Additional Bolus Dose Research Articles

Use of a Single Injection Femoral Nerve Block in the Patients of Total Knee Replacement with Concomitant Epidural Analgesia

Since central neuraxial analgesia cannot provide adequate post operative pain relief when it is used alone in patients who had undergone Total Knee Replacement Surgery (TKR), an alternative analgesic method is usually advised. The alternatives include either systemic analgesics (opioids, Non Steroidal Anti Inflamatory Drugs, [NSAIDs], etc) or peripheral nerve blocks. When complete analgesia is aimed in such patients, combining the sciatic nerve blocks along with the Femoral Nerve Blocks (FNBs) will be beneficial. But performing femoral and sciatic nerve blocks together in patients with regional or general anaesthesia will be too cumbersome and in this direction, the major clinical trials are yet to decide on their feasibility. Thus, in an attempt to keep the analgesia methods very simple and effective, the physicians may decide on doing a single nerve block when an ongoing epidural analgesia infusion is in situ. To evaluate the safety, convenience and the efficacy of a single injection femoral nerve block in patients who had undergone TKR surgeries, who had received concomitant epidural sensory analgesia. The patients who had undergone TKR were inserted with an epidural catheter for continuous analgesia and this was supplemented with an additional single injection femoral block. Postoperatively, each patient was recorded with a Visual Analogue Score (VAS) of pain assessment. The total number of patients who required additional bolus doses of epidural and additional analgesics, the individual patient ratings, and the complications, if any, were noted and analyzed on day 1(D1) and day 2(D2) of the surgery. The mean time for developing a VAS score of at least 3 was 8.55±1.78 hours. The VAS assessment mean scores were compared to that of D2 and the ratio which was obtained was 0.4±0.32. The mean VAS scores were higher on D2 as compared to those on D1 and they were statistically significant (P<.0001). A categorical score comparison too revealed higher scores on D2 (P<.001). A total of 52% patients required bolus doses of epidural analgesia with bupivacaine on D2 as compared to those on D1 (16%). Additional analgesia on demand was noted in 21% patients on D1 in contrast to 67% patients on D2. The rating of the analgesia as 'excellent' by 29% patients, as 'good' by 46% patients, as 'adequate' by 17% patients and as 'poor' by 8% patients was noted on D1. Similarly, the ratings as 'excellent' by 4% patients, as 'good' by 29% patients, as 'adequate' by 58% patients, and as 'poor' by 8% patients, was recorded for D2, respectively (P<.001). A single injection femoral nerve block provides adequate analgesia for the patients who undergo TKR surgery, when an active epidural is in-situ on the day of the surgery. It keeps the analgesic mode as simple and comfortable and it achieves lower pain scores on the day of the surgery, also with least complications, in patients with an ongoing epidural local anaesthetic infusion.

Bispectral index-guided intraoperative sedation with dexmedetomidine and midazolam infusion in orthopaedic surgery of lower limbs

Objective To compare and evaluate the effect and safety of dexmedetomidine(DEX) and midazolam sedation in lower limbs orthopaedic surgery. Methods Fifty-two patients undergoing lower limbs surgery were randomly assigned to group D (n=27,DEX, 0.5 μg·kg-1·h-1, loading dose 0.5 μg/kg) and group M(n=25, midazolam, 50 μg·kg-1·h-1, loading dose 30 μg/kg). An infusion was administered after mounting a bispectral index (BIS) monitor under combined spinal-epidural anesthesia. The target BIS level was≤85. An additional bolus dose of the study drug or cessation of the infusion was adjusted according to the BIS level, and the change should be recorded. Respiratory rates (RR), heart rate (HR), pulse oxygen saturation (SpO2), mean arterial blood pressure (MAP) were continually monitored. Sedation should be evaluated according to the Ramsay sedation scale(RSS) before the drug withdrawal. Results HR was lower in group D (72±7) bpm than that in group M (83±8) bpm (P<0.05) 30 min after infusion. There was no significant difference in the RR, MAP and RSS score between two groups. Dose adjustments were required in six and seven patients Groups D and M, respectively. Five patients needed to raise the mandible due to SpO2 decline by glossocoma in Group M, but none in Group D. Conclusion DEX infusion mildly decreased heart rate in the later periods of lower limbs surgery, with no significant influences on the MAP. Compared with midazolam, DEX might show more advantages in maintaining the unobstructed of the respiratory tract, and be more suitable for sedation in lower limbs surgery. Key words: Bispectral index; Dexmedetomidine; Midazolam; Lower limbs of orthopaedic surgery

Unfractionated heparin administration in patients treated with bivalirudin during primary percutaneous coronary intervention is associated lower mortality and target lesion thrombosis: a report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

BackgroundBivalirudin reduces bleeding events and is associated with a lower mortality than the combination of unfractionated heparin (UFH) and glycoprotein IIb/IIIa inhibitor during primary percutaneous coronary intervention (PCI). However, the...

