Anesthesia and analgesia
-
Anesthesia and analgesia · Jul 2002
Case ReportsThe use of the intubating laryngeal mask endotracheal tube with intubating devices.
Despite adequate visualization of the vocal cords using specialized airway devices, anatomical factors and the physical characteristics of the tube may cause difficulty when performing endotracheal intubation. The endotracheal tube designed for use with the intubating laryngeal mask airway may facilitate intubation in these circumstances.
-
Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Clinical TrialNew landmarks for the anterior approach to the sciatic nerve block: imaging and clinical study.
In this study, we assessed the reliability of the inguinal crease and femoral artery as anatomic landmarks for the anterior approach to the sciatic nerve and determined the optimal position of the leg during this approach. An imaging study was conducted before the clinical study. The sciatic nerve was located twice in 20 patients undergoing ankle or foot surgery, once with the leg in the neutral position and once with the leg in the externally rotated position. The patient was lying supine. A 22-gauge, 150-mm insulated b-beveled needle connected to a nerve stimulator was inserted 2.5 cm distal to the inguinal crease and 2.5 cm medial to the femoral artery and was directed posteriorly and laterally with a 10 degrees -15 degrees angle relative to the vertical plane. The sciatic nerve was located in all patients at a depth of 10.6 +/- 1.8 cm when the leg was in the neutral position and 10.4 +/- 1.5 cm when the leg was in the externally rotated position (not significant). In the neutral position and in the externally rotated position, the time needed to identify anatomic landmarks was 28 +/- 15 s and 26 +/- 14 s, respectively (not significant), and the time needed to locate the sciatic nerve was 79 +/- 53 s and 46 +/- 25 s (P < 0.006), respectively. We conclude that the inguinal crease and femoral artery are reliable and effective anatomic landmarks for the anterior approach to the sciatic nerve and that the optimal position of the leg is the externally rotated position. ⋯ This new anterior approach to the sciatic nerve using the inguinal crease and femoral artery as landmarks is an easy and reliable technique.
-
Anesthesia and analgesia · Jul 2002
Comparative Study Clinical TrialThe plasma supplemented modified activated clotting time for monitoring of heparinization during cardiopulmonary bypass: a pilot investigation.
The standard celite or kaolin activated clotting time (ACT) correlates poorly with heparin levels during cardiopulmonary bypass (CPB). We compared a modified kaolin ACT, in which plasma was supplemented, to a standard undiluted kaolin ACT for monitoring heparin levels during CPB. Fifteen patients undergoing normothermic CPB were enrolled in this prospective study. Heparin management was performed according to the Hepcon HMS results (Medtronic, Minneapolis, MN). The ACTs were performed with the ACT II device (Medtronic). Hepcon HMS calculations, standard kaolin ACTs, and plasma supplemented modified ACTs (mACTs), prepared by diluting blood samples 1:1 with human plasma (Behring, Marburg, Germany), were measured every 30 min during CPB. The data obtained were correlated to the plasma chromogenic anti-Xa activity as a reference assay for heparin levels. A total of 64 samples were evaluated. The chromogenic anti-Xa activity ranged from 0.2 to 5.5 IU/mL. The Hepcon HMS calculations ranged from 2.7-8.2 IU/mL of heparin, the standard ACT ranged from 424 to >999 s, and the mACT ranged from 210 to 801 s. The correlation to the chromogenic anti-Xa method was r = 0.43 for the standard kaolin ACT and r = 0.69 for the plasma mACT. The plasma mACT provided an improved correlation to chromogenically measured levels of anti-Xa activity during CPB. The improved correlation most likely results from a correction of the effects of the impairment of the coagulation system caused by hemodilution and consumption of procoagulants on extracorporeal surfaces. ⋯ During cardiopulmonary bypass, the plasma modified kaolin activated clotting time (ACT) provides a better correlation with heparin levels than the standard kaolin ACT.
-
Anesthesia and analgesia · Jul 2002
The dose-related efficacy of diltiazem for enhancing diaphragmatic fatigability in dogs.
Nicardipine, a calcium channel blockade, enhances the production of diaphragmatic fatigue. We studied the dose-related effects of diltiazem, another calcium channel blockade, on diaphragmatic fatigability in dogs. Animals were divided into three groups of eight each. In each group, diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. During this fatigue-producing period, Group I received no study drug, Group II was infused with diltiazem 0.1 mg. kg(-1). h(-1), and Group III was infused with diltiazem 0.5 mg. kg(-1). h(-1). We assessed diaphragmatic contractility by transdiaphragmatic pressure (Pdi). After the fatigue-producing period, in Group I, Pdi at low-frequency (20-Hz) stimulation decreased from baseline values (P < 0.05), whereas there was no change in Pdi at high-frequency (100-Hz) stimulation. In Groups II and III, with an infusion of diltiazem, Pdi at both stimuli decreased from baseline values (P < 0.05). The decrease in Pdi to each stimulus was more in Group III than in Group II (P < 0.05). We conclude that diltiazem causes a dose-related augmentation of fatigability in the diaphragm of dogs. ⋯ Diaphragmatic muscle fatigue is implicated as a cause of respiratory failure. Diltiazem, a calcium channel blockade, enhances diaphragmatic fatigability in dogs in a dose-related manner.
-
Anesthesia and analgesia · Jul 2002
Letter Case ReportsKnotting of an epidural catheter like a tie.