Risk factors for and circumstances of needlestick and sharps injuries of doctors in operating rooms: A study focusing on surgeries using general anesthesia at Kurume University Hospital, Japan.

Healthcare workers are exposed to serious infectious diseases via needlestick and sharps injuries. The operating room is a particularly important environment in which the risk for needlestick injuries is increased for surgical doctors. According to national surveillance studies, the proportion of needlestick and sharps injuries in operating rooms has been increasing for unknown reasons. In this study, we examined risk factors for and circumstances of injuries in operating rooms by combining and analyzing incidence reports and electronic records of every surgery in Kurume University Hospital (Kurume, Japan). The annual injury rate (reflecting the reporting rate) rose continuously from fiscal years 2007-2012. We conducted analyses focusing on surgeries that used general anesthesia, which accounted for 88.1% of the injuries. An analysis of the time of injury found that the number of injuries increased toward the end of the surgical procedure. A comparative analysis of surgeries by doctors who had experienced injury revealed risk for the injury increased when a procedure ended after 20:00. In addition, a comparative analysis of doctors with and without injury experience who had similar level of operating time per year revealed that the number of working years was not lower in the injured doctors. Although the data analyzed in this study were confined to one university hospital, our approach and these results will form a basis on which to consider more effective measures to prevent injury in operating rooms.

[Combined spinal-epidural anesthesia for a patient with HTLV-1 associated myelopathy].

An 81-year-old female with HTLV-1 associated myelopathy (HAM) was scheduled for transurethral lithotomy. She had had paresthesia and spastic paresis in the lower extremities for the past 15 years. The preoperative respiratory function test revealed a vital capacity of 1.3 l (58% of the predicted value). We selected combined spinal-epidural anesthesia (CSEA) for her to avoid postoperative respiratory complications due to general anesthesia. After placement of a thoracic epidural catheter, spinal anesthesia was achieved by administration of bupivacaine 7.5 mg, resulting in the sensory block level to T 6, five min later. The intraoperative blood pressure remained high at 150-200 mmHg, in spite of the administration of nicardipine. Postoperatively, neither the deterioration in the neurological findings of HAM nor the exacerbation of respiratory function was observed. The present report suggests that CSEA can be one of the choices of anesthesia for a patient with HAM.

The use of amplitude-integrated electroencephalography combined with continuous conventional electroencephalography during therapeutic hypothermia for an infant with postnatal cardiac arrest.

INTRODUCTION: Amplitude-integrated electroencephalography (aEEG) has been employed in therapeutic hypothermia (TH) trials of neonates after perinatal hypoxic-ischemic encephalopathy (HIE). We present a case report involving the use of aEEG during TH with continuous conventional electroencephalography (cEEG) for an infant who experienced postnatal intraoperative cardiac arrest. CASE DESCRIPTION: A five-month-old infant developed cardiac arrest during operation. Return of spontaneous circulation was achieved after one hour of cardiopulmonary resuscitation. Therapeutic hypothermia was applied with neuromuscular blockades. During the TH, the brain function and seizures were monitored with aEEG, which can also display continuous cEEG. Intermittent and discrete seizures were detected on aEEG and confirmed with raw cEEG during the TH and rewarming periods. Several kinds of antiepileptic drugs (AEDs) were administered to manage seizures according to the findings of aEEG with cEEG. Seizures were controlled by the treatments, and she showed no clinical seizures after TH and AED discontinuation. DISCUSSION AND EVALUATION CONCLUSIONS: This case indicated the possibility that the use of aEEG with continuous cEEG for a postnatal infant after cardiac arrest was feasible to detect and assess seizures and the effects of antiepileptic therapy while undergoing TH.

A significant complication that occurred during insertion of dual guidewires into the right internal jugular vein for central venous catheterization.

