Reintubation in the ICU following cardiac surgery: is it more difficult than first-time intubation in the operating room?: A prospective observational study.

BACKGROUND: After cardiac surgery, a patient's trachea is usually extubated; however, 2 to 13% of cardiac surgery patients require reintubation in the ICU. OBJECTIVE: The objective of this study was to compare the initial intubation in the cardiac operating room with reintubation (if required) in the ICU following cardiac surgery. DESIGN: A prospective, observational study. SETTING: Department of Anesthesiology and Intensive Care Medicine, Clinical Hospital of Santiago, Spain. PATIENTS: With approval of the local ethics committee, over a 44-month period, we prospectively enrolled all cardiac surgical patients who were intubated in the operating room using direct laryngoscopy, and who required reintubation later in the ICU. MAIN OUTCOME MEASURES: The primary endpoint was to compare first-time success rates for intubation in the operating room and ICU. Secondary endpoints were to compare the technical difficulties of intubation (modified Cormack-Lehane glottic view, operator-reported difficulty of intubation, need for support devices for direct laryngoscopy) and the incidence of complications. RESULTS: A total of 122 cardiac surgical patients required reintubation in the ICU. Reintubation was associated with a lower first-time success rate than in the operating room (88.5 vs. 97.6%, P = 0.0048). Reintubation in the ICU was associated with a higher incidence of Cormack-Lehane grades IIb, III or IV views (34.5 vs. 10.7%, P < 0.0001), a higher incidence of moderate or difficult intubation (17.2 vs. 6.5%, P = 0.0001) and a greater need for additional support during direct laryngoscopy (20.5 vs. 10.7%, P = 0.005). Complications were more common during reintubations in the ICU (39.3 vs. 5.7%, P < 0.0001). CONCLUSION: Compared with intubations in the operating room, reintubation of cardiac surgical patients in the ICU was associated with more technical difficulties and a higher incidence of complications. CLINICAL TRIAL NUMBER: Ethics committee of Galicia number 2015-012.

Paravertebral cervical nerve block in a patient suffering from a Pancoast tumor.

In patients with aggressive tumors resistant to conventional pain treatment, regional anaesthesia frequently becomes an alternative therapy. Cervical paravertebral nerve block among several access options to the brachial plexus is barely ever used. We present a case with severe shoulder and upper extremity pain owing to an expanding Pancoast tumor exhibiting compression upon the brachial plexus. Continuous intrathecal morphine infusion and adjuvant treatment was not sufficient to render the patient pain-free. With the addition of paravertebral nerve blockade the patient's pain improved substantially, however without impacting his longevity.

Is ultrasound guidance superior to conventional nerve stimulation for coracoid infraclavicular brachial plexus block?

BACKGROUND AND OBJECTIVES: In different peripheral nerve blocks, it has been speculated that needle guidance by ultrasound improves onset time and success rate compared with the more frequently used nerve stimulation-guided technique. In the present study, we tested the hypothesis that ultrasound guidance improves onset time of coracoid infraclavicular brachial plexus block (IBPB) when compared with a nerve stimulation-guided technique. METHODS: Seventy patients scheduled for hand or forearm surgery were randomly assigned to receive coracoid IBPB using either ultrasound guidance (group U, n = 35), or nerve stimulation (group S, n = 35). Patients were assessed for sensory and motor block every 5 mins after injection of local anesthetic. Onset time, the primary end point, was defined as the time required for complete sensory and motor block. Time required to perform the block, success rate, and time to resolution of motor blockade were also recorded (secondary end points). RESULTS: Onset of complete sensory and motor blockade was similar in the 2 groups (17 mins [8 mins] in group U and 19 mins [8 mins] in group S; P = 0.321). Time required to perform the block was shorter in group U (3 mins [1 min]) as compared with group S (6 mins [2 mins]; P < 0.0001). No differences were observed in success rate (89% in group U and 91% in group S; P = 0.881) and time to resolution of motor blockade (237 mins [45 mins] in group U and 247 mins [57 mins] in group S; P = 0.418). CONCLUSIONS: The present investigation demonstrates that ultrasound guidance and nerve stimulation provide similar onset time, success rate, and duration of motor blockade for coracoid IBPB; however, ultrasound guidance reduces the time required to perform the block.

Two unusual cases of urinary incontinence during continuous sciatic nerve block with stimulating catheters.

One of the advantages of lower extremity peripheral nerve blocks compared with neuroaxial Neuraxial techniques is the lack of effect on urinary function. We report two cases of urinary incontinence during continuous sciatic nerve block with stimulating catheters placed using the posterior gluteal Labat approach. The two patients were able to control micturition 6 h after the catheter was removed.

