Introduction of a modified obstetric early warning system -(-MOEWS-)- at an Ethiopian referral hospital: a feasibility assessment.

Early warning scores are points-based or colour-coded systems used to detect changes in physiological parameters and prompt earlier recognition and management of deteriorating patients. Vital signs recorded within a coloured zone corresponding to degree of derangement ('trigger') should prompt an action. The report of the UK Confidential Enquiry into Maternal and Child Health recommends the use of modified versions in the obstetric population. Currently, there is limited research into the effects of early warning scores in low-resource settings where maternal mortality remains high, and there is a need for low-cost, simple methods to reduce this. A modified obstetric early warning system (MOEWS) was introduced for parturients who had undergone surgical intervention at Felege Hiwot Referral Hospital, a tertiary centre in Bahir Dar, Ethiopia. A guideline was developed to accompany the MOEWS, together with training of healthcare workers. Prior to introduction, the quality of postoperative monitoring was assessed through retrospective case note review. This was reassessed at 8 months and 11 months postimplementation, with assessment of response to 'triggers'. A questionnaire and qualitative interviews were undertaken to establish views of healthcare workers on its acceptability and usability. Recording of postoperative vital signs improved with the implementation of the MOEWS and was sustained at both monitoring periods. The number of patients with vital signs within the coloured zones ('trigger') was reduced, although documented action to these remained low. Staff were positive towards the MOEWS, its impact on patient care and felt confident using the system. The introduction of a MOEWS in an Ethiopian referral hospital in this study appeared to improve the monitoring of postoperative patients. With modifications to suit the setting and senior clinician involvement, coupled with regular training, the early warning score is a feasible and acceptable tool to cope with the unique demands faced in this low-resource setting.

ECG in suspected pulmonary embolism.

OBJECTIVE: To establish the diagnostic value of prespecified ECG changes in suspected pulmonary embolism (PE). METHODS: Retrospective case-control study in a district general hospital setting. We identified 189 consecutive patients with suspected PE whose CT pulmonary angiogram (CTPA) was positive for a first PE and for whom an ECG taken at the time of presentation was available. We matched these for age±3 years with 189 controls with suspected PE whose CTPA was negative. We considered those with large (n=76) and small (n=113) clot load separately. We scored each ECG for the presence or absence of eight features that have been reported to occur more commonly in PE. RESULTS: 20%-25% of patients with PE, including those with large clot load, had normal ECGs. The most common ECG abnormality in patients with PE was sinus tachycardia (28%). S1Q3T3 (3.7%), P pulmonale (0.5%) and right axis deviation (4.2%) were infrequent findings. Right bundle branch block (9.0%), atrial dysrhythmias (10.1%) and clockwise rotation (20.1%) occurred more frequently but were also common in controls. Right ventricular (RV) strain pattern was significantly more commonly in patients than controls, 11.1% vs 2.6% (sensitivity 11.1%, specificity 97.4%; OR 4.58, 95% CI 1.63 to 15.91; p=0.002), particularly in those with large clot load, 17.1% vs 2.6% (sensitivity 17.1%, specificity 97.4%; OR 7.55, 95% CI 1.62 to 71.58; p=0.005). CONCLUSION: An ECG showing RV strain in a breathless patient is highly suggestive of PE. Many of the other ECG changes that have been described in PE occur too infrequently to be of predictive value.

Intravenous leiomyomatosis with intracardiac extension: first reported case in Australia.

Intravenous leiomyomatosis (IVL) with cardiac extension is a rare uterine tumour. We present an unusual case of uterine leiomyoma that progressed along the inferior vena cava into the right atrium. Complete one stage removal of the tumour was performed using cardiopulmonary bypass and circulatory arrest. The literature review reveals that this is the first reported case in Australia of IVL with intracardiac extension which was successfully removed with a single stage procedure.

Simplified cerebral protection using unilateral antegrade cerebral perfusion and moderate hypothermic circulatory arrest.

BACKGROUND: Antegrade cerebral perfusion is one of the most reliable methods of organ protection during hypothermic circulatory arrest for aortic arch surgery. We used a simplified antegrade cerebral perfusion technique with low mortality and morbidity. METHODS: Between January 2005 and August 2008, 21 patients underwent aortic arch surgery with unilateral antegrade selective cerebral perfusion through the brachiocephalic artery and moderate hypothermic circulatory arrest. The mean age for patients was 58.0+/-11.1 (27-82) years. Cardiopulmonary bypass was commenced and the ascending aorta was cross-clamped. Patients were cooled to 22-28 degrees C, whilst the proximal anastomosis was performed. The brachiochephalic artery was cannulated using a balloon tipped 15Fr catheter used for retrograde cardioplegia. Antegrade cerebral perfusion was established at the rate of 10 ml//kg/min. The perfusion pressure was controlled between 50 and 70 mm Hg whilst the distal anastomosis was completed. RESULTS: There were no operative deaths and no permanent neurological deficits. Four patients had temporary confusion. Mean antegrade cerebral perfusion time was 21.6+/-8.0 (12-48)min. Eight out of 20 patients had circulatory arrest at 28 degrees C and their mean circulatory arrest time was 22.8+/-4.7 (16-32)min. DISCUSSION: The mortality and neurological outcomes of aortic surgery using unilateral antegrade cerebral perfusion with moderate hypothermic circulatory arrest produced satisfactory results. Bilateral cannulation and deep hypothermia appear to be unnecessary in most cases. The coagulopathy from deep hypothermia is thereby avoided.