Thromboembolic Complications During Weaning from Right Ventricular Assist Device Support

We report on two patients who experienced life-threatening thromboembolic complications during prolonged weaning from Levitronix CentriMag right ventricular assist device support. Right ventricular assist device flow in both patients was reduced below 2 L/min for a period of 72 or 36 h to closely monitor patients' hemodynamics and echocardiography because the extent of right ventricular recovery was difficult to assess. Thrombus formation occurred despite adjusting the heparin dosage to achieve partial prothrombin time values between 60 and 70 s. Periods of reduced flow during Levitronix CentriMag support must be kept short, and an additional bolus dose of heparin should be considered.

Single Centre Experience of Surgery Management of Patients with Von Willebrand's Disease Using High Purity Von Willebrand Factor Concentrate with Low Factor VIII Content

Good haemostatic control is paramount for surgery in patients with von Willebrand's disease (VWD) and can be achieved with either desmopressin or plasma derived von Willebrand factor (VWF). Wilfactin is a plasma-derived von Willebrand factor concentrate with a low FVIII content. It was developed for the treatment of VWD and has been shown to produce safe and efficacious haemostasis, either alone or with supplementary FVIII. We report our experience in a retrospective study of all patients with VWD who underwent at least one invasive or surgical procedure during 1997 to 2001 and received Wilfactin. There were 30 evaluable patients (Table 1), all with either contraindications or unresponsive to desmopressin. The target VWF activity was 80–100 iu/dl and monitored in patients on continuous infusion and those with severe VWD or undergoing complicated procedures. Efficacy was primarily determined clinically. Thirty patients had a total of 75 surgical or invasive procedures. Of these, 64 were managed by bolus dosing and 11 by continuous infusion. Bolus dosing was given just prior to the procedure for 24 patients whose mean FVIII:C level was 47 iu/dl. Three patients had an additional priming bolus dose the day prior to the intervention and 2 patients received a bolus dose of FVIII in addition to the VWF just prior to the intervention. The mean FVIII:C of these patients was 32 iu/dl. The mean pre-operative dose per injection of VWF was 42 IU/kg. Continuous infusion was administered with an initial bolus dose of 40 iu/kg, followed by an infusion of 4 iu/kg until haemostasis or complete wound healing was achieved. The precise schedule and duration however, depended on the length and type of surgery, baseline VWF activity and post treatment values (Table 2). Of the 11 procedures managed with a continuous infusion; 5 were started the day before the procedure (D-1). Two received an extra bolus dose 12– 24 hours prior to the procedure. A FVIII bolus of 35 iu/kg with the VWF was given just prior to the intervention in 2 procedures on the same patient with severe VWD and FVIII levels of 2 iu/dl. Haemostatic efficacy for both bolus and continuous infusion was good with only one bleeding episode recorded, due to a surgical bleed requiring re-intervention. VWF activity and FVIII levels were within target range, and FVIII levels were maintained at between 90 and 175 iu/dl. No patients developed a thrombosis and there was no record of inhibitor formation to date. Our experience with Wilfactin in surgical management has been good. Bolus dosing was used primarily for minor procedures or patients with mild VWD. For more complicated procedures or severe VWD, continuous dosing was used. Only 2 patients received co-administration of FVIII. The low FVIII content in Wilfactin is reassuring in many cases, avoiding the post operative high Factor VIII levels and risk of thrombosis.Table 1. Patient demographicsNo. of patients (N)Male/Female (N)Mean age at surgery (n)Mean VWF activity (Ricof) iu/dlMean FVIII level iu/dlVWD Type 1216/1537 (6–70)29 (<10–69)54 (6–120)VWD Type 271/622 (7–37)10 (5–13)37 (23–48)VWD Type 321/149 (40–58)7 (5–10)5 (2–8)Total308/2234* (6–72)15 overall mean32 overall mean* 14 procedures in paediatric patientsTable 2. Continuous infusion: Schedule and ProceduresPatient TypeVWF Activity iu/dlFVIII:C iu/dlInterventionInfusion initiation day12–24hr Pre infusion Bolus VWF (iu)Factor VIII Bolus (iu)Treatment duration (days)3<108Orthopaedic surgeryD 0Yes 4000No5Orthopaedic surgeryD-1NoNo61A731ENT surgeryD-1NoNo23<52ENT surgeryD-1NoNo2ENT surgeryD 0NoYes D01Orthopedic surgeryD 0NoYes D021b6981Gynaecological surgeryD 0NoNo51b59120Gynaecological surgeryD-1NoNo31<1022General surgeryD 0NoNo41<1018Orthopedic surgeryD-1NoNo3Orthopedic surgeryD 0Yes 3000No3

