LOWER POSTPRANDIAL PLASMA GLUCOSE AND INSULIN AFTER ADDITION OF ACACIA CORIACEA FLOUR TO WHEAT BREAD

Many Australian Aboriginal bushfoods contain slowly digested carbohydrate which elicit low postprandial blood glucose and insulin responses compared to Western foods, such as wheat bread. This study has shown that incorporation of flour made from a slowly digested seed, Acacia coriacea , into wheat bread (18 g/82 g wheat flour) significantly reduces the initial rise in plasma glucose levels ( p < 0.05) and the area under the plasma glucose curve ( p < 0.005) in six healthy subjects. Insulin values were also lowered at 60 minutes ( p < 0.025) and 90 minutes ( p < 0.05). Our findings suggest that Acacia flour, when used to dilute wheat flour in the manufacture of breads, produces a very palatable food which could be useful in the diets of diabetic individuals.     

EXTRADURAL BUPIVACAINE OR LIGNOCAINE ANAESTHESIA FOR ELECTIVE CAESAREAN SECTION: THE ROLE OF MATERNAL POSTURE

Extradural anaesthesia was induced in 64 patients in eitherthe sitting or the lateral position, for elective Caesareansection with either 0.5% plain bupivacaine or 2% lignocainewith adrenaline 1 in 200 000. Onset was significantly shorterand a significantly greater number of patients were ready forsurgery within 35 min following injection of lignocaine in thelateral position. Hypotension (defined as a 25% or greater reductionin arterial pressure) occurred in 36% of patients. Significantlymore patients who had received the first injection of localanaesthetic agent in the sitting position required ephedrineto correct maternal hypotension. Most frequently, hypotensioncoincided with transfer of patients to theatre and thus wasassociated with movement of the patient in the presence of extensivesympathetic block.     

AN EVALUATION OF THE AVL 937C BLOOD-GAS AND pH MICROANALYSER

The AVL 937C blood-gas and pH microanalyser was evaluated withparticular reference to its use in obstetrics and in neonatalpaediatrics in which its ability to analyse blood samples assmall as 40 (ilitre would be of particular value. Analysingsamples of cord blood, maternal venous blood and foetal scalpblood, the reproducibility over the range of values measuredwas excellent with samples of 40–100 (ilitre. SD of thevariation in values measured on samples collected in syringeswere Po2 0.11 kPa; Pco2 0.21 kPa; pH 0.005 unit. The same valuesfor specimens collected in capillary tubes were: Po2 0.19 kPa;Pco2 0.43 kPa; pH 0.013 unit. Analysis of tonometered bloodsamples showed a similar high standard of accuracy. The 91–98%confidence limits for the measurement of blood-gas values insamples collected in syringes were: Po2 –0.22 to +0.49kPaj Pco2 –0.53 to +0.42 kPa. The same values for samplescollected in capillary tubes were: Po2 –0.38 to +0.70kPa;Pco2 –0.97 to +0.86kPa     

Temporomandibular joint dysfunction in children presenting as otalgia

Thirty-one children between the ages of 6 and 16 years with otalgia but normal eardrums were investigated for temporomandibular joint dysfunction. Ear disease was excluded by microscopic examination, pure tone audiometry and impedance tympanometry. Dental disease was excluded by clinical and radiographic examination. Temporomandibular joint dysfunction was diagnosed by finding tenderness of the joint or masticatory muscles in at least two separate sites at one examination. Twenty-one patients were assessed as having joint dysfunction and in 18 of these the diagnosis was made when the child was seen in pain. Tympanometry on painful ears did not reveal any abnormality or trend in the values for compliance or middle ear pressure. Simple methods of treatment were effective in all cases. Temporomandibular joint dysfunction should be suspected in any child who complains of recurrent otalgia in the absence of dental and otological disease.     

CANINE CORONARY BLOOD FLOW RESPONSES TO HYPOXAEMIA: THE INFLUENCE OF HALOTHANE

Electromagnetic flow meters were used to measure blood flowin the coronary and pulmonary arteries of six anaesthetizeddogs following thoracotomy. Halothane 1% (v//v) caused a reductionin arterial pressure, coronary artery flow, cardiac output andmyocardial and total body oxygen consumption and an increasein coronary vascular resistance. Hypoxaemia caused large increasesin coronary artery flow during both cardiac systole and diastole,but not until Pa_O22 was less than 5.3 kPa. This response wasnot influenced by the presence of halothane. Although myocardialoxygen availability and consumption were maintained during hypoxaemia,total body oxygen availability and consumption were markedlyreduced.     

Differential flow from multihole epidural catheters

The pressures used in vivo to administer epidural doses of local anaesthetic were recorded for 16- and 18-gauge multihole catheters. Observations were made on 10 patients in labour for each catheter gauge. The pressure range for the 16-gauge catheters was 39.9-266 kPa, with a mean of 167.2 kPa, and for 18-gauge, a range of 53.2-266 kPa, mean, 159 kPa. Similar pressures were then applied in vitro to 10 catheters of each gauge, and the flow of fluid observed from the three holes. For each size of catheter, with increasing pressure, flow appeared at the proximal, then the middle, and finally the distal hole. This emphasises that the effect of epidural doses can vary depending on the pressure of injection, especially if the catheter had been passed partially through the dura.     

Left Ventricular Mechanical Assist Devices and Cardiac Device Interactions: An Observational Case Series

Background: Nonpulsatile left ventricular assist devices (LVADs) are increasingly used for treatment of refractory heart failure. A majority of such patients have implanted cardiac devices, namely implantable cardioverter-defibrillators (ICDs) or cardiac resynchronization therapy-pacemaker (CRT-P) or cardiac resynchronization therapy-defibrillator (CRT-D) devices. However, potential interactions between LVADs and cardiac devices in this category of patients remain unknown.
Methods: We reviewed case records and device logs of 15 patients with ICDs or CRT-P or CRT-D devices who subsequently had implantation of a VentrAssist LVAD (Ventracor Ltd., Chatswood, Australia) as destination therapy or bridge to heart transplantation. Pacemaker and ICD lead parameters before and after LVAD implant were compared. In addition, ventricular tachyarrhythmia event logs and potential electromagnetic interference reports were evaluated.
Results: Right ventricular (RV) sensing decreased in the first 6 months post-LVAD. Mean R-wave amplitude preimplant was 10.9 ± 5.25 mV compared with 7.2 ± 3.4 mV during follow-up (P = 0.02). RV impedance also decreased from 642 ± 240 ohms at baseline to 580 ± 212 ohms at follow-up (P = 0.007). There was a significant increase in RV stimulation threshold following implantation of the LVAD from 0.8 ± 0.6 V at baseline to 1.4 ± 1.0 V in the first 6 months postimplant (P = 0.01). A marked increase in ventricular tachyarrhythmia burden was observed in three patients. One patient displayed electromagnetic interference between the LVAD and defibrillator, resulting in inappropriate defibrillation therapy.
Conclusions: LVADs have a definite impact on cardiac devices in respect with alteration of lead parameters, ventricular tachyarrhythmias, and electromagnetic interference.