ABSTRACT
BACKGROUND: Hypothermia is common during arthroscopic shoulder surgery under general anesthesia, and anesthetic-impaired thermoregulation is thought to be the major cause of hypothermia. This prospective, randomized, double-blind study was designed to compare perioperative temperature during arthroscopic shoulder surgery with interscalene brachial plexus block (IBPB) followed by general anesthesia vs. general anesthesia alone. METHODS: Patients scheduled for arthroscopic shoulder surgery were randomly allocated to receive IBPB followed by general anesthesia (group GB, n = 20) or general anesthesia alone (group GO, n = 20), and intraoperative and postoperative body temperatures were measured. RESULTS: The initial body temperatures were 36.5 ± 0.3℃ vs. 36.4 ± 0.4℃ in group GB vs. GO, respectively (P = 0.215). The body temperature at 120 minutes after induction of anesthesia was significantly higher in group GB than in group GO (35.8 ± 0.3℃ vs. 34.9 ± 0.3℃; P < 0.001). The body temperatures at 60 minutes after admission to the post-anesthesia care unit were 35.8 ± 0.3℃ vs. 35.2 ± 0.2℃ in group GB vs. GO, respectively (P < 0.001). The concentrations of desflurane at 0, 15, and 120 minutes after induction of anesthesia were 6.0 vs. 6.0% (P = 0.330), 5.0 ± 0.8% vs. 5.8 ± 0.4% (P = 0.001), and 3.4 ± 0.4% vs. 7.1 ± 0.9% (P < 0.001) in group GB vs. GO, respectively. CONCLUSIONS: The present study demonstrated that preoperative IBPB could reduce both the intraoperative concentration of desflurane and the reduction in body temperature during and after arthroscopic shoulder surgery.
Subject(s)
Humans , Anesthesia , Anesthesia, General , Arthroscopy , Body Temperature , Body Temperature Regulation , Brachial Plexus Block , Brachial Plexus , Double-Blind Method , Hypothermia , Prospective Studies , ShoulderABSTRACT
BACKGROUND: Sugammadex is a novel neuromuscular reversal agent, but its associated hypersensitivity reaction and high cost have been obstacles to its widespread use. In the interest of reducing the necessary dosage of sugammadex, the reversal time of the combined use of sugammadex and neostigmine from moderate neuromuscular blockade were investigated. METHODS: The patients enrolled ranged in age from 18 to 65 years old with American Society of Anesthesiologists class 1 or 2. The subjects were randomly assigned into one of the four groups (Group S2, S1, SN, and N; n = 30 per group). The reversal agents of each groups were as follows: S2 - sugammadex 2 mg/kg, S1 - sugammadex 1 mg/kg, SN - sugammadex 1 mg/kg + neostigmine 50 microg/kg + glycopyrrolate 10 microg/kg, N - neostigmine 50 microg/kg + glycopyrrolate 10 microg/kg. The time to recovery of the train-of-four (TOF) ratio was checked in each group. RESULTS: The time to 90% recovery of TOF ratio was 182.6 +/- 88.9, 371.1 +/- 210.4, 204.3 +/- 103.2, 953.2 +/- 379.7 sec in group S2, S1, SN and N, respectively. Group SN showed a significantly shorter recovery time than did group S1 and N (P < 0.001). However, statistically significant differences between the S2 and SN groups were not be observed (P = 0.291). No hypersensitivity reactions occurred in all groups. CONCLUSIONS: For the reversal from rocuronium-induced moderate neuromuscular blockade, the combined use of sugammadex and neostigmine may be helpful to decrease the recovery time and can also reduce the required dosage of sugammadex. However, the increased incidence of systemic muscarinic side effects must be considered.
Subject(s)
Humans , Glycopyrrolate , Hypersensitivity , Incidence , Neostigmine , Neuromuscular BlockadeABSTRACT
It is uncommon that anesthesiologists experience patients with thyroid storms. In our case, the patient had been medicated for 5 years, however, she developed agranulocytosis. Anti-thyroid drugs were stopped and hyperthyroidism progressed. Her symptoms and laboratory results revealed manifestation of thyroid storm: TSH of 7.77 ng/dl, T3 of 403.1 ng/dl, and T4 of 22.15 microg/dl. The euthyroid state had not been achieved before the surgery. From the judgment of difficulty controls of hyperthyroidism, the surgeon requested for an emergency operation. We report a case of total intravenous anesthesia with propofol and remifentanil which achieved hemodynamic stability.