Dexmedetomidine for sedation during electroencephalographic analysis in children with autism, pervasive developmental disorders, and seizure disorders

Study ObjectiveTo assess the efficacy of dexmedetomidine in providing sedation during electroencephalographic (EEG) analysis in children with autism, seizure disorders, or pervasive developmental disorders (PDDs). DesignRetrospective chart review. SettingUniversity medical center. MeasurementsThe charts of 42 children, aged two to 11 years, who received dexmedetomidine for sedation during EEG analysis, were studied. Information collected included route of administration of dexmedetomidine (oral and/or intravenous [IV]), loading dose, and infusion rate. Heart rate, blood pressure, respiratory rate, and level of sedation were monitored every 5 minutes, and oxygen saturation was monitored continuously during the procedure. Interventions (administration of fluid or use of an anticholinergic agent) for hypotension or bradycardia were identified. Main Results18 children received oral dexmedetomidine (range, 2.9-4.4 μg/kg) before placement of an IV. Forty patients received an IV loading dose of dexmedetomidine (2.1 ± 0.8 μg/kg), which was given in increments of 0.5 to one μg/kg every three to 5 minutes until a sedation score of 3 to 4 was achieved. Effective sedation was eventually achieved in all patients. An IV infusion of dexmedetomidine was started (1.5 ± 0.2 μg kg−1 hr−1) in all patients. During performance of the EEG, adjustments in the infusion rate (increase or decrease) or additional bolus doses were necessary in 25 patients. No significant hemodynamic or respiratory effects were noted. ConclusionsDexmedetomidine provides effective sedation during EEG analysis in children with autism or PDD.

Manipulation of frozen shoulder under monitored anesthesia care with propofol and remifentanil

Background: Manual manipulation under anesthesia in primary frozen shoulder is recommended for restoring range of motion and improving function. Usually, manipulation is performed briefly under general anesthesia, which accompanies some anesthesia-related risks for outpatients. Methods: 12 patients suffered from primary frozen shoulder were received manipulation under monitored anesthesia care (MAC) with propofol (1mg/kg) and remifentanil (25μg) as an initial dose. And then we injected additional bolus dose (propofol 20mg, remifentanil 10μg) in case of inadequate sedation. After manipulation, sodium hyaluronate 20mg, 0.75% ropivacaine 22.5mg and ketorolac 30mg were injected into the glenohumeral joint. Clinical data were gathered at baseline and at 4 weeks after manipulation. Results: The procedure was carried out successfully under MAC. Clinical results including improvements of visual analogue scale of pain and range of motion were comparable to previous studies. 2 patients who received relatively large doses of anesthetics have required triple airway maneuver and manual mask ventilation for 1 to 2 minutes respectively because of desaturation below 90%. There are not any serious adverse effects. Conclusions: MAC with propofol and remifentanil makes it possible to get adequate level of sedation for shoulder manipulation and to reduce recovery time from anesthesia at the same time. MAC, therefore, is the adequate outpatient anesthetic method for shoulder manipulation. (Korean J Anesthesiol 2008; 55: 326~31)

Comparison of Blood Loss according to Different Anesthetic Technique for Total Hip Replacement