We report a significant complication that occurred during double guidewire insertion. The first guidewire (GW1) was inserted under ultrasonographic guidance, whereas the second guidewire (GW2) was inserted by the landmark-based method. Subsequently, GW2 penetrated and entangled with GW1, which caused difficulty in removing both guidewires. A dilator was used to dilate the puncture site, allowing simultaneous removal of both guidewires with minimal invasion. The first guidewire was found to be pointing in a cranial direction, indicating the manner in which the second guidewire's puncture needle had penetrated it. Thus, when double cannulation is performed, guidewire position should be confirmed.

[A case of ventricular tachycardia that was probably caused by coronary artery spasm induced by pericardial manipulation].

We present a case of ventricular tachycardia (VT) that was probably caused by coronary artery spasm. A 74-year-old man was scheduled to undergo right lower lobectomy for lung cancer. Although he had never suffered from any episodes of ischemic heart disease, he had several risk factors for coronary artery disease (CAD); i. e., a history of smoking, a low high-density lipoprotein cholesterol level, and diabetes mellitus type 2. Anesthesia for one-lung ventilation was maintained by inhalation of sevoflurane (1-1.5%), the continuous intravenous infusion of remifentanil (0.1-0.15 µg x kg(-1) x min(-1)), and the intermittent administration of epidural (T4-5) 2% mepivacaine (4 ml) and 0.75% ropivacaine (5 ml). During manipulation of the pericardium, the patient's systolic blood pressure suddenly increased to 200 mmHg, followed by an ST elevation on his electrocardiogram. Despite the immediate infusion of nitroglycerin (1 mg), he developed non-sustained VT, lasting for about 30 seconds. Then, diltiazem (0.5 µg x kg(-1) x min(-1)) was continuously administered, and the infusion rate of remifentanil was increased to 0.3 µg x kg(-1) x min(-1). The patient recovered smoothly from anesthesia and his postoperative course was uneventful. Anesthesiologists should be aware of the possibility of coronary artery spasms induced by sudden modulation of the autonomic nervous system, particularly in patients who are at high risk of CAD.

[A case of a giant ovarian cyst anesthetized with the use of an inferior vena cava filter].

An intraperitoneal giant tumor can form deep venous thrombosis (DVT), leading to pulmonary embolism (PE) when it is removed. We report a case of a giant ovarian cystic tumor with possible DVT. A 52-year-old woman (149 cm in height, 85 kg in weight, and 150 cm in ventral girth) underwent the laparoscopic resection of the cyst. Preoperative angiography showed the obstruction of the inferior vena cava (IVC) just below the level of the right renal vein due to the compression by the tumor, and computed tomography suggested the existence of distal DVT. Anesthesia was induced with propofol and fentanyl, and the trachea was intubated using rocuronium. A permanent type IVC filter was placed near the obstruction site to prevent PE. Transesophageal echocardiography (TEE) was employed to detect the thrombotic echogram at the right atrium. Anesthesia was maintained with inhalation of sevoflurane and intravenous infusion of remifentanil. The content of the cyst (40.5 l) was suctioned slowly in about 50 min to avoid reexpansion pulmonary edema and circulatory collapse. Neither thrombotic echogram nor the acute decrease in end-tidal carbon dioxide pressure was observed throughout the anesthesia. Operation was performed uneventfully, and she recovered from anesthesia. We consider that IVC filters and TEE are useful to manage surgical patients with a huge ovarian cyst.

A case of delayed emergence from anesthesia caused by postoperative brain edema associated with unexpected cerebral venous sinus thrombosis.

