for a repeat study. The scans of 10 patients including one unilateral amputee were evaluated. Of these 19 limbs there were 4 failed injections (21%). The remaining 15 completed repeat studies were analysed both subjectively and semiquantitatively by 2 different observers who were blind to the patient's name and scan date. Subjectively the images of each individual were similar with reports highlighting the same abnormalities. Semiquantitatively areas of increased uptake on both images were significantly correlated for each individual (Pearson's Rho correlation coefficient = 0.96, r2 = 0.92, p < 0.0001) as were areas of poor uptake reported, reflecting decreased tissue perfusion (Pearson's Rho = 0.93, r2 = 0.86, p < 0.0001). There were no side-effects. 99mTc-MAA has proven to be a safe, generally acceptable, and reproducible technique for assessing tissue perfusion in the extremities which provides an accurate means of differentiating viable from non-viable tissue in patients with foot ulcers.

Investigating the capillary circulation of the foot with 99mTc-macroaggregated albumin: a prospective study in patients with diabetes and foot ulceration.

Macroaggregated albumin has been used to assess capillary circulation for over 20 years. The aim of the present study was to use 99mTc-macroaggregated albumin (99mTc-MAA) perfusion scanning to assess capillary circulation in feet with ischaemic ulcers in patients with diabetes, and relate the appearances to outcome. Twenty-three patients with diabetes presented with a total of 41 neuroischaemic foot ulcers. Perfusion scanning was performed by direct femoral artery injection of approximately 400,000 particles of 99mTc-MAA and imaging with a gamma camera. Patients were followed prospectively for 3 months. Scans were graded independently by a radiologist who was unaware of the site of the ulcers. Significant associations were detected between a radiologist's assessment of increased tissue perfusion and complete healing after 3 months (p = 0.047) and poor tissue perfusion on the image and failure to heal (p = 0.0005). This technique may be useful in deciding whether to persist with conservative treatment in patients with diabetes and foot ulceration.

Effect of acute mild hypoglycaemia on counterregulatory responses to moderate hypoglycaemia induced immediately afterwards in healthy men.

1. This study was designed to determine whether a 1 h period of mild hypoglycaemia (3.3 or 3.7 mmol/l) affected the response to an episode of moderate hypoglycaemia (2.5 mmol/l) immediately afterwards. 2. Eleven non-obese healthy men (age 26 +/- 1 years, mean +/- SEM) underwent three separate 3 h hyper-insulinaemic glucose clamps in single-blind, random order. On all three occasions, blood glucose was 4.5 mmol/l for the first hour, and on a control visit was maintained at this level for the second hour. In the other two visits, blood glucose was lowered to 3.7 or 3.3 mmol/l during the second hour. In the third hour, blood glucose was lowered to 2.5 mmol/l on all three visits. 3. In the second hour, adrenaline rose significantly (P < 0.05, analysis of variance) with a blood glucose of 3.3 and 3.7 mmol/l, as did cortisol and heart rate at 3.3 mmol/l, but glucagon, prolactin, sweating rate, symptom score and blood pressure were the same during the second hour on all three visits. 4. In the final hour at 2.5 mmol/l, there were no differences in adrenaline, noradrenaline, glucagon, prolactin, cortisol, symptom score, heart rate, blood pressure or sweating rate. 5. Thus, the overall magnitude of hormonal responses to moderate hypoglycaemia (2.5 mmol/l) are not modified by exposure to mild hypoglycaemia (3.3 or 3.7 mmol/l) for 1 h immediately beforehand.

Antecedent insulin level and pattern of induction of acute hypoglycaemia do not affect subsequent counterregulatory responses in healthy subjects.