The mean blood loss is about 500−1,700 ml by general anesthesia technique in total hip replacement (THR) and the amount of blood loss is dependent on the degree of induced hypotension. We performed this study to evaluate the differences on the amount of blood loss and the number of transfused patients according to different anesthetic technique under the similar hypotension level. Methods: Forty-seven patients of ASA physical status class 1, 2 and 3, scheduled for THR, were randomly assigned into epidural anesthesia group (E group), combined general epidural anesthesia group (GE group) and general anesthesia group (G group). G group was maintained with sevoflurane anesthesia and the monitoring of central and arterial blood pressure was performed. The remifentanil (0.1μg/kg/min) was infused continuously for the target mean arterial pressure of 60 ± 5 mmHg. GE group received general anesthesia with the same technique of G group and epidural anestheia was combined after general anesthesia. The remifentanil (0.1μg/kg/min) was infused continuously for the target mean arterial blood pressure of 60 ± 5 mmHg. E group received epidural anesthesia with 0.75% ropivacaine and additional bolus dose of local anesthetics was injected if the mean arterial blood pressure did not reach 60 ± 5 mmHg. Results: The mean volume of blood loss and the number of transfused patients was significantly less in E or GE group at 24 hour after surgery (P ＜ 0.05), however we could not find any significant differences during intraoperative period. Conclusions: Epidural or combined general epidural anesthesia technique is a good method to reduce bleeding and the number of transfused patients.

Reports of Death with Use of Propofol (Diprivan) for Nonprocedural (Long-term) Sedation and Literature Review

Reports of Death with Use of Propofol (Diprivan) for Nonprocedural (Long-term) Sedation and Literature Review

Continuous sciatic block for leg and foot surgery in 160 children

The aim of this study was to assess the safety and efficacy of continuous sciatic block for lower limb surgery in children. A total of 160 pediatric patients aged 4 months to 12 years weighing 3.5-50 kg, were given continuous sciatic block plus single shot 3-in-1 block for leg and foot surgery. After general anesthesia, the sciatic nerve was located by using loss of resistance to saline by the mid-thigh approach. An 18 gauge epidural needle was introduced at the junction of the proximal two-third with the distal one-third of a line extending from the apex of popliteal triangle to the midpoint of the line joining the greater trochanter and the ischial tuberosity. A 20 g catheter was threaded through the needle for 5-10 cm and 0.25% bupivacaine 0.75 ml.kg(-1) was injected. A single shot 3-in-1 block was also given to facilitate the use of a tourniquet with 0.25% bupivacaine 0.25 ml. In 20 patients a nerve stimulator was used in addition to loss of resistance. The intraoperative sedation comprised propofol and ketamine infusions and 50% nitrous oxide in oxygen by LMA. Eight-two percent of patients showed no response to surgery; 14% patients showed some response to the medial incision over the ankle and needed additional bolus doses of ketamine and propofol. Block was considered to have failed in 4% who required an increase in propofol and ketamine infusions. A total of 154 patients had good postoperative pain relief for 72 h with continuous infusion of 0.05% bupivacaine. The other six were given oral codeine and diclofenac. There were no complications attributable to sciatic block in any patient. Sciatic block with a single shot 3-in-1 block for tourniquet pain and light general anesthesia provides good intraoperative conditions for leg and foot surgery and adequate postoperative pain relief. Additional sedation to minimize the discomfort of a cast may be a consideration in the first 24 h.

Pharmacodynamics and pharmacokinetics of high-dose oxycodone infusion during and after coronary artery bypass grafting

Objective: In small to moderate doses, oxycodone has similar analgesic efficacy to morphine with fewer side effects. The present study evaluated the pharmacokinetics and dynamics of high doses of oxycodone during anesthesia for primary coronary artery bypass grafting. Design: A randomized, prospective clinical evaluation. Setting: A major Scandinavian university clinic. Participants: Two groups with 10 patients each were studied. Interventions: Invasive hemodynamics, echocardiograms, and electrocardiograms were monitored. Oxycodone kinetics, histamine liberation, and plasma cortisol levels were measured. Anesthesia was induced with 1.0 mg/kg of oxycodone and, thereafter, in a random order, maintained with a continuous infusion of oxycodone at a rate of either 0.5 mg/kg/h (group OX 0.5, 10 patients) or 1.0 mg/kg/h (group OX 1.0, 10 patients). An additional bolus dose of 0.5 mg/kg (OX 0.5) or 1.0 mg/kg (OX 1.0) of oxycodone was given before the incision. Enflurane was administered according to hemodynamic criteria. Measurements and Main Results: The induction of and the course of anesthesia were hemodynamically stable in all patients. Enflurane was given to every patient. The mean total doses of oxycodone were 3.5 mg/kg (OX 0.5) and 6.2 mg/kg (OX 1.0). The median t 1/2 of oxycodone varied from 5.1 to 5.9 hours. No hemodynamic differences were found between the groups. No histamine liberation was detected. During anesthesia, the predominant waves in the EEG were θ- and δ-waves. The mean times to awakening were 3.8 hours and 7.0 hours in the groups OX 0.5 and 1.0, respectively. All patients were intubated until the first postoperative morning. No recall of awareness was reported. Conclusion: A combination of oxycodone and enflurane provides hemodynamically stable anesthesia. No advantages were gained with the higher dose. Elimination of oxycodone was slower than reported previously.

