Introduction
The global prevalence of hypertension is approximately 3.5%, increasing with age to reach 18% among young adults. Blood pressure (BP) in children varies based on age, sex, and height. Hypertension, a condition characterized by advancements in etiology, definition, management, and prevention, exhibits an estimated prevalence of 3-5% in the United States, potentially higher among specific ethnic groups such as African Americans, Mexicans, and Hispanics. Reports indicate a prevalence of up to 10% in certain isolated geographic areas, and for individuals with obesity, rates can climb to 11%. A 2014 study by the National Institute of Pediatrics in Mexico found that among patients with hypertension, 92% (35 patients) had a history of kidney disease, including 34.3% with chronic kidney disease and 25.7% with acute renal failure, underscoring hypertensions role as a frequent complication of acute kidney injury (AKI). In 2001, at the Central Hospital of the Social Security Institute in Paraguay, out of 520 nephrology patients, 62 experienced acute renal failure, accounting for 12% of the cohort. Hypertension is defined as BP at or above the 95th percentile, confirmed by two measurements taken 3 min apart. It is classified into two categories: grade I (at or above the 95th percentile up to 12 mmHg above or between 130/80 and 139/89) and grade II (above the 95th percentile by more than 12 mmHg or ≥ 140/90)1.
One of the most extensive epidemiological studies to date, the RICARDIN study collected data from over 11,000 adolescents across 10 centers in Spain. They found a hypertension prevalence of approximately 3%, a figure that could rise to 5%2,3.
A retrospective cohort study was carried out in two pediatric centers in Montreal, Canada, focusing on children (≤ 18 years) admitted to the pediatric intensive care unit (ICU) from 2003 to 2010. The study included 1,978 patients with a median age at admission of 4.3 years (interquartile range: 1.1-11.8), 44% of whom were female. Of these, 325 (16.4%) developed AKI4.
A systematic review spanning 1990-2014 was conducted using databases such as PubMed, African Journals Online, the World Health Organization (WHO), Global Health Library, and the Web of Science. This review aimed to assess the outcomes of AKI. In Sub-Saharan Africa, the severity of the disease was notable, with 1,042 (66%) of 1,572 children and 178 (70%) of 253 adults, requiring dialysis. Overall mortality rates were 34% in children and 32% in adults5.
The relationship between AKI and increased BP remains uncertain. To explore this, a retrospective cohort study assessed whether hospital-acquired AKI was independently associated with an elevation in BP during the first 2 years post-discharge among previously normotensive adults. This study was conducted in collaboration with Kaiser Northern California and Stanford University School of Medicine, Stanford. According to multivariate models, AKI was independently associated with a 22% increase (95% confidence interval: 12-33%) in the likelihood of elevated BP6.
The clinical manifestations of hypertension are often asymptomatic, but when symptoms do occur, they are generally non-specific and can include headaches, epistaxis, visual disturbances, facial paralysis, polyuria, polydipsia, and failure to thrive among others. In cases of severe hypertension, known as a hypertensive crisis, it can impact target organs, leading to conditions such as left ventricular hypertrophy and congestive heart failure, as well as microalbuminuria, proteinuria, and renal failure2.
AKI is characterized by a sudden loss or a decrease in kidney function, resulting in the body´s inability to maintain homeostasis. This condition is typically indicated by an increase in the serum concentration of nitrogenous waste products, adjusted for age and sex, as shown in table 1, along with reduced urine output and glomerular filtration rate (GFR)5. The RIFLE classification, according to the Acute Dialysis Quality Initiative7, categorizes the severity of AKI based on the increase in creatinine levels.
Table 1 AKIN classification 2007
Stage | Serum creatinine | Urine output |
---|---|---|
I | 1.5-1.9 times baseline or ≥ 0.3 mg/dL increase | < 0.5 mL/kg/h for 6-12 h |
II | 2-3 times baseline | < 0.5 mL/kg/h for 12 h |
III | > 3 times baseline or > 4 mg/dL or > 0.5 mg/dL increase or Initiation of renal replacement therapy | < 0.3 mL/kg/h for ≥ 24 h or anuria for ≥ 12 h |
The primary complications arising from AKI include hypertension due to volume overload, metabolic acidosis, hyponatremia, hyperkalemia, hypocalcemia, and hyperphosphatemia. Hypertension in the context of AKI is primarily attributed to volume overload. The preferred treatment involves the administration of diuretics, specifically furosemide, which is effective when the creatinine clearance rate is below 50 ml/min/1.73 m2-7.
It has been demonstrated that, in hospitalized children, AKI is associated with an increased requirement for mechanical ventilation, prolonged hospital and ICU stays, and elevated mortality rates8. In our region, an updated prevalence of arterial hypertension is lacking. Consequently, the primary objective of this study was to estimate the prevalence of arterial hypertension in patients with acute renal failure. Secondary objectives included the identification of clinical characteristics, etiology, mortality rates, and follow-up outcomes among children in Culiacan, Sinaloa. We hypothesized that the prevalence would be higher compared to other regions, secondary to more timely detection.
Methods
A cross-sectional study was conducted, gathering information from the medical records of children attended in the emergency room (ER) (for both consultation and hospitalization) and the hospitalization wards (internal medicine, surgery, oncology, infectious diseases, gastroenterology, and intensive care) at a secondary-level hospital in Culiacan, Sinaloa. Records from January 2012 to December 2021 were reviewed.
