Ropivacaine with or without clonidine improves pediatric tonsillectomy pain.

OBJECTIVE: To determine if preemptive analgesia with ropivacaine hydrochloride with or without clonidine hydrochloride decreases pain and hastens recovery after tonsillectomy. DESIGN: Prospective, randomized, triple-blinded trial. SETTING: University referral center; pediatric ambulatory practice. PARTICIPANTS: Sixty-four children, aged 3 to 15 years, undergoing tonsillectomy. INTERVENTIONS: Patients received injections in the tonsillar fossae of isotonic sodium chloride, ropivacaine, or ropivacaine plus clonidine prior to tonsil excision. MAIN OUTCOME MEASURES: Visual analogue (pain) scale scores at rest and when drinking, opioid use, recovery time to normal activity, and incidence of symptoms such as otalgia. RESULTS: Pain was reduced on postoperative day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups as compared with the isotonic sodium chloride-treated group (P<.05). Pain was also decreased in the ropivacaine plus clonidine-treated group on postoperative days 3 and 5 (P<.05). Intravenous narcotic use was decreased on day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups (P<.05). Cumulative codeine use was similar at day 3 for all patients, but was decreased at day 5 in the ropivacaine plus clonidine-treated group (P<.05). The incidence of otalgia decreased from 89% (16/18) in the isotonic sodium chloride-treated group to 63% (12/19) in the ropivacaine-treated and 61%(11/18) in the ropivacaine plus clonidine-treated groups (P<.01). Recovery to normal activity was shortened from 8.1 +/- 1.6 days to 5.8 +/- 2.9 days (mean +/- SD) in the isotonic sodium chloride-treated and ropivacaine plus clonidine-treated groups, respectively (P =.03). CONCLUSION: Preincisional injection of ropivacaine with clonidine prior to tonsillectomy has a preemptive analgesic effect that outlasts the local anesthetic and decreases pain, opioid use, and the time to return to normal activity.

A unique approach to postoperative analgesia for ambulatory surgery.

Postoperative analgesia for the ambulatory surgery patient is frequently inadequate. Continuous regional analgesia improves outcome and patient satisfaction in hospitalized patients. This paper describes the successful use of continuous regional analgesia following orthopedic surgery in the ambulatory setting.

Cerebral microembolism diagnosed by transcranial Doppler during total knee arthroplasty: correlation with transesophageal echocardiography.

BACKGROUND: Tourniquet deflation following total knee arthroplasty (TKA) frequently results in release of emboli into the pulmonary circulation. Small emboli may gain access to the systemic circulation via a transpulmonary route or through a patent foramen ovale. This study examined the incidence of cerebral microembolism after tourniquet release by transcranial Doppler (TCD) ultrasonography and its correlation with echogenic material detected in the left atrium. METHODS: Twenty-two adult patients (9 men, 13 women) undergoing TKA were studied with simultaneous TCD ultrasonography and transesophageal echocardiography. Data were recorded after anesthesia induction and tourniquet inflation and during tourniquet deflation. Emboli counts were performed manually off-line. Echogenic material in the left atrium was qualitatively assessed and correlated with TCD data. Patients were examined postoperatively for focal neurologic deficits. RESULTS: Fifteen patients had unilateral TKA (six left, nine right) and seven had bilateral TKA. Cerebral emboli were detected in 9 of 15 patients (60%) with unilateral TKA and in 4 of 7 patients (57%) with bilateral TKA. Echogenic material was identified in the left atrium in eight patients (two through a patent foramen ovale and six from the pulmonary veins). Emboli counts were significantly higher in patients with bilateral TKA compared with those with unilateral TKA (P<0.05). Duration of tourniquet time in patients with emboli was longer only during bilateral TKA (P<0.05). All patients with echogenic material in the left atrium detected by transesophageal echocardiography had emboli as assessed by TCD ultrasonography. No focal neurologic deficits were identified. CONCLUSIONS: Cerebral microembolism occurs frequently during tourniquet release, even in the absence of a patient foramen ovale. This passage most likely occurs through the pulmonary capillaries or the opening of recruitable pulmonary vessels.