Cerebral venous sinus thrombosis (CVST) is rare but displays various and often dramatic clinical symptoms. Few cases of CVST have been reported in the field of anesthesiology. We encountered an unexpected case of CVST that presented with delayed emergence from anesthesia after resection of a brain tumor. A 55-year-old man was scheduled for resection of an oligoastrocytoma in his right frontal lobe. After smooth induction of general anesthesia, anesthesia was maintained uneventfully for about 7 h with target-controlled infusion (TCI) of propofol and remifentanil, except for a seizure generated when the right anterior central gyrus was stimulated to allow motor evoked potential monitoring. Immediately after the cessation of TCI, spontaneous respiration was restored. However, the patient was unexpectedly comatose, and no response to painful stimuli or coughing during tracheal suctioning was observed. A computed tomogram taken 2 h after surgery showed diffuse brain edema, even though the neurosurgeons did not notice any cerebral swelling during closing of the dura mater. A magnetic resonance venogram revealed thromboses in the superior sagittal and straight sinuses. On the 9th postoperative day, the patient died without recovering consciousness or his brainstem reflexes. Anesthesiologists should be aware of CVST as a cause of delayed emergence from anesthesia after craniotomy.

[Anesthetic management of a patient with Rett syndrome associated with trismus and apnea attacks].

Rett syndrome (RTT) is a congenital neurological disorder associated with mutations in the gene encoding MECP2 on the X chromosome. An 18-year-old woman (150 cm in height and 29 kg in weight) had been diagnosed with RTT and showed myotonic trismus, frequent attacks of apnea, mental retardation, spastic paraplegia, scoliosis, and microcephalus with micrognathia. She was scheduled to undergo laparoscopic fundoplication and gastrostomy under general anesthesia. Nasal bronchofiberscopic intubation (BFI) was planned because difficult airway due to trismus and micrognathia was expected. Referring to the bispectral index (BIS), anesthesia was induced with intermittent intravenous thiopental (total 125 mg), resulting in successful opening of the mouth by 1.5 of a finger width and establishment of manual ventilation. Following intravenous administration of rocuronium (20 mg), oral BFI was easily accomplished despite Cormack grade III. Anesthesia was satisfactorily maintained with inhalation of sevoflurane (1.0-1.5%) and continuous infusion of remifentanil (0.1-0.2 microg x kg(-1) x min(-1)) with the BIS value ranging from 30 to 50. She recovered smoothly from anesthesia using sugammadex (50 mg). However, she immediately demonstrated trismus and an attack of apnea with shivering, which were successfully resolved by warming the body and intravenous fentanyl (50 microg bolus and subsequent infusion at a rate of 10 microg x hr(-1)). The postoperative course was uneventful. Characteristically, RTT shows an extremely wide range of neurological symptoms. Therefore, it is of great importance to respond to each of those symptoms during the perioperative management of patients with RTT.

Postoperative neurological complications and risk factors for pre-existing silent brain infarction in elderly patients undergoing coronary artery bypass grafting.

PURPOSE: Elderly patients with multiple infarctions revealed a high prevalence of postoperative stroke after coronary artery bypass grafting (CABG). However, postoperative neurological complications and characteristics of silent brain infarction (SBI) have not been evaluated in elderly patients undergoing CABG. METHODS: Four hundred forty-nine patients (≥60 years old) scheduled for CABG underwent cerebral magnetic resonance imaging (MRI) and MR angiography preoperatively to assess cerebral infarctions and carotid and intracranial artery stenosis. Atherosclerosis of the ascending aorta was assessed by epiaortic ultrasound during surgery. Patients were sorted by their history of cerebrovascular disease (CVD) and the presence of infarction by MRI: SBI (infarction without CVD), BI (symptomatic brain infarction; CVD and infarction), and controls (no findings of either CVD or infarction). RESULTS: SBI was found in 35.5% of the 449 patients and increased with age. The prevalence of pre-existing multiple infarctions was less frequent in SBI than in BI. The incidence of postoperative stroke and cognitive dysfunction was 1.3% and 4.9% in controls (n = 225), 5.7% and 15.2% in SBI (n = 158), and 9.1% and 18.2% in BI (n = 66). Patients with SBI were older and had more renal dysfunction and preoperative cognitive impairment. Stepwise logistic regression demonstrated that age, renal dysfunction, preoperative cognitive impairment, atherosclerosis of the ascending aorta, and intracranial arterial stenosis were associated significantly with SBI. CONCLUSION: Patients with SBI were ranked at moderate risk of neurological complications after CABG between control and BI. Increased age, renal dysfunction, and preoperative cognitive impairment appeared to be strongly associated with SBI.

