Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1998
Infraclavicular brachial plexus block: parasagittal anatomy important to the coracoid technique.
Infraclavicular brachial plexus block is a technique well suited to prolonged continuous catheter use. We used a coracoid approach to this block to create an easily understood technique. We reviewed the magnetic resonance images of the brachial plexus from 20 male and 20 female patients. Using scout films, the parasagittal section 2 cm medial to the coracoid process was identified. Along this oblique section, we located a point approximately 2 cm caudad to the coracoid process on the skin of the anterior chest wall. From this point, we determined simulated needle direction to contact the neurovascular bundle and measured depth. At the skin entry site, the direct posterior insertion of a needle will make contact with the cords of the brachial plexus where they surround the second part of the axillary artery in all images. The mean (range) distance (depth along the needle shaft) from the skin to the anterior wall of the axillary artery was 4.24 +/- 1.49 cm (2.25-7.75 cm) in men and 4.01 +/- 1.29 cm (2.25-6.5 cm) in women. Hopefully, this study will facilitate the use of this block. ⋯ We sought a consistent, palpable landmark for facilitation of the infraclavicular brachial plexus block. We used magnetic resonance images of the brachial plexus to determine the depth and needle orientation needed to contact the brachial plexus. Hopefully, this study will facilitate the use of this block.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialThe effect of magnesium sulphate on hemodynamics and its efficacy in attenuating the response to endotracheal intubation in patients with coronary artery disease.
Laryngoscopy and endotracheal intubation may produce adverse hemodynamic effects. Magnesium has direct vasodilating properties on coronary arteries and inhibits catecholamine release, thus attenuating the hemodynamic effects during endotracheal intubation. We studied 36 patients with coronary artery disease (CAD) scheduled for elective coronary artery bypass grafting to evaluate the hemodynamic effects of magnesium and its efficacy in attenuating the response to endotracheal intubation. Patients received either 0.1 mL/kg (50%) magnesium sulfate (50 mg/kg) (Group A, n = 19) or isotonic sodium chloride solution (Group B, n = 17) before the induction of anesthesia and 0.05 mL/kg of isotonic sodium chloride solution (Group A) or lidocaine 2% (1 mg/kg) (Group B) before intubation. The hemodynamic variables were recorded before induction, after the trial drug, after induction, and after endotracheal intubation. Automatic ST segment analysis was performed throughout the study period. Magnesium sulfate administration was associated with increased cardiac index (P < 0.01), a minimal increase in heart rate, and a significant decrease in mean arterial pressure (MAP) and systemic vascular resistance (SVR) (P < 0.001). None of the patients in the magnesium group had significant ST depression compared with three patients in the control group. The magnesium group patients had a significantly lesser increase in MAP (P < 0.05) and SVR (P < 0.01) compared with the control group patients who received lidocaine before endotracheal intubation. Thus, magnesium is an useful adjuvant to attenuate endotracheal intubation response in patients with CAD. ⋯ Endotracheal intubation produces adverse hemodynamic effects, which may be more detrimental in patients with coronary artery disease than in healthy patients. The present study shows that magnesium administered before endotracheal intubation can attenuate this response better than lidocaine.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Comparative Study Clinical TrialA granisetron-droperidol combination prevents postoperative vomiting in children.
This study was performed to compare the efficacy of a granisetron-droperidol combination with each antiemetic alone to prevent postoperative vomiting after tonsillectomy with or without adenoidectomy in children. One hundred eighty pediatric patients, ASA physical status I, aged 4-10 yr, were enrolled in a prospective, randomized, double-blind investigation and assigned to one of three treatment regimens: granisetron 40 microg/kg (Group G), droperidol 50 microg/kg (Group D), or granisetron 40 microg/kg plus droperidol 50 microg/kg (Group GD) (n = 60 in each group). These drugs were administered i.v. after an inhaled induction. The same standard general anesthetic technique and postoperative analgesia were used throughout. The rate of complete response, defined as no emesis and no need for rescue antiemetic, 0-3 h after anesthesia was 83% in Group G, 60% in Group D, and 97% in Group GD (P = 0.029 versus Group G, P = 0.001 versus Group D). The corresponding rates 3-24 h after anesthesia were 83%, 55%, and 97% (P = 0.029 versus Group G, P = 0.001 versus Group D). No clinically important adverse events were observed in any of the groups. In conclusion, a granisetron-droperidol combination is superior to each antiemetic alone in complete response in children undergoing general anesthesia for tonsillectomy. ⋯ We compared the efficacy of granisetron plus droperidol with each antiemetic alone for the prevention of postoperative vomiting in children. The granisetron-droperidol combination was highly effective against postoperative emesis.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Comparative Study Clinical TrialDesflurane and isoflurane produce similar alterations in systemic and pulmonary hemodynamics and arterial oxygenation in patients undergoing one-lung ventilation during thoracotomy.
We tested the hypothesis that desflurane (DES) and isoflurane (ISO) produce similar effects on systemic and pulmonary hemodynamics and arterial oxygenation before, during, and after one-lung ventilation (OLV) in patients undergoing thoracotomy. After obtaining informed consent, anesthesia was induced with sodium thiopental or thiamylal, fentanyl, and vecuronium in 61 ASA physical status II-IV patients. Patients were randomly assigned to receive either DES (n = 30) or ISO (n = 31) in 100% O2 in separate groups. Hemodynamic data (radial and pulmonary artery [PA] catheters) were recorded, and blood gas values were obtained before and after induction; at selected intervals before, during, and after OLV; and before emergence. DES significantly (P < 0.05) increased heart rate (HR) and decreased mean arterial pressure (MAP) and cardiac output (CO). PA pressures and pulmonary vascular resistance (PVR) increased; systemic vascular resistance (SVR) was unchanged. Increases in HR and CO and decreases in MAP and SVR occurred during OLV and DES. Reductions in PaO2 (411 +/- 88 to 271 +/- 131 mm Hg 5 min after beginning OLV; mean +/- SD) and content (CaO2) and increases in shunt fraction (Qs/Qt; 0.25 +/- 0.12 to 0.40 +/- 0.19 at 5 min after beginning OLV) were also observed. ISO increased HR and PA pressures but did not alter MAP, CO, and PVR, in contrast to the findings with DES. Reductions in MAP and SVR and increases in CO and PA pressures were observed during OLV in the presence of ISO. Similar to the findings during DES, decreases in PaO2 and CaO2 and increases in Qs/Qt occurred during OLV and ISO. We conclude that DES and ISO produce very similar alterations in systemic and pulmonary hemodynamics and arterial oxygenation in patients undergoing OLV during thoracotomy. ⋯ Desflurane and isoflurane produce similar cardiovascular and pulmonary effects before, during, and after one-lung ventilation in patients undergoing lung surgery.