BIS Monitoring Predicts Recovery Time in Patients Receiving Intraprocedural Midazolam During Endoscopy

BIS (Bispectral Index) monitoring, an EEG-based technology, tracks sedative effect and may improve sedation management. We investigated BIS responses during routine procedural sedation at three academic centers utilizing a refined BIS algorithm developed for monitoring moderate sedation to determine whether BIS values prior to last intraprocedural midazolam administration predict subsequent wakeup time. METHODS: With IRB approval and informed consent, 204 patients undergoing various procedures: colonoscopy (COL), esophagogastoduodenoscopy (EGD) and advanced therapeutic endoscopy (ATE) including ERCP and EUS, were enrolled. The endoscopist and staff administered sedation (midazolam) and analgesia (meperidine or fentanyl) according to routine protocols and clinical assessment. Physicians and staff were blinded to BIS values (lower values indicate deeper sedation) during the procedures. BIS recordings, drug administration, clinical events/markers and emergence times were observed and recorded by personnel not involved in direct patient care. Painful observations are defined as: grimacing, moaning, and wincing and long wakeup time was defined as >3 minutes to achieve verbal response or eye-opening following scope-out. EEG recordings were obtained with an A2000 BIS-XP Monitor and Quatro Sensors (Aspect Medical Systems; Newton MA) and downloaded to a laptop computer. BIS values were calculated off-line with the modified algorithm (BIS 4.1). SPSS was used to relate BIS values with clinical endpoints and drug administration. From the drug annotations, we used pharmacokinetic modeling to estimate opioid effect site concentrations. RESULTS: 38/204 patients received additional intraprocedural midazolam. 0/14 patients with BIS value>85 had long wakeups (0%). 9/23 (39%) of patients with BIS value <85 had long wakeups (39%), p<0.01 based on chi square analysis. Estimated mean opioid effect site levels were significantly lower (0.95 nanograms/ml versus 1.43 nanograms/ml, p < 0.05) in patients with more than 10 painful annotations per case. CONCLUSIONS: Patients who receive additional bolus doses of midazolam when BIS values are < 85 are at higher risk of prolonged recovery, whereas administration of adequate opioid levels reduces the number of painful episodes during each procedure. These findings highlight the need to separately tailor the administration of analgesics and sedatives to the needs of each patient and suggest that BIS may help in agent selection.

The Comparison of Ropivacaine and Bupivacaine in Epidural Patient Controlled Analgesia (PCA)

Background: Local anesthetics combined with an opiate are frequently used as a postoperative epidural PCA regimen. Ropivacaine is known to have a selective blockade of the sensory nerve without motor blockade. This study is designed to show advantages of ropivacaine over bupivacaine. Methods: Patients undergoing elective abdominal and orthopedic surgeries were randomly selected and divided into two groups, B and R. The patients in group B and R received 0.2% bupivacaine and 0.2% ropivacaine respectively through an epidural catheter using a PCA pump. Both local anesthetic solutions were mixed with 4g/ml of fentanyl. The PCA pumps of both groups were set in the same manner. A basal rate of 2 ml/hr was infused from 1hour after the onset of surgery. This basal rate was continued postoperatively. A bolus dose and lock out time were set at 2 ml and 20 minutes respectively. The Visual analogue pain scale (VAS), demand dose, complication and additional intramuscular analgesic requirements were checked up to 24 hours after surgery in 6-hour interval. Results: The VAS was significantly lower in group R than in group B at 6, 12, 18 and 24 hours after the surgery (P 0.05). Total additional bolus doses of the PCA pump were not significantly different in either group at 6, 12, 18 and 24 hours after surgery. The patients in group R showed more satisfaction and less additional intramuscular injections. Conclusions: 0.2% Ropivacaine, mixed with 4g/ml of fentanyl, was more effective than bupivacaine, mixed with the same concentration of fentanyl, in controlling postoperative pain using an epidural PCA pump.

