Comparison of plasma concentrations of levobupivacaine with and without epinephrine for thoracic paravertebral block: A randomised trial.

BACKGROUND: Thoracic paravertebral block (TPVB) is effective for analgesia for unilateral thoracic surgery. However, since the paravertebral space is highly vascular, injection of local anaesthetics into the paravertebral space may induce systemic local anaesthetic toxicity. We examined the effect of addition of epinephrine to paravertebral levobupivacaine on its plasma concentration. METHODS: In a randomised single blind trial, twenty-four male patients who were scheduled to undergo elective unilateral pulmonary lobectomy or segmentectomy under general anaesthesia combined with TPVB were enrolled in this study. They were randomly divided into two groups: one group received a single bolus thoracic paravertebral injection of 1 mg/kg of 0.25% levobupivacaine with 5 µg/mL epinephrine and the other group received a single bolus thoracic paravertebral injection of 1 mg/kg of 0.25% levobupivacaine alone. Arterial blood samples were obtained for plasma levobupivacaine assay after injection. The peak plasma concentration (Cmax) and the time to peak plasma concentration (Tmax), for levobupivacaine were calculated. RESULTS: There were no significant differences in patients' characteristics between the two groups. The mean arterial Cmax values of levobupivacaine were 0.48 ± 0.11 µg/mL with epinephrine and 0.71 ± 0.31 µg/mL without epinephrine (P = 0.041). The mean arterial Tmax values of levobupivacaine were 46.0 ± 35.6 min with epinephrine and 12.0 ± 7.2 min without epinephrine (P = 0.005). CONCLUSION: The addition of 5-µg/mL epinephrine to a single bolus thoracic paravertebral injection of 1-mg/kg levobupivacaine significantly decreased Cmax and delayed Tmax of levobupivacaine. The addition of epinephrine to levobupivacaine may be a useful strategy to reduce systemic levobupivacaine toxicity. CLINICAL TRIAL REGISTRATION NUMBER: UMIN 000021942.

Comparison of catheter-over-needle and catheter-through-needle on leakage from the catheter insertion site during continuous femoral nerve block.

The aim of this study was to compare the incidences of leakage from the catheter insertion site during continuous femoral nerve block when using the catheter-through-needle, Contiplex Touhy™ (CT) and the newly developed catheter-over-needle, Contiplex C™ (CC). Forty adult patients who were scheduled to undergo continuous femoral nerve block for pain control following knee surgery were enrolled and were randomly assigned to a CT group or a CC group. After finishing surgery, a catheter for continuous femoral nerve block was placed using ultrasound. A catheter was advanced along the femoral nerve 5-6 cm beyond the needle tip. Then 0.25% levobupivacaine was continuously administered at a rate of 5 ml/h until 9:00 am on postoperative day 1. The incidence of leakage of the local anesthetic from the insertion site in the CT group was significantly higher than that in the CC group. In the CT group, leakage from the catheter insertion site was observed in 11 of 20 patients during the observation period. On the other hand, none of the patients in the CC group showed leakage. Contiplex C™ is more effective than Contiplex Touphy™ for prevention of leakage of local anesthetics from the insertion site during continuous femoral nerve block.

Incidence and mortality associated with Clostridium difficile infection at a Japanese tertiary care center.

BACKGROUND: Although increases in Clostridium difficile infection (CDI) incidence and severity have been observed in numerous countries, the incidence of CDI in Japan remains unclear. The goal of this study was to determine the incidence and outcomes of CDI at a Japanese tertiary care center. MATERIALS AND METHODS: Retrospective cohort study in patients with CDI was conducted at a 550-bed, tertiary care, academic center in Sapporo, Japan from September 2010 through August 2012. CDI cases diagnosed by enzyme immunoassays were categorized per internationally recognized surveillance definitions. Data on demographic characteristics, medication exposures, CDI presentation, and CDI treatment were collected on all CDI cases. Factors associated with 30-day all-cause mortality after the completion of CDI treatment were also investigated. RESULTS: There were 32,296 admissions and 350,074 patient-days from 22,863 patients during the study period; 126 patients were diagnosed with CDI. The median age of CDI case patients was 78 years. Healthcare facility-onset (HO) CDI accounted for 86.5% of CDI cases, with a HO-CDI incidence of 3.11 cases per 10,000 patient-days. Three patients underwent surgery for CDI (2.4%) and 19 patients (15%) died within a 30 days of completing CDI treatment. Factors independently associated with mortality were diabetes mellitus and shock at time of CDI diagnosis. CONCLUSIONS: The CDI incidence was lower than that typically reported from North American hospitals, but the proportion of patients requiring surgical therapy and dying within 30 days of CDI in non-outbreak settings was higher. More study is needed to determine why CDI incidence is low relative to CDI-associated outcomes in Japan.

