ABSTRACT
Aim: We aimed to describe the neurosonological findings related to cerebral hemodynamics acquired using transcranial Doppler and to determine the frequency of elevated ICP by optic nerve sheath diameter (ONSD) measurement in patients with severe coronavirus disease (COVID-19) hospitalized in the intensive care unit of a national referral hospital in Peru. Methods: We included a retrospective cohort of adult patients hospitalized with severe COVID-19 and acute respiratory failure within the first 7 days of mechanical ventilation under deep sedoanalgesia, with or without neuromuscular blockade who underwent ocular ultrasound and transcranial Doppler. We determine the frequency of elevated ICP by measuring the diameter of the optic nerve sheath, choosing as best cut-off value a diameter equal to or >5.8 mm. We also determine the frequency of sonographic patterns obtained by transcranial Doppler. Through insonation of the middle cerebral artery. Likewise, we evaluated the associations of clinical, mechanical ventilator, and arterial blood gas variables with ONSD ≥5.8 mm and pulsatility index (PI) ≥1.1. We also evaluated the associations of hemodynamic findings and ONSD with mortality the effect size was estimated using Poisson regression models with robust variance. Results: This study included 142 patients. The mean age was 51.39 ± 13.3 years, and 78.9% of patients were male. Vasopressors were used in 45.1% of patients, and mean arterial pressure was 81.87 ± 10.64 mmHg. The mean partial pressure of carbon dioxide (PaCO2) was elevated (54.08 ± 16.01 mmHg). Elevated intracranial pressure was seen in 83.1% of patients, as estimated based on ONSD ≥5.8 mm. A mortality rate of 16.2% was reported. In the multivariate analysis, age was associated with elevated ONSD (risk ratio [RR] = 1.07). PaCO2 was a protective factor (RR = 0.64) in the cases of PI ≥ 1.1. In the mortality analysis, the mean velocity was a risk factor for mortality (RR = 1.15). Conclusions: A high rate of intracranial hypertension was reported, with ONSD measurement being the most reliable method for estimation. The increase in ICP measured by ONSD in patients with severe COVID-19 on mechanical ventilation is not associated to hypercapnia or elevated intrathoracic pressures derived from protective mechanical ventilation.
ABSTRACT
La dapsona es una sulfona utilizada en una variedad de enfermedades dermatológicas que incluye el pénfigo, lametahemoglobinemia es un síndrome clínico potencialmente mortal debido a la disminución del aporte de oxígenodesde la sangre hacia los tejidos; la metahemoglobinemia adquirida es la forma más frecuente y es un conocidoefecto adverso del uso de dapsona. Describimos el caso de un varón con pénfigo foliáceo y tratamiento reciente condapsona, que presentó cianosis, disnea y choque circulatorio ante concentraciones elevadas de metahemoglobina(21%); el tratamiento inicial incluyó oxigenoterapia, soporte ventilatorio invasivo, hemodinámico y administraciónde azul de metileno intravenoso, ante la ausencia de respuesta clínica se realizó exanguinotransfusión como terapiade segunda línea con respuesta óptima, el nivel sérico de metahemoglobina fue 2,3% tres horas posteriores alrecambio sanguíneo.
Dapsone is a sulphone used for a variety of dermatologic conditions including pemphigus. Methemoglobinemia isa potentially lethal syndrome due to a diminished supply of oxygen from blood to tissues, the acquired form is themost frequent presentation and it is a recognized adverse effect of dapsone. We report the case of a male patientwith pemphigus treated with dapsone that developed cyanosis, dyspnea and shock in the presence of elevatedconcentrations of methemoglobin (21%). Initial treatment included oxygen, invasive ventilatory support andintravenous administration of methylene blue, but due to lack of response, exchange transfusion was performedwith optimal response, serum level of methemoglobin after the procedure was 2.3%.