A Multimodal Approach to Control Postoperative Pathophysiology and Rehabilitation in Patients Undergoing Abdominothoracic Esophagectomy

This two-armed study was designed to determine whether recovery after esophageal resection may be improved by introducing a new multimodal approach. For 8 mo after the new approach was introduced, all patients undergoing abdominothoracic esophageal resection were studied (Group 2; n = 42). For comparison, a retrospective analysis was also conducted using the data of all patients who had undergone this operation in the 8 mo before the introduction of the new regimen, when the traditional therapy was still in use (Group 1; n = 49). All patients received an epidural catheter at the level of T6-9 before the induction of general analgesia. Afterward, Group 1 patients were operated under general anesthesia. For postoperative pain relief, a mixture of bupivacaine 1.25 mg/mL and sufentanil 1 micro g/mL was administered during 5 days without titration of the quality of analgesia. Patients in Group 2 received a preoperative bolus of 10-15 mL bupivacaine 2.5 mg/mL and 20-30 micro g sufentanil. After sensory block up to T4 was confirmed, general anesthesia was introduced and intraoperatively combined with a continuous infusion of 5 mL/h of a solution containing bupivacaine 1.75 mg/mL and sufentanil 1 micro g/mL. Postoperatively, the epidural infusion rate was adjusted to the need of the individual patients, who were able to administer themselves additional bolus doses of 2 mL with a lockout time of 20 min. Early tracheal extubation and forced mobilization were pursued to improve recovery. Demographic data of both groups were comparable. The pain relief of Group 2 patients was superior to that of patients in Group 1. The nitrogen balance of a subgroup of nine matched pairs of patients with comparable nutritional status was less negative in Group 2 patients on Postoperative Days 1 and 2. Patients in Group 2 were tracheally extubated earlier (mean 6.7 vs 25.1 h after admission to the intensive care unit [ICU]), mobilized earlier (mean 1.2 vs 2.0 days after surgery), discharged from the ICU earlier (mean 1.7 vs 4.0 days), and fulfilled criteria for discharge from the ICU (mean 1.8 vs 4.1 days) and from the intermediate care unit earlier (4.9 vs 6.4 days). We conclude that the multimodal approach may improve recovery and thus reduce costs after abdominothoracic esophageal resection. Implications: Analgesia and blockade of the perioperative stress response, combined with other aspects of postoperative therapy, may improve recovery after surgery. The intensive care unit stay after esophageal resection was reduced by a new regimen (thoracic epidural analgesia, early tracheal extubation, forced mobilization). This approach may influence the cost of major surgery. (Anesth Analg 1998;86:228-34)

A multimodal approach to control postoperative pathophysiology and rehabilitation in patients undergoing abdominothoracic esophagectomy.