A successful strategy for increasing the influenza vaccination rate of healthcare workers without a mandatory policy outside of the United States: a multifaceted intervention in a Japanese tertiary care center.

OBJECTIVE: Although mandatory vaccination programs have been effective in improving the vaccination rate among healthcare workers, implementing this type of program can be challenging because of varied reasons for vaccine refusal. The purpose of our study is to measure improvement in the influenza vaccination rate from a multifaceted intervention at a Japanese tertiary care center where implementing a mandatory vaccination program is difficult. DESIGN: Before-and-after trial. PARTICIPANTS AND SETTING: Healthcare workers at a 550-bed, tertiary care, academic medical center in Sapporo, Japan. INTERVENTIONS: We performed a multifaceted intervention including (1) use of a declination form, (2) free vaccination, (3) hospital-wide announcements during the vaccination period, (4) prospective audit and real-time telephone interview for healthcare workers who did not receive the vaccine, (5) medical interview with the hospital executive for noncompliant (no vaccine, no declination form) healthcare workers during the vaccination period, and (6) mandatory submission of a vaccination document if vaccinated outside of the study institution. RESULTS: With the new multifaceted intervention, the vaccination rate in the 2012-2013 season increased substantially, up to 97%. This rate is similar to that reported in studies with a mandatory vaccination program. Improved vaccination acceptance, particularly among physicians, likely contributed to the overall increase in the vaccination rate reported in the study. CONCLUSIONS: Implementation of comprehensive strategies with strong leadership can lead to substantial improvements in vaccine uptake among healthcare workers even without a mandatory vaccination policy. The concept is especially important for institutions where implementing mandatory vaccination programs is challenging.

Myofascial involvement of supra- and infraspinatus muscles contributes to ipsilateral shoulder pain after muscle-sparing thoracotomy and video-assisted thoracic surgery.

OBJECTIVE: This study examined the hypothesis that ipsilateral upper extremity elevation for muscle-sparing thoracotomy procedures contributes to the postoperative shoulder pain. DESIGN: Prospective observational study. SETTING: Medical center. PARTICIPANTS: ASA physical status 1-2 patients undergoing elective lung surgeries including pneumonectomy, lobectomy, and segmentectomy performed through either the anterolateral approach or video-assisted thoracotomy surgery. INTERVENTIONS: Postoperative observation of ipsilateral shoulder pain. MEASUREMENTS AND MAIN RESULTS: Postoperative examinations of sites of shoulder pain (clavicle, anterior, lateral,or posterior aspect of acromion, posterior neck, supraspinatus, infraspinatus, and these entire areas) with or without trigger points, visual analog scale score of wound pain, and requested counts of analgesics. The number of patients who suffered from postoperative shoulder pain was 37 of 70 (52.9%). Demographic data, anterolateral/VATS ratio, VAS scores, and requested counts of rescue analgesics requirement were similar in the groups of patients with and without postoperative shoulder pain. The segmentectomy caused a significantly higher incidence of postoperative shoulder pain compared with other procedures (p < 0.05). The supra- and infraspinatus were significantly higher areas of painful regions compared to the other sites. The 16 of 37 patients (43.2%) with shoulder pain showed defined trigger points in their painful areas. CONCLUSION: These results supported the hypothesis that myofascial involvement contributed, to some extent, to shoulder pain after muscle-sparing thoracotomy with ipsilateral upper extremity elevation.

The cellular mechanisms underlying the inhibitory effects of isoflurane and sevoflurane on arginine vasopressin-induced vasoconstriction.

PURPOSE: Arginine vasopressin (AVP) is a potent vasoconstrictor that is sometimes used for the treatment of refractory vasodilatory shock. AVP constricts vascular smooth muscle by increasing both intracellular calcium concentration ([Ca(2+)](i)) and myofilament Ca(2+) sensitivity. However, the modulation of AVP-mediated vasoconstriction by volatile anesthetics remains to be determined. This study investigates the effects of isoflurane and sevoflurane on AVP-induced vasoconstriction and elucidates the underlying mechanisms, with an emphasis on the Ca(2+)-mediated pathways and Ca(2+) sensitization pathways of rat aortic smooth muscle. METHODS: The effects of isoflurane and sevoflurane on AVP-induced vasoconstriction and on the AVP-induced increase in [Ca(2+)](i) and Rho activity in rat aorta were investigated by isometric force recording, by measuring [Ca(2+)](i) using fluorescence dye, and by Western blotting techniques. RESULTS: Arginine vasopressin (10⁻7M) elicited a transient contractile response that was inhibited by isoflurane and sevoflurane in a concentration-dependent manner. AVP (10⁻7 M) induced a transient increase in intracellular Ca(2+) concentration ([Ca(2+)](i)). Isoflurane and sevoflurane also inhibited an AVP-induced increase in [Ca(2+)](i) in a concentration-dependent manner. AVP (10⁻7 M) increased the Rho activity that was attenuated by 2 minimum alveolar concentration of sevoflurane (P < 0.01), but not by an equipotent concentration of isoflurane. CONCLUSION: Arginine vasopressin-induced vasoconstriction is mediated by an increase in [Ca(2+)](i) and by the activation of the Rho-Rho kinase pathway in rat aortic smooth muscle. Although both isoflurane and sevoflurane, at clinically relevant concentrations, attenuate AVP-induced contraction, the cellular mechanisms of their inhibitory effects appear to differ.

