Effects of Intraoperative Low-Dose Ketamine on Persistent Postsurgical Pain after Breast Cancer Surgery: A Prospective, Randomized, Controlled, Double-Blind Study.

BACKGROUND: Compared to acute postsurgical pain, studies regarding the role of ketamine in persistent postsurgical pain (PPSP) are limited. OBJECTIVES: The aim of this clinical trial was to test if intraoperative low-dose ketamine without postoperative infusion would reduce PPSP development after breast cancer surgery. STUDY DESIGN: We used a randomized, double-blinded, placebo study design. SETTING: This study was conducted at Pusan National University Hospital, Republic of Korea, between December 2013 and August 2016. METHODS: A total of 184 patients scheduled for breast cancer surgery were randomly assigned to either the control or ketamine group. Before skin incision, a bolus (0.5 mg/kg of ketamine or placebo), followed by a continuous infusion (0.12 mg/kg/h of ketamine or placebo), was administered until the end of the surgery. The patients were interviewed via telephone 1, 3, and 6 months after surgery. The first question was whether the patient had surgery-related pain. If answered affirmatively, questions from the Numeric Rating Scale for pain at rest (NRSr) and for coughing (NRSd) were also asked. Our primary outcome was the incidence of PPSP at 3 months after surgery. RESULTS: For PPSP analysis, 168 patients were included. The number of patients who experienced pain was significantly lower in the ketamine group at 3 months (86.9% in the control group vs 69.0% in the ketamine group, P = .005) postoperatively. However, the NRSr and NRSd did not differ between the groups throughout the follow-up. LIMITATIONS: There were no postoperative low-dose ketamine infusion groups to compare due to hospital regulations. Dosage of ketamine was too low to reduce the severity of PPSP. And by using propofol and remifentanil for anesthesia, different results can be deduced with volatile anesthetics. Data from written questionnaires would have been more specific than telephone interviews for long-term assessment. CONCLUSIONS: Though intraoperative low-dose ketamine without postoperative infusion significantly reduced the incidence of PPSP up to 3 months after breast cancer surgery, it failed to reduce clinically significant PPSP and improve patients' quality of life. KEY WORDS: Analgesia, breast cancer, chronic pain, ketamine, mastectomy, morphine, pain, postoperative, propofol.

Pretreatmet with 5% lidocaine patch reduces cannula-induced and propofol-induced pain: a randomized, double-blind, placebo-controlled study.

BACKGROUND: The purpose of this study was to determine the efficacy of 5% lidocaine patch in reducing propofol-induced pain and cannula-induced pain. METHODS: In a randomized, double-blind study, 126 patients were divided into one of three groups: pretreatment with a 5% lidocaine patch (Lidotop®) and premixed 2 ml of normal saline with 1.5 mg/kg of 1% propofol (Group A); pretreatment with a placebo patch and premixed 2 ml of normal saline with 1.5 mg/kg of 1% propofol (Group B); or pretreatment with a placebo patch and premixed 2 ml of 2% lidocaine (40 mg) with 1.5 mg/kg of 1% propofol (Group C) for induction of anesthesia. Pain severity was evaluated on a four-point verbal rating scale during intravenous cannulation, propofol injection, and 24 h after the operation (recall). RESULTS: Eighteen patients (47.4%) in Group A complained of cannula-induced pain compared with 35 (94.6%) in Group B and 36 (94.7%) in Group C (P < 0.001). Group A patients showed significantly lower incidence of propofol-induced pain and recall of propofol-induced pain compared with Group B (P < 0.001 and P = 0.01), whereas there was no difference compared with Group C. CONCLUSIONS: Preoperative transdermal administration of 5% lidocaine patch is an effective and simple method in reducing propofol-induced pain as well as cannula-induced pain.

Combined spinal-epidural anesthesia for radical hysterectomy in a patient with Sjȍgren syndrome with progressive interstitial lung disease.