Eligibility criteria included clinical records of children who attended the ER and were hospitalized with BP above the 95th percentile for age, height, and sex during episodes of acute renal failure. Exclusion criteria encompassed children with acute-on-chronic kidney disease, a previous diagnosis of arterial hypertension, and those younger than 1 year. Exclusion criteria were incomplete data in the clinical history and record.
The clinical history served as a measurement tool, indirectly providing sociodemographic data (such as sex, age, and height) and information on nutritional status. In addition, BP measurement was assessed. Analyses included the GFR, urine output, plasma creatinine, complete blood count, serum electrolytes, arterial blood gases, comorbidities, antihypertensive treatment, and hypertension control at 6 months post-discharge in the nephrology outpatient clinic. Serum electrolytes and arterial blood gases were also evaluated to determine the correlation between the findings and existing medical literature in the selected patients.
The AKI Network 2007 classification was utilized for AKI classification in pediatric patients. BP monitoring involves measurements at home or the nearest in case of not having the necessary material for the measurement. In this case, a stethoscope and a manual sphygmomanometer were required. Measurements were taken 3 times weekly and at follow-up consultations, avoiding stimulants or caffeine, with the patient seated for a minimum of 5 min.
The measurement of creatinine by the laboratory was validated using isotope dilution mass spectrometry, standardized as the reference method. The formula employed to estimate the GFR was based on the updated Schwartz equation from 2009, which is defined as (with height in meters, K as a constant of 0.413 for children aged 1 year to adolescence, and CrP as plasma creatinine).
For the quantification of proteinuria, it was essential to collect a 24-h urine sample the day before the patient´s follow-up visit to pediatric nephrology. Proteinuria levels were classified as nephrotic with > 1 g/m2/day and non-nephrotic when they were between 100 and 1,000 mg/m2/day.
The outcome variable, the persistence of arterial hypertension, was assessed according to age, sex, and height, evaluated by the attending physician and nurse during hospital admission, and recorded in the section corresponding to the diagnosis. The diagnosis documented in the medical records was determined based on criteria from the WHO and the American Academy of Pediatrics, as detailed in tables 1-3.
Table 2 Blood pressure percentiles for males according to age and height
Age (years) | Percentiles (Height) | Systolic BP by height percentile | Diastolic BP by height percentile | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
P5 | P10 | P25 | P50 | P75 | P90 | P95 | P5 | P10 | P25 | P50 | P75 | P90 | P95 | ||
1 | 50th | 80 | 81 | 83 | 85 | 87 | 88 | 89 | 34 | 35 | 36 | 37 | 38 | 39 | 39 |
90th | 94 | 95 | 97 | 99 | 100 | 102 | 103 | 49 | 50 | 51 | 52 | 53 | 53 | 54 | |
95th | 98 | 99 | 101 | 103 | 104 | 106 | 106 | 54 | 54 | 55 | 56 | 57 | 58 | 58 | |
99th | 105 | 106 | 108 | 110 | 112 | 113 | 114 | 61 | 62 | 63 | 64 | 65 | 66 | 66 | |
2 | 50th | 84 | 85 | 87 | 88 | 90 | 92 | 92 | 39 | 40 | 41 | 42 | 43 | 44 | 44 |
90th | 97 | 99 | 100 | 102 | 104 | 105 | 106 | 54 | 55 | 56 | 57 | 58 | 58 | 59 | |
95th | 101 | 102 | 104 | 106 | 108 | 109 | 110 | 59 | 59 | 60 | 61 | 62 | 63 | 63 | |
99th | 109 | 110 | 111 | 113 | 115 | 117 | 117 | 66 | 67 | 68 | 69 | 70 | 71 | 71 | |
3 | 50th | 86 | 87 | 89 | 91 | 93 | 94 | 95 | 44 | 44 | 45 | 46 | 47 | 48 | 48 |
