Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Clinical TrialAttenuation of cardiovascular responses to tracheal extubation: comparison of verapamil, lidocaine, and verapamil-lidocaine combination.
We recently showed that verapamil attenuated hemodynamic responses to tracheal extubation. The aim of the current study was to compare the efficacy of a combination of intravenous (I.V.) verapamil (0.1 mg/kg) and I.V. lidocaine (1 mg/kg) with that of each drug alone in suppressing the cardiovascular changes during tracheal extubation and emergence from anesthesia. One hundred adult patients (ASA physical status I) who were to undergo elective minor surgery were randomly assigned to one of four groups (n = 25 each): Group S = saline plus saline (control), Group V = verapamil 0.1 mg/kg I.V. plus saline, Group L = lidocaine 1 mg/kg I.V. plus saline, and Group V-L = verapamil 0.1 mg/kg I.V. plus lidocaine 1 mg/kg I.V. These medications were given 2 min before tracheal extubation. Anesthesia was maintained with 1.0%-2.0% sevoflurane and 60% nitrous oxide (N2O) in oxygen. Muscle relaxation was achieved with vecuronium, and a residual neuromuscular blockade was reversed with neostigmine 0.05 mg/kg (combined with atropine 0.02 mg/kg). Changes in heart rate (HR) and arterial blood pressure (AP) were measured during and after tracheal extubation. In the control group, the HR and systolic and diastolic AP increased significantly during tracheal extubation. Verapamil, lidocaine, and their combination attenuated the increases in these variables. The beneficial effect was the greatest with the combination of verapamil and lidocaine. These findings suggest that verapamil 0.1 mg/kg and lidocaine 1 mg/kg given I.V. concomitantly 2 min before tracheal extubation is a simple and more effective prophylaxis than verapamil or lidocaine alone for attenuating the cardiovascular changes associated with tracheal extubation. ⋯ Tachycardia and hypertension associated with tracheal extubation, which may lead to myocardial ischemia, represent a potential risk for patients with coronary arterial disease. To seek effective pharmacological prophylaxis against these complications, we compared the attenuation of hemodynamic changes among verapamil, lidocaine, and a verapamil/lidocaine combination using ASA physical status I patients and found the combination to be effective.
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Anesthesia and analgesia · Nov 1997
Clinical TrialThe effect of age on retrieval of local anesthetic solution from the epidural space.
We conducted this prospective study to determine whether advancing age is correlated with retrieval of local anesthetic solution from the epidural space. Three hundred forty-six patients (ASA physical status I or II, 20-93 yrs of age, 177 female and 169 male patients) undergoing epidural anesthesia were enrolled. The epidural space was identified by a loss of resistance technique using air, and a catheter was introduced 3 cm. Three milliliters of 2% lidocaine with epinephrine was injected as a study dose by hand at a rate of 1 mL/s with the patient in the supine position. The syringe was immediately aspirated to retrieve the local anesthetic solution. A retrieved volume of 0.5 mL or more with a glucose concentration less than 6 mg/dL was defined as retrieval positive, and a volume of less than 0.5 mL was defined as retrieval negative. There was a significant correlation between age and retrieval volume among all the patients (Y = 0.008X-0.222, P < 0.0001) with a significant increase in the positive retrieval incidence and volume from the patients in their 50s (11%, 0.6 +/- 0.3 mL) to the patients in their 60s (26%, 1.0 +/- 0.6 mL) (P < 0.05 for both). The incidence of positive retrieval and the retrieval volume were greater in the patients in their 60s and older (30%, 1.1 +/- 0.63 mL) than in the younger than 60 (10%, 0.6 +/- 0.3 mL) (P < 0.0001 and P < 0.001). The glucose concentration was 2.3 +/- 1.2 mg/dL in the positive cases. We conclude that there is a weak positive correlation between age and the local anesthetic solution retrieved from the epidural space. ⋯ We conducted a study in 346 patients to determine whether advancing age could be correlated with retrieval of local anesthetic solution from the epidural space. We found a weak positive correlation between advanced age and the amount of solution retrievable from the epidural space. Further studies are required to determine whether this phenomenon may call for dose adjustments in patients aged more than 60 yrs.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Comparative Study Clinical TrialA comparative efficacy study of hyperbaric 5% lidocaine and 1.5% lidocaine for spinal anesthesia.
