Early and late reversal of rocuronium and vecuronium with neostigmine in adults and children.

UNLABELLED: We investigated the influence of the timing of neostigmine administration on recovery from rocuronium or vecuronium neuromuscular blockade. Eighty adults and 80 children were randomized to receive 0.45 mg/kg rocuronium or 0.075 mg/kg vecuronium during propofol/fentanyl/N2O anesthesia. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation and adductor pollicis electromyography. Further randomization was made to control (no neostigmine) or reversal with 0.07 mg/kg neostigmine/0.01 mg/kg glycopyrrolate given 5 min after relaxant, or first twitch (T1) recovery of 1%, 10%, or 25%. Another eight adults and eight children received 1.5 mg/kg succinylcholine. At each age, spontaneous recovery of T1 and TOF was similar after rocuronium and vecuronium administration but was more rapid in children (P < 0.05). Spontaneous recovery to TOF0.7 after rocuronium and vecuronium administration in adults was 45.7 +/- 11.5 min and 52.5 +/- 15.6 min; in children, it was 28.8 +/- 7.8 min and 34.6 +/- 9.0 min. Neostigmine accelerated recovery in all reversal groups (P < 0.05) by approximately 40%, but the times from relaxant administration to TOF0.7 were similar and independent of the timing of neostigmine administration. Recovery to T1 90% after succinylcholine was similar in adults (9.4 +/- 5.0 min) and children (8.4 +/- 1.1 min) and was shorter than recovery to TOF0.7 in any reversal group after rocuronium or vecuronium administration. Recovery from rocuronium and vecuronium blockade after neostigmine administration was more rapid in children than in adults. Return of neuromuscular function after reversal was not influenced by the timing of neostigmine administration. These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. IMPLICATIONS: These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. Although spontaneous and neostigmine-assisted recovery is more rapid in children than in adults, in neither is return of function as rapid as after succinylcholine administration.

Hyperbaric spinal ropivacaine: a comparison to bupivacaine in volunteers.

BACKGROUND: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia. METHODS: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant. RESULTS: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given. CONCLUSION: Ropivacaine is half as potent and in equipotent doses has a similar profile to bupivacaine with a higher incidence of side effects. Low-dose hyperbaric spinal ropivacaine does not appear to offer an advantage over bupivacaine for use in outpatient anesthesia.

Dilution of spinal lidocaine does not alter the incidence of transient neurologic symptoms.

BACKGROUND: Although it has been suggested that the dilution of 5% hyperbaric lidocaine before injection for spinal anesthesia may decrease the incidence of transient neurologic symptoms, previous studies have not noted a decreased incidence between 5% and 2% lidocaine. The aim of the current study was to determine whether the incidence of transient neurologic symptoms could be altered by further diluting spinal lidocaine from 2.0% to 0.5%. METHODS: One hundred nine patients with American Society of Anesthesiologists physical status 1 or 2 undergoing outpatient knee arthroscopy were randomized in a double-blind fashion to receive 50 mg hyperbaric spinal lidocaine as a 2.0%, 1.0%, or 0.5% concentration. On the third postoperative day, patients were contacted by a blinded investigator and questioned regarding the incidence of postoperative complications, including transient neurologic symptoms, defined as pain or dysthesia in one or both buttocks or legs occurring within 24 h of surgery. RESULTS: The incidence of transient neurologic symptoms did not differ among patients receiving 2.0% (incidence of 15.8%), 1.0% (incidence of 22.2%), and 0.5% (incidence of 17.1%) lidocaine (P = 0.756). CONCLUSIONS: For ambulatory patients undergoing arthroscopy, the incidence of transient neurologic symptoms is not reduced by decreasing spinal lidocaine concentrations from 2.0% to 1.0% or 0.5%. The incidences of transient neurologic symptoms with the 0.5%, 1.0%, and 2.0% solutions are similar to previously reported incidences for 5.0% lidocaine, suggesting that dilution of lidocaine from 5.0% to 0.5% does not change the incidence of these symptoms.

Prospective study of the incidence of transient radicular irritation in patients undergoing spinal anesthesia.

