Intravenous opioids reduce airway irritation during induction of anaesthesia with desflurane in adults.
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Desflurane is not used for the induction of anaesthesia despite its favourable pharmacokinetic characteristics because it causes airway irritation. We investigated whether pretreatment with i.v. narcotics reduced unwanted effects. One hundred and eighty adults were randomized to three groups (60 per group) to receive i.v. saline, fentanyl 1 microgram kg-1 and morphine 0.1 mg kg-1, respectively, before inhalational induction with desflurane in nitrous oxide and oxygen. Mean time to loss of response to commands was 4.0 min, without significant differences between groups. The incidence of coughing was greater (25%) in the control group than in the fentanyl (5.0%) and morphine groups (8.3%). The incidence of apnoea was 20.0% in the control group versus 13.3 and 5.0% in the fentanyl and morphine groups, respectively. Laryngospasm developed in 11.7% of controls compared with 3.3 and 1.7% in the fentanyl and morphine groups, respectively. More patients in the control group had excitatory movements (46.7%) than in the fentanyl (16.7%) and morphine (8.3%) groups. These results demonstrate that i.v. opioids reduce airway irritability significantly during inhalational induction with desflurane in adults. (+info)
Additional observations were made in the use of the bispectral (BIS) index with the use of ketamine and in performing general anesthesia without the use of local anesthesia in nonintubated patients. Twenty-five subjects undergoing extraction procedures in an outpatient setting were analyzed using bispectral analysis with ketamine and midazolam. Despite repeated injections of midazolam during the procedure, only transient decreases of the BIS occurred to the 80s, with a low value of 77 in all but 1 patient where ketamine was used. In comparison, values in the 50-70 range are typically seen immediately after the administration of sedative doses of midazolam, propofol, or methohexital. In the second study, once propofol anesthesia was initiated, BIS readings in the 30s were commonly seen in patients during their procedure. The lowest BIS level observed was 18. Bispectral analysis was useful to trend the present anesthetic state and adjust the dose of propofol accordingly. In no case was laryngospasm or total airway obstruction observed. In 1 case, partial airway obstruction secondary to retro-positioning of the tongue occurred with a subsequent decrease in oxygen saturation to 89%. This was rectified by repositioning the patient to alleviate the obstruction. Consistent with previous studies utilizing ketamine, BIS values are consistently higher when compared with other hypnotic agents. With the subsequent injection of midazolam, the BIS level did not decrease to anticipated levels. In the final study reviewed, when local anesthesia was not used during general anesthesia, bispectral analysis was a useful adjunct in helping maintain a steady state of general anesthesia in nonintubated patients undergoing third molar extractions. Bispectral analysis offers additional information on the depth of the hypnotic state and is useful in helping control the depth of anesthesia. A limitation of the index includes the inability to titrate the level of sedation induced by hypnotic agents such as midazolam when ketamine is concomitantly administered. (+info)
Complications of flexible bronchoscopy in children: prospective study of 1,328 procedures.
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Complications of flexible bronchoscopy (FB) were prospectively evaluated during 1,328 diagnostic procedures in children, not in intensive care units. A total 92.8% of the procedures were performed in conscious patients under sedation and 7.2% under deep sedation. Supplementary oxygen was provided in approximately 80% of cases via endoscopic face mask (n=783) or nasal prongs (n=290). At least one complication was recorded in 91 cases (6.9%). Minor complications (n=69; 5.2%) included moderate and transient episodes of desaturation (n=15), isolated excessive coughing (n=22), excessive nausea reflex with coughing (n=20), transient laryngospasm (n=6) and epistaxis (n=6). Major complications (n=22; 1.7%) included oxygen desaturation to <90%, either isolated (n=10) or associated with laryngospasm (n=6), coughing (n=4), bronchospasm (n=1), and pneumothorax (n=1). Major complications involving oxygen desaturation were associated with age <2 yrs (13 of 529 versus 8 of 778) and laryngotracheal abnormalities (7 of 85 versus 14 of 1,222). The overall frequency of complications was similar in conscious (6.7%) but sedated patients and patients under deep (7.3%) sedation. However, the frequency of transient desaturation was significantly higher in children undergoing FB under deep sedation. Transient fever after bronchoalveolar lavage was observed in 52 of 277 cases (18.8%). Flexible bronchoscopy is a safe procedure with <2% major complications. Careful analysis of indications and clinical status for each patient, and proper anaesthesia and monitoring during the examination ensure that the procedure is successful, with a minimum of complications. (+info)
Prevention of oxaliplatin-related neurotoxicity by calcium and magnesium infusions: a retrospective study of 161 patients receiving oxaliplatin combined with 5-Fluorouracil and leucovorin for advanced colorectal cancer.
