Anesthesiology
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In patients undergoing neurosurgical procedures at high risk for venous air embolism (VAE), the presence of a right-to-left shunt adds an additional risk for paradoxical air embolism (PAE). Although this is a rare complication, it can have devastating results. The most common form of right-to-left shunt is a patient foramen ovale (PFO), which can be detected by contrast echocardiography. ⋯ Of these, four were detected by TEE. This is less than the expected incidence based on the known incidence of PFO in the general population. The usefulness of preoperative ECHO as a screening test for PFO in patients undergoing neurosurgical procedures is limited, but when a PFO is found, valuable information is acquired to help manage these patients.
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To determine in infants and children the neuromuscular effect of pipecuronium during alfentanil-N2O/O2 anesthesia, the authors studied 32 ASA Physical Status 1 and 2 pediatric patients undergoing minor elective surgery, divided into three groups according to their age: group 1 included 12 infants, 1.9 +/- 0.2 months old (mean +/- SE; range, 20 days to 3 months), weighing 5.2 +/- 0.3 kg; group 2, 10 infants, 6.1 +/- 0.9 months old (range, 3-11 months), 6.9 +/- 0.4 kg; and group 3, 10 children 5.6 +/- 0.9 yr old (range, 2-9 yr), 19.6 +/- 2.2 kg. Neuromuscular blockade at the ulnar nerve-adductor pollicis muscle was measured by electromyography. Incremental iv doses of pipecuronium were given (one 20 micrograms/kg first dose, followed by 10 micrograms/kg increments) to reach a 95 +/- 2% twitch depression (ED95). ⋯ In 3- to 12-month-old infants ED50 and ED95 were 25.8 +/- 1.5 micrograms/kg and 48.7 +/- 3.5 micrograms/kg, respectively, and both significantly (P less than 0.05) less than those in children. In 0- to 3-month-old infants ED50 and ED95 were 23.7 +/- 1.7 micrograms/kg and 46.5 +/- 2.9 micrograms/kg, respectively, and also significantly (P less than 0.05) less than those measured in children. Time from maximal initial neuromuscular blockade to 75% recovery was 64.5 +/- 8.8 min in children and significantly shorter (P less than 0.05) in the two infant groups (0- to 3-month-old: 38.7 +/- 5.7 min, 3- to 12-month-old: 43.8 +/- 5.3 min, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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Few studies have examined the possible adverse effects that epidural injection of depot corticosteroid preparations may have on meningeal membranes and nervous tissue. Thirty-six healthy adult white rabbits received 0.3 ml/kg epidural injections of either lactated Ringer's solution (negative control group), 1% lidocaine containing methylprednisolone acetate (study group), or normal saline containing talc (positive control group). Animals were killed either 4 or 10 days after injection and stained sections of the spinal cord and meningeal membranes were examined by light microscopy. ⋯ All animals that received epidural injections of normal saline containing talc had marked infiltration of tissue macrophages in the epidural space. There was no thickening of the meningeal membranes or nerve roots in any animal. The complete lack of inflammatory changes and meningeal thickening demonstrated in this pilot study helps to confirm the safety of methylprednisolone acetate when injected into the epidural space.