Is the effect of sugammadex always rapid in onset?

The aim of this literature review was to compare the duration of the recovery effects of sugammadex. We therefore systematically searched Medline for relevant reports that investigated the recovery time to a train-of-four (TOF) ratio of 0.9 after sugammadex administration. Thirty-three reports were retrieved. For the recommended dose of 2 mg/kg of sugammadex, some studies noted maximum reversal times to a TOF ratio of 0.9 of up to 12 minutes. One study recorded a maximum delay of 22.3 minutes after the recommended dose of 4 mg/kg of sugammadex. Regarding the reversal of rocuronium immediately after its administration, a maximum delay of 16.6 minutes was noted after 16 mg/kg of sugammadex. Whereas reversal with sugammadex is likely within 2-3 minutes, unexpectedly long sugammadex recovery times were occasionally recognized in elderly patients, patients with slower hemodynamic circulation, patients with pulmonary disease, some obese patients, and some cases of renal failure. Additionally, variability in the onset of sugammadex effect was observed in healthier patients (up to 22.3 minutes). This review confirms the known rapid reversal by the recommended doses of sugammadex. However, due to possibility of an increased recovery time, any patient who receives sugammadex to reverse neuromuscular block should have his or her TOF checked prior to extubation.

A prospective, observational study comparing postoperative residual curarisation and early adverse respiratory events in patients reversed with neostigmine or sugammadex or after apparent spontaneous recovery.

Six years ago, a study performed in our department reported that the incidence of postoperative residual curarisation (PORC) was 39%. The reassessment of neuromuscular monitoring and reversal of neuromuscular block in routine anaesthetic practice is relevant now that sugammadex has become available. The incidence of PORC, defined by a train-of-four (TOF) <90%, was evaluated at post-anaesthesia care unit (PACU) arrival in patients whose neuromuscular block had been reversed with neostigmine or sugammadex and those in whom reversal was felt unnecessary (adequate spontaneous recovery). During the PACU stay we recorded the oxygen saturation (SpO(2)) at arrival, episodes of SpO(2) <90%, airway manoeuvres and/or stimulation required to maintain SpO(2) >90%, and the need for re-intubation. In total, 624 patients were studied. Fifteen percent (66/441) of the patients who were not reversed, 15% (21/139) of those who were reversed with neostigmine and 2% (1/44) of those who received sugammadex exhibited PORC (P=0.06). No patient required reintubation in the PACU. The absence of neuromuscular monitoring and pharmacological reversal before extubation were not associated with PORC. A TOF <90% at PACU arrival was not associated with SpO(2) <90% during the PACU stay. Body mass index was the only independent predictor of SpO(2) <90% during the stay in the PACU. These findings indicate that in recent years, the incidence of PORC, defined by a TOF <90%, has dramatically decreased in our institution. The differences in PORC were not statistically significant between patients who received sugammadex for reversal and patients with spontaneous recovery or neostigmine reversal.

Reversal of rocuronium-induced neuromuscular block with sugammadex in heart failure patients: a prospective observational study.

The aim of this study was to assess the hemodynamic stability and efficacy of 2 mg/kg sugammadex in reversing rocuronium-induced neuromuscular block in patients with heart failure. Twelve patients who had an ejection fraction < or = 25% and who were undergoing general anesthesia for cardiac resynchronization therapy, an automated implantable cardioverter-defibrillator, or battery replacement of the device were included. Neuromuscular function was monitored by acceleromyography of the adductor pollicis muscle. Each patient received 0.6 mg/kg of rocuronium and maintenance doses of 0.1 mg/kg when required. When the second twitch appeared at the end of surgery, the patients received 2 mg/kg sugammadex. After the administration of sugammadex, the time for recovery to a normalized train-of-four (TOF) ratio of 0.9 was 2.78 +/- 0.67 min. Blood pressure and heart rate remained stable up to 10 min after the administration of sugammadex and then increased by the 30-min assessment. Three patients had episodes of SpO2 < 90% in the postanesthesia care unit. No sugammadex-related adverse events were reported. Sugammadex can adequately restore neuromuscular function in heart failure patients under hemodynamically stable conditions. However, longer reversal times are required than previously observed in healthy, young patients.

Dialysability of sugammadex and its complex with rocuronium in intensive care patients with severe renal impairment.