90th | 100 | 101 | 103 | 105 | 107 | 108 | 109 | 59 | 59 | 60 | 61 | 62 | 63 | 63 | |
95th | 104 | 105 | 107 | 109 | 110 | 112 | 113 | 63 | 63 | 64 | 65 | 66 | 67 | 67 | |
99th | 111 | 112 | 114 | 116 | 118 | 119 | 120 | 71 | 71 | 72 | 73 | 74 | 75 | 75 | |
4 | 50th | 88 | 89 | 91 | 93 | 95 | 96 | 97 | 47 | 48 | 49 | 50 | 51 | 51 | 52 |
90th | 102 | 103 | 105 | 107 | 109 | 110 | 111 | 62 | 63 | 64 | 65 | 66 | 66 | 67 | |
95th | 106 | 107 | 109 | 111 | 112 | 114 | 115 | 66 | 67 | 68 | 69 | 71 | 71 | 71 | |
99th | 113 | 114 | 116 | 118 | 120 | 121 | 122 | 74 | 75 | 76 | 77 | 78 | 78 | 79 | |
5 | 50th | 90 | 91 | 93 | 95 | 96 | 98 | 98 | 50 | 51 | 52 | 53 | 54 | 55 | 55 |
90th | 104 | 105 | 106 | 108 | 110 | 111 | 112 | 65 | 66 | 67 | 68 | 69 | 69 | 70 | |
95th | 108 | 109 | 110 | 112 | 115 | 115 | 116 | 69 | 70 | 71 | 72 | 73 | 74 | 74 | |
99th | 115 | 116 | 118 | 120 | 123 | 123 | 123 | 77 | 78 | 79 | 80 | 81 | 81 | 82 | |
6 | 50th | 91 | 92 | 94 | 96 | 98 | 99 | 100 | 53 | 53 | 54 | 55 | 56 | 57 | 57 |
90th | 105 | 106 | 108 | 110 | 111 | 113 | 113 | 68 | 68 | 69 | 70 | 71 | 72 | 72 | |
95th | 109 | 110 | 112 | 114 | 115 | 117 | 117 | 72 | 72 | 73 | 74 | 75 | 76 | 76 | |
99th | 116 | 117 | 119 | 121 | 123 | 124 | 125 | 80 | 80 | 81 | 82 | 83 | 84 | 84 | |
7 | 50th | 93 | 93 | 95 | 96 | 97 | 99 | 99 | 55 | 56 | 56 | 57 | 58 | 58 | 59 |
90th | 106 | 107 | 108 | 109 | 111 | 112 | 113 | 69 | 70 | 70 | 71 | 72 | 72 | 73 | |
95th | 110 | 111 | 112 | 113 | 115 | 116 | 116 | 73 | 74 | 74 | 75 | 76 | 76 | 77 | |
99th | 117 | 118 | 119 | 120 | 122 | 123 | 124 | 81 | 81 | 82 | 82 | 83 | 84 | 84 | |
8 | 50th | 95 | 95 | 96 | 98 | 99 | 100 | 101 | 57 | 57 | 57 | 58 | 59 | 60 | 60 |
90th | 108 | 109 | 110 | 111 | 113 | 114 | 114 | 71 | 71 | 71 | 72 | 73 | 74 | 74 | |
95th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
99th | 119 | 120 | 121 | 122 | 123 | 125 | 125 | 82 | 82 | 83 | 83 | 84 | 85 | 86 | |
9 | 50th | 96 | 97 | 98 | 100 | 101 | 102 | 103 | 58 | 58 | 58 | 59 | 60 | 61 | 61 |
90th | 110 | 110 | 112 | 113 | 114 | 116 | 116 | 72 | 72 | 72 | 73 | 74 | 75 | 75 | |
95th | 114 | 114 | 115 | 117 | 118 | 119 | 120 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
99th | 121 | 121 | 123 | 124 | 125 | 127 | 127 | 83 | 83 | 84 | 84 | 85 | 86 | 87 | |
10 | 50th | 98 | 99 | 100 | 102 | 103 | 104 | 105 | 59 | 59 | 59 | 60 | 61 | 62 | 62 |
90th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 73 | 73 | 73 | 74 | 75 | 76 | 76 | |
95th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
99th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 84 | 84 | 85 | 86 | 86 | 87 | 88 | |
11 | 50th | 100 | 101 | 102 | 103 | 105 | 106 | 107 | 60 | 60 | 60 | 61 | 62 | 63 | 63 |
90th | 114 | 114 | 116 | 117 | 118 | 119 | 120 | 74 | 74 | 74 | 75 | 76 | 77 | 77 | |
95th | 118 | 118 | 119 | 121 | 122 | 123 | 124 | 78 | 78 | 78 | 79 | 80 | 81 | 81 | |
99th | 125 | 125 | 126 | 128 | 129 | 130 | 131 | 85 | 85 | 86 | 87 | 87 | 88 | 89 | |
12 | 50th | 102 | 103 | 104 | 105 | 107 | 108 | 109 | 61 | 61 | 61 | 62 | 63 | 64 | 64 |
90th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
95th | 119 | 120 | 121 | 123 | 124 | 125 | 126 | 79 | 79 | 79 | 80 | 81 | 82 | 82 | |
99th | 127 | 127 | 128 | 130 | 131 | 132 | 133 | 86 | 86 | 87 | 88 | 88 | 89 | 90 | |
13 | 50th | 104 | 105 | 106 | 107 | 109 | 110 | 110 | 62 | 62 | 62 | 63 | 64 | 65 | 65 |
90th | 117 | 118 | 119 | 121 | 122 | 123 | 124 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
95th | 121 | 122 | 123 | 124 | 126 | 127 | 128 | 80 | 80 | 80 | 81 | 82 | 83 | 83 | |
99th | 128 | 129 | 130 | 132 | 133 | 134 | 135 | 87 | 87 | 88 | 89 | 89 | 90 | 91 | |
14 | 50th | 106 | 106 | 107 | 109 | 110 | 111 | 112 | 63 | 63 | 63 | 64 | 65 | 66 | 66 |
