Ronald K. Knight

Increased augmentation index in patients with cystic fibrosis

Increased large artery stiffness occurs in a range of inflammatory conditions indicating an ageing of the vasculature and additionally being an independent risk factor for cardiovascular events. We determined large artery parameters in adults with cystic fibrosis (CF). 50 clinically stable adult patients with CF (mean±sd age 28.0±8.2 yrs) and 26 controls matched for age, sex and body mass index were studied. Central aortic blood pressure, augmentation index (AIx) and aortic pulse wave velocity (PWV) were determined using applanation tonometry. Lung function, diabetic status and C-reactive protein (CRP) were also determined. Mean±sd AIx was greater in patients than controls, 8.5±11.1% and -1.8±13.1%, respectively (p<0.001), while PWV was similar. Although AIx was greatest in the sub-group with CF-related diabetes (CFRD), it was also increased in the non-CFRD sub-group when compared with controls. In patients, AIx was related to log10 CRP (r = 0.33) and forced vital capacity (r =  -0.34; both p<0.05), and CRP remained predictive in multiple regression. AIx is increased in adults with CF, in the presence of a normal blood pressure and independent of diabetic status. AIx was related to the systemic inflammatory status. These findings have implications for management and require further exploration so that cardiovascular health can be maintained.

The effect of exercise on large artery haemodynamics in cystic fibrosis

BACKGROUND Adult patients with cystic fibrosis (CF) have resting abnormal large artery haemodynamics. Here, we obtain further insight in patients with CF by evaluating haemodynamic response to physiological stress. METHODS Thirty-six stable CF patients mean (SD) age 28.9 (9.0)years and 25 controls matched for age, gender and body mass index were studied. Central haemodynamic parameters; including augmentation index (AIx) and wasted left ventricular pressure energy (∆E(W)) were determined pre, during and post light intensity cycle ergometry. RESULTS During exercise, despite a similar heart rate and blood pressure, patients had comparatively greater ∆E(W) (P=0.03) and trend towards greater AIx (P=0.07) than controls. Exercise ∆E(W) was greatest in patients with CF related diabetes (n=11). In all subjects, exercise ∆E(W) was related to age (r=0.54, P<0.001) and FEV(1)% predicted (r=-0.32, P=0.01). CONCLUSIONS Adults with CF have an abnormal haemodynamic response to exercise. This finding has deleterious implications for myocardial performance.

Adenocarcinoma arising in a retained esophageal remnant

Fistulation between the trachea and an infected mucocele arising from an excluded retained esophageal segment is an interesting and unusual complication of esophageal bypass surgery. We present such a case in which there was also malignant transformation in the cyst wall, manifested by invasive adenocarcinoma and widespread high-grade glandular dysplasia.

Dynamic vascular changes following intravenous antibiotics in patients with cystic fibrosis

BACKGROUND Adults with cystic fibrosis (CF) have altered large artery haemodynamics which is associated with a persisting systemic inflammatory state. We hypothesized that a short-term intervention favorably influencing the inflammatory status may modify their haemodynamic state. METHODS Adult patients with CF were studied immediately preceding and following 2 weeks of intravenous antibiotics. Large artery haemodynamics, principally heart rate-adjusted augmentation index (AIx) were obtained. Blood pressure (BP), spirometry and CRP were also measured. RESULTS Complete data was available for 15 patients; mean (SD) age 28 (6)years. CRP was reduced while FEV1% predicted improved. Following treatment AIx was lower: 10.9 (10.9)% to 8.1 (10.9)% (p<0.05) while BP was similar and a trend toward lower heart rate (p=0.06). Change in AIx was related to baseline FEV1% predicted (r=0.77) and BMI (r=0.71) (both P<0.01). CONCLUSION The abnormal central haemodynamics evident in adults with CF is modulated with a short intervention of intravenous antibiotics.

Alpha-1-antitrypsin deficiency and a pleural shadow

In children salmonella osteomyelitis usually develops from haematogenous spreadl. Since the advent of antibiotics the condition has most commonly been seen in patients with sickle-cell anaemia or other haemoglobinopathies, systemic lupus erythematosus, neoplasms, or immunosuppression. About 60% have diarrhoea or positive stool cultures on presentation2. Salmonella osteomyelitis frequently involves the diaphyses of long bones as well as vertebrae, and most cases are caused by non-typhi serotypes3. Salmonellosis can be divided into five syndromes-enterocolitis, enteric fever, bacteraemia, local infection and the chronic carrier state. These may overlap or coexist. Salmonella osteoarticular infection in a healthy adult is very unusual. In the few reported cases it has usually been chronic in nature4 or been preceded by a diarrhoeal illness. To our knowledge S. enteritidis has never previously been reported as causing osteoarticular infection in a healthy patient without predisposing factors. In patients with secondary salmonella infections who have negative stool cultures, the organism is believed to have been dormant in the reticuloendothelial system or bowel and to have been activated by depression of the hosts defences2. Our patient showed no signs of immunodepression. Salmonella osteoarticular infection tends to become chronic and can be difficult to eradicate4. Extensive and often multiple debridement may be required in addition to lengthy antibiotic treatment.