Molecular interactions of Escherichia coli ExoIX and identification of its associated 3'-5' exonuclease activity.

The flap endonucleases (FENs) participate in a wide range of processes involving the structure-specific cleavage of branched nucleic acids. They are also able to hydrolyse DNA and RNA substrates from the 5'-end, liberating mono-, di- and polynucleotides terminating with a 5' phosphate. Exonuclease IX is a paralogue of the small fragment of Escherichia coli DNA polymerase I, a FEN with which it shares 66% similarity. Here we show that both glutathione-S-transferase-tagged and native recombinant ExoIX are able to interact with the E. coli single-stranded DNA binding protein, SSB. Immobilized ExoIX was able to recover SSB from E. coli lysates both in the presence and absence of DNA. In vitro cross-linking studies carried out in the absence of DNA showed that the SSB tetramer appears to bind up to two molecules of ExoIX. Furthermore, we found that a 3'-5' exodeoxyribonuclease activity previously associated with ExoIX can be separated from it by extensive liquid chromatography. The associated 3'-5' exodeoxyribonuclease activity was excised from a 2D gel and identified as exonuclease III using matrix-assisted laser-desorption ionization mass spectrometry.

Management of life-threatening subcutaneous emphysema using subcutaneous penrose drains and colostomy bags.

Subcutaneous emphysema is a common complication post cardiothoracic surgery. Severe subcutaneous emphysema may cause respiratory obstruction and sometimes tracheostomy or intubation is required. We report a case of massive subcutaneous emphysema following aortic valve replacement. It was not relieved with initial bilateral chest tubes, but the subcutaneous Penrose drains produced a dramatic improvement and provided effective decompression of the subcutaneous emphysema. We also describe the colostomy bags, which covered the drains. These were useful for keeping the area sterile and measuring the amount of air through the individual drains.

Mitral valve replacement in a severely calcified posterior annulus: a novel technique.

We describe a technique for insertion of a mitral valve prosthesis in the presence of severe posterior annular calcification by plicating the left atrial tissue over the sewing ring. Extensive calcification often creates the technical difficulty of seating the prosthetic valve resulting in peri prosthetic leakage. Extensive decalcification may weaken the annulus and result in prosthetic valve dehiscence and atrioventricular dissociation.

Prior elevation of IL-18 promotes rapid early IFN-gamma production during staphylococcal infection.

Systemic Staphylococcus aureus infection is associated with significant morbidity and mortality arising from both bacterial and host immune factors. IL-18 is a pro-inflammatory cytokine of the IL-1 superfamily that exhibits broad functional effects in innate and acquired immune responses and which has been found in high levels in several chronic inflammatory and autoimmune diseases. Over-expression of IL-18 may promote early resolution of infection or could promote a detrimental exaggerated immune response. This was explored in a model of S. aureus infection. We report increased mortality in Swiss mice that were given recombinant IL-18 prior to inoculation with S. aureus LS-1. IL-18 administration prior to infection induced preferentially enhanced IFN-gamma mRNA expression in peripheral blood leukocytes and spleen, especially splenic NK cells. This correlated with increased IFN-gamma protein detection in serum, and leukocyte and spleen cultures at subsequent discrete time points. These data suggest that increased mortality following gram-positive infection in autoimmune diseases could in part reflect the impact of high levels of pleiotropic pro-inflammatory cytokines such as IL-18 present prior to the onset of infection.

A new technique for repair of atrioventricular disruption complicating mitral valve replacement.

Atrioventricular disruption is an uncommon but often lethal complication in mitral valve replacement. We present the case of a 79-year-old woman in whom the disruption after mitral valve replacement was successfully repaired using BioGlue surgical adhesive, bovine pericardium, and polytetrafluoroethylene (Teflon) patch.

Nitric oxide preferentially induces type 1 T cell differentiation by selectively up-regulating IL-12 receptor beta 2 expression via cGMP.

Nitric oxide plays an important role in immune regulation. We have shown that although high concentrations of NO generally were immune-suppressive, low concentrations of NO selectively enhanced the differentiation of T helper (Th)1 cells but not Th2 cells. This finding provided an explanation for the crucial role of NO in defense against intracellular pathogens. However, the mechanism for the selective induction of Th1 cells was unknown. We report here that at low concentrations, NO activates soluble guanylyl cyclase, leading to the up-regulation of cGMP, which selectively induces the expression of IL-12 receptor beta2 but has no effect on IL-4 receptor. Because IL-12 and IL-4 are the key cytokines for induction of Th1 and Th2 cells, respectively, these results, therefore, provide the mechanism for the selective action of NO on T cell subset differentiation. Furthermore, this selectivity also applies to CD8+ cytotoxic and human T cells and, thus, demonstrates the general implication of this observation in immune regulation. Our results also provide an example of the regulation of cytokine receptor expression by NO. The selectivity of such action via cGMP suggests that it is amenable to therapeutic intervention.

Median sternotomy and extended left anterior thoracotomy for repair of traumatic aortic transection with ruptured right atrium.

A 22-year-old man presented with traumatic aortic transtion associated with rupture of the right atrium and underwent urgent median sternotomy to repair the right atrium. A T-shaped extended left anterior thoracotomy was performed, and ruptured descending thoracic aorta was repaired under total bypass. A Y-shaped connector was inserted in the arterial catheter to allow cannulation of both ascending aorta and femoral arteries. A 4-cm long Hemoshield graft was used to repair the aortic transection. The patient made a full recovery and was discharged 13 days after the accident.