BACKGROUND: Renal excretion is the primary route for the elimination of sugammadex. We evaluated the dialysability of sugammadex and the sugammadex-rocuronium complex in patients with severe renal impairment in the intensive care unit (ICU). METHODS: Six patients in the ICU with acute severe renal impairment received general anaesthesia for transoesophageal echocardiography, to replace their tracheal tubes, or for bronchoscopy. Five of the six patients were in the ICU after cardiac/vascular surgery and one for pneumonia-induced respiratory failure. They all received rocuronium 0.6 mg kg(-1), followed 15 min later by sugammadex 4.0 mg kg(-1). Two patients were studied for two dialysis episodes and four patients for four episodes. Rocuronium and sugammadex concentrations were measured in plasma and dialysate at several time points before, during, and after high-flux dialysis. Dialysis clearance in plasma and dialysate, and reduction ratio (RR) (the extent of the plasma concentration reduction at the end of a dialysis episode when compared with before dialysis) were calculated for each dialysis episode. RESULTS: Dialysis episodes lasted on average 6 h. Observed RRs indicated mean reductions of 69% and 75% in the plasma concentrations of sugammadex and rocuronium, respectively, during the first dialysis episode. Reductions were around 50% during sequential dialysis episodes. On average, dialysis clearance of sugammadex and rocuronium in blood was 78 and 89 ml min(-1), respectively. CONCLUSIONS: Haemodialysis using a high-flux dialysis method is effective in removing sugammadex and the sugammadex-rocuronium complex in patients with severe renal impairment.

Repeat dosing of rocuronium 1.2 mg kg-1 after reversal of neuromuscular block by sugammadex 4.0 mg kg-1 in anaesthetized healthy volunteers: a modelling-based pilot study.

BACKGROUND: Re-intubation and re-operation may occasionally be required after neuromuscular block (NMB) reversal. This study evaluated block onset times of a second dose of rocuronium (1.2 mg kg(-1)) after sugammadex reversal of rocuronium 0.6 mg kg(-1). METHODS: In this open-label study of healthy anaesthetized volunteers, subjects received rocuronium 0.6 mg kg(-1), were antagonized at 1-2 post-tetanic counts with sugammadex 4.0 mg kg(-1), and received rocuronium 1.2 mg kg(-1) at 5, 7.5, 10, 15, 20, 22.5, 25, 27.5, 30, 45, or 60 min after sugammadex. Spontaneous recovery occurred after repeat rocuronium dose. Primary endpoints were the onset time of maximal block (time to lowest T(1) value reached) and the clinical duration of block (until T(1)=25%) after repeat rocuronium dose. RESULTS: Sixteen subjects were included. For subjects receiving rocuronium 1.2 mg kg(-1) 5 min after sugammadex (n=6), mean (sd) onset time (to T(1)=0) was 3.06 (0.97) min; range, 1.92-4.72 min. For repeat dose time points ≥25 min (n=5), mean onset was faster (1.73 min) than for repeat doses <25 min (3.09 min) after sugammadex. The duration of block ranged from 17.7 min (rocuronium 5 min after sugammadex) to 46 min (repeat dose at 45 min). Mean duration was 24.8 min for repeat dosing <25 min vs 38.2 min for repeat doses ≥25 min. CONCLUSIONS: Rapid re-onset of NMB occurred after repeat dose of rocuronium 1.2 mg kg(-1) as early as 5 min after sugammadex in healthy volunteers. Re-onset of block took longer if second rocuronium dose was <25 min after sugammadex. The duration of action of second rocuronium dose increased with later repeat dose time points.

Successful minimally invasive emergency surgery for descending necrotising mediastinitis.

We present a case of descending necrotising mediastinitis in a healthy young patient, complicated by pneumonia of the right inferior lobe of the lung with parapneumonic effusions. We describe a successful outcome following adequate antibiotics, effective surgical drainage by thoracoscopy and parasternotomy, and hyperbaric oxygen therapy.

Safety and tolerability of single intravenous doses of sugammadex administered simultaneously with rocuronium or vecuronium in healthy volunteers.