Propofol protects against anandamide-induced injury in human umbilical vein endothelial cells.

Endocannabinoid anandamide, arachidonylethanolamine (AEA), is considered to be a causative mediator of hemorrhagic or septic shock, inducing death of several types of cells by producing free radicals such as reactive oxygen species (ROS). Propofol contains a phenolic hydroxyl group that donates electrons to the free radicals, and thus functions as an antioxidant. The purpose of this study was to investigate the protective effect of propofol against AEA-induced cell injury. After incubation with propofol at concentrations of 10, 50 or 100 µM, human umbilical vein endothelial cells (HUVECs) were stimulated with 10 µM of AEA for 24 h. ROS production, caspase-3 activity, and cell viability were evaluated 1, 8, and 24 h after the administration of 10 µM of AEA, respectively. Propofol (50 µM) significantly attenuated cell death induced by AEA, showing a protective effect against ROS production and caspase-3 activity. These results suggest that propofol at concentrations used during clinical anesthesia protects HUVECs against AEA-induced injury, in part by suppressing apoptosis.

Prognostic factors associated with mortality in patients undergoing emergency surgery for abdominal aortic aneurysms.

PURPOSE: Surgical mortality rates following emergency surgery for ruptured abdominal aortic aneurysms (AAAs) remain high. This study investigated the mortality rate and identified prognostic factors affecting mortality in patients undergoing emergency repair of AAAs in our hospital. METHODS: Between January 2005 and June 2010, a total of 42 patients underwent emergency surgery for AAAs and were included in this retrospective study. The following variables concerning each patient were collected by chart review and compared between survivors and nonsurvivors: age; gender; preoperative levels of hemoglobin (Hb), hematocrit (Ht), platelets (Plts), base excess (BE), and serum glucose and lactate; presence of preoperative shock defined as hypotension (systolic blood pressure of less than 80 mmHg); incidence of blood transfusion, whether AAA was ruptured or impending; interval from admission to the hospital or arrival in the operating room until aortic cross-clamping; surgical duration; and volume of intraoperative blood loss and transfusion, total fluid infusion, and urine output. RESULTS: Nine patients died within 30 days postoperatively, a 30-day mortality rate of 21.4%. Among these nine nonsurvivors, eight had shown persistent preoperative shock (P = 0.0004 vs. survivors). Compared with the survivors, nonsurvivors were significantly older (P = 0.0052) and had lower preoperative levels of Hb/Ht (P < 0.0001), Plts (P = 0.0003), and BE (P < 0.0001), an elevated lactate level (P = 0.0048), shorter interval from admission (P = 0.0459) or arrival in the operating room (P = 0.0288) until aortic clamping, and intraoperatively more hemorrhage (P = 0.0038) associated with larger amounts of blood transfusion (P = 0.0083) and less urine output (P = 0.0004). CONCLUSIONS: The authors clarified that certain features such as age, persistent preoperative shock, and greater amounts of transfusion associated with greater blood loss and anemia were factors affecting the mortality in patients undergoing emergency surgery for AAAs. It might be of great importance to correct preoperative shock and anemia caused by massive bleeding before the onset of hemodynamic deterioration.

A case of nonsustained ventricular tachycardia immediately following modified electroconvulsive therapy in a depressive patient.