Comparison of continuous infusion versus automated bolus for postoperative patient-controlled analgesia with popliteal sciatic nerve catheters.

BACKGROUND: This investigation was designed to compare a new methodology of automated regular bolus with a continuous infusion of local anesthetic for continuous popliteal sciatic block; both regimens were combined with patient-controlled analgesia (PCA). METHODS: Fifty patients undergoing hallux valgus repair were randomly allocated to receive an infusion of 0.125% levobupivacaine administered through a popliteal catheter as an automated regular bolus (n = 25) or as a continuous infusion (n = 25), both combined with PCA. Postoperative pain scores, incremental doses delivered by the PCA, local anesthetic consumed per hour, and the need for rescue tramadol analgesia were recorded. RESULTS: Both dosing regimens provided similar postoperative analgesia. Consumption of local anesthetic (5.14 ml/h, 5-5.75 ml/h) and dose request from the PCA (1, 0-5.4) was lower in the automated bolus group as compared to the continuous infusion group (5.9 ml/h, 5.05-7.8 ml/h; doses by PCA: 6.5, 0-20.5; P < 0.05). The need for rescue tramadol was similar in the two groups. CONCLUSION: In continuous popliteal sciatic block, local anesthetic administered as an automated regular bolus in conjunction with PCA provided similar pain relief as a continuous infusion technique combined with PCA; however, the new dosing regimen reduced the need for additional PCA and the overall consumption of local anesthetic.

Low volume and high concentration of local anesthetic is more efficacious than high volume and low concentration in Labat's sciatic nerve block: a prospective, randomized comparison.

BACKGROUND: Various factors markedly affect the onset time and success rate, of peripheral nerve blockade. This prospective, randomized, double-blind study, compared a dose of mepivacaine 300 mg, in a 20 or 30 mL injection volume for sciatic nerve blockade using Labat's posterior approach. METHODS: A total of 90 patients undergoing foot surgery were randomly allocated to receive sciatic nerve block with 20 mL of 1.5% mepivacaine (n = 45) or 30 mL of 1% mepivacaine (n = 45). All blocks were performed with the use of a nerve stimulator (stimulation frequency 2 Hz; intensity 1.5-0.5 mA). In the two groups, appropriate nerve stimulation was elicited at <0.5 mA and the targeted evoked motor response was plantar flexion of the foot. Time required for onset of sensory and motor block in the distribution of the tibial and common peroneal nerves were recorded. A successful block was defined as a complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot. RESULTS: A greater success rate was observed with 20 mL of 1.5% mepivacaine (96.6%) than with 30 mL of 1% mepivacaine (68.9%; P < 0.05). Time to onset of complete sensory and motor block was shorter after injection of 20 mL of 1.5% mepivacaine (11 +/- 6 min and 13 +/- 7 min, respectively) than after 30 mL of 1% mepivacaine (17 +/- 8 min and 19 +/- 8 min, respectively, P < 0.05). CONCLUSION: In Labat's sciatic nerve blockade, administering a low volume and a high concentration of local anesthetic (1.5% mepivacaine) is associated with a higher success rate and a shorter onset time than a high volume and a low concentration of solution (1% mepivacaine).

A "new" automated bolus technique for continuous popliteal block: a prospective, randomized comparison with a continuous infusion technique.

BACKGROUND: We designed the present, prospective, randomized, double-blind study to compare the administration of an automated intermittent bolus dose with a conventional technique of continuous infusion of local anesthetic for postoperative analgesia in continuous popliteal sciatic nerve blockade. METHODS: Forty-four patients undergoing hallux valgus repair were randomly assigned to receive either a continuous infusion of 0.125% levobupivacaine with an infusion rate of 5 mL/h (continuous infusion group, n=22) or automated bolus doses of 5 mL every hour of the same local anesthetic (automated bolus group, n=22) for 24 h. Postoperative pain scores were assessed using a verbal rating pain score. The amount of rescue tramadol medication for pain was also recorded. RESULTS: In patients of the automated bolus group there was a reduction in pain scores (P<0.05) during the postoperative period, when compared to patients of the continuous infusion group. Five patients in the automated bolus group (24%) and 11 patients of the continuous group (52%) required rescue tramadol analgesia (P=0.055). CONCLUSION: The present investigation demonstrated that local anesthetic administered by an automated bolus technique provided better postoperative pain relief than a continuous infusion technique for continuous popliteal nerve block after foot surgery.