90th | 119 | 120 | 121 | 122 | 124 | 125 | 125 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
95th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 81 | 81 | 81 | 82 | 83 | 84 | 84 | |
99th | 130 | 131 | 132 | 133 | 135 | 136 | 129 | 88 | 88 | 89 | 90 | 90 | 91 | 92 | |
15 | 50th | 109 | 110 | 112 | 113 | 115 | 117 | 117 | 61 | 62 | 63 | 64 | 65 | 66 | 66 |
90th | 122 | 124 | 125 | 127 | 129 | 130 | 131 | 76 | 77 | 78 | 79 | 80 | 80 | 81 | |
95th | 126 | 127 | 129 | 131 | 133 | 134 | 135 | 81 | 81 | 82 | 83 | 85 | 85 | 85 | |
99th | 134 | 135 | 136 | 138 | 140 | 142 | 142 | 88 | 89 | 90 | 91 | 93 | 93 | 93 | |
16 | 50th | 111 | 112 | 114 | 116 | 118 | 119 | 120 | 63 | 63 | 64 | 65 | 66 | 67 | 67 |
90th | 125 | 126 | 128 | 130 | 131 | 133 | 134 | 78 | 78 | 79 | 80 | 81 | 82 | 82 | |
95th | 129 | 130 | 132 | 134 | 135 | 137 | 137 | 82 | 83 | 83 | 84 | 85 | 86 | 87 | |
99th | 136 | 137 | 139 | 141 | 143 | 144 | 145 | 90 | 90 | 90 | 92 | 93 | 94 | 94 | |
17 | 50th | 114 | 115 | 116 | 118 | 120 | 121 | 122 | 65 | 66 | 66 | 67 | 68 | 69 | 70 |
90th | 127 | 128 | 130 | 132 | 134 | 135 | 136 | 80 | 81 | 81 | 82 | 83 | 84 | 84 | |
95th | 131 | 132 | 134 | 136 | 138 | 139 | 140 | 84 | 85 | 86 | 87 | 87 | 88 | 89 | |
99th | 139 | 140 | 141 | 143 | 145 | 146 | 147 | 92 | 93 | 93 | 94 | 95 | 96 | 97 |
Table 3 Blood pressure percentiles for females according to age and height
Age (years) | Percentiles (Height) | Systolic BP by height percentile | Diastolic BP by height percentile | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
P5 | P10 | P25 | P50 | P75 | P90 | P95 | P5 | P10 | P25 | P50 | P75 | P90 | P95 | ||
1 | 50th | 83 | 84 | 85 | 86 | 88 | 89 | 90 | 38 | 39 | 39 | 40 | 41 | 41 | 42 |
90th | 97 | 97 | 98 | 100 | 101 | 102 | 103 | 52 | 53 | 53 | 54 | 55 | 55 | 56 | |
95th | 100 | 101 | 102 | 104 | 105 | 106 | 107 | 56 | 57 | 57 | 58 | 59 | 59 | 60 | |
99th | 108 | 108 | 109 | 111 | 112 | 113 | 114 | 64 | 64 | 65 | 65 | 66 | 67 | 67 | |
2 | 50th | 85 | 85 | 87 | 88 | 89 | 91 | 91 | 43 | 44 | 44 | 45 | 46 | 46 | 47 |
90th | 98 | 99 | 100 | 101 | 103 | 104 | 105 | 57 | 58 | 58 | 59 | 60 | 61 | 61 | |
95th | 102 | 103 | 104 | 105 | 107 | 108 | 109 | 61 | 62 | 62 | 63 | 64 | 65 | 65 | |
99th | 109 | 110 | 111 | 112 | 114 | 115 | 116 | 69 | 69 | 70 | 70 | 71 | 72 | 72 | |
3 | 50th | 86 | 87 | 88 | 89 | 91 | 92 | 93 | 47 | 48 | 48 | 49 | 50 | 50 | 51 |
90th | 100 | 100 | 102 | 103 | 104 | 106 | 106 | 61 | 62 | 62 | 63 | 64 | 64 | 65 | |
95th | 104 | 104 | 105 | 107 | 108 | 109 | 110 | 65 | 66 | 66 | 67 | 68 | 68 | 69 | |
99th | 111 | 111 | 113 | 114 | 115 | 116 | 117 | 73 | 73 | 74 | 74 | 75 | 76 | 76 | |
4 | 50th | 88 | 88 | 90 | 91 | 92 | 94 | 94 | 50 | 50 | 51 | 52 | 52 | 53 | 54 |
90th | 101 | 102 | 103 | 104 | 106 | 107 | 108 | 64 | 64 | 65 | 66 | 67 | 67 | 68 | |
95th | 105 | 106 | 107 | 108 | 110 | 111 | 112 | 68 | 68 | 69 | 70 | 71 | 71 | 72 | |
99th | 112 | 113 | 114 | 115 | 117 | 118 | 119 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
5 | 50th | 89 | 90 | 91 | 93 | 94 | 95 | 96 | 52 | 53 | 53 | 54 | 55 | 55 | 56 |
90th | 103 | 103 | 105 | 106 | 107 | 109 | 109 | 66 | 67 | 67 | 68 | 69 | 69 | 70 | |
95th | 107 | 107 | 108 | 110 | 111 | 112 | 113 | 70 | 71 | 71 | 72 | 73 | 73 | 74 | |
99th | 114 | 114 | 116 | 117 | 118 | 120 | 120 | 78 | 78 | 79 | 79 | 80 | 81 | 81 | |
6 | 50th | 91 | 92 | 93 | 94 | 96 | 97 | 98 | 54 | 54 | 55 | 56 | 56 | 57 | 58 |
90th | 104 | 105 | 106 | 108 | 109 | 110 | 111 | 68 | 68 | 69 | 70 | 70 | 71 | 72 | |
95th | 108 | 109 | 110 | 111 | 113 | 114 | 115 | 72 | 72 | 73 | 74 | 74 | 75 | 76 | |
99th | 115 | 116 | 117 | 119 | 120 | 121 | 122 | 80 | 80 | 80 | 81 | 82 | 83 | 83 | |
