Acceleration in linear growth after splenectomy for hypersplenism in homozygous sickle cell disease

Chronic hypersplenism in homozygous sickle cell (SS) disease markedly increases haemolysis and the resulting erythropoietic expansion is likely to have a high metabolic cost. Splenectomy for hypersplenism in SS disease is followed by highly significant changes in haematological indices and an increase in height, but not weight, velocity. This pattern is similar to that observed in the trichuris dysentery syndrome after treatment, and differs from the increases in both height and weight velocity that follow nutritional supplementation of severely malnourished children. It is postulated that accelerated linear growth after the reduction in erythropoietic stress may implicate a specific nutrient deficiency in hypersplenic children with SS.

Osmolar gap with minimal acidosis in combined methanol and methyl ethyl ketone ingestion

Methyl ethyl ketone is a common solvent but data on overdose in humans are scarce. We report a case of co-ingestion of methyl ethyl ketone together with methanol associated with a hyperosmolar coma without anion gap metabolic acidosis. Blood levels of methyl ethyl ketone and its metabolite, 2-butanol, indicated that this solvent did contribute approximately 20 mosm/L to an observed osmolar gap of 99 mosm/L. At the levels detected, methyl ethyl ketone may have inhibited methanol metabolism, contributing to the low serum formate (1.3 mmol/L) and normal anion gap despite a blood methanol of 67 mmol/L.

Continuous intra-arterial oxygen monitoring: accuracy and reliability in the surgical intensive care unit

The accuracy and reliability of an invasive intra-arterial oxygen sensor catheter was evaluated in 20 critically ill surgical intensive care unit (SICU) patients. All patients required continuous arterial blood pressure monitoring, at least 72 hours of ventilator support, and intermittent arterial blood gas sampling for clinical management. The intra-arterial sensor provided continuous PO2 (PsO2) values on a bedside electronic monitor. PsO2 values were sampled every 60 seconds and automatically stored on a bedside personal computer. Arterial blood gas (ABG) PaO2 values were collected and matched by collection time with corresponding PsO2 values. During 1,238 hours of continuous intra-arterial monitoring, 74,280 PsO2 values and 246 ABG PaO2 values were collected. Of the 246 PaO2 results, 175 (71.3%) had a matching PsO2. Regression of matched PsO2 and PaO2 values yielded a correlation coefficient of 0.58 and standard error of the estimate (SEE) of 33.1 (P < 0.0005). Even though matched PsO2 and PaO2 measurements demonstrated a linear relationship, only 34 per cent of the variation in PsO2 could be attributed to changes in PaO2. Technical sensor or instrument problems affected PsO2 monitoring in 17 of 20 patients and 28 of the 33 sensors tested. The authors conclude that continuous intra-arterial monitoring of PsO2 is a novel idea, but technical issues limit its use in acutely ill, conscious SICU patients.

Interpretation of color change in blood with varying degree of methemoglobinemia

The ability to detect the characteristic "chocolate" brown color of methemoglobin containing blood was tested in a double blind study. We prepared three concentrations of methemoglobin by adding sodium nitrite to 1-2 ml of venous, heparinized blood that was "arterialized" by mixing with room air in vacutainer tubes. House officers (HO) were asked, in a standardized protocol, to make observations ("chocolate", "abnormal" or "normal") about the methemoglobin blood alone (first in Vacutainer, and then on filter paper), and then in comparison with control blood, again in Vacutainer, then filter paper. Each HO assessed only one methemoglobin concentration. Three methemoglobin blood samples were studied with 12-14%, 26-35% and 68% methemoglobin concentrations respectively. We found that the ability to detect visually an abnormal appearance of methemoglobin was significantly improved when the test sample was compared to control blood. The descriptive term "darker than normal" was much more commonly used than "chocolate" to describe the methemoglobin blood.

Lead intoxication in children

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