Modified electroconvulsive therapy (mECT) with the use of hypnotics and muscle relaxants is an optional and prevailing treatment for depression in patients who have failed on antidepressant regimens. We describe a patient who developed ventricular tachycardia (VT) immediately after mECT. A 64-year-old man with no remarkable past history underwent a course of mECT for drug-resistant depression. Anesthesia was induced with intravenous thiopental (150 mg) followed by rocuronium (50 mg). Three minutes after the administration of rocuronium, the brain was electrically stimulated using a pulse wave. The first mECT session was performed uneventfully. However, the second session 2 days later elicited acute hypertension (182/134 mmHg) and tachycardia (130 bpm), resulting in the appearance of single and couplets of premature ventricular contractions on the electrocardiogram followed by VT lasting about 10 s. The chest was immediately compressed several times, then normal sinus rhythm was spontaneously restored without administering antiarrhythmic agents. The patient recovered from anesthesia without complications. Postoperatively, close examination was unable to definitively determine the cause of VT, resulting in the cancellation of subsequent mECT sessions. It is important to bear in mind that mECT can induce life-threatening arrhythmias such as VT.

A case of serious laryngeal edema unpredictably detected during laryngoscopy for orotracheal intubation following induction of anesthesia.

We report a case of unpredictable and serious laryngeal edema probably caused by preoperative esophagogastroduodenoscopy (EGD). A 54-year-old man with type 2 diabetes mellitus was scheduled to undergo coronary artery bypass grafting (CABG). Two days before surgery, EGD was performed to explore the cause of occult bleeding, resulting in a slightly sore throat and an increased white blood cell count (18,300/µl). Without premedication, general anesthesia was uneventfully induced with intravenous midazolam (10 mg) and fentanyl (50 µg), followed by inhalation of sevoflurane (3%) and intravenous rocuronium (50 mg). Thereafter, manual ventilation was easily performed with a bag and mask. However, on laryngoscopy for orotracheal intubation, serious swelling with rubor and light pus in the epiglottis extending to the arytenoid cartilage was detected, leading to the cancellation of surgery. Immediately following intravenous drip of hydrocortisone (300 mg) and bolus of sugammadex (200 mg), the patient recovered smoothly from anesthesia without complications such as dyspnea, but his sore throat persisted. He was diagnosed with acute epiglottitis. Treatment consisted of intravenous cefazolin (2 g/day) and hydrocortisone (300 mg/day tapered to 100 mg/day) for 9 consecutive days. Consequently, the patient recovered gradually from the inflammation and underwent CABG as scheduled 28 days later. Anesthesiologists should be aware that EGD performed just before anesthesia could unpredictably cause acute epiglottitis, especially in immunocompromised patients, such as those with diabetes.

[Factors that affect the mortality in patients receiving emergency surgery for ruptured abdominal aortic aneurysms].

This retrospective study was performed to identify the perioperative factors affecting the mortality rate in 28 patients, who had received emergency surgery for ruptured abdominal aortic aneurysms from January, 2005 to June, 2008. Five (17.9%) of these 28 patients died of massive bleeding, sepsis, or multiple organ failure during or within 11 days after surgery. Various factors which might influence the outcomes were compared between the survivors and non-survivors. Preoperative hypotension defined as a systolic blood pressure < or = 80 mmHg associated with hemorrhagic shock was the only significant factor affecting the mortality. There were no significant differences in age, gender, the time from the admittance to the hospital to aortic cross clamping, duration of surgery, and the amount of blood products transfused and intraoperative blood loss, between the two groups. Of great importance is that preoperative hypotension should be corrected before the onset of hemodynamic deterioration.

Anesthetic management of a patient with deteriorated cardiac function following cardiopulmonary resuscitation.

