Induced hypocapnia is effective in treating pulmonary hypertension following mitral valve replacement

Mitral valve stenosis is often associated with increased pulmonary vascular resistance resulting in pulmonary hypertension, which may lead to or exacerbate right heart dysfunction. Hypocapnia is a known pulmonary vasodilator. The purpose of this study was to evaluate whether induced hypocapnia is an effective treatment for pulmonary hypertension following elective mitral valve replacement in adults. In a prospective, crossover controlled trial, 8 adult patients with mitral stenosis were studied in the intensive care unit following elective mitral valve replacement. Hypocapnia was induced by removal of previously added dead space. Normocapnic [baseline], hypocapnic and recovery hemodynamic parameters including cardiac output, pulmonary vascular resistance, pulmonary artery pressure and systemic oxygen delivery and consumption were recorded. Moderate hypocapnia [an end-tidal carbon dioxide concentration reduced to 28 +/- 5 mmHg] resulted in decreases in pulmonary vascular resistance and mean pulmonary artery pressure of 33% and 25%, respectively. Hypocapnia had no other hemodynamic or respiratory effects. The changes in pulmonary vascular resistance and mean pulmonary artery pressure were reversible. Moderate hypocapnia was effective in decreasing pulmonary vascular tone in adults following mitral valve replacement. The application of this maneuver in the immediate postoperative period may provide a bridge until pulmonary vascular tone begins to normalize following surgery

Ultrasound evaluation of the anatomical characteristics of the internal jugular vein and carotid artery - facilitation of internal jugular vein cannulation

Literature review revealed major variations in the anatomic characteristics of the right internal jugular vein [IJV] and carotid artery [CA] by the use of the ultrasound machine. The purpose of this study is to examine the anatomical characteristics of the right IJV and CA and to evaluate the IJV cannulation outcomes by the standard ultrasound guided vs. ultrasound localized technique as suggested by [in and colleagues. Additionally, the study assessed the impact of changing the ultrasound transducer direction on the location of right IJV relative to the CA. Patients [n = 100] were randomly assigned to either and ultrasound-guided or ultrasound-localized technique for IJV cannulation. The "Site Rite" II ultrasound transducer was directed perpendicular to the floor at the apex of the clavicle-sternocleidomastoid triangle at the level of the cricoid cartilage with the head turned to contralateral side of cannulation and table tilted to 30° in Trendelenburg position. Cannulation outcomes, including successful cannulation, access time, success time, and difficult cases were evaluated. Aborted difficult cases included prolonged procedural tulle exceeding four minutes and carotid puncture, and these were examined by technique. IJV size and its location relative to CA. The location of the IJV relative to CA was evaluated firstly with the ultrasound transducer directed perpendicular to the floor and secondly with the transducer directed perpendicular to the skin [Fig 1]. With the ultrasound transducer directed perpendicular to the floor, the depth of the IJV from the skin [15 mm] was comparable to its diameter [14.1 mm], while the CA A-P diameter was around halt' that of the IJV [7.4 mm] [Table 2]. Also, the majority of patients showed lateral [51%] and posterolateral [14%] positions of the IJV relative to the CA. Directing the transducer perpendicular to the skin resulted in more anterolateral positions [77%] with 6% total overlap. Cannulation of the IJV was successful in 94% in both randomization groups, with 91.5% of the patients achieving first pass cannulation in the ultrasound-guided group and 87.2% in the ultrasound-localized [Table 3]. Access time [6.9 +/- 13 sec and 5.9 +/- 14.6 sec] and success time [13.5 + 14.2 sec and 13.2 + 15.0 sec] were comparable for both groups. Reasons for aborted difficult cannulation included prolonged procedural time in 2% and carotid puncture in 4%. in both techniques. Compared to the successful cases, difficult cases were characterized by a significantly greater degree of anterolateral [exceeding 15°] location of the IJV relative to the CA [p-value=0..046] and a significantly smaller IJV site [mean 10.3 mm vs. 14.3 mm. p-value = 0.035] [Table 4]. However in multivariate analysis controlling for the technique utilized, only the relation between the size of IJV and the occurrence of difficult cases remained significant. With each 1 mm decrease in IJV size, there was a 37% significant increase in the risk of difficult cases. Findings of the study show that both ultrasound guided and ultrasound localized techniques yield similar cannulation outcomes. Additional to the anteraloteral position of the IJV relative to the CA, a small IJV site constitutes a powerful predictor for the incidence of prolonged procedure time and carotid puncture for IJV canulation. Finally the transducer direction has a significant impact on the assessment of the location of the IJV relative to the CA

Intubating conditions and injection pain cisatracurium or rocuronium versus rocuronium cisatracurium combination

The present report evaluates the incidence of pain on intravenous injection and the condition oftracheal intubation at one minute following the administration of cisatracurium or rocuronium versus rocuronium-cisatracurium combination. We studied 60 patients, ASA 1, aged 18-60 years, undergoing elective surgical procedures. The patients were randomly assigned to 3 groups who received intravenously either 0.15 mg/kg cisatracurium [2ED[95]], 0,6 mg rocuronium [2ED[95]] or a combination of 0.075 mg/kg cisatracurium [ED[95]], plus 0.3 mg rocuronium [1ED[95]]. In the awake patients, the pain on injection of muscle relaxant was assessed on a four point scale [none, mild, moderate, severe]. Administration of the relaxant was followed by 1-2 mg/kg of lidocaine and 2 mg/kg propofol. Oro-tracheal intubation was performed 60 seconds following the administration of the relaxant. The intubating conditions were assessed and rated as excellent, good, fair or poor. The administration of 2ED[95] cisatracurium resulted in poor intubating conditions at 60s, without pain on injection. In contrast, the administration of 2ED[95] rocuronium resulted in excellent or good intubating conditions at 60s associated with high incidence of pain on injection in most of the patients. However, the combination of 1ED[95] cisatracurium with 1ED[95] rocuronium provided similar intubating conditions to the 2ED[95] rocuronium alone, associated with a significantly less pain on injection

Muallem endo - tracheal tube introducer: [METTI] an aid for the difficulty airway.