7 | 50th | 93 | 93 | 95 | 96 | 97 | 99 | 99 | 55 | 56 | 56 | 57 | 58 | 58 | 59 |
90th | 106 | 107 | 108 | 109 | 111 | 112 | 113 | 69 | 70 | 70 | 71 | 72 | 72 | 73 | |
95th | 110 | 111 | 112 | 113 | 115 | 116 | 116 | 73 | 74 | 74 | 75 | 76 | 76 | 77 | |
99th | 117 | 118 | 119 | 120 | 122 | 123 | 124 | 81 | 81 | 82 | 82 | 83 | 84 | 84 | |
8 | 50th | 95 | 95 | 96 | 98 | 99 | 100 | 101 | 57 | 57 | 57 | 58 | 59 | 60 | 60 |
90th | 108 | 109 | 110 | 111 | 113 | 114 | 114 | 71 | 71 | 71 | 72 | 73 | 74 | 74 | |
95th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
99th | 119 | 120 | 121 | 122 | 123 | 125 | 124 | 82 | 82 | 83 | 83 | 84 | 85 | 86 | |
9 | 50th | 96 | 97 | 98 | 100 | 101 | 102 | 103 | 58 | 58 | 58 | 59 | 60 | 61 | 61 |
90th | 110 | 110 | 112 | 113 | 114 | 116 | 116 | 72 | 72 | 72 | 73 | 74 | 75 | 75 | |
95th | 114 | 114 | 115 | 117 | 118 | 119 | 120 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
99th | 121 | 121 | 123 | 124 | 125 | 127 | 127 | 83 | 83 | 84 | 84 | 85 | 86 | 87 | |
10 | 50th | 98 | 99 | 100 | 102 | 103 | 104 | 105 | 59 | 59 | 59 | 60 | 61 | 62 | 62 |
90th | 112 | 112 | 114 | 115 | 116 | 118 | 118 | 73 | 73 | 73 | 74 | 75 | 76 | 76 | |
95th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
99th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 84 | 84 | 85 | 86 | 86 | 87 | 88 | |
11 | 50th | 100 | 101 | 102 | 103 | 105 | 106 | 107 | 60 | 60 | 60 | 61 | 62 | 63 | 63 |
90th | 114 | 114 | 116 | 117 | 118 | 119 | 120 | 74 | 74 | 74 | 75 | 76 | 77 | 77 | |
95th | 118 | 118 | 119 | 121 | 122 | 123 | 124 | 78 | 78 | 78 | 79 | 80 | 81 | 81 | |
99th | 125 | 125 | 126 | 128 | 129 | 130 | 131 | 85 | 85 | 86 | 87 | 87 | 88 | 89 | |
12 | 50th | 102 | 103 | 104 | 105 | 107 | 108 | 109 | 61 | 61 | 61 | 62 | 63 | 64 | 64 |
90th | 116 | 116 | 117 | 119 | 120 | 121 | 122 | 75 | 75 | 75 | 76 | 77 | 78 | 78 | |
95th | 119 | 120 | 121 | 123 | 124 | 125 | 126 | 79 | 79 | 79 | 80 | 81 | 82 | 82 | |
99th | 127 | 127 | 128 | 130 | 131 | 132 | 133 | 86 | 87 | 87 | 88 | 88 | 89 | 90 | |
13 | 50th | 104 | 105 | 106 | 107 | 109 | 110 | 110 | 62 | 62 | 62 | 63 | 64 | 65 | 65 |
90th | 117 | 118 | 119 | 121 | 122 | 123 | 124 | 76 | 76 | 76 | 77 | 78 | 79 | 79 | |
95th | 121 | 122 | 123 | 124 | 126 | 127 | 128 | 80 | 80 | 80 | 81 | 82 | 83 | 83 | |
99th | 128 | 129 | 130 | 132 | 133 | 134 | 135 | 87 | 87 | 88 | 89 | 89 | 90 | 91 | |
14 | 50th | 106 | 106 | 107 | 109 | 110 | 111 | 112 | 63 | 63 | 63 | 64 | 65 | 66 | 66 |
90th | 119 | 120 | 121 | 122 | 124 | 125 | 125 | 77 | 77 | 77 | 78 | 79 | 80 | 80 | |
95th | 123 | 123 | 125 | 126 | 127 | 129 | 129 | 81 | 81 | 81 | 82 | 83 | 84 | 84 | |
99th | 130 | 131 | 132 | 133 | 135 | 136 | 136 | 88 | 88 | 89 | 90 | 90 | 91 | 92 | |
15 | 50th | 107 | 108 | 109 | 110 | 111 | 113 | 113 | 64 | 64 | 64 | 65 | 66 | 67 | 67 |
90th | 120 | 121 | 122 | 123 | 125 | 126 | 127 | 78 | 78 | 78 | 79 | 80 | 81 | 81 | |
95th | 124 | 125 | 126 | 127 | 129 | 130 | 131 | 82 | 82 | 82 | 83 | 84 | 85 | 85 | |
99th | 131 | 132 | 133 | 134 | 136 | 137 | 138 | 89 | 89 | 90 | 91 | 91 | 92 | 93 | |
16 | 50th | 108 | 108 | 110 | 111 | 112 | 114 | 114 | 64 | 64 | 65 | 66 | 66 | 67 | 68 |
90th | 121 | 122 | 123 | 124 | 126 | 127 | 128 | 78 | 78 | 79 | 80 | 81 | 81 | 82 | |
95th | 125 | 126 | 127 | 128 | 130 | 131 | 132 | 82 | 82 | 83 | 84 | 85 | 85 | 86 | |
99th | 132 | 133 | 134 | 135 | 137 | 138 | 139 | 90 | 90 | 90 | 91 | 92 | 93 | 93 | |
17 | 50th | 108 | 109 | 110 | 111 | 113 | 114 | 115 | 64 | 65 | 65 | 66 | 67 | 67 | 68 |
90th | 122 | 122 | 123 | 125 | 126 | 127 | 128 | 78 | 79 | 79 | 80 | 81 | 81 | 82 | |
95th | 125 | 126 | 127 | 129 | 130 | 131 | 132 | 82 | 83 | 83 | 84 | 85 | 85 | 86 | |