BACKGROUND: There is considerable controversy regarding the role of subarachnoid 5% hyperbaric lidocaine in the syndrome transient radicular irritation (TRI). This randomized, double-blinded, prospective study was designed to determine the incidence of TRI and identify factors possibly contributing to its development. METHODS: One hundred fifty-nine ASA physical status 1 or 2 patients undergoing outpatient knee arthroscopy or unilateral inguinal hernia repair were prospectively randomized to receive spinal anesthesia with 5% hyperbaric lidocaine with epinephrine (60 mg with 0.2 mg epinephrine for arthroscopy or 75 mg with 0.2 mg epinephrine for hernia repair), 2% isobaric lidocaine without epinephrine (60 mg for arthroscopy or 75 mg for hernia repair), or 0.75% hyperbaric bupivacaine without epinephrine (7.5 mg for arthroscopy or 9.0 mg for hernia repair) in a double-blinded fashion. On the 3rd postoperative day, patients were contacted by a blinded investigator and questioned regarding the incidence of postoperative complications including TRI, defined as back pain with radiation down one or both buttocks or legs occurring within 24 h after surgery. Postoperatively, time from injection to block resolution, ambulation, voiding, and ready for discharge were recorded by a postanesthesia care unit nurse blinded to the group assignment. RESULTS: The incidence of TRI was greater in patients receiving lidocaine than in those receiving bupivacaine (16% vs. 0%; P = 0.003). There was no difference in the incidence of TRI between the patients receiving 5% hyperbaric lidocaine with epinephrine and those receiving 2% isobaric lidocaine without epinephrine (16% vs. 16%; P = 0.98). The incidence of TRI was greater in patients undergoing arthroscopy than in those undergoing hernia repair (13% vs. 5%; P = 0.04). There was no difference in discharge times in patients receiving bupivacaine versus those receiving hyperbaric lidocaine with epinephrine (292 vs. 322 min; P = 0.61). CONCLUSIONS: The incidence of TRI is greater with lidocaine than bupivacaine, decreasing the lidocaine concentration to 2% does not prevent TRI, and surgical position may be an important contributing factor. Discharge times at our institution are not different when equipotent doses of 0.75% hyperbaric bupivacaine or 5% hyperbaric lidocaine with 0.2 mg epinephrine are used in ambulatory patients undergoing spinal anesthesia.

Pharmacokinetics of ropivacaine and bupivacaine for bilateral intercostal blockade in healthy male volunteers.

BACKGROUND: Intercostal blockade produces the highest serum local anesthetic concentrations of all regional anesthetic techniques. The purpose of this study was to determine the pharmacokinetic properties of ropivacaine and bupivacaine after bilateral intercostal blockade. METHODS: The pharmacokinetics of ropivacaine (n = 7) and bupivacaine (n = 7) were determined in adult human volunteers from venous samples drawn over 24 h after bilateral intercostal blockade of T5-T11 with 140 mg of either drug (0.25% plain solutions, 56 ml). Sensory (pinprick, temperature, and touch) and motor blockade (RAM-test and integrated electromyography) were assessed every 2 h. RESULTS: There was no significant difference between the maximum plasma concentrations (Cmax) obtained for either drug (ropivacaine 1.1 +/- 0.4 microgram/ml, bupivacaine 0.9 +/- 0.2 microgram/ml, P = 0.39), and there were no toxic signs observed in the obtained plasma concentration ranges. Plasma concentrations tended to peak (tmax) earlier with ropivacaine (21 +/- 9 versus 30 +/- 8 min, P = 0.09). The terminal half-life (t1/2 beta) of ropivacaine (2.3 +/- 0.8 h) was significantly less than that for bupivacaine (4.6 +/- 2.6 h, P = 0.04). Sensory blockade measured by pinprick was of shorter duration with ropivacaine (6.0 +/- 2.5 h versus bupivacaine 10.0 +/- 3.0 h; P < 0.001). Likewise, motor blockade was less intense and of shorter duration for ropivacaine by RAM-test (P = 0.02). CONCLUSIONS: The results of this pharmacokinetic study indicate that 0.25% ropivacaine and 0.25% bupivacaine (56 ml, 140 mg) produce peak plasma levels less than those considered toxic when used in bilateral intercostal blockade. Studies of ropivacaine for intercostal blockade in surgical patients are necessary before the optimum concentration for efficacy and anesthetic/analgesic duration is identified.

The normal and abnormal scrotum in children: evaluation with color Doppler sonography.

