Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialNasotracheal intubation in patients with immobilized cervical spine: a comparison of tracheal tube cuff inflation and fiberoptic bronchoscopy.
Tracheal intubation may pose problems in patients with cervical spine injury (CSI). In patients without CSI, the success rate of blind nasotracheal intubation is increased by endotracheal tube (ETT) cuff inflation in the pharynx. The purpose of this study was to assess the efficacy of ETT cuff inflation in the pharynx as an aid to blind nasotracheal intubation in patients with an immobilized cervical spine. The technique was compared with fiberoptic bronchoscopy. Twenty ASA physical status I and II patients undergoing elective surgery in which the trachea was to be intubated nasally were enrolled in this prospective, randomized study. The cervical spine of each patient was immobilized. The trachea of each patient was intubated twice, once using fiberoptic bronchoscopy and once blindly using the technique of ETT cuff inflation in the pharynx. A maximum of three attempts was allowed for intubation using ETT cuff inflation. A maximum of 3 min was allowed for intubation using fiberoptic bronchoscopy. When ETT cuff inflation was used, intubation was successful in 19 of 20 patients (95%); the first attempt at intubation was successful in 14 of 20 patients (70%). Intubation was successful in 19 of 20 patients (95%) when using fiberoptic bronchoscopy. Mean times to intubate were 20.8 +/- 23 s when the ETT cuff was inflated in the pharynx and 60.1 +/- 56 s when using fiberoptic laryngoscopy (P < 0.01). We conclude that both ETT cuff inflation in the pharynx and fiberoptic bronchoscopy are valuable for nasotracheal intubation in patients with an immobilized cervical spine and that ETT cuff inflation can be used as an alternative to fiberoptic bronchoscopy in patients with CSI. ⋯ We compared the technique of endotracheal tube cuff inflation in the pharynx for blind nasotracheal intubation in patients with an immobilized cervical spine with fiberoptic bronchoscopy. There was no significant difference between the success rates of the techniques.
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Anesthesia and analgesia · Aug 1998
The effect of thoracic paravertebral blockade on intercostal somatosensory evoked potentials.
The paravertebral nerve blocks used in upper abdominal or thoracic surgery provide excellent pain relief and can inhibit some aspects of the neuroendocrine stress response to surgical trauma, which suggests that a very high-quality afferent block can be effected. To confirm this, we evaluated intercostal somatosensory evoked potentials (SSEPs) in 10 patients undergoing paravertebral nerve blocks as a treatment for chronic pain. SSEPs were recorded before and after ipsilateral thoracic paravertebral deposition of 1.5 mg/kg bupivacaine 0.5%. Sensory loss to temperature was demonstrated in all patients at the level of injection and had a mean superior spread of 1.4 (range 0-4) dermatomes and a mean inferior spread of 2.8 (range 0-7) dermatomes. SSEPs were abolished (the normal waveform was rendered unrecognizable with unmeasurable latencies and a mean amplitude of zero) in all patients at the level of injection. In addition, a two-dermatome SSEP abolition was found in four patients and a three-dermatome abolition was found in two patients. SSEPs were modified, but not significantly, at all other test points. We conclude that cortical responses to thoracic dermatomal stimulation can be abolished at the block level and adjacent dermatomes by thoracic paravertebral nerve blockade. Equivalent results have not been demonstrated with more central forms of afferent blockade, which suggests that thoracic paravertebral nerve blocks may be uniquely effective. ⋯ To improve outcomes after major surgery, as much nociceptive information as possible should be prevented from entering the central nervous and neuroendocrine systems. We have shown that local anesthetics alongside the vertebral column can abolish the usual brain recordings that follow intercostal nerve stimulation, which suggests that paravertebral nerve blocks may be uniquely effective.
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Anesthesia and analgesia · Aug 1998
Is there a bilateral block of the thoracic sympathetic chain after unilateral intrapleural analgesia?