99th | 133 | 133 | 134 | 136 | 137 | 138 | 139 | 90 | 90 | 91 | 91 | 92 | 93 | 93 |
Data processing was conducted automatically through the SPSS version 25.0 system, with data entry performed twice to minimize typographical errors. For statistical analysis, absolute numbers and percentages were utilized as summary measures.
A statistical method was applied that began with a descriptive analysis to identify the frequencies of the variables using cross tables. Pearson´s χ2 was calculated to evaluate the association between variables; p lower than 0.05 would indicate a significant sensitivity analysis. To manage missing data, we resorted to complementary information from progress notes and contributions from parents, physicians, and nurses. The main purpose of this analysis was to establish a significant relationship between the variables studied, focusing on the statistical significance of these associations. The research protocol was approved by the teaching coordination of the Hospital Pediátrico de Sinaloa "Rigoberto Aguilar Pico," located in Culiacán, Sinaloa. Emphasis was placed on the exclusive use of primary records already existing in the clinical files, always guaranteeing the confidentiality and anonymity of the patients involved.
Results
Figure 1 illustrates the flowchart of the analysis conducted on 174 medical records of children treated over the past 9 years. Of these, 134 cases were discarded; 94.7% were due to the patients being under 1 year of age, 1.6% because of exacerbated chronic renal failure, and 3.7% were removed due to insufficient information in the file and from the parents.
Among the 174 patients assessed, 22.98% (n = 40) experienced hypertension during their hospitalization. Fifty percent had grade I hypertension and 50% grade II, with a χ2 p-value of 0.007, which is significant.
In terms of the patients´ nutritional status, 60% (n = 26) (p = 0.492) were found to have adequate nutrition for their age and sex. As for the severity of the acute renal failure, 62.5% (n = 25) were classified as grade III (Table 4), a result that was not statistically significant.
Table 4 Clinical characteristics of patients included in the study, complete group
Variables | Patients with acute renal failure 100% (n = 40) | p*-value |
---|---|---|
Hypertension | Normotensive 77.02% (134) | N/A |
Hypertensive 22.98% (40) | ||
Hypertension stage | Stage I 50% (20) | 0.007 |
Stage II 50% (20) | ||
Sex | Male 60% (24) | 0.384 |
Female 40% (16) | ||
Age | Older infants 12.5% (5) | 0.284 |
Pre-school 10% (4) | ||
Schoolage 32.5% (13) | ||
Teenager 45% (18) | ||
Nutritional condition | Average 65% (26) | 0.492 |
Mild malnutrition 5% (2) | ||
Moderate malnutrition 2.5% (1) | ||
Severe malnutrition 10% (4) | ||
Overweight 7.5% (3) | ||
Obesity 10% (4) | ||
Renal failure stage | Stage I 12.5% (5) | N/A |
Stage II 25% (10) | ||
Stage III 62.5% (25) |
*Pearsons χ2.
The primary clinical and laboratory findings included: 55% (n = 22) had diuresis within the normal range for their age, 72.5% (n = 29) exhibited normochromic normocytic anemia, 47.5% (n = 19) (p = 0.749) had leukocyte counts within the normal range, 65% (n = 26) (p = 0.740) experienced thrombocytopenia, 60% (n = 24) (p = 0.702) had normal sodium levels, 62.5% (n = 25) (p = 0.413) showed normochloremia, 65% (n = 26) (p = 0.777) maintained potassium within normal limits, 80% (n = 32) (p = 0.358) had phosphorus within normal limits, 65% (n = 26) (p = 0.916) had glucose levels within normal parameters, and 27.5% (n = 11) (p = 0.231) suffered from metabolic acidosis. None of these findings were statistically significant (Table 5).