BACKGROUND: Sugammadex rapidly reverses rocuronium- and vecuronium-induced neuromuscular block. To investigate the effect of combination of sugammadex and rocuronium or vecuronium on QT interval, it would be preferable to avoid the interference of anaesthesia. Therefore, this pilot study was performed to investigate the safety, tolerability, and plasma pharmacokinetics of single i.v. doses of sugammadex administered simultaneously with rocuronium or vecuronium to anaesthetized and non-anaesthetized healthy volunteers. METHODS: In this phase I study, 12 subjects were anaesthetized with propofol/remifentanil and received sugammadex 16, 20, or 32 mg kg(-1) combined with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1); four subjects were not anaesthetized and received sugammadex 32 mg kg(-1) with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1) (n=2 per treatment). Neuromuscular function was assessed by TOF-Watch SX monitoring in anaesthetized subjects and by clinical tests in non-anaesthetized volunteers. Sugammadex, rocuronium, and vecuronium plasma concentrations were measured at several time points. RESULTS: No serious adverse events (AEs) were reported. Fourteen subjects reported 23 AEs after study drug administration. Episodes of mild headache, tiredness, cold feeling (application site), dry mouth, oral discomfort, nausea, increased aspartate aminotransferase and gamma-glutamyltransferase levels, and moderate injection site irritation were considered as possibly related to the study drug. The ECG and vital signs showed no clinically relevant changes. Rocuronium/vecuronium plasma concentrations declined faster than those of sugammadex. CONCLUSIONS: Single-dose administration of sugammadex 16, 20, or 32 mg kg(-1) in combination with rocuronium 1.2 mg kg(-1) or vecuronium 0.1 mg kg(-1) was well tolerated with no clinical evidence of residual neuromuscular block, confirming that these combinations can safely be administered simultaneously to non-anaesthetized subjects. Rocuronium and vecuronium plasma concentrations decreased faster than those of sugammadex, reducing the theoretical risk of neuromuscular block developing over time.

How rational is muscle relaxation during cardiac surgery?

The incidence of postoperative residual curarisation after a neuromuscular blocking drug infusion is important. The greater risk for postoperative residual curarisation than with a single bolus can only be tackled by neuromuscular transmission monitoring, and selectively antagonising the block. Such monitoring is seldom used in cardiac surgery. If the neuromuscular block is not monitored intraoperatively in patients who receive a continuous infusion of a neuromuscular blocking drug, adequate sedation should be provided until proper recovery of neuromuscular function, which can take multiple hours. Therefore, we should avoid administering large doses of neuromuscular blocking drugs, even in the context of planned postoperative ventilation. One single bolus of neuromuscular blocking drug, given at induction to facilitate intubation, should provide, first of all, a rapid free airway, which is often compromised after opioid induction in cardiac surgery. For these purposes, rocuronium is particularly indicated. Moreover, by only administering a single neuromuscular blocking drug bolus at induction, postoperative residual curarisation can be avoided, becoming more and more important in fast tracking. Finally, in patients undergoing cardiac surgery, cost-effective combinations of drugs and techniques need to be used that provide adequate anaesthesia and analgesia, as well as appropriate muscle relaxation, while offering ideal operative conditions with minimal risk of myocardial ischaemia and residual curarisation. Therefore the continuous administration of neuromuscular blocking drugs, during cardiac surgery, seems unnecessary.

Surgical treatment of atrial fibrillation.

Atrial fibrillation is a very common arrhythmia that carries a considerable risk of thromboembolic complications. Surgical treatment is an effective way to convert atrial fibrillation into sinus rhythm and significantly prevents thromboembolism postoperatively. In this review we describe recent advancements in the surgical options and detail our strategy for the surgical treatment of atrial fibrillation.

Large bolus dose vs. continuous infusion of cisatracurium during hypothermic cardiopulmonary bypass surgery.

BACKGROUND AND OBJECTIVE: We investigated whether a high bolus dose of cisatracurium (8x ED95) given at induction can provide muscle relaxation for the major part of a cardiac procedure with hypothermic cardiopulmonary bypass, avoid important postoperative residual curarization and cause no waste of product. METHODS: Twenty patients were randomly assigned either to Group 1 (n = 10) or Group 2 (n = 10). Those in Group 1 were given cisatracurium in a high bolus dose (0.4 mg kg(-1)). Those in Group 2 received cisatracurium 0.1 mg kg(-1) at induction followed after 30 min by a continuous infusion of cisatracurium. As an escape medication in case of patient movement, a bolus dose of cisatracurium 0.03 mg kg(-1) was given. RESULTS: In Group 1 (large cisatracurium bolus dose), the clinical duration of effect (until T1/T0 = 25%) was 110 min. Six of 10 patients in Group 1 required additional boluses of cisatracurium intraoperatively. Four of these six had received an additional bolus near the end of surgery and had a train-of-four (TOF) ratio = 0 at the end. The other four patients in Group 1 had a final TOF ratio >0.9. In Group 2 (continuous cisatracurium infusion), only two patients had a TOF ratio >0.9 at the end of surgery, no patient moved and none received additional boluses. The total amount of cisatracurium used in the bolus and infusion Groups was 34.5 +/- 7.8 and 21.3 +/- 5.7 mg, respectively (P = 0.0004). CONCLUSIONS: For continued neuromuscular block during hypothermic cardiac surgery, a high bolus dose of cisatracurium appears to be safe, although it is not an alternative to a continuous infusion, as its neuromuscular blockade does not cover the intraoperative period and a high incidence of movements occurs. In the patients who received a high bolus dose of cisatracurium, postoperative residual curarization appeared after additional boluses had been given. The consumption of cisatracurium by high bolus was significantly greater than with continuous infusion.