INTRODUCTION: Interstitial lung disease (ILD), which is the most common form of respiratory involvement of Sjȍgren syndrome (SS), is highly associated with postoperative pulmonary complications after surgery. We report the successful anesthetic management of a cervical cancer patient with SS and ILD under combined spinal-epidural anesthesia (CSE) to avoid postoperative pulmonary complications. CASE DESCRIPTION: A 41-year-old woman with SS complicated by recently progressive ILD was scheduled for an elective radical hysterectomy under the diagnosis of cervical cancer. We performed CSE with separate needle technique (SNT) using two different interspaces. An epidural catheter was inserted at T11-T12 before administration of spinal medication at L3-L4. We could achieve successful anesthetic management for radical hysterectomy, maintaining stable hemodynamic variables. Postoperative analgesia, using epidural catheter, was effective and devoid of any postoperative pulmonary morbidity. DISCUSSION AND EVALUATION: CSE could offer a high level of sensory blockade, profound muscular blockade, longer duration of surgical anesthesia, excellent postoperative pain control, and reduction in the incidence of pulmonary morbidity. Therefore it would be excellent anesthetic option for the patients with pulmonary impairment. CONCLUSION: CSE with SNT may be particularly advantageous in patients with pulmonary impairment such as progressive ILD when general anesthesia is associated with high risk of postoperative complications.

Dexmedetomidine Injection during Strabismus Surgery Reduces Emergence Agitation without Increasing the Oculocardiac Reflex in Children: A Randomized Controlled Trial.

OBJECTIVE: Dexmedetomidine is known to reduce the incidence of emergence agitation, which is a common complication after inhalational anesthesia like sevoflurane or desflurane in children. However, the dose of dexmedetomidine used for this purpose is reported variously and the most effective dose is not known. In this study, we tried to find the most effective dose of dexmedetomidine to reduce the incidence of emergence agitation in children undergoing strabismus surgery without the complications like oculocardiac reflex (OCR) or postoperative vomiting. METHODS: We randomized 103 pediatric patients aged 2-6 years and undergoing elective strabismus surgery into four groups. Anesthesia was induced with sevoflurane and maintained with desflurane. At the start of induction, dexmedetomidine, delivered at 0.25, 0.5, or 1 µg/kg, or saline was infused intravenously in the D0.25, D0.5, D1 groups, respectively. The primary outcome measure was the incidence of emergence agitation and the secondary outcome measure was the incidence of intraoperative OCR, postoperative vomiting, and desaturation events. RESULTS: The incidence of emergence agitation was 60, 48, 44, and 21% (P = 0.005) and the incidence of intraoperative OCR was 36, 36, 36, and 37% (P = 0.988) in the control, D0.25, D0.5, and D1 groups, respectively. And, postoperative vomiting rate and desaturation events were low in the all groups. CONCLUSION: Dexmedetomidine decreased the incidence of emergence agitation without increasing intraoperative oculocardiac reflex. Dexmedetomidine delivered at 1 µg/kg was more effective at reducing emergence agitation than lower doses in children undergoing strabismus surgery under desflurane anesthesia. TRIAL REGISTRATION: Clinical Research Information Service KCT0000141.

Continuous Ilioinguinal-iliohypogastric Nerve Block for Groin Pain in a Breast-feeding Patient after Cesarean Delivery.

Ilioinguinal and iliohypogastric (II/IH) nerve injury is one of the most common nerve injuries following pelvic surgery, especially with the Pfannenstiel incision. We present a case of intractable groin pain, successfully treated with a continuous II/IH nerve block. A 33-year-old woman, following emergency cesarean section due to cephalopelvic disproportion, presented numbness in left inguinal area and severe pain on the labia on the second postoperative day. The pain was burning, lancinating, and exacerbated by standing or movement. However, she didn't want to take additional medicine because of breast-feeding. A diagnostic II/IH nerve block produced a substantial decrease in pain. She underwent a continuous II/IH nerve block with a complete resolution of pain within 3 days. A continuous II/IH nerve block might be a goodoption for II/IH neuropathy with intractable groin pain in breast-feeding mothers without adverse drug reactions in their infants.

Thoracic paravertebral block for nephrectomy: a randomized, controlled, observer-blinded study.