Table 5 Clinical characteristics of the patients included in the study (follow-up)
Variables | Patients with acute renal failure 100% (n = 40) | p*-value |
---|---|---|
Diuresis | Average 55% (22) | 0.071 |
Oliguria 20% (8) | ||
Polyuria 5% (2) | ||
Anuria 20% (8) | ||
Hemoglobin | Normal 27.5% (11) | 0.749 |
Anemia 72.5% (29) | ||
Leukocytes | Average 47.5% (19) | 0.740 |
Leukocytosis 27.5% (11) | ||
Leukopenia 25% (10) | ||
Platelets | Average 35% (14) | 0.053 |
Thrombocytopenia 65% (26) | ||
Sodium | Average 60% (24) | 0.702 |
Hypernatremia 7.5% (3) | ||
Hyponatremia 32.5% (13) | ||
Chlorine | Average 62.5% (25) | 0.413 |
Hyperchloremia 37.5% (15) | ||
Potassium | Average 65% (26) | 0.777 |
Hyperkalemia 20% (8) | ||
Hypokalemia 15% (6) | ||
Phosphorus | Average 80% (32) | 0.358 |
Hyperphosphatemia 17.5% (7) | ||
Hypophosphatemia 2.5% (1) | ||
Glucose | Average 65% (26) | 0.916 |
Hyperglycemia 35% (14) | ||
Blood gas | Metabolic acidosis 27.5% (11) | 0.231 |
*Pearsons χ2.
Regarding cardiovascular manifestations, 85% (n = 34) (p = 0.338) of the patients showed no alterations, and 5% (n = 2) showed pleural effusion. Neurological assessments revealed no alterations in 77.5% (n = 31) (p = 0.466), and 17.5% (n = 7) appearing drowsy. Renally, 42.5% of the patients (n = 17) (p = 0.231) showed no alterations, with 20% (n = 8) experiencing metabolic acidosis, and 10% (n = 4) showing pallor and anasarca. Finally, among gastrointestinal manifestations, 65% of the patients (n = 26) (p = 0.934) had no alterations, 15% (n = 6) reported abdominal pain, and 10% (n = 4) experienced hematemesis (Supplementary table 1). All reported data were not statistically significant.
At the time of discharge, 65% (n = 26) of the 40 patients included in the study were under control, whereas 36% exhibited persistent arterial hypertension. These findings were not statistically significant, with a p-value of 0.517. The mortality rate stood at 32% (13 patients), with the highest prevalence in the 12-17-year age group (20%).
The primary causes of AKI were renal in 92.5% of cases. Septic shock was identified in 35% (n = 14) of cases, tumor lysis syndrome in 7.5% (n = 3), combined septic and hypovolemic shock in 5% (n = 2), and septic shock with cardiogenic shock also in 5% (n = 2). At the pre-renal level, hypovolemic shock accounted for 2.5% (n = 1), and post-renal, neurogenic bladder was identified in 5% (n = 2) (Table 6). None of these findings were statistically significant, with a p-value of 0.520.
Table 6 Description of pediatric patients according to their etiology
Classification (%) | Etiology 100% (n = 40) | p*-value | |
---|---|---|---|
Pre-renal (2.5%) | Hypovolemic shock 2.5% (1) | 0.520 | |
Renal (92.5%) | Septic shock 35% (14) Tumor lysis syndrome 7.5% (3) Septic shock and hypovolemic shock 5% (2) Septic shock and cardiogenic shock 5% (2) Acyclovir tubulointerstitial nephritis 5% (2) PIMS 2.5% (1) Sepsis 2.5% (1) Sepsis and Tumor Lysis Syndrome 2.5% (1) Sepsis and rapidly progressive glomerulonephritis 2.5% (1) Hemolytic Uremic Syndrome 2.5% (1) Lupus nephropathy 2.5% (1) Post-Strep Glomerulonephritis 2.5% (1) |
- Septic shock, multiple organ failure and arrest cardiorespiratory 2.5%
(1) - Septic shock, Tumor lysis syndrome, and acidosis tube type 2.5% (1) - Septic shock and graft-versus-host disease 2.5% (1) - Cardiogenic shock 2.5% (1) - Drowning 2.5% (1) - IgA glomerulopathy 2.5% (1) - Multiple organ failure 2.5% (1) |
|
Post-renal (5%) | Neurogenic bladder 5% (2) |
*Pearsons χ2.
Table 7 reveals the relationship between the control of arterial hypertension and follow-up in nephrology consultations, indicating that 100% (n = 6) of the patients who achieved control of arterial pressure demonstrated statistically significant outcomes, with a p-value of 0.000080.
Table 7 Follow-up of arterial hypertension
Follow-up in the Nephrology outpatient clinic (n = 6) | Arterial hypertension 100% (n = 6) | p*-value | |
---|---|---|---|
Present | 100% controlled (6) | Not controlled 0% (0) | 0.000080 |
*Pearsons χ2.
Table 8 presents data on proteinuria from follow-up visits at the nephrology outpatient clinic, showing that 33.3% (n = 2 patients) had proteinuria in the non-nephrotic range and 50% (n = 3 patients) exhibited no proteinuria. This was statistically significant, with a p-value of 0.050. Notably, all patients who attended the follow-up (six patients) did not present with hypertension.