Postoperative residual curarisation: complication or malpractice?

Neuromuscular blocking drugs are often used in anaesthesia; in some types of surgery, their continuous infusion is indicated to limit the otherwise high incidence of movement. A large amount of postoperative residual curarisation is found after a single bolus, but more especially when continuous infusions are used in healthy patients and even more so in those with organ dysfunction or undergoing special types of surgery. Therefore, one should always optimise the dose requirements over time using neuromuscular transmission monitoring. Such monitoring should also help the clinician to antagonise selectively the neuromuscular block at the end of surgery. One should probably avoid routine antagonisation, especially in certain subgroups of patients, until a selective and safe reversal agent has been developed. At present, then, the only objective and reliable guide to facilitating the decision for selective antagonisation is the neuromuscular transmission monitor. Recent data and editorials warning about postoperative residual curarisation after boluses and infusions of neuromuscular blocking drugs have made residual curarisation one of the most feared complications in anaesthesia. There may be a consequent issue of malpractice if neuromuscular transmission monitoring is not used and/or pharmacological antagonisation is not performed.

Initial experience with an endoscopic radial artery harvesting technique.

OBJECTIVE: The purpose of the study was to investigate the feasibility of an endoscopic radial artery harvesting technique to improve esthetic results and possibly reduce the incidence of neurologic complications observed with the open method. METHODS: Between July 1, 2002, and October 1, 2003, a total of 54 patients underwent endoscopic radial artery harvesting at our institution. Standard endoscopic equipment and a Harmonic Scalpel (Ethicon Endo-Surgery, Inc, Cincinnati, Ohio) were used. Mean age of the patients was 63 +/- 8.1 years, and 16% were female. All patients underwent a preoperative Allen test and duplex ultrasonography to demonstrate adequate ulnar collateral flow. The nondominant arm was used for radial artery harvesting. Mean clinical follow-up was 13 +/- 4.6 months. RESULTS: The artery was harvested through a 3-cm incision at the wrist and was divided at the elbow either through a small counterincision (n = 16) or endoscopically with the use of clips, Endoloop, and endoscopic scissors (n = 38). Mean harvest time was 42.2 +/- 16.9 minutes but decreased from 85 minutes for the first cases to 25 minutes for the last 5 cases. Mean harvested length was 19.6 +/- 1.7 cm. Harvesting complications included 1 conversion, 2 postoperative hematomas, 1 injury, 8 endoscopically controlled bleedings, and 15 cases of at least some superficial radial nerve paresthesia at 6 weeks (clinically relevant in 4 cases). Selective postoperative angiography revealed 1 occluded graft and 1 stenotic graft requiring percutaneous transluminal coronary angioplasty of the native vessel. Eighty-seven percent of the patients were enthusiastic about this new procedure. CONCLUSIONS: Endoscopic radial artery harvesting is a feasible procedure that requires a definite learning curve. Although nerve paresthesias were not completely eliminated in our experience, the technique provided ample patient satisfaction. Further clinical follow-up is required to determine long-term patency rates.

Implications of the use of neuromuscular transmission monitoring on immediate postoperative extubation in off-pump coronary artery bypass surgery.