Failure to awaken after general anesthesia due to cerebrovascular events.

Failure to awaken after general anesthesia is a rare complication that may be caused by residual drug effect, systemic abnormalities, or neurologic injury. Failure to awaken often is initially attributed to residual drug effect, potentially delaying correct diagnosis. Three cases of failure to awaken because of neurologic injury are reviewed. Differential diagnosis of failure to awaken is discussed, and the importance of distinguishing pathologic causes from residual anesthetic is stressed.

Local anesthetic infusion through nerve sheath catheters for analgesia following upper extremity amputation. Clinical report.

BACKGROUND AND OBJECTIVES: Reports about the efficacy of local anesthetic perfusion of nerve stumps following lower extremity amputation are conflicting. We report our experience with this technique following amputation of the upper extremity. METHODS: Six consecutive patients undergoing proximal upper extremity amputations (four forequarter amputations and two shoulder disarticulations) for malignancy were prospectively observed. In all patients, catheters were placed within the amputated nerve sheaths at the conclusion of the procedure. Bupivacaine. 0.25%, was administered through each catheter as a bolus and then as a continuous infusion for at least 72 hours after surgery. Narcotic usage, level of pain as reported verbally, and presence of phantom limb pain during the infusion were recorded. For at least 1 year after operation, data were gathered on the presence of phantom limb pain and its intensity during each follow-up visit. RESULTS: Complete analgesia was achieved in all patients by postoperative day 2. Narcotic usage was low. Three of the six patients reported phantom limb pain during follow-up evaluation. CONCLUSIONS: Continuous local anesthetic perfusion of amputated nerves via a catheter placed under direct vision provided excellent postoperative analgesia. The incidence of phantom limb pain for cancer patients did not differ from that previously reported but was easily managed pharmacologically. The technique may also be efficacious for traumatic amputations.

Cardiac arrest during total knee replacement using a long-stem prosthesis.

Sudden cardiac arrest, a rare and often fatal complication of total joint replacement, usually occurs during the insertion of polymethyl methacrylate cement and a prosthesis. We describe a cardiac arrest during insertion of a customized long-stem prosthesis (without the use of a tourniquet) for revision of an earlier total knee replacement. We attribute this complication to the "fat embolism syndrome" (FES)--hypoxemia from an acute pulmonary embolism composed of fat and marrow elements extruded into the venous circulation--coupled with systemic hypotension from absorption of the cement monomer. The syndrome appears to be more common when long-stem prostheses are used. Hypoxemia also correlates with the release of tissue-thromboplastic products as well as the bone marrow elements. Phase 1 of the syndrome consists of particulate obstruction of the pulmonary circulation that causes cor pulmonale and bradycardia or other dysrhythmia. Phase 2 is characterized by respiratory and neurologic manifestations associated with the classic conception of the syndrome. Intraoperative increases in pulmonary artery and pulmonary artery occlusion pressures and pulmonary vascular resistance during unexplained hypoxemia should alert the clinician to the possibility of FES. Proper diagnosis relies on recognizing the three most common clinical manifestations: hypoxemia, neurologic derangements, and fever. Other manifestations of FES are petechiae, thrombocytopenia, anemia, lipuria, changes on ECG, tachycardia, and dyspnea.

Serum bupivacaine concentrations after intraarticular injection for pain relief after knee arthroscopy.

Intraarticular injection of local anesthetic drugs after arthroscopic knee surgery is used to provide postoperative analgesia. Toxic serum levels of bupivacaine have been reported after its use both in regional anesthesia and for intraarticular injection. The toxicity of the former is related to needle misplacement and the latter is presumed to be absorptive. This study evaluates the effect of tourniquet inflation and the addition of epinephrine on serum concentrations of bupivacaine after intraarticular injection. The results shows that the peak serum bupivacaine concentrations can be reduced by adding epinephrine and injecting it after tourniquet inflation.