This is a brief report evaluating a new single use endotracheal tube introducer [METTI] which has a soft curved atraumatic tip. The introducer was tried in 44 patients, whose direct laryngoscopic view was simulated to Cormack IIIb score, and in six patients with real Cormack III score. The overall success rate of railroading of the tracheal tube over the introducer was 94% from the first attempt

Remifentanil for modulation of hemodynamics in a patient undergoing laparoscopic resection of pheochromocytoma

The present report monitors the hemodynamic fluctuations in a 63 year-old female patient undergoing laparoscopic resection of right adrenal pheochromocytoma during remifentanil-based anesthesia. Anesthesia was induced with lidocaine 1 mg.kg -1, propofol 3.5 mg.kg -1, and cisatracurium 0.2 mg -1.kg -1 and a remifentanil infusion was started at a rate of 1 micro g. Kg -1.min -1. Anesthesia was then maintained with remifentanil infusion [0.5 Micro g -1 kg -1.min], sevoflurane 1-2% [end-tidal] in a mixture of air/oxygen [3:1], and a continuous infusion of cisatracurium. There were no significant changes of BP and HR following tracheal intubation or surgical incision. However, creation of pneumoperitoneum as well as tumor manipulation resulted in a dramatic increase of systolic BP and pulmonary artery pressure, associated with a decrease in cardiac output. These hemodynamic changes were unresponsive to an increase in the remifentanil infusion rate up to 1.5 micro g.kg -1.min -1, but were controlled by increasing the concentration of sevoflurane up to 6%, and by a nitroglycerin [NTG] infusion. Ten min after removal of the tumor, and despite discontinuation of the NTG infusion as well as a reduction in the remifentanil infusion and sevoflurane concentration, the BP decreased down to 64/43 mmHg. In conclusion, the present report shows in a patient undergoing laparoscopic resection of adrenal pheochromocytoma that remifentanil does not prevent the severe hypertensive episodes associated with intraperitoneal carbon dioxide insufflation or tumor manipulation. However, it can be titrated to prevent the hemodynamic reflex response to tracheal intubation and surgical stimulation

Multimodal spinal anesthesia

Cystoscopy and extracorporeal shock wave lithotripsy [ESWL] are common urologic procedures in the treatment of ureteral calculi. Spinal anesthesia with local anesthetics is the anesthetic technique of choice for these procedures. Sufentanil and/or clonidine have been combined with local anesthetics to provide effective and safe neuroaxial anesthesia. Our objectives were to review the efficacy and safety of combining both sufentanil and clonidine with reduced doses of intrathecal lidocaine in patients undergoing cystoscopy and ESWL. We reviewed the medical records of 12 patients who underwent such urologic procedures using an intrathecal mixture consisting of 20 mg of lidocaine, 10 micro g of sufentanil, and 50 micro g clonidine from May 1[st], 1998 to December 31[st], 1998. Patients' demographics, intraoperative analgesia and adverse side effects as well as recovery times were reviewed. All 12 patients tolerated their urologic treatments using this combination of drugs without requiring conversion to another anesthetic technique or significant supplementation with intravenous analgesics. Motor power returned to normal by the end of the procedure. The systolic blood pressure dropped 26 +/- 8% intraoperatively and 25 +/- 9% postoperatively. The incidences of other adverse side effects were low. Time spent in recovery area was short, 45 +/- 15 minutes [mean +/- standard deviation]. Conclusions: Intrathecal admixtures of sufentanil 10 micro g, clonidine 50 micro g, and lidocaine 20 mg can provide effective and prolonged analgesia in patients undergoing cystoscopy and ESWL. Patients had recovery of their motor power in their lower extremities by the end of the procedure. No urinary retention was noted. Mild hypotension was the most common adverse side effect and was the main confounding factor for the prolongation of the discharge time

Anesthetic management for a patient with my asthenia gravis undergoing coronary artery bypass graft

Purpose: Report the clinical management of a patient having Myasthenia Gravis [MG], undergoing cardiopulmonary bypass [CPB]. Clinical features: A 71-yr-old man having MG [Osserman IIB], was admitted for coronary artery bypass graft [CABG] under CPB. Optimization of the patient was achieved preoperatively. Thymectomy was done following midsternotomy. Continuous monitoring of the neuromuscular transmission [NMT] was maintained throughout the perioperative period. The hemodilutional effect of CPB was counteracted by the hypothermia resulting in maintenance of cisatracurium requirements at the same levels as the prebypass period. Extubation of the trachea was done after ensuring adequate recovery of the NMT and respiratory function. Oral myasthenic therapy was resumed following extubation. A myasthenic patient can safely undergo CPB provided adequate preoperative optimization is achieved. Continuous monitoring of the NMT must be throughout the perioperative period. Thymectomy is recommended in the myasthenic patient since it may improve the outcome. Extubation of the trachea is to be done after ensuring adequate NMT and respiratory function