BACKGROUND AND OBJECTIVE: When continuous infusions of neuromuscular blocking drugs are administered during lengthy interventions and no routine antagonism of their effects is applied, there is a dramatic incidence of residual curarization. We have examined whether the use of neuromuscular transmission monitoring results in differences in the incidence of postoperative residual curarization, the use of antagonist agents, and the endotracheal extubation rate and outcome after continuous infusion of rocuronium in patients undergoing off-pump coronary artery bypass surgery. METHODS: Twenty patients were assigned to group 1 (n = 10, non-blinded neuromuscular transmission monitoring) or group 2 (n = 10, blinded neuromuscular transmission monitoring). In group 1, patients were given rocuronium at an infusion rate of 6 microg kg(-1) min(-1). The rate was manually adjusted in order to maintain T1/T0 at 10%. In group 2, a rocuronium infusion was started 30 min after induction of anaesthesia, at a rate of 6 microg kg(-1) min(-1); this rate was left unchanged during surgery. The rocuronium infusion was discontinued on completion of all vascular anastomoses; propofol was stopped at the beginning of closure of the subcutis and pirinitramide (piritramide) 15 mg was administered intravenously. Remifentanil was discontinued at the beginning of skin closure and neostigmine (50 microg kg(-1)) administered at the end of surgery when the train-of-four ratio was < 0.9 in group 1, and routinely in group 2. A 20 min test period for spontaneous ventilation was allowed once surgery had been accomplished. When the train-of-four ratio was > or = 0.9 (group 1), patients were extubated if also breathing spontaneously, fully awake and able to follow commands. When they met the clinical criteria for normal neuromuscular function after induced blockade, patients in group 2 were extubated when fully awake and able to follow commands. RESULTS: In group 1, the rate of rocuronium infusion required to keep T1/T0 at 10% was 5 +/- 1.9 microg kg(-1) min(-1); this was not significantly different from the fixed rate in group 2 (P = 0.15). One patient in group 2 was excluded. Eight out of 10 and eight out of nine patients in groups 1 and 2, respectively, reached the extubation criteria. Three out of eight, and five out of eight, patients from groups 1 and 2, respectively, were extubated in the operating room. At that time of endotracheal extubation, all three patients from group 1, but only four of the five patients from group 2 had a train-of-four ratio > or = 0.9. In group 2, one patient was reintubated in the intensive care unit. The incidence of pharmacological reversal was high in group 1. CONCLUSIONS: Although we found no additional benefit of using neuromuscular transmission monitoring, it seems an absolute necessity for safety reasons. Pharmacological antagonism was mandatory. However, in our opinion, it is not wise routinely to perform immediate postoperative extubation in off-pump coronary artery bypass surgery.

Postoperative residual curarization with cisatracurium and rocuronium infusions.

BACKGROUND AND OBJECTIVE: Monitoring of neuromuscular blockade still often relies on clinical judgement. Moreover, there are substantial national differences in the use of agents to 'reverse' their effects. We investigated the recovery characteristics and incidence of postoperative residual curarization after cisatracurium and rocuronium infusions for long duration interventions without systematic antagonism. METHODS: In 30 patients undergoing major surgery, we measured infusion dose requirements for rocuronium and cisatracurium during propofol anaesthesia. Infusions were discontinued at the beginning of surgical closure; spontaneous recovery of neuromuscular function was awaited in both groups. Neostigmine (50 microg kg(-1)) was administered only when a patient started to wake without a train-of-four ratio (TOF) of 0.9. RESULTS: In the cisatracurium and rocuronium groups, four (27%) and one (7%) patients, respectively, had a TOF ratio > or = 0.9 at the end of surgery. The TOF ratio in each group at that time was 51 +/- 32% for cisatracurium and 47 +/- 31% for rocuronium (P = 0.78). Six patients (40%) in the cisatracurium group and seven (47%) in the rocuronium group required neostigmine. The TOF ratio at the time of reversal was 63 +/- 7% for cisatracurium and 40 +/- 19% for rocuronium (P = 0.01). The time interval between the end of surgery and a TOF ratio of 0.9 was 10 +/- 9 min for cisatracurium and 18 +/- 13 min for rocuronium (P = n.s.). CONCLUSIONS: Patients receiving a cisatracurium or rocuronium infusion have a high incidence of postoperative residual curarization when the block is not antagonized. When 'reversal' is not attempted, cisatracurium seems to be safer than rocuronium.

Anaesthetic management and outcome in right-lobe living liver-donor surgery.