A prospective, randomized comparison between the popliteal and subgluteal approaches for continuous sciatic nerve block with stimulating catheters.

In this prospective, blinded study, we randomized 56 patients undergoing hallux valgus repair to receive continuous sciatic nerve block using a subgluteal (n = 28) or a posterior popliteal approach (n = 28) with a perineural stimulating catheter. Postoperatively, the stimulating catheter was connected to a patient-controlled analgesia pump with 0.0625% levobupivacaine (basal infusion rate of 3 mL/h, patient-controlled bolus dose of 3 mL, and lockout time of 20 min). Both approaches provided similar postoperative analgesia; however, local anesthetic consumption was larger in the popliteal group (4.9 +/- 1.4 mL/h) compared with the subgluteal group (3.8 +/- 1.1 mL/h; P < 0.05). We conclude continuous postoperative analgesia using stimulating catheters was effective at both injection sites; however, a subgluteal approach reduced the overall amount of local anesthetic.

What is the minimum effective volume of local anesthetic required for sciatic nerve blockade? A prospective, randomized comparison between a popliteal and a subgluteal approach.

For sciatic nerve blockade, no study has defined the optimal volume of local anesthetic required to block the nerve. The current, prospective, randomized investigation was designed to find a minimum volume of 1.5% mepivacaine required to block the sciatic nerve using the subgluteal and posterior popliteal approaches. A total of 56 patients undergoing foot surgery were randomly assigned to receive sciatic nerve block by means of a posterior subgluteal (group subgluteal, n = 28) or a posterior popliteal (group popliteal, n = 28) approaches. All blocks were performed with the use a nerve stimulator (stimulating frequency, 2 Hz, intensity 1.5-0.5 mA) and a perineural stimulating catheter. In all patients, plantar flexion of the foot was elicited at <0.5 mA, to maintain consistency among groups. The volume of local anesthetic used in each patient was based on the modified Dixon's up-and-down method. Complete anesthesia was defined as complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot 20 min after injection. The mean volume of local anesthetic required to block the sciatic nerve was 12 +/- 3 mL in the subgluteal group and 20 +/- 3 mL in the popliteal group (P < 0.05). The ED95 for adequate block of the sciatic nerve was 17 mL in the subgluteal group and 30 mL in the popliteal group. The authors conclude that a larger volume of local anesthetic is necessary to block the sciatic nerve at a more distal site (popliteal approach) as compared with a more proximal level (subgluteal approach).

Does the site of injection distal to the greater trochanter make a difference in lateral sciatic nerve blockade?

UNLABELLED: The two components of the sciatic nerve become more distant from one another in their course down the lower limb. This may have clinical implications if a small volume of local anesthetic is used with a single injection technique. In this prospective, randomized, double-blind study, we compared two different injection sites, 20 cm and 30 cm distal to the greater trochanter, in terms of onset time and success rate of sciatic nerve blockade after a single injection of 20 mL of 1.5% mepivacaine. Fifty patients undergoing foot surgery were randomly allocated to receive a lateral sciatic nerve blockade using one of 2 levels: 20 cm distal to the greater trochanter (group proximal; n = 25) and 30 cm distal to the greater trochanter (group distal; n = 25). Twenty milliliters of 1.5% mepivacaine was injected after a flexion plantar response was obtained at <0.5 mA. Time required for onset of sensory and motor blockade of the foot was recorded. Success rate was defined as complete sensory and motor blockade in all sciatic nerve distributions associated with a pain-free surgery. Onset of complete sensory and motor blockade was faster in group proximal (12 +/- 7 min and 15 +/- 8 min, respectively) compared with group distal (19 +/- 9 min and 23 +/- 9 min; P < 0.05). Group proximal also had a more frequent success rate compared with group distal (88% versus 56%, respectively; P < 0.05). It is concluded that in lateral sciatic nerve blockade, a more proximal approach to the sciatic nerve predicts a shorter onset time and more frequent success than a more distal injection site when a single injection and a small volume of local anesthetic is used. IMPLICATIONS: In lateral sciatic nerve blockade, a more proximal approach to the sciatic nerve provides shorter onset times and more frequent success than a more distal injection site when a single injection of 20 mL of mepivacaine 1.5% is used.

High thoracic epidural anesthesia and coronary artery disease in surgical and non-surgical patients.