The use of color Doppler sonography to evaluate the symptomatic testes in children with scrotal pain or swelling was prospectively studied with a fourth-generation color sonographic unit with a 7-MHz linear transducer. The 32 patients were 1 day to 18 years old (mean age, 8.6 years). Results were correlated with scintigraphic findings in 23 patients, with the final diagnosis established by surgery in 12 patients, and with clinical follow-up in all patients. Eight cases of testicular torsion, including two of acute torsion and six of late torsion, were correctly detected by color Doppler sonography and confirmed surgically. In the remaining patients, perfusion of the testis was correctly detected by color Doppler examination. The final diagnoses in these patients included torsion of the appendix testis (15 patients), epididymitis (five patients), epididymo-orchitis (one patient), yolk sac tumor of the testis (one patient), hydrocele (one patient), and local reaction to an insect bite (one patient). The ability to detect blood flow in the normal contralateral testis was also evaluated in 28 patients. Blood flow was demonstrated in normal testes larger than 1 cm3. Detection of flow in the very small normal prepubertal testis was often difficult, and no flow was identified in one testis. Flow was identified in central arteries in only six of 13 testes smaller than 1 cm3. We conclude that color Doppler sonography is helpful in the initial evaluation of pediatric testes, providing accurate evaluation of the involved hemi-scrotum in our patients and also providing the benefit of both structural and flow information. Until our sensitivity to low-velocity flow improves, we would not suggest the exclusive use of color Doppler sonography in the evaluation of testicular perfusion in the prepubertal patient. We advocate the addition of testicular scintigraphy to corroborate the presence of testicular perfusion when flow in intratesticular arteries cannot be established with certainty by color Doppler sonography.

An unusual case of meconium peritonitis associated with perforated hydrocolpos.

Meconium peritonitis results from intestinal wall perforation with meconium spillage into the peritoneum during intrauterine life. Anal atresia is associated with meconium peritonitis and is also associated with cloacal malformation. A female neonate presented with a distended abdomen, anal atresia, and meconium peritonitis as diagnosed by calcification in the peritoneal cavity on abdominal radiograph. Sonography and cystography demonstrated a cloacal malformation with perforation of the hydrocolpos and resultant spillage of meconium into the peritoneum. There was no evidence of further perforation of bowel at surgery. This unusual case of meconium peritonitis is reported.

Abscess of the iliopsoas muscle diagnosed by magnetic resonance imaging and ultrasonography.

We have reported a case of abscess of the iliopsoas muscle, in which a limp and hip pain pointed toward pathology of the hip. The diagnosis in such cases may be difficult unless there is close attention to the clinical history and a good physical examination is obtained. One ultrasonographic examination of the hip in such a patient, subtle differences between the iliopsoas muscles should alert the radiologist to examine the psoas muscle. Ultrasonography is instrumental in demonstrating the solid or cystic nature of the iliopsoas mass, while MRI depicts the extent and proximity of adjacent organs. Once an iliopsoas abscess is diagnosed, treatment includes parenteral antibiotics and drainage.

Unusual presentation of perforation of the gallbladder.

Perforation of the gallbladder is a known sequela of acalculus cholecystitis or trauma. A perforated gallbladder may be acute or chronic and can present with vague symptoms making the diagnosis difficult. With delayed recognition there is increased morbidity and mortality. The preoperative diagnosis requires an awareness of the symptoms and signs of acalculus cholecystitis as well as factors that predispose to the development of the diseased gallbladder. Awareness of the radiographic findings associated with a perforated gallbladder and acalculus cholecystitis is also important. The following is a case report of a child with a perforated gallbladder with a radiographic presentation not previously described. A review of the clinical pathogenesis and reported radiographic findings is also included.

Intussusception: clinical and radiographic factors influencing reducibility.

Hydrostatic reduction of intussusception by barium or air enema has been widely accepted. The five-year experience with this procedure at two children's hospitals is reviewed and the results compared to previous studies. Various clinical and radiographic factors are evaluated in relation to the reduction rate. The findings show that the more distal the intussusception is encountered, the lower the rate of reduction. However, 25% are reduced within the rectum with no evidence of increased complications. Small bowel obstruction and prolonged duration of signs and symptoms decreased the rate of reduction statistically but there is no significant increase in complication rate in those attempted, contrary to a previous report. The cresent sign (dissection sign) and age of the patient are not significant factors in reduction as reported by other studies.