OBJECTIVE: This study evaluated whether adding a preoperative single thoracic paravertebral block (TPVB) to intravenous patient-controlled analgesia (IV PCA) would improve postoperative analgesia compared with using IV PCA alone in patients undergoing nephrectomy. DESIGN: Prospective, randomized, controlled, observer-blinded trial. SETTING: University hospital. SUBJECTS: Thirty-four adult patients undergoing elective open nephrectomy. METHODS: The patients were randomized to receive a TPVB plus IV PCA (group T) or IV PCA alone (group C). A single 18-mL injection of 0.75% ropivacaine was administered preoperatively under ultrasound guidance; fentanyl was used for IV PCA. Each patient's postoperative pain score based on a verbal numerical rating scale, postoperative fentanyl consumption, inspiratory volume by incentive spirometry, and complications were evaluated at 1, 3, 6, 12, and 24 hours after surgery. Changes in heart rate (HR), systolic arterial pressure (SAP), and mean arterial pressure (MAP) were evaluated following skin incision. RESULTS: The postoperative pain score and fentanyl consumption were significantly lower in group T than in group C at all time points up to 24 hours after surgery. The postoperative inspiratory volumes were not significantly different. The changes in HR were similar, while the increases in SAP and MAP after skin incision were lower in group T than in group C. CONCLUSIONS: A preoperative single TPVB improved postoperative analgesia by reducing the postoperative pain score and fentanyl consumption in patients undergoing nephrectomy.

Unilateral, single needle approach using an epidural catheter for bilateral superior hypogastric plexus block.

The superior hypogastric plexus block (SHPB) is used for treating pelvic pain, especially in patients with gynecological malignancies. Various approaches to this procedure have been reported due to the anatomic obstacles of a high iliac crest or large transverse process of the 5(th) lumbar vertebra. Here, we report a new technique of superior hypogastric plexus block using a unilateral single-needle approach to block the bilateral superior hypogastric plexus with a Tuohy needle and epidural catheter. We have confidence that this new technique can be another option in performing the SHPB when the conventional bilateral approach is difficult to perform.

Levobupivacaine-induced contraction of isolated rat aorta is calcium dependent.

Levobupivacaine is a long-acting local anesthetic that intrinsically produces vasoconstriction in isolated vessels. The goals of this study were to investigate the calcium-dependent mechanism underlying levobupivacaine-induced contraction of isolated rat aorta in vitro and to elucidate the pathway responsible for the endothelium-dependent attenuation of levobupivacaine-induced contraction. Isolated rat aortic rings were suspended to record isometric tension. Cumulative levobupivacaine concentration-response curves were generated in either the presence or absence of the antagonists verapamil, nifedipine, SKF-96365, 2-aminoethoxydiphenylborate, Gd(3+), N(W)-nitro-l-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), and methylene blue, either alone or in combination. Verapamil, nifedipine, SKF-96365, 2-aminoethoxydiphenylborate, low calcium concentrations, and calcium-free Krebs solution attenuated levobupivacaine-induced contraction. Gd(3+) had no effect on levobupivacaine-induced contraction. Levobupivacaine increased intracellular calcium levels in vascular smooth muscle cells. L-NAME, ODQ, and methylene blue increased levobupivacaine-induced contraction in endothelium-intact aorta. SKF-96365 attenuated calcium-induced contraction in a previously calcium-free isotonic depolarizing solution containing 100 mmol/L KCl. Levobupivacaine-induced contraction of rat aortic smooth muscle is mediated primarily by calcium influx from the extracellular space mainly via voltage-operated calcium channels and, in part, by inositol 1,4,5-trisphosphate receptor-mediated release of calcium from the sarcoplasmic reticulum. The nitric oxide - cyclic guanosine monophosphate pathway is involved in the endothelium-dependent attenuation of levobupivacaine-induced contraction.

Lipid emulsion reverses Levobupivacaine-induced responses in isolated rat aortic vessels.

BACKGROUND: The goal of this in vitro study was to investigate the effects of lipid emulsion (LE) on local anesthetic levobupivacaine-induced responses in isolated rat aorta and to determine whether the effect of LE is related to the lipid solubility of local anesthetics. METHODS: Isolated rat aortic rings were suspended for isometric tension recording. The effects of LE were determined during levobupivacaine-, ropivacaine-, and mepivacaine-induced responses. Endothelial nitric oxide synthase and caveolin-1 phosphorylation was measured in human umbilical vein endothelial cells treated with levobupivacaine alone and with the addition of LE. RESULTS: Levobupivacaine produced vasoconstriction at lower, and vasodilation at higher, concentrations, and both were significantly reversed by treatment with LE. Levobupivacaine and ropivacaine inhibited the high potassium chloride-mediated contraction, which was restored by LE. The magnitude of LE-mediated reversal was greater with levobupivacaine treatment than with ropivacaine, whereas this reversal was not observed in mepivacaine-induced responses. In LE-pretreated rings, low-dose levobupivacaine- and ropivacaine-induced contraction was attenuated, whereas low-dose mepivacaine-induced contraction was not significantly altered. Treatment with LE also inhibited the phosphorylation of endothelial nitric oxide synthase induced by levobupivacaine in human umbilical vein endothelial cells. CONCLUSIONS: These results indicate that reversal of levobupivacaine-induced vasodilation by LE is mediated mainly through the attenuation of levobupivacaine-mediated inhibition of L-type calcium channel-dependent contraction and, in part, by inhibition of levobupivacaine-induced nitric oxide release. LE-mediated reversal of responses induced by local anesthetics may be related to their lipid solubility.

