Diagnostic value of two-dimensional echocardiography in cardiac hydatid disease

Echinococcal infection of the heart is rare. The preoperativefindings, with special attention to two-dimensional echocardiography(2DE), of six patients with cardiac echinococcosis and theirsurgical and pathological correlations are reported. Cardiachydatid cysts (HCs) were located in the cardiac apex in threepatients, in the upper part of the interventricular septum extendingtowards the anterior aspect of the heart in one and in the postero-superiorright atrial wall in another patient. The remaining patienthad multiple intrapericardial cysts. In three patients the cystspresented as well defined, rounded, echolucent masses withinthe myocardial wall bulging into the cardiac chambers. In twopatients, the cysts had ruptured into a cardiac chamber withloss of the characteristic ‘cystic’ appearance;these cysts presented as an echogenic or solid mass protrudinginto a cardiac chamber. Finally, another patient had one HCwith echolucent appearance and another HC in a different locationwith echogenic appearance; this last cyst corresponded to adegenerated HC. In two cases the cyst showed a loculated internalaspect. In one patient the myocardial segment involved by thecyst had a dyskinetic movement. In all six patients, 2DE accuratelydemonstrated the location and morphological details of the cardiaccysts, permitted recognition of the ruptured and/or degeneratedcysts and was superior to thoracic computed tomography and angiographyin the preoperative assessment of these patients. Nuclear magneticresonance imaging (one patient) gave no further informationto that obtained by 2DE. We conclude that 2DE is the techniqueof choice for an early diagnosis of this rare entity.     

Duration of symptoms and the effects of a more aggressive surgical policy: two factors affecting prognosis of infective endocarditis

One hundred and six patients were analysed in order to assessthe effect of a more aggressive surgical policy in relationto the delays in diagnosis of infective endocarditis. The averageduration of symptoms before diagnosis was 9.7 weeks, even thoughthe patients had sought medical advice at a relatively earlystage of their illness (2.2 weeks). Three of the 29 (10.3%)patients who were treated surgically died and all three wereoperated upon five weeks or later after diagnosis. Seventy-sevenpatients did not have surgery and 15 died (19.5%). The outcome of surgical treatment for prosthetic valve endocarditiswas no worse than for native valve endocarditis. The mortalityof prosthetic valve endocarditis including early infectionswas 32% with medical but only 10% with surgical management comparedwith 14.5% and 10.5% in native valve endocarditis.Endocarditiscannot always be prevented but earlier diagnosis would reducemortality and prevent complications. When medical treatmentis failing then surgery should be considered early and urgentlyparticularly in staphylococcal infection or when large mobilevegetations are recognized; surgery is mandatory in fungal endocarditis.Earlier diagnosis would greatly reduce the current high incidenceof surgery, but that depends on a much heightened index of suspicionamongst both general practitioners and hospital physicians.     

Low-flow anaesthesia

An 8-week survey was conducted to determine whether the introduction of low-flow anaesthesia (a fresh gas flow of 4 litres/minute or less) into routine use would be acceptable to members of a representative anaesthetic department and if the consequent reduction in use of volatile anaesthetics would result in financial savings. The hourly consumption of the volatile agents was measured during anaesthesia conducted using either conventional or low fresh gas flows. Anaesthetists' acceptance of low-flow anaesthesia was assessed using a questionnaire. Data were gathered on 286 patients undergoing inhalational anaesthesia for routine operative procedures. A 54.7% reduction in the consumption of isoflurane and a 55.9% reduction in that of enflurane was found. Of the 28 anaesthetists at the hospital, 21 would use low-flow anaesthesia routinely. The routine use of low-flow anaesthesia would therefore be acceptable and could result in annual savings of 26,870 pounds at Northwick Park Hospital.     

Beat-to-Beat Variability in Stroke Volume During VVI Pacing as Predictor of Hemodynamic Benefit from DDD Pacing

To determine whether the magnitude of Beat-to-Beat variability in stroke volume (SVJ during VVI pacing can predici hemodynamic benefit from DDD pacing, we undertook Doppier recordings of systolic and diastolic LV flow during VVI and DDD pacing in 20 patients (age 54 ± 9 years)with DDD pacemakers implanted due to AV block. SV increased by 19%± 10% from VVI to DDD (P < 0.01). This increase was greater (29%± 9%)in patients with a ratio of early (E)/late (A) filling < 1 compared to those with E/A > 1 (10%± 9%) (P < 0.001). Beat-to-Beat variability in SV was greater in VVI (13%± 8%)compared to DDD (4%± 1%) (P < 0.001). Patients with E/A < 1 showed greater Beat-to-Beat variability in SV during VVI pacing (19 ± 6%)compared to those with E/A > 1 (8%± 4%) (P < 0.001). Beat-to-Beat variability in SV during VVI pacing correlated with both percent change in SV from VVI to DDD (r = 0.89, P < 0.001)and E/A (r = -0.71, P < 0.001). In conclusion, patients with E/A < 1 derive greater hemodynamic benefit at rest from DDD pacing compared with E/A > 1. In addition, patients with complete AV block who show large variations in SV during VVI pacing may obtain greater hemodynamic benefit at rest from DDD pacing than patients with small variations.     

Nephrectomy for benign disease? A case of isolated renal echinococcosis

Cystic hydatid disease may be found in virtually any organ, although involvement of the urinary tract is relatively uncommon. We report a case of isolated renal hydatid disease presenting with hydatiduria. A short review of the literature regarding diagnosis and management of renal echinococcosis is also presented.     

Modification of the iso-shunt lines for low inspired oxygen concentrations

Arterial Po₂ (Pa_o2) has been related to inspired oxygen concentration(Fl_o2 range 0.21–0.60) in 20 patients, breathing spontaneously,while recovering from a range of conditions treated in an intensivetherapy unit. There was a highly significant linear trend (P< 0.001) for the mean venous admixture ("virtual shunt"),calculated from the iso-shunt diagram (model A), to increasefrom 0.11 to 0.19 as Fl_o2 decreased from 0.60 to 0.21. As thisappeared to be caused by relative ventilation/perfusion (V/Q.)mismatch, we prepared a second model (model B) with a variabletwo-compartment relative V/Q mismatch in addition to a shunt.Regression of the degree of mismatch on the shunt gave goodagreement between predicted and observed Pa_o2 values (mean bias–0.17 kPa, pooled within patient SD 1.22). Model B isnow proposed to extend the applicability of the iso-shunt diagramfor Fl_o2 values less than 0.35. Published postoperative Pa_o2data from other workers showed good agreement with our finalmodel (mean bias 0.10 kPa, pooled SD 0.41). The new diagrammay therefore have wide applicability in the field of anaesthesiaand intensive care. (Br. J. Anaesth. 1994; 72: 515–522)