This two-armed study was designed to determine whether recovery after esophageal resection may be improved by introducing a new multimodal approach. For 8 mo after the new approach was introduced, all patients undergoing abdominothoracic esophageal resection were studied (Group 2; n = 42). For comparison, a retrospective analysis was also conducted using the data of all patients who had undergone this operation in the 8 mo before the introduction of the new regimen, when the traditional therapy was still in use (Group 1; n = 49). All patients received an epidural catheter at the level of T6-9 before the induction of general analgesia. Afterward, Group 1 patients were operated under general anesthesia. For postoperative pain relief, a mixture of bupivacaine 1.25 mg/mL and sufentanil 1 microg/mL was administered during 5 days without titration of the quality of analgesia. Patients in Group 2 received a preoperative bolus of 10-15 mL bupivacaine 2.5 mg/mL and 20-30 microg sufentanil. After sensory block up to T4 was confirmed, general anesthesia was introduced and intraoperatively combined with a continuous infusion of 5 mL/h of a solution containing bupivacaine 1.75 mg/mL and sufentanil 1 microg/mL. Postoperatively, the epidural infusion rate was adjusted to the need of the individual patients, who were able to administer themselves additional bolus doses of 2 mL with a lockout time of 20 min. Early tracheal extubation and forced mobilization were pursued to improve recovery. Demographic data of both groups were comparable. The pain relief of Group 2 patients was superior to that of patients in Group 1. The nitrogen balance of a subgroup of nine matched pairs of patients with comparable nutritional status was less negative in Group 2 patients on Postoperative Days 1 and 2. Patients in Group 2 were tracheally extubated earlier (mean 6.7 vs 25.1 h after admission to the intensive care unit [ICU]), mobilized earlier (mean 1.2 vs 2.0 days after surgery), discharged from the ICU earlier (mean 1.7 vs 4.0 days), and fulfilled criteria for discharge from the ICU (mean 1.8 vs 4.1 days) and from the intermediate care unit earlier (4.9 vs 6.4 days). We conclude that the multimodal approach may improve recovery and thus reduce costs after abdominothoracic esophageal resection. Analgesia and blockade of the perioperative stress response, combined with other aspects of postoperative therapy, may improve recovery after surgery. The intensive care unit stay after esophageal resection was reduced by a new regimen (thoracic epidural analgesia, early tracheal extubation, forced mobilization). This approach may influence the cost of major surgery.

Continuous extradural infusion of ropivacaine 2 mg ml-1 for pain relief during labour

We have assessed the dose-response relationship of a solution of ropivacaine 2 mg ml-1, given as a continuous extradural infusion to women in labour. A total of 133 parturients were allocated randomly to one of four groups to receive a fixed rate ropivacaine infusion of 4, 6, 8 or 10 ml h-1 with additional bolus doses as necessary. Contraction pain, quality of analgesia, sensory block, motor block and neonatal Apgar scores were assessed. There were no significant differences between groups in terms of analgesia or motor block, although significantly more bolus doses were required by the group receiving 4 ml h-1 (P < 0.05 compared with the other groups), and a significantly higher total dose of ropivacaine was administered to the 10-ml h-1 group compared with the 6-ml h-1 group (P = 0.044). There were no significant differences between groups in terms of obstetric or neonatal outcome. We conclude that ropivacaine 2 mg ml-1 was effective and well tolerated when given as a continuous extradural infusion at 6-8 ml h-1 and may be used as the sole analgesic during labour.

Continuous Caudal Anaesthesia with Chloroprocaine as an Adjunct to General Anaesthesia in Neonates

TOBIAS, J. D.; RASMUSSEN, G. E.; HOLCOMB, G. W.; BROCK, J. W. III; MORGAN, W. M. Author Information

Continuous caudal anaesthesia with chloroprocaine as an adjunct to general anaesthesia in neonates.

The authors prospectively evaluated the use of a continuous caudal epidural infusion of chloroprocaine as an adjunct to general anaesthesia during intra-abdominal surgery in neonates. The technique was used in 25 neonates ranging in age from 1 to 28 days and in weight from 2.2 to 4.9 kg. Following anaesthetic induction and tracheal intubation, an initial bolus dose of chloroprocaine 3% (1 or 1.5 ml.kg-1) was followed by a continuous infusion of 1 or 1.5 ml.kg-1.hr-1 administered through a caudal epidural catheter. No parenteral opioids were administered. The duration of the surgical procedures varied from one hour five minutes to three hours 15 min. The first three neonates received a bolus dose of 1.0 ml.kg-1 followed by an infusion of 1.0 ml.kg-1.hr-1 chloroprocaine 3%. These three neonates required an additional bolus dose followed by an increase in the infusion to 1.5 ml.kg-1.hr-1 to provide surgical anaesthesia. Adequate intraoperative anaesthesia was achieved in all 25 neonates with an infusion of 1.5 ml.kg-1.hr-1 of chloroprocaine 3%. This was evidenced by a lack of haemodynamic response to surgical manipulation. No neonate required more than 0.2% isoflurane or 70% nitrous oxide in oxygen. No episodes of haemodynamic instability (decreased blood pressure/bradycardia) related to the caudal epidural anaesthesia were noted. Twenty-three of 25 of the neonates' tracheas were extubated immediately (within 10 minutes) following the surgical procedure. Caudal anaesthesia with a continuous infusion of chloroprocaine can be used as an adjunct to general anaesthesia during abdominal surgery in neonates. Our initial experience suggests that the combined technique may eliminate the need for parenteral opioids and limit the intraoperative requirements for inhalational anaesthetic agents.