Propofol has delayed myocardial protective effects after a regional ischemia/reperfusion injury in an in vivo rat heart model.

BACKGROUND: It is well known that propofol protects myocardium against myocardial ischemia/reperfusion injury in the rat heart model. The aim of this study was to investigate whether propofol provides a protective effect against a regional myocardial ischemia/reperfusion injury in an in vivo rat heart model after 48 h of reperfusion. METHODS: Rats were subjected to 25 min of left coronary artery occlusion followed by 48 h of reperfusion. The sham group received profopol without ischemic injury. The control group received normal saline with ischemia/reperfusion injury. The propofol group received profopol with ischemia/reperfusion injury. The intralipid group received intralipid with ischemia/reperfusion injury. A microcatheter was advanced into the left ventricle and the hemodynamic function was evaluated. The infarct size was determined by triphenyltetrazolium staining. The serum level of cardiac troponin-I (cTn-I) was determined by ELISA (enzyme-linked immunosorbent assay). RESULTS: Propofol demonstrated protective effects on hemodynamic function and infarct size reduction. In the propofol group, the +dP/d(tmax) (P = 0.002) was significantly improved compared to the control group. The infarct size was 49.8% of the area at risk in the control group, and was reduced markedly by administration of propofol to 32.6% in the propofol group (P = 0.014). The ischemia/reperfusion-induced serum level of cTn-I was reduced by propofol infusion during the peri-ischemic period (P = 0.0001). CONCLUSIONS: Propofol, which infused at clinically relevant concentration during the peri-ischemic period, has delayed myocardial protective effect after regional myocardial ischemia/reperfusion injury in an in vivo rat heart model after 48 h of reperfusion.

Direct effect of ropivacaine involves lipoxygenase pathway activation in rat aortic smooth muscle.

PURPOSE: Ropivacaine is a long-acting amino-amide local anesthetic that induces vasoconstriction in vitro and in vivo. The aim of this study was to investigate the pathways involved in arachidonic acid metabolism associated with S-ropivacaine-induced contraction of rat aortic smooth muscle in vitro. METHODS: Rat thoracic aortic rings without endothelium were isolated and suspended for isometric tension recording. Cumulative dose-response curves were generated with concentrations of 10(-5) to 10(-3) M ropivacaine enantiomer in the presence or absence of quinacrine dihydrochloride, nordihydroguaiaretic acid, quinacrine dihydrochloride plus nordihydroguaiaretic acid, indomethacin, fluconazole, AA-861, and verapamil. The maximal S-ropivacaine-induced contractile response achieved at 3x10(-4) M was also assessed in aortic rings pretreated with normal or calcium-free Krebs solution. RESULTS: Ropivacaine enantiomers induced dose-dependent biphasic contractions in aortic rings. S-ropivacaine (10(-4), 3x10(-4) M) induced a stronger contraction than R-ropivacaine. Quinacrine dihydrochloride (2x10(-5), 4x10(-5) M) attenuated the S-ropivacaine-induced biphasic contraction in a dose-dependent manner. Indomethacin (3x10(-5), 6x10(-5) M), nordihydroguaiaretic acid (10(-5) M), and AA-861 (10(-5) M) also attenuated the S-ropivacaine-induced dose-dependent biphasic contraction, whereas fluconazole (3x10(-5)) had no effect. Combined pretreatment with quinacrine dihydrochloride and nordihydroguaiaretic acid almost completely abolished the S-ropivacaine-induced contraction. S-ropivacaine-induced contractile responses were attenuated by verapamil (10(-5) M) and calcium-free Krebs solution. CONCLUSION: S-ropivacaine induces dose-dependent biphasic contractions in rat aortic smooth muscle through a mechanism requiring extracellular calcium that is mediated by activation of the lipoxygenase pathway and, to a lesser extent, the cyclooxygenase pathway.