Effect of altitude on mortality of end-stage renal disease patients on hemodialysis in Peru.

BACKGROUND: In Latin America, the prevalence of end-stage kidney disease (ESKD) has risen tremendously during the last decade. Previous studies have suggested that receiving dialysis at high altitude confers mortality benefits; however, this effect has not been demonstrated at >2000 m above sea level (masl) or in developing countries. METHODS: This historical cohort study analyzed medical records from six Peruvian hemodialysis (HD) centers located at altitudes ranging from 44 to 3827 masl. Adult ESKD patients who started maintenance HD between 2000 and 2010 were included. Patients were classified into two strata based on the elevation above sea level of their city of residence: low altitude (<2000 masl) and high altitude (≥2000 masl). Death from any cause was collected from national registries and Cox proportional hazards models were built. RESULTS: A total of 720 patients were enrolled and 163 (22.6%) resided at high altitude. The low-altitude group was significantly younger, more likely to have diabetes or glomerulonephritis as the cause of ESKD and higher hemoglobin. The all-cause mortality rate was 84.3 per 1000 person-years. In the unadjusted Cox model, no mortality difference was found between the high- and low-altitude groups {hazard ratio [HR] 1.20 [95% confidence interval (CI) 0.89-1.62]}. After multivariable adjustment, receiving HD at high altitude was not significantly associated with higher mortality, but those with diabetes as the cause of ESKD had significantly higher mortality [HR 2.50 (95% CI 1.36-4.59)]. CONCLUSIONS: In Peru, patients receiving HD at high altitudes do not have mortality benefits.

Report of a case of probable overlap between systemic erythematous lupus and polyarteritis nodosa / Reporte de un caso de probable overlap de lupus eritematoso sistémico con panarteritis nudosa

ABSTRACT Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease with a wide range of clinical manifestations that may affect any organ. Polyarteritis nodosa (PAN) is defined as necrotizing inflammatory changes in the medium and small vessels, a rare form of systemic necrotizing vasculitis in childhood. This article discusses the case of a patient with a history of deep venous thrombosis of the left leg, who presented with erythematosus purple lesions in her right hand, associated with pain, intermittent claudication, progressive limping and generalized edema. While in hospital, she was diagnosed with SLE with renal involvement and medium vessel vasculitis mainly of the upper limbs. She also met the criteria for PAN, a rare association that is seldom described in the medical literature.

RESUMEN El lupus eritematoso sistémico (LES) es una enfermedad autoinmune heterogénea con una amplia variedad de manifestaciones clínicas que pueden afectar cualquier órgano. La panarteritis nudosa (PAN) se define como cambios inflamatorios necrotizantes en arterias medianas o pequenas, siendo una vasculitis necrotizante sistêmica rara en la infancia. Presentamos el caso de una paciente con antecedente de trombosis venosa profunda del miembro inferior izquierdo, que presenta lesiones violáceas eritematosas en la mano derecha, asociadas a dolor, claudicación intermitente, limitación funcional progresiva, así como edema generalizado. Durante la hospitalización se llega al diagnóstico de LES con compromiso renal y vasculitis de vasos medianos con predominio de miembros superiores que cumple criterios de PAN, asociación rara muy poco descrita en la bibliografía.

Oxygen saturation in healthy children aged 5 to 16 years residing in Huayllay, Peru at 4340 m.

Hypoxemia is a major life-threatening complication of childhood pneumonia. The threshold points for hypoxemia vary with altitude. However, few published data describe that normal range of variation. The purpose of this study was to establish reference values of normal mean Sao(2) levels and an approximate cutoff point to define hypoxemia for clinical purposes above 4300 meters above sea level (masl). Children aged 5 to 16 yr were examined during primary care visits at the Huayllay Health Center. Huayllay is a rural community located at 4340 m in the province of Pasco in the Peruvian Andes. We collected basic sociodemographic data and evaluated three outcomes: arterial oxygen saturation (Sao(2)) with a pulse oximeter, heart rate, and respiratory rate. Comparisons of main outcomes among age groups (5-6, 7-8, 9-10, 11-12, 13-14, and 15-16 yr) and sex were performed using linear regression models. The correlation of Sao(2) with heart rate and respiration rate was established by Pearson's correlation test. We evaluated 583 children, of whom 386 were included in the study. The average age was 10.3 yr; 55.7% were female. The average Sao(2), heart rate, and respiratory rate were 85.7% (95% CI: 85.2-86.2), 80.4/min (95% CI: 79.0-81.9), and 19.9/min (95% CI: 19.6-20.2), respectively. Sao(2) increased with age (p < 0.001). No differences by sex were observed. The mean minus two standard deviations of Sao(2) (threshold point for hypoxemia) ranged from 73.8% to 81.8% by age group. At 4300 m, the reference values for hypoxemia may be 14.2% lower than at sea level. This difference must be considered when diagnosing hypoxemia or deciding oxygen supplementation at high altitude. Other studies are needed to determine whether this reference value is appropriate for clinical use.