Continuous infusions of alfentanil and propofol for coronary artery surgery

To study the anesthetic efficacy of two different background infusion rates for alfentanil in a total intravenous anesthesia (TIVA) technique using propofol. Therefore, the effects of these infusions on hemodynamic stability and on the suppression of hemodynamic and somatic responses to noxious stimuli were compared. Prospective and randomized. The study was performed in a university hospital setting. Two patient groups were compared. Anesthesia was induced in group 1 (n = 16) with alfentanil 50 micrograms/kg and in group 2 (n = 14) with alfentanil 75 micrograms/kg, infused in 4 min, as well as with an infusion of propofol at a rate of 10 mg/kg/h in both groups. After 4 min, the alfentanil infusion was reduced to 1 microgram/kg/min in group 1 and to 2 micrograms/kg/min in group 2. The propofol infusion was reduced following sternal spread to 3 mg/kg/h. Responses indicating inadequate anesthesia were treated with additional alfentanil bolus doses. Induction of anesthesia in group 1 was associated with significant decreases in systolic and diastolic (-13%) blood pressures, cardiac index (-16%) and left ventricular stroke work index (-31%). Hemodynamic changes were similar in group 2, except for the greater fall in systemic vascular resistance during maintenance of anesthesia. There was no difference in the incidence of breakthrough hypertension between the two groups (in 44% and 43% of the patients, respectively) and in the number of alfentanil bolus supplements. There were also no differences in the incidence of ischemia, myocardial infarction or duration of postoperative ventilation. Because both infusions provided equally stable anesthesia, the lower infusion regimen for alfentanil is the more appropriate technique. Using this technique, the administration of additional alfentanil boluses just before stressful surgical episodes will further improve hemodynamic stability.

Pancuronium Infusion for Neuromuscular Block in Children in the Pediatric Intensive Care Unit

When neuromuscular blockade becomes necessary in the intensive care unit, there are several options available in regard to both the drug and the mode of delivery (continuous versus intermittent administration).Despite extensive experience with intermediate acting drugs such as atracurium or vecuronium, these muscle relaxants are costly and may account for a significant portion of the pharmacy charges. We undertook an open label study to evaluate the efficacy and dosing requirements for a less costly drug, pancuronium. The study group included 25 patients ranging in age from 3 mo to 17 yr and in weight from 3.2 to 68 kg. If the patient had not previously received neuromuscular blocking agents (NMBAs), pancuronium was administered as a bolus dose of 0.1 mg/kg followed by a continuous infusion of 0.05 mg centered dot kg-1 centered dot h-1. A nerve stimulator was applied to either the ulnar or peroneal nerve and a standard train-of-four (TOF) was monitored every 2 h. In patients that had previously received other NMBAs, no bolus dose of pancuronium was administered and the infusion was started at 0.05 mg centered dot kg-1 centered dot h-1. The pancuronium infusion was increased or decreased by increments of 0.01 mg centered dot kg-1 centered dot h-1 to maintain one to two twitches of the TOF. In patients that required an increase in the infusion rate, an additional bolus dose equivalent to the current hourly rate was administered and then followed by the increase in the infusion rate. Pancuronium infusion requirements varied from 0.03 to 0.22 mg centered dot kg-1 centered dot h-1 (mean = 0.07 +/- 0.03 mg centered dot kg-1 centered dot h-1). The infusion requirement was 0.05 to 0.08 mg centered dot kg-1 centered dot h-1 in 71 of 98 days (72.4%) and 0.03 to 0.09 mg centered dot kg-1 centered dot h-1 in 84 of the 98 days (85.7%). There was an increased infusion requirement in patients receiving anticonvulsants (0.056 vs 0.14 mg centered dot kg-1 centered dot h-1, P < 0.5) and in patients that required pancuronium for more than 5 days (0.059 on Day 1 vs 0.083 mg centered dot kg-1 centered dot h-1 on Day 5, P = 0.03). Pancuronium can be used by continuous infusion in children for neuromuscular block. Its use may be significantly less costly than newer NMBAs such as atracurium or vecuronium. (Anesth Analg 1995;81:13-6)