Table 8 Relation of proteinuria during follow-up in the nephrology outpatient clinic
Follow-up in the Nephrology outpatient clinic (n = 6) | Proteinuria grade 100% (n = 6) | p*-value | |||
---|---|---|---|---|---|
Present | Yes 33.30% (2) | Not 50% (3) | Nephrotic range 0% (0) | With no laboratories 16.70% (1) | 0.050 |
*Pearsons χ2.
Discussion
In this series, school children and adolescents predominated (77.5%). Furthermore, in an investigation conducted in an ICU in Canada, a predominance of acute renal failure in the male sex (60%) was detected, similar to this series. However, there were differences between the age groups (school children)4.
The global prevalence of hypertension is 3.5% and increases with age to 18% in young adults. In Spain, it is around 3%. In the National Institute of Pediatrics in Mexico, in 2014, a prevalence study of hypertension associated with acute renal failure reported a rate of 25.7%. In our study, the rate was 22.98%, which is consistent1. Compared with the retrospective study in Canada, our study reported a higher incidence of hypertension with AKI (22.98%). On the other hand, 65% of patients had grade III renal failure, which has been linked to the presence of septic shock and tumor lysis syndrome, with underlying diseases including acute lymphoblastic leukemia, Burkitt´s lymphoma, pyelonephritis, and acute appendicitis.
Regarding diagnosis, infectious diseases were significantly more frequent in the population with AKI, similar to the findings of Duzova et al., who observed ischemic injury (28%) and sepsis (18.2%)9 in 472 patients with acute renal injury. Our study aligns with these findings, particularly with septic shock (Table 6).
During their hospital stay, 47% of the patients required management with vasopressors: vancomycin (52.5%), methotrexate (10%), non-steroidal anti-inflammatory drugs (17.5%), and steroids (70%), which have been associated with increased arterial hypertension, resulting in their limited use.
The treatment strategy focuses on therapeutic measures, generally consisting of correcting blood volume, water-electrolyte alterations, blood replacement, addressing the underlying cause, and employing dialysis methods. Early and efficient extrarenal clearance contributes to reduced mortality10. Renal replacement therapy should be initiated early, especially in certain cases of AKI (hemolytic uremic syndrome, tumor lysis, and post-operative cardiac conditions)11-13. In this series, both conventional hemodialysis and peritoneal dialysis were performed.
Another finding in our study was a lower in-hospital mortality rate in patients with acute renal failure (27%), compared to results reported by Touza et al., who recorded a mortality rate of 32.4% in 136 children admitted to a pediatric ICU14.
According to Askenazi et al., between 34% and 50% of children who experienced acute kidney damage progressed to chronic renal failure during follow-up. This data supports the recommendation for prolonged follow-up in children who have suffered from acute kidney damage15. In our study, 17.5% (n = 13) attended their follow-up appointment at the pediatric nephrology outpatient clinic.
In the demographic characteristics of the patients included in the study, it was shown that 50% (n = 20) were from Culiacán, 10% (n = 4) from Navolato, 7.5% (n = 3) from Mazatlán and Cosala, and finally, 2.5% (n = 1) from Tijuana (Table 9). In addition, in the follow-up, only 15% (n = 6) attended: three patients were from Culiacán, and three patients were from Mazatlán, Navolato, and Guasave, respectively. None of the data obtained was statistically significant (p = 0.473).
Table 9 Demographic characteristics of the patients included in the study
Municipalities | 100% (n = 40) | Follow-up (with arterial hypertension) 0% (n = 0) | Follow-up (no high blood pressure) 100% (n = 6) | p*-value |
---|---|---|---|---|
Culiacán | 50% (20) | 0% (0) | 50% (3) | 0.473 |
Navolato | 10% (4) | 0% (0) | 16.6% (1) | |
Guasave | 5% (2) | 0% (0) | 16.6% (1) | |
Escuinapa | 2.5% (1) | 0% (0) | 0% (0) | |
Mazatlán | 7.5% (3) | 0% (0) | 16.6% (1) | |
Guamúchil | 2.5% (1) | 0% (0) | 0% (0) | |
Ahome | 5% (2) | 0% (0) | 0% (0) | |
Sinaloa of Leyva | 2.5% (1) | 0% (0) | 0% (0) | |
Mocorito | 2.5% (1) | 0% (0) | 0% (0) | |
Cosala | 7.5% (3) | 0% (0) | 0% (0) | |
Rosario | 2.5% (1) | 0% (0) | 0% (0) | |
Another state (Tijuana) | 2.5% (1) | 0% (0) | 0% (0) |
**Pearsons χ2.
Our study describes a relationship between follow-up in nephrology consultations and total BP control, underscoring the importance of proper referral to their follow-up appointment in nephrology. In the follow-up of our study, the development of proteinuria was observed in 33.3% of patients, which is the most significant isolated factor in determining the progression of kidney disease.
One limitation identified in this investigation was the lack of detailed BP characteristics recorded in the files. Based on the data obtained from this study, it is crucial to continue with the timely detection of arterial hypertension due to its multiple repercussions in pediatric patients.
The prevalence of arterial hypertension in patients with renal failure was comparable to that reported in other studies. Therefore, strategies for timely detection and follow-up should be reinforced. These findings emphasize the importance of strict monitoring of kidney function, even in patients with no prior kidney disease but who have known risk factors for AKI due to their significant impact on life quality and function.