A 73-year-old woman suffering from an abdominal aortic aneurysm (AAA), unstable angina, and low cardiac function (32% of ejection fraction) was scheduled for abdominal aortic replacement and coronary artery bypass grafting. However, before the scheduled operation the patient fell into cardiopulmonary arrest with ventricular fibrillation due to rupture of the AAA. Immediate cardiopulmonary resuscitation (CPR) using epinephrine and electrical defibrillation restored the spontaneous circulation. Following CPR, a continuous high-dose dopamine infusion (15 µg/kg/min) was initiated and emergent abdominal aortic replacement was performed. On arrival at the operating room, the patient showed serious hypotension, atrial fibrillation with multifocal ventricular premature contractions, and metabolic acidosis. Transesophageal echocardiography (TEE) suggested that the circulatory collapse might have resulted from diastolic dysfunction and deteriorated compliance of the left ventricular (LV) wall, possibly due to myocardial stunning induced by myocardial ischemia, and tachycardia induced by hypovolemia, both of which are influenced by high doses of catecholamine. We accordingly transfused adequate amounts of blood products and gradually decreased the infusion rate of dopamine to 4 µg/kg/min, while carefully monitoring blood pressure, central venous pressure, and TEE. By the end of surgery hemodynamic parameters had recovered to near normal levels. In post-resuscitated and hypovolemic patients, caution should be taken when administering high levels of exogenous catecholamines, which can induce myocardial stunning and circulatory collapse.

[Anesthetic management for gastrectomy in two gastric cancer patients after coronary artery bypass grafting using right gastroepiploic artery].

We report two cases for anesthetic management of gastrectomy for gastric cancer which took place after receiving coronary artery bypass grafting (CABG) using the right gastroepiploic artery (RGEA). The first patient was a 75-year-old man after CABG using the RGEA 14 years before. He was diagnosed with gastric cancer and was scheduled for total gastrectomy. Preoperative coronary angiography (CAG) showed complete occlusion of the right coronary artery (RCA), whereas RGEA was patent. Because percutaneous coronary intervention (PCI) was hard to perform on the occluded RCA, proximal gastrectomy was carried out without lymph node dissection. The surgeons judged the surgery enough for radical treatment. Surgery was accomplished without any problems. The second patient was a 76-year-old man after CABG using the RGEA 15 years before. He was diagnosed with advanced gastric cancer and was scheduled for distal gastrectomy. Preoperative CAG showed the RCA partially occluded and the RGEA remaining patent. He received the scheduled surgery after confirmation of the success of PCI, performed preoperatively for reperfusion of the occluded segments. Although the RGEA was incised during the surgery, gastrectomy was accomplished without any problems in the cardiac function.

Chemotaxis of human articular chondrocytes and mesenchymal stem cells.

Migration of chondrocytes and mesenchymal stem cells (MSCs) may be important in cartilage development, tissue response to injury, and in tissue engineering. This study analyzed growth factors and cytokines for their ability to induce migration of human articular chondrocytes and bone marrow-derived mesenchymal stem cells in Boyden chamber assays. In human articular chondrocytes serum induced dose- and time-dependent increases in cell migration. Among a series of growth factors and cytokines tested only PDGF induced a significant increase in cell migration. The PDGF isoforms AB and BB were more potent than AA. There was an aging-related decline in the ability of chondrocytes to migrate in response to serum and PDGF. Human bone marrow MSC showed significant chemotaxis responses to several factors, including FBS, PDGF, VEGF, IGF-1, IL-8, BMP-4, and BMP-7. In summary, these results demonstrate that directed cell migration is inducible in human articular chondrocytes and MSC. PDGF is the most potent factor analyzed, and may be useful to promote tissue integration during cartilage repair or tissue engineering.

Stage-specific secretion of HMGB1 in cartilage regulates endochondral ossification.