PURPOSE OF REVIEW: Even though high thoracic epidural anesthesia has been shown to be highly efficacious in the control of symptoms in refractory angina, its general use is still restricted. In patients who undergo coronary revascularization, however, the technique is becoming more and more popular. The present review outlines the use of high thoracic epidural anesthesia in patients with ischemic heart disease who underwent coronary revascularization in order to further reveal high thoracic epidural anesthesia's low complication rate and to analyze why physicians still refrain from using it more frequently. RECENT FINDINGS: The incidence of severe hemodynamic complications after high thoracic epidural anesthesia is low in patients with coronary artery disease. The main advantage would be a myocardial sympathectomy leading to an improvement in the oxygen input-demand relationship. Likewise, a decrease in mortality due to respiratory complications could not be shown. In patients undergoing myocardial revascularization with full anticoagulation there is an increased risk of epidural hematoma formation. Its precise risk is difficult to evaluate. There is an overall low rate of epidural hematomas as a result of high thoracic epidural anesthesia. With the available data, the incidence has been estimated at between 1/1500 and 1/10,000. SUMMARY: Epidural anesthesia does not decrease mortality or the incidence of myocardial infarction after coronary artery bypass grafting. It reduces the incidence of arrhythmias and respiratory complications and improves the quality of analgesia. High thoracic epidural anesthesia has been shown to be a safe and efficient technique for refractory angina that reduces the frequency of ischemic events and improves the clinical condition of patients.

Plantar flexion seems more reliable than dorsiflexion with Labat's sciatic nerve block: a prospective, randomized comparison.

Labat's classic approach to the sciatic nerve has not been able to show which motor response of the foot provides a more frequent rate of complete sensory and motor block. In this prospective, randomized, double-blind study, we compared plantar flexion with dorsiflexion with regard to onset time and efficacy of sciatic nerve block using the classic posterior approach. A total of 80 patients undergoing hallux valgus repair were randomly allocated to receive sciatic nerve block after evoked plantar flexion (n=40) or dorsiflexion (n=40). Twenty milliliters of 0.75% ropivacaine was injected after the motor response was elicited at <0.5 mA. Success rate was defined as complete sensory and motor block in all sciatic nerve distributions associated with a pain-free surgery. Time required for onset of sensory and motor block of the foot was recorded. Success was more frequent after elicited plantar flexion (87.5%) than dorsiflexion (55%; P <0.05). Onset of complete sensory and motor block of the foot was faster after elicited plantar flexion (10 +/- 10 min and 13 +/- 10 min, respectively) compared with dorsiflexion (20 +/- 11 min and 24 +/- 12 min; P <0.05). We conclude that plantar flexion of the foot predicts a shorter onset time and a more frequent success rate than dorsiflexion with Labat's classic posterior sciatic nerve block.

Sedation after spinal anesthesia in elderly patients: a preliminary observational study with the PSA-4000.

PURPOSE: Neuraxial blockade is known to have a sedative effect, decreasing the need for inhalational and iv anesthetic agents. The purpose of the present study was to quantify the sedative effect of spinal anesthesia and to determine the time of maximum sedation. METHODS: This is an observational study in which 20 unsedated patients were scheduled to undergo urologic and orthopedic surgeries under spinal anesthesia. Patients with pre-existing neurological conditions or receiving psychotropic medications were excluded from the study. All received 1.5 mL (11.25 mg) of hyperbaric bupivacaine 0.75% intrathecally. No sedative or narcotic was administered intravenously or intrathecally. The Patient State Analyzer, (PSA-4000) was used to monitor sedation along with Observer's Assessment of Alertness and Sedation (OAA/S) scores every five minutes. Differences in patient state index (PSI) and OAA/S scores are expressed as median and range and were evaluated by Wilcoxon's signed rank test for non-parametric data; P < 0.05 was considered significant. PSI, OAA/S and time at lowest score are expressed as median(range). RESULTS: PSI scores decreased from baseline 99 (96-99) to 78 (56-87) at 35(14.5-54) min into the spinal anesthetic (P < 0.05). OAA/S scores decreased from baseline 5 to 4 (range 3-5) at the time of the lowest PSI scores (P < 0.05). CONCLUSIONS: In this elderly patient population, spinal anesthesia induced changes in the processed electroencephalogram with reduction in PSI and OAA/S scores. The reduction in afferent input to the reticular activating system could possibly explain the sedation that has been observed and the reduction in the PSA scores.

Sciatic nerve block via posterior Labat approach is more efficient than lateral popliteal approach using a double-injection technique: a prospective, randomized comparison.

