Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2004
Case ReportsGrand mal convulsion after an accidental intravenous injection of ropivacaine.
A 36-yr old, ASA physical status I patient scheduled for hip arthroplasty under regional anesthesia received at the end of surgery an i.v. injection of approximately 200 mL of a 0.15% ropivacaine solution (300 mg = 4.6 mg/kg) in approximately 5 min. The bag prepared for postoperative epidural infusion was accidentally connected to a peripheral i.v. line. The patient developed grand mal convulsions, hypotension, and respiratory arrest. No arrhythmias were observed. Twenty minutes after the event, the arterial plasma concentration of ropivacaine was 3.10 microg/mL. Using a pharmacokinetic model, the peak plasma concentration at the time of the accidental administration was estimated at 17.04 microg/mL. The patient recovered uneventfully. ⋯ An accidental i.v. injection of approximately 300 mg of ropivacaine was followed by seizures without any arrhythmia. The patient recovered uneventfully.
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Anesthesia and analgesia · Feb 2004
Case ReportsA suspected case of delayed onset malignant hyperthermia with desflurane anesthesia.
Desflurane has been identified as a weak triggering anesthetic of malignant hyperthermia that, in the absence of succinylcholine, may produce a delayed onset of symptoms. The prolonged interval after exposure may occur more than 6 h after the induction of anesthesia. The unintended underdosing of this patient with dantrolene and the prompt reversal of symptoms may be an attribute of the genetic expression of a weak triggering volatile anesthetic such as desflurane. ⋯ There are multiple genetic variations for malignant hyperthermia (MH) at the ryanodine receptor. Desflurane, as a sole trigger of MH, is weak, and on two occasions in the literature (including this case), less than optimal doses of dantrolene were given with a good result. There may be possible to engineer the risk of MH out of an anesthetic once the genetics of the ryanodine receptor are better understood.
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Anesthesia and analgesia · Feb 2004
Case ReportsSevere hypotension in the prone position in a child with neurofibromatosis, scoliosis and pectus excavatum presenting for posterior spinal fusion.
A 34-mo-old boy with neurofibromatosis, scoliosis, and pectus excavatum developed severe hypotension when positioned prone. A magnetic resonance image study revealed neurofibromas encircling the great vessels. During the next anesthetic the patient was placed in the prone position on transverse bolsters and hypotension ensued again. A transesophageal echocardiogram (TEE) revealed compression of the right ventricle by the sternum. When the child was turned supine, the blood pressure returned to baseline. The patient was returned to the prone position, this time with bolsters placed longitudinally, without problem. This case supports a cardiac evaluation, possible intraoperative TEE, and avoidance of sternal pressure in patients with chest wall deformities requiring prone positioning. ⋯ A child with neurofibromatosis, scoliosis, and a chest wall deformity presenting for spinal fusion developed severe hypotension while prone. This was due to compression of the heart by the sternum, not compression of the great vessels by neurofibromas. Sternal pressure in prone patients with chest wall deformities should be avoided. Unique management included the use of transesophageal echocardiography to determine the cause of the hypotension.
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Anesthesia and analgesia · Feb 2004
Clinical TrialLumbar puncture associated with pneumocephalus: report of a case.
Pneumocephalus is a well known complication of spinal and epidural anesthesia, but it is extremely rare after diagnostic or therapeutic lumbar puncture. This uncommonness can obscure the clinical diagnosis and lead to unnecessary procedures and prolonged patient discomfort. We report a 72-yr-old woman with normal pressure hydrocephalus who underwent an unremarkable lumbar puncture that was complicated by a postprocedure pneumocephalus that manifested as a continuous headache. The pneumocephalus resolved spontaneously after 4 days. Possible mechanisms for this occurrence, along with steps that can be taken to prevent this complication, are discussed. ⋯ We report a case of symptomatic pneumocephalus in a woman with normal pressure hydrocephalus after an unremarkable lumbar puncture. The possible mechanisms for this occurrence, along with steps that can be taken to prevent this complication, are discussed.
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Anesthesia and analgesia · Feb 2004
Case ReportsThe presence of working memory without explicit recall in a critically ill patient.
We describe an intubated patient sedated with propofol who interacted with caregivers, demonstrating intact "working memory." When neuromuscular blockade and bispectral index (BIS) monitoring were instituted, a greatly reduced amount of sedative achieved BIS values less than 60. Neither the sedation that allowed working memory nor the lighter sedation that produced BIS values less than 60 resulted in recall. This experience suggests that working memory demonstrated when BIS values are less than 60 is unlikely to lead to recall. ⋯ The presence of intact working memory during sedation is a poor predictor of explicit recall when bispectral index values are maintained less than 60.