1. This study was designed to determine whether the duration and pattern of prior insulin exposure modulate the symptomatic and counterregulatory responses to hypoglycaemia. 2. Ten healthy non-obese subjects (five males/five females age 25 +/- 1 years, mean +/- SEM) were made hypoglycaemic in three ways: (i) a hyperinsulinaemic (60 m-units min-1 m-2; plasma insulin concentration 95 m-units/I) clamp, with 1 h of euglycaemia, blood glucose level 4.5 mmol/l, followed by 30 min of hypoglycaemia, at a stable glucose nadir of 2.0 mmol/l (i.e. euglycaemic then hypoglycaemic clamp: E + HC); (ii) an identical hypoglycaemic clamp without preceding hyperinsulinaemic euglycaemia (i.e. a hypoglycaemic clamp: HC); (iii) insulin infusion only, discontinued at a blood glucose level of 3.0 mmol/l (II). Blood glucose level reached the same nadir as on E + HC and HC, and did not fall further. At the glucose nadir, and 15 and 30 min after, the plasma insulin concentration was 23, 7 and 4 m-units/l, respectively, on the II visit. 3. At the glucose nadir, plasma glucagon level, plasma adrenaline level, sweating rate, heart rate, blood pressure, and overall and individual symptom scores (using visual analogue scales) were the same on E + HC, HC and II. 4. There were no significant differences in neurohormonal response between E+HC and HC, but more subjects felt hypoglycaemic on E + HC on arrival at the glucose nadir (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Does ethanol cause hypoglycaemia in overnight fasted patients with type 1 diabetes?

Drinking ethanol is widely believed to predispose to hypoglycaemia in patients with Type 1 diabetes, the suggested mechanism being suppression of hepatic gluconeogenesis. The hypoglycaemic effect of ethanol was investigated by measuring steady-state glucose infusion rate during a hypoinsulinaemic (mean plasma insulin 14 +/- 1.3 (SEM) mU l-1), euglycaemic (blood glucose 5 mmol l-1) clamp. Nine patients with Type 1 diabetes fasted overnight and then had, in single-blind fashion, ethanol 0.5 g kg-1 by intravenous bolus followed by 0.25 g kg-1 h-1 or matched volumes of saline. After 1 h of ethanol or saline, all infusions were stopped and blood glucose monitored for a further 90 min. A 60-min ethanol infusion leading to a steady-state blood concentration of 26.2 +/- 1.4 mmol l-1 (120.7 mg %) did not alter the glucose infusion rate needed to maintain euglycaemia (1.22 +/- 0.12 mg kg-1 min-1 before and 1.23 +/- 0.12 during ethanol infusion), the initial rate of fall of blood glucose (ethanol 0.039 mmol l-1 min-1 vs control (0.033), the lowest blood glucose (4.43 mmol l-1 vs 4.31), or the rate of blood glucose recovery (ethanol 0.050 mmol l-1 min-1 vs control 0.054). We conclude that a moderate amount of ethanol, administered intravenously under controlled conditions, does not lead to hypoglycaemia in patients with Type 1 diabetes who have fasted overnight.

Impotence in diabetes: aetiology, implications for treatment and preferred vacuum device.

In an assessment of the contributions of autonomic neuropathy and vascular disease to the aetiology of male impotence in diabetes, evidence of autonomic neuropathy was identified in 23/39 (59%) individuals complaining of impotence. Thirteen of 26 men aged < 60 years tested with an intracorporeal injection of papaverine experienced little or no response and seven had tumescence but no rigidity. Radioisotope phallography demonstrated vascular disease in six of these seven, suggesting evidence of a vascular component in 19/26 (73%). Only one patient had non-organic impotence. Overall, evidence of vascular disease alone was demonstrated in 10/26 (38%), vascular disease plus autonomic neuropathy in 9/26 (35%), and autonomic neuropathy alone in 6/26 (23%). Many diabetic men complaining of impotence appear to have a significant vascular component which renders intracorporeal papaverine treatment ineffective. We compared the performance of a vacuum constriction-band (Erecaid) and condom-type (Synergist) device in 10 randomly selected men from this group. The devices, provided in random order for 5 months each, were assessed by questionnaire and interview of both the patient and partner. Two couples defaulted and another could use neither device. Although erectile capacity could be restored in the remainder, subsequent intercourse was only deemed satisfactory to both partners in five couples, who unanimously preferred the constriction-band device. In treatment with vacuum devices the constriction-band type seems to be the device of choice; the condom type should probably be reserved for those unable to use the constriction-band type.