BACKGROUND: For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine. METHODS: A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery. RESULTS: A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05). CONCLUSION: A double injection with a relatively low volume of 0.75% ropivacaine generated a higher success rate and a shorter onset time of sensory and motor blockade after the classic Labat approach than after a lateral popliteal approach.

A comparison of lateral popliteal versus lateral midfemoral sciatic nerve blockade using ropivacaine 0.5%.

BACKGROUND AND OBJECTIVES: The midfemoral approach to the sciatic nerve (MF) is a new technique that has been used for postoperative analgesia after knee surgery. The aim of the present study was to compare efficacy, performance time, and patient acceptance of the midfemoral approach to that of the lateral approach at the level of the popliteal fossa (popliteal block [PB]). METHODS: Sixty-three patients were enrolled in this prospective, randomized study. Thirty-two patients received a lateral sciatic nerve block (group PB) and 31 patients a midfemoral block (group MF). Ropivacaine 0.5% (30 mL) was used in both groups. RESULTS: The quality of nerve blockade was comparable in both groups. Onset of sensory block for peroneal and tibial nerves was significantly shorter in group MF than in group PB, 5 (1-20) minutes and 5 (1-20) minutes versus 10 (1-40) minutes and 10 (1-45) minutes, respectively. Onset of motor block in both territories was also shorter in group MF compared with PB, 6 (2-35) minutes and 5 (2-55) minutes versus 15 (2-60) minutes and 15 (2-60) minutes, respectively (P <.05). There was no difference in duration of sensory and motor blockade, 16 (7-32) hours versus 16 (6-43) hours and 16 (8-32) hours versus 16 (6-25) hours. There was no significant difference between both groups with respect to difficulty of nerve block performance. Patient discomfort during needle puncture was also similar. CONCLUSIONS: The midfemoral approach to the sciatic nerve for ankle and foot surgery resulted in a reliable anesthetic, comparable to that of the lateral popliteal approach. This technique is simple, safe, and provides postoperative analgesia as effective as that obtained with the lateral approach.

The effects of three different approaches on the onset time of sciatic nerve blocks with 0.75% ropivacaine.

UNLABELLED: We studied three different injection techniques of sciatic nerve block in terms of block onset time and efficacy with 0.75% ropivacaine. A total of 75 patients undergoing foot surgery were randomly allocated to receive sciatic nerve blockade by means of the classic posterior approach (group classic; n = 25), a modified subgluteus posterior approach (group subgluteus; n = 25), or a lateral popliteal approach (group popliteal; n = 25). All blocks were performed with the use of a nerve stimulator (stimulation frequency, 2 Hz; intensity, 2-0.5 mA) and 30 mL of 0.75% ropivacaine. Onset of nerve block was defined as complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot. In the three groups, an appropriate sciatic stimulation was elicited at <0.5 mA. The failure rate was similar in the three groups (group popliteal: 4% versus group classic: 4% versus group subgluteus: 8%). The onset of nerve block was slower in group popliteal (25 +/- 5 min) compared with group classic (16 +/- 4 min) and group subgluteus (17 +/- 4 min; P < 0.001). There was no significant difference in the onset of nerve block between group classic and group subgluteus. No differences in the degree of pain measured at the first postoperative administration of pain medication were observed among the three groups. We conclude that the three approaches resulted in clinically acceptable anesthesia in the distribution of the sciatic nerve. The subgluteus and classic posterior approaches generated a significantly faster onset of anesthesia than the lateral popliteal approach. IMPLICATIONS: Comparing three different approaches to the sciatic nerve with 0.75% ropivacaine, the classic and subgluteal approaches exhibited a faster onset time of sensory and motor blockade than the lateral popliteal approach.

Lower extremity nerve blocks.

PURPOSE OF REVIEW: The purpose of this review is to present the most important recent studies into the clinical use of peripheral nerve blocks for anesthesia and postoperative analgesia of the lower limb surgery. RECENT FINDINGS: There is increasing interest in lower extremity peripheral nerve blocks because of their potential advantages and concerns over interactions of centroneuraxis blocks and anticoagulants. Several authors have studied different approaches to the blockade of peripheral nerves with their advantages or disadvantages. Continuous peripheral nerve blocks have showed prolonged analgesia and great patient satisfaction with low side effects. Recent imaging techniques (e.g. ultrasound, magnetic resonance, tomography scans) have been developed to improve the performance of lower peripheral nerve blocks. Finally, complications of these techniques have been examined. SUMMARY: Introduction of new methods and techniques are increasing and improving the use of lower peripheral nerve blocks. These techniques are gaining interest after the important increase of the lower molecular weigh heparins.