We compared the clinical efficacy of 1.5% lidocaine in dextrose 7.5% in water, which is currently available as a commercial preparation but approved for use only in obstetrical patients, with the traditional 5% lidocaine in dextrose 7.5% in water for spinal anesthesia in patients undergoing lower abdominal procedures. Fifty-one male patients scheduled to undergo inguinal herniorrhaphy were randomly divided into two groups based on the spinal anesthetic received: Group I received 1.5% lidocaine in dextrose 7.5% in water, and Group II received 5% lidocaine in dextrose 7.5% in water. After intrathecal injection of the anesthetic, each patient was evaluated for the speed of onset, the time to recovery, and the quality of the surgical anesthesia and motor block that ensued by an anesthesiologist blinded to the technique. With the exception of the patients in Group I, who achieved a higher dermatome level of sensory analgesia, we were unable to demonstrate any significant clinical differences between the two lidocaine solutions. Our results indicate that lidocaine 1.5% in dextrose 7.5% in water is clinically indistinguishable from the 5% solution as a spinal anesthetic for lower abdominal surgery. ⋯ In this study, two concentrations of lidocaine are compared as spinal anesthetics in 51 male patients undergoing inguinal hernia repair. Patients were assessed for the onset, quality, and duration of the spinal block. The study results indicate that 1.5% lidocaine is as effective as the 5% solution as a spinal anesthetic for patients undergoing inguinal hernia repair.
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Anesthesia and analgesia · Nov 1997
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of inhaled nitric oxide and its combination with intravenous almitrine on Pao2 during one-lung ventilation in patients undergoing thoracoscopic procedures.
The aim of this study was to assess whether hypoxemia during one-lung ventilation (OLV) can be prevented by inhaled nitric oxide (NO) (Part I) or by its combination with intravenous (IV) almitrine (Part II) in 40 patients undergoing thoracoscopic procedures. In Part I, 20 patients were divided into two groups: one received O2 (Group 1) and one received O2/NO (Group 2). In Part II, 20 patients were divided into two groups: one received O2 (Group 3) and one received O2/NO/almitrine (Group 4). In Groups 2 and 4, NO (20 ppm) was administered during the entire period of OLV, and almitrine was continuously infused (16 microg x kg(-1) x min[-1]) in Group 4. Arterial blood gases were measured during two-lung ventilation with patients in the supine position, after positioning in the lateral decubitus position, and then every 5 min for a 30-min period during OLV. During OLV, Pao2 values decreased similarly in Groups 1 and 2. After 30 min of OLV, the mean Pao2 values in Groups 1 and 2 were 132 +/- 14 mm Hg (mean +/- sem) and 149 +/- 27 mm Hg (not significant [NS]), and the Pao2 value was less than 100 mm Hg in four patients in Group 1 and five patients in Group 2. Pao2 values were greater in Group 4 than in Group 3 after 15 and 30 min of OLV. After 30 min of OLV, the mean Pao2 values were 146 +/- 16 mm Hg in Group 3 and 408 +/- 33 mm Hg in Group 4 (P < 0.001). Pao2 was less than 100 mm Hg during OLV (NS) in four patients in Group 3 and in no patient in Group 4. We conclude that NO inhalation alone has no effect on Pao2 evolution during OLV, although its combination with IV almitrine limits the decrease of Pao2 during OLV. This beneficial effect of NO/almitrine could be attributed to an improvement in ventilation-perfusion relationships. ⋯ Decrease in oxygenation during one-lung ventilation is quite common. Our study showed that inhaled nitric oxide alone did not influence Pao2 evolution. We then tried adding intravenous almitrine to nitric oxide with amazingly good results on Pao2. This nonventilatory technique should be of great use during special thoracic acts, such as thoracoscopic procedures.