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PURPOSE: Oxaliplatin is active in colorectal cancer. Sensory neurotoxicity is its dose-limiting toxicity. It may come from an effect on neuronal voltage-gated Na channels, via the liberation one its metabolite, oxalate. We decided to use Ca and Mg as oxalate chelators. EXPERIMENTAL DESIGN: A retrospective cohort of 161 patients treated with oxaliplatin + 5-fluorouracil and leucovorin for advanced colorectal cancer, with three regimens of oxaliplatin (85 mg/m(2)/2w, 100/2w, 130/3w) was identified. Ninety-six patients received infusions of Ca gluconate and Mg sulfate (1 g) before and after oxaliplatin (Ca/Mg group) and 65 did not. RESULTS: Only 4% of patients withdrew for neurotoxicity in the Ca/Mg group versus 31% in the control group (P = 0.000003). The tumor response rate was similar in both groups. The percentage of patients with grade 3 distal paresthesia was lower in Ca/Mg group (7 versus 26%, P = 0.001). Acute symptoms such as distal and lingual paresthesia were much less frequent and severe (P = 10(-7)), and pseudolaryngospasm was never reported in Ca/Mg group. At the end of the treatment, 20% of patients in Ca/Mg group had neuropathy versus 45% (P = 0.003). Patients with grade 2 and 3 at the end of the treatment in the 85 mg/m(2) oxaliplatin group recovered significantly more rapidly from neuropathy than patients without Ca/Mg. CONCLUSIONS: Ca/Mg infusions seem to reduce incidence and intensity of acute oxaliplatin-induced symptoms and might delay cumulative neuropathy, especially in 85 mg/m(2) oxaliplatin dosage. (+info)
Chronic cough following cardiac transplantation: vagal Mitempfindung?
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Since operation a cardiac transplant recipient has suffered from chronic, non-productive but intense coughing spells triggered by stimulation of the right external ear. This demonstrates the unusual phenomenon of acquired aberrant sensory referral. (+info)
Induction and maintenance characteristics of anesthesia with desflurane and nitrous oxide in infants and children.
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To determine the induction and maintenance characteristics of desflurane in pediatric patients, the authors anesthetized 206 infants and children aged 1 month to 12 yr with nitrous oxide plus desflurane and/or halothane in oxygen. Patients were assigned to one of four groups: anesthesia was 1) induced and maintained with desflurane after premedication with an oral combination of meperidine, diazepam, and atropine; 2) induced and maintained with desflurane; 3) induced with halothane and maintained with desflurane; or 4) induced and maintained with halothane. An unblinded observer recorded time to loss of consciousness (lid reflex), time to intubation, and clinical characteristics of the induction and maintenance of anesthesia. Moderate-to-severe laryngospasm (49%) and moderate-to-severe coughing (58%) occurred frequently during induction of anesthesia with desflurane; the incidence of these was not altered by premedication. In contrast, laryngospasm and coughing were rare during induction of anesthesia with halothane. In unpremedicated patients, time to loss of lid reflex (mean +/- SD) was similar for desflurane (2.4 +/- 1.2 min) and halothane (2.1 +/- 0.8 min). During induction of anesthesia, before laryngoscopy and intubation, mean arterial pressure less than 80% of baseline was more common with halothane; heart rate and mean arterial pressure greater than 120% of baseline were more common with desflurane. Intraoperatively, heart rate greater than 120% of baseline was more common with desflurane; blood pressures were similar for the two anesthetics. The authors conclude that the high incidence of airway complications during induction of anesthesia with desflurane limits its utility for inhalation induction in pediatric patients. Anesthesia can be safely maintained with desflurane if induced with a different anesthetic. (+info)
Laryngospasm during subarachnoid block.
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Central neuraxial block is associated with increased vagal tone. We report a patient who developed laryngospasm and stridor under spinal anaesthesia. This was treated successfully with i.v. atropine and fluids. We propose that the laryngospasm was secondary to increased vagal tone under the spinal anaesthetic. Such a manifestation of increased vagal tone under spinal anaesthesia has not been reported previously. (+info)
Central nervous system control of the laryngeal muscles in humans.
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Laryngeal muscle control may vary for different functions such as: voice for speech communication, emotional expression during laughter and cry, breathing, swallowing, and cough. This review discusses the control of the human laryngeal muscles for some of these different functions. Sensori-motor aspects of laryngeal control have been studied by eliciting various laryngeal reflexes. The role of audition in learning and monitoring ongoing voice production for speech is well known; while the role of somatosensory feedback is less well understood. Reflexive control systems involving central pattern generators may contribute to swallowing, breathing and cough with greater cortical control during volitional tasks such as voice production for speech. Volitional control is much less well understood for each of these functions and likely involves the integration of cortical and subcortical circuits. The new frontier is the study of the central control of the laryngeal musculature for voice, swallowing and breathing and how volitional and reflexive control systems may interact in humans. (+info)