Severe methemoglobinemia after dental anesthesia: a warning about propitocaine-induced methemoglobinemia in neonates.

Methemoglobinemia is a fatal complication of local anesthesia. We describe a case report of female neonate who developed severe methemoglobinemia after extraction of neonatal teeth conducted with general anesthesia plus local injection of Citanest-Octapressin(®) (propitocaine of approximately 10 mg/kg). Central cyanosis appeared within an hour after surgery. The percentage of methemoglobin reached up to 43.9%. Not only pediatric dentists but also anesthesiologists generally agree with the idea that local anesthesia provides various benefits in painful procedures in neonates. However, this case may serve as a warning when using Citanest-Octapressin(®), which is still commercially available for neonatal patients.

Landiolol attenuates tachycardia in response to endotracheal intubation without affecting blood pressure.

PURPOSE: Beta-adrenergic receptor antagonists (beta-antagonists) have long been used to control perioperative tachyarrhythmias. The effects of a beta(1)-antagonist, landiolol, on perioperative hemodynamics are unknown. We aimed to determine the appropriate dosage of landiolol for the treatment of hemodynamic changes in response to endotracheal intubation. METHODS: Sixty-four patients without heart disease or hypertension, were assigned to receive saline (group C) or landiolol (0.1 or 0.3 mg.kg(-1); groups L1 and L3). Anesthesia was induced with propofol (2 mg.kg(-1) iv) followed by saline or landiolol iv. After ventilation with facemask using 2% sevoflurane in 100% oxygen for 90 sec, endotracheal intubation was performed. After intubation, anesthesia was maintained using 1% sevoflurane in combination with 50% nitrous oxide. Values of heart rate and mean arterial blood pressure were recorded before induction to five minutes after intubation. RESULTS: In group C, heart rate and mean blood pressure increased simultaneously after tracheal intubation, compared with baseline values. Heart rate values were attenuated immediately before as well as after intubation in group L3, compared with groups C and L1. Heart rate did not increase after tracheal intubation in group L1, compared with baseline. In contrast, mean arterial blood pressure values did not differ among groups. CONCLUSIONS: The newly developed beta(1)-antagonist landiolol (0.1 and 0.3 mg.kg(-1)) may help prevent tachycardia without affecting blood pressure during the induction of anesthesia.

The use of bone cement induces an increase in serum astroglial S-100B protein in patients undergoing total knee arthroplasty.

UNLABELLED: Cerebral microemboli can occur during arthroplasty with the use of bone cement. Astroglial S-100B protein is a sensitive marker of cerebral damage. Therefore, we designed this study to determine the effect of bone cement on the brain by investigating serum levels of S-100B protein in patients undergoing bone surgery with or without bone cement. Fourteen patients undergoing knee arthroplasty (n = 7) or reamed intramedullary nailing for tibial fracture (n = 7) requiring a pneumatic tourniquet were enrolled in this study. Bone cement containing polymethyl methacrylate and methyl methacrylate was used for every patient undergoing knee arthroplasty. Serum samples were obtained from venous blood before the induction of general anesthesia, 15 min after deflation of a pneumatic tourniquet, and 3 days after the operation. The serum level of S-100B protein was significantly increased 15 min after a pneumatic tourniquet deflation in the knee arthroplasty group compared with the tibial fracture group (0.41 and 0.08 ng/mL, respectively; P < 0.05). In all patients studied, no neurological abnormalities were noted in the postoperative period. These results suggest that, in patients undergoing knee arthroplasty, bone cement may transiently induce astroglial injury, although it does not alter neurological outcome. IMPLICATIONS: Serum S-100B protein was significantly increased 15 min after a pneumatic tourniquet deflation in patients undergoing knee arthroplasty with bone cement, but not in those undergoing reamed intramedullary nailing for tibial fracture without bone cement. These results suggest that bone cement may transiently induce astroglial injury.