High mobility group box 1 protein (HMGB1) is a chromatin protein that has a dual function as a nuclear factor and as an extracellular factor. Extracellular HMGB1 released by damaged cells acts as a chemoattractant, as well as a proinflammatory cytokine, suggesting that HMGB1 is tightly connected to the process of tissue organization. However, the role of HMGB1 in bone and cartilage that undergo remodeling during embryogenesis, tissue repair, and disease is largely unknown. We show here that the stage-specific secretion of HMGB1 in cartilage regulates endochondral ossification. We analyzed the skeletal development of Hmgb1(-/-) mice during embryogenesis and found that endochondral ossification is significantly impaired due to the delay of cartilage invasion by osteoclasts, osteoblasts, and blood vessels. Immunohistochemical analysis revealed that HMGB1 protein accumulated in the cytosol of hypertrophic chondrocytes at growth plates, and its extracellular release from the chondrocytes was verified by organ culture. Furthermore, we demonstrated that the chondrocyte-secreted HMGB1 functions as a chemoattractant for osteoclasts and osteoblasts, as well as for endothelial cells, further supporting the conclusion that Hmgb1(-/-) mice are defective in cell invasion. Collectively, these findings suggest that HMGB1 released from differentiating chondrocytes acts, at least in part, as a regulator of endochondral ossification during osteogenesis.

Effects of systemic deep hypothermia and subarachnoid block on the longitudinally conducting evoked spinal cord potentials in man.

The present study reports the effects of systemic deep hypothermia (SDH) and subarachnoid block (SAB) on the longitudinally conducting evoked spinal cord potential (conducting ESCP) in man. Before induction of anesthesia, a pair of bipolar catheter electrodes was introduced to the epidural space: one at the level of the cervical enlargement and the other at the lumbosacral enlargement. The conducting ESCP was produced by electrical stimulation through the upper electrode and recorded through the lower electrode, and vice versa. SDH Study: Subjects were 6 patients who underwent replacement surgery of an aortic aneurysm with deep hypothermia anesthesia. The peak latency of the ESCP was gradually prolonged and the duration was widened with cooling via extracorporeal circulation. The amplitude of ESCP showed a biphasic change over the course of cooling with a turning point of around 30 degrees C in esophageal temperature. The ESCP was well observed until blood temperatures as low as near 10 degrees C. The result shows that ESCP is available as an intra-operative monitoring parameter of the spinal function even under SDH. SAB Study: Subjects were 7 patients, 6 of whom had SAB and the remaining 1 intravenous application of a local anesthetic. The conducting ESCP was markedly depressed or disappeared completely even after SAB with clinical doses of various local anesthetics, while it was hardly affected by the intravenous application. The result implies that SAB causes, at least partially, the conduction block within the spinal cord.

Neuroprotective effect of epidural electrical stimulation against ischemic spinal cord injury in rats: electrical preconditioning.

BACKGROUND: Electroconvulsion therapy is likely to serve as an effective preconditioning stimulus for inducing tolerance to ischemic brain injury. The current study examines whether electrical stimuli on the spinal cord is also capable of inducing tolerance to ischemic spinal cord injury by transient aortic occlusion. METHODS: Spinal cord ischemia was induced by occlusion of the descending thoracic aorta in combination with maintaining systemic hypotension (40 mmHg) during the procedure. Animals implanted with epidural electrodes were divided into four groups according to electrical stimulation and sham. Two groups consisted of rapid preconditioning (RE group, n = 8) and sham procedure (RC group, n = 8) 30 min before 9 min of spinal cord ischemia. In the two groups that underwent delayed preconditioning, rats were exposed to 9 min of aortic occlusion 24 h after either pretreatment with epidural electrical stimulation (DE group, n = 8) or sham (DC group, n = 8). In addition, rats were exposed to 6-11 min of spinal cord ischemia at 30 min or 24 h after epidural electrical stimulation or sham stimulation. The group P50 represents the duration of spinal cord ischemia associated with 50% probability of resultant paraplegia. RESULTS: Pretreatment with electrical stimulation in the DE group but not the RE group protected the spinal cord against ischemia, and this stimulation prolonged the P50 by approximately 15.0% in the DE group compared with the DC group. CONCLUSIONS: Although the optimal setting for this electrical preconditioning should be determined in future studies, the results suggest that epidural electrical stimulation will be a useful approach to provide spinal protection against ischemia.