This study was designed to ascertain, by telethermography and clinical observation, the effect of injecting anesthetic solutions into the intrapleural space on thoracic sympathetic chains and splanchnic nerves. We studied 15 patients with neoplastic (n = 8) or benign (n = 7) pain, divided into three groups of 5 patients each. The first group received 20 mL of bupivacaine 0.25% in the intrapleural space, the second received 20 mL of bupivacaine 0.5%, and the third received 20 mL of isotonic sodium chloride solution. Each patient was examined telethermographically 30, 60, 90, and 120 min after the blockade. Visceral pain intensity was measured in eight patients using a visual analog scale. Patients receiving bupivacaine had a uniform bilateral increase of cutaneous temperature (+2 degrees C). In those with diffuse visceral pain, the mean value of the pain score decreased from 82 +/- 10 mm at the time of injection to 16 +/- 5 at 120 min. We conclude that intrapleural bupivacaine 0.25% and 0.5% results in bilateral blockade of the thoracic sympathetic chain and also of the splanchnic nerves, which pass in front of the spinal column between the two thoracic sympathetic chains. Our data indicate that intrapleural analgesia can be used in the treatment of not only unilateral visceral and somatic pain, but also diffuse abdominal visceral pain. The bilateral increase of the cutaneous temperature of the trunk (measured telethermographically) and the reduction of the diffuse visceral pain suggest a bilateral block of the sympathetic chain and of the splanchnic nerves. ⋯ We subjected 10 patients to monolateral intrapleural analgesia. Five other patients served as controls. The bilateral increase of the cutaneous temperature of the trunk (measured telethermographically) and the reduction of the diffuse visceral pain suggest a bilateral block of the sympathetic chain and of the splanchnic nerves. Our data indicate that intrapleural analgesia can be used in the treatment of not only unilateral visceral and somatic pain, but also diffuse abdominal visceral pain.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Clinical TrialAcetaminophen as an adjunct to morphine by patient-controlled analgesia in the management of acute postoperative pain.
Opioids play a fundamental role in the management of postoperative pain, but their use is associated with a number of side effects, including nausea and vomiting, sedation, and respiratory depression. Co-administration of a nonopioid has been proposed as a method of reducing opioid intake and minimizing side effects. Sixty-one ASA physical status I and II patients were enrolled in a double-blind, randomized, placebo-controlled, parallel study to investigate the effect of a combination of acetaminophen and morphine after open reduction and internal fixation of acute limb fractures. Patients were randomized to receive either oral acetaminophen (1 g every 4 h) or placebo as an adjuvant to morphine by patient-controlled analgesia (PCA) postoperatively. They were assessed daily for 72 h or until the PCA was discontinued according to standardized guidelines. The outcome variables collected were pain scores (11-point scale), amount of morphine self-administered, duration of PCA use, compliance with study design, incidence of nausea and sedation, and overall patient satisfaction. The acetaminophen group had lower pain scores on Day 1 (2.1 vs 3.3; P = 0.03) and a shorter average duration of PCA use (35.8 vs 45.5 h; P = 0.03). Overall patient satisfaction was also significantly greater in the acetaminophen group (8.7 vs 7.9; P = 0.04). These data suggest that acetaminophen is a useful adjunct to morphine PCA. ⋯ This study assesses the benefit of combining two analgesics for the treatment of postoperative pain. Such a combination improves the quality of pain relief and patient satisfaction.
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Anesthesia and analgesia · Aug 1998
Randomized Controlled Trial Comparative Study Clinical TrialEffects of spinal needle type on lateral distribution of 0.5% hyperbaric bupivacaine.
To evaluate the influence of needle type on the lateral distribution of 0.5% hyperbaric bupivacaine, 30 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent and underwent dural puncture by either a 25-gauge Whitacre (n = 15) or a 25-gauge Quincke (n = 15) spinal needle. The needle hole was turned toward the dependent side and 8 mg of 0.5% hyperbaric bupivacaine was injected over 30 s. The lateral position was maintained for 15 min while a blind observer recorded loss of pinprick sensation and degree of motor block on both the dependent and nondependent sides every 5 min until regression of motor block by 1 degree on the dependent side. Thirty minutes after the patients were placed in the supine position, unilateral sensory block was observed in 10 patients in the Whitacre group (66%) and in 2 patients in the Quincke group (13%) (P < 0.05). No differences in the rate of unilateral motor block were observed (73% and 40% in Whitacre and Quincke groups, respectively). We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected slowly into patients in the lateral position for 15 min, the Whitacre spinal needle provides a more marked differential block of sensory nerve roots between dependent and nondependent sides compared with the Quincke needle. ⋯ Because unilateral spinal anesthesia can be advantageous for lower limb surgery, we evaluated the influence of the Whitacre and Quincke spinal needle types on the lateral distribution of small-dose 0.5% hyperbaric bupivacaine injected slowly into adult patients.