A case of Gitelman syndrome with severe hyponatraemia and hypophosphataemia

Gitelman syndrome (GS) is a renal tubular disorder of the thiazide-sensitive sodium chloride cotransporter, which is located in the distal tubule of the loop of Henle. We present a rare case of GS complicated by severe hyponatraemia and hypophosphataemia. A 17-year-old boy was admitted to our institution with fever and lethargy. The workup revealed typical features of GS, i.e. hypokalaemia, hypomagnesaemia and metabolic alkalosis. In this report, we discuss the differential diagnoses and rationale for accepting GS as the most likely diagnosis. This case was complicated by severe hyponatraemia (115 mmol/L) and hypophosphataemia (0.32 mmol/L). We concluded that the syndrome of inappropriate secretion of antidiuretic hormones could not be ruled out and that respiratory alkalosis was the most likely aetiology of hypophosphataemia. This case report also generates an interesting discussion on water and electrolyte metabolism.

Clinically significant contrast induced acute kidney injury after non-emergent cardiac catheterization - risk factors and impact on length of hospital stay

To evaluate the frequency and risk factors associated with clinically significant contrast-induced nephropathy [CIN] in patients undergoing non-emergent coronary angiography. Descriptive study. The Aga Khan University Hospital, Karachi, from January 2005 to December 2007. Case records of patients who underwent coronary angiography with a serum creatinine of >/= 1.5 mg/dl at the time of procedure were evaluated. Clinically significant contrast induced nephropathy [CSCIN] was defined as either doubling of serum creatinine from baseline value within a week following the procedure or need for emergency hemodialysis after the procedure. One hundred and sixteen patients met the inclusion criteria. Mean age was 64.0 +/- 11.5 years, 72% were males. Overall prevalence of CIN was 17% [rise of serum creatinine by >/= 0.5 mg/dl] while that of clinically significant CIN [CSCIN] was 9.5% [11 patients]. Patients with CSCIN had significantly lower left ventricular ejection fraction [p = 0.03, OR: 0.24; 95% CI = 0.06 - 0.91] and higher prevalence of cerebrovascular disease [p < 0.001, OR: 14.66; 95% CI = 3.30 - 65.08]. Mean baseline serum creatinine was significantly higher, 3.0 +/- 1.5 vs. 2.0 +/- 1.1 mg/dl [p = 0.03, OR: 1.47; 95% CI = 1.03 - 2.11] whereas mean GFR estimated by Cockcroft-Gault formula was significantly lower at 25 +/- 7.4 vs. 41.0 +/- 14.6 ml/minute [p = 0.001, OR = 0.89, 95% CI = 0.84 - 0.95] at the time of procedure in patients with CSCIN. Mean length of hospital stay was significantly higher in this group compared to those without CIN, 9.0 +/- 5.1 vs. 3.0 +/- 3.2 days [p = 0.001, OR = 1.31, 95% CI = 1.12 - 1.54]. Multivariate analysis revealed low GFR [p = 0.001, OR = 0.88; 95% CI = 0.82 - 0.95] and low ejection fraction [p = 0.03, OR = 0.20; 95% CI = 0.04 - 0.91] to be independent factors associated with CSCIN. No significant differences were noted between the two groups in patients with hypertension, diabetes and heart failure. CSCIN is a significant concern in high risk groups despite prophylaxis. Patients with lower EF, cerebrovascular disease and low GFR at the time of procedure are more likely to have CIN.