Journal of clinical monitoring
-
Thermoregulatory vasoconstriction locally increases arterial wall tension and arteriolar resistance, thereby altering physical properties of the arteries. The arterial pressure waveform is an oscillatory phenomenon related to those physical characteristics; accordingly, we studied the effects of thermoregulatory vasomotion on central and distal arterial pressures, using three hydraulic coupling systems having different dynamic responses. ⋯ Thermoregulatory vasoconstriction alters radial arterial pressure waveform, artifactually increasing its peak systolic pressure compared with the femoral artery. Poor dynamic responses of recording systems further distort the waveforms. Consequently, radial artery pressure may be misleading in vasoconstricted patients.
-
Case Reports
Chronic methemoglobinemia: improving hemoglobin saturation monitoring during anesthesia.
Methemoglobin interferes with the accuracy of pulse oximetry data. Methemoglobinemia is caused by many factors, both congenital and acquired. However, the increasing usage of dapsone, which converts hemoglobin to methemoglobin, is increasing the number of patients with methemoglobinemia. We present the case of a patient with dapsone-induced methemoglobinemia who was successfully treated with methylene blue, which converts methemoglobin back to hemoglobin.
-
Our objective was to assess the effect of venous resistance in a clinically relevant range on flow rates through intravenous (i.v.) cannulae. ⋯ To achieve maximum benefit from a large-bore cannula, a suitably large vein must be chosen. Further, where venous access is difficult and high flow potential from an infusion system is required, two separate infusions through small cannulae may be a preferable option to a single large bore.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Doppler-guided cannulation of the internal jugular vein: a prospective, randomized trial.
The internal jugular vein (IJ) is commonly used as an access to the central venous system. Despite the high success rate for cannulation of the IJ, the incidence of complications (1% to 16%) has remained essentially the same, with most complications resulting from unintentional punctures of surrounding structures. In an attempt to reduce the complication rate of this technique, we evaluated the use of a Doppler-guided needle device to cannulate the IJ. ⋯ The Doppler-guided cannulation technique can reduce the number of attempts required for successful IJ cannulation.
-
Pulmonary arterial catheter (PAC) placement under fluoroscopy is a useful and safe method to diagnose certain congenital cardiac anomalies [1]. However, when a PAC for intraoperative monitoring is placed without the aid of fluoroscopy, it may be inadvertently placed into anomalous veins. The following report presents a case of persistent left superior vena cava (PLSVC) with absence of right superior vena cava, which was not detected by a PAC inserted via the right internal jugular vein.