BACKGROUND AND OBJECTIVE: We reviewed retrospectively the anaesthetic management and perioperative course of eight right hepatectomies for living liver donation. METHODS: After preoperative psychiatric evaluation, eight ASA I-II individuals donated the right lobe of their liver to a family member. A graft-recipient body weight ratio of 0.8-1.0% was required for patient selection. Indications for liver transplantation were: hepatitis C viral-related cirrhosis in six patients; combined hepatitis C and B viral cirrhosis in one patient; multifocal hepatocellular carcinoma--four lesions, involving both liver lobes--of hepatitis C viral-related cirrhosis in another patient. Indication for adult-to-adult living-donor liver transplantation was retained in the latter because of rapid deterioration of liver disease, rare recipient's blood group and extended, unresectable hepatocellular carcinoma. Hepatitis C viral-related cirrhosis was casually the primary indication for adult-to-adult living-donor liver transplantation in this group. The condition of the donated hepatic lobe was optimized by appropriate drug and perfusion management. Preoperative investigations included: blood tests (full cell count and film, thyroid function tests, pregnancy tests, full virological tests and bacteriological cultures, and immunological typing), chest radiograph, electrocardiogram plus Doppler cardiac ultrasound, spirometry, aminopyrine breath test, liver Doppler examination, magnetic resonance imaging, angiography and cholangiography and a volumetric study of the whole liver and the right lobe. Haemoglobin and lactate concentrations, liver function tests and international normalized ratio were measured before and after operation. The volume and weight of the resected right lobe was calculated. Anaesthesia was induced with propofol 300 mL h(-1) and sufentanil 0.3 microg kg(-1) intravenously; cisatracurium, 0.15 mg kg(-1), was given to facilitate tracheal intubation. Anaesthesia was maintained during normocapnic ventilation of the lungs with oxygen 40% in air, isoflurane 1-1.5 MAC and sufentanil. Routine anaesthetic monitoring included electrocardiography, pulse oximetry, invasive blood pressure, central venous pressure, urine output, state of neuromuscular blockade and core temperature. Periods of hypotension (<80% of the preoperative blood pressure) or haemodynamic instability (requiring inotropic or vasoactive support) were registered. Total blood loss and transfusion (homologous, autologous or cell-saver blood) requirements were measured; volume replacements were derived. RESULTS: Data are presented as mean (range). There was no morbidity or mortality and no periods of intraoperative hypotension or haemodynamic instability. The operation time averaged 619 (525-780)min. Four donors were extubated in the operating room immediately after surgery; the others were extubated in the intensive care unit, where the mean extubation time was 16.3 (5-25)h after arrival. The estimated blood loss was 967 (550-1,600)mL. No homologous blood was administered; five donors received autologous blood, intraoperatively; three donors received a cell-saver blood transfusion. Intraoperative fluid replacement was with crystalloids, colloids and 4% albumin. Total urine output was 1,472 (700-3100)mL. Although intraoperative hypothermia occurred all subjects were normothermic at the end of operation. The pre- and immediately postoperative haemoglobin concentration averaged 13.6 (9.8-15.6) and 10.5 (6.9-13.0)gdL(-1), respectively. On the first postoperative day, the haemoglobin was 11.7 (8.4-15.1)gdL(-1). The donors' liver function tests were transiently elevated in the initial postoperative period. The intensive care unit discharge time was 2 (1-3) days. The hospital stay was 13 (7-17) days. There was no morbidity or mortality. CONCLUSIONS: The study demonstrates that right-lobe living-donor surgery was well tolerated, without intraoperative hypotension or haemodynamic instability, without perioperative anaesthetic or surgical complications, and with an excellent general outcome.

A paravenous approach for the saphenous nerve block.

BACKGROUND AND OBJECTIVES: This study assesses a paravenous approach for saphenous nerve block at approximately the level of the tibial tuberosity, and compares it with the conventional technique of blind subcutaneous infiltration between the tibial tuberosity and the gastrocnemius muscle. METHODS: In dissections of 5 cadavers, the saphenous nerve was found very close to the saphenous vein bilaterally. Subsequently, in 20 volunteers, a bilateral saphenous nerve block was performed with 5 mL mepivacaine on each side. Randomly assigned, the block was performed by blind subcutaneous injection using a 23-gauge needle of 2.5 cm on one side and by a paravenous subcutaneous approach on the other. RESULTS: The paravenous approach produced a saphenous nerve block in all 20 volunteers whereas the blind subcutaneous approach was successful in only 6 (33%) (P <.05). Seven volunteers had a painless minor hematoma at the paravenous site and 2 had a hematoma at the classical site. CONCLUSION: The saphenous nerve can be blocked effectively by a paravenous approach using only 5 mL of local anesthetic solution. This approach is advantageous because of its easily identifiable landmark.