Subject(s)
Humans , Agranulocytosis , Anesthesia, Intravenous , Emergencies , Hemodynamics , Hyperthyroidism , Judgment , Propofol , Thyroid Crisis , ThyrotoxicosisABSTRACT
BACKGROUND: Carcinoma-associated fibroblasts (CAFs) contribute to carcinogenesis and cancer progression, although their origin and role remain unclear. We recently identified and investigated the in situ identity and implications of gastric submucosa-resident mesenchymal stem cells (GS-MSCs) in the progression of gastric carcinogenesis. METHODS: We isolated GS-MSCs from gastric submucosa using hydrogel-supported organ culture and defined their identity. Isolated cells were assessed in vitro by immunophenotype and mesengenic multipotency. Reciprocal interactions between GS-MSCs and gastric cancer cells were evaluated. To determine the role of GS-MSCs, xenografts were constructed of gastric cancer cells admixed with or without GS-MSCs. RESULTS: Isolated cells fulfilled MSCs requirements in regard to plastic adherence, stromal cell immunophenotype, and multipotency. We demonstrated a paracrine loop that gastric cancer cells enhanced the migration, proliferation, and differentiation of GS-MSCs; additionally, GS-MSCs promoted the proliferation of gastric cancer cell in vitro. Xenograft experiments showed that GS-MSCs significantly promoted cancer growth and angiogenesis. GS-MSCs that integrated into gastric cancer became not only CAFs but also rarely endothelial cells which contributed to the formation of cellular and vascular cancer stroma. CONCLUSIONS: Endogenous GS-MSCs play an important role in gastric cancer progression.
Subject(s)
Carcinogenesis , Endothelial Cells , Fibroblasts , Heterografts , Mesenchymal Stem Cells , Organ Culture Techniques , Plastics , Stomach Neoplasms , Stromal Cells , Transplantation, HeterologousABSTRACT
Intraoperative formation and management of a thrombus in right atrium has been reported occasionally. Nevertheless, it is rare that a right atrial thrombus with unstable hemodynamic changes detected by transesophageal echocardiography is resolved spontaneously. We report upon the 44-year-old woman, who had a right atrial thrombus detected by transesophageal echocardiography during laparoscopic assisted vaginal hysterectomy and resolved during thromboembolectomy.
Subject(s)
Adult , Female , Humans , Echocardiography, Transesophageal , Heart Atria , Hemodynamics , Hysterectomy, Vaginal , Laparoscopy , ThrombosisABSTRACT
BACKGROUND: Pain after laparoscopy is multifactorial and different treatments have been proposed to provide pain relief. Multimodal analgesia is now recommended to prevent and treat post-laparoscopy pain. Dexmedetomidine, an alpha2 agonist, has well-known anesthetic and analgesic-sparing effects. We evaluated the analgesic effect of perioperative dexmedetomidine infusion during laparoscopic cholecystectomy with multimodal analgesia. METHODS: Forty-two patients aged 20 to 60 years old were allocated randomly into one of 2 groups (n = 21, in each). All patients underwent laparoscopic cholecystectomy under multimodal analgesia. The patients in group P received dexmedetomidine 1 microg/kg during 10 min before induction and then 0.5 microg/kg/h continuously until the removal of the gall bladder while the patients in the group C received saline by the same methods as group P. Total analgesic consumption and VAS score were recorded for the first 24 hr. RESULTS: There were no significant differences in VAS scores between group P and group C during 24 hr after laparoscopic cholecystectomy. VAS scores of group P were lower than that of group C during the 1st hr after operation. The amount of ketorolac required during the 24 hr after the operation was significantly less in group P compared to group C. CONCLUSIONS: The administration of dexmedetomidine during laparoscopic cholecystectomy with multimodal analgesia has minimal benefits on the reduction of the postoperative pain score. The amount of ketorolac requirements during 24 hr after the operation showed significant difference. Dexmedetomidine might be helpful for the postoperative pain after laparoscopic cholecystectomy with multimodal analgesia.
Subject(s)
Aged , Humans , Analgesia , Cholecystectomy, Laparoscopic , Dexmedetomidine , Ketorolac , Laparoscopy , Pain, Postoperative , Urinary BladderABSTRACT
BACKGROUND: Reduction of intraoperative bleeding is necessary to achieve the ideal surgical field for the endoscopic sinus surgery (ESS). Intraoperative intra nasal bleeding is influenced by various anesthetics. This study compared surgical field condition between propofol/remifentanil (PR) based anesthesia and desflurane/remifentanil (DR) based anesthesia. METHODS: American Society of Anesthesiologists physical status class I or II patients undergoing ESS were randomly assigned to group PR (n = 36) or group DR (n = 32). The extent of the preoperative surgical lesion was classified as high (> 12) and low (< or = 12) Lund-Mackay (LM) scores according to the computed tomography findings. The target mean blood pressure was maintained at 70-80 mmHg. Only one surgeon was involved in rating the visibility of the surgical field on a numeric rating scale (NRS) every 10 minutes. RESULTS: There was a different surgical field grade from PR to DR. The mean (SD) surgical field score of NRS for the PR and DR was 2.3 (0.57) and 2.7 (0.67), respectively (P = 0.006). Especially in the high-LM score patients, the mean (SD) of surgical field score for the PR and DR was 2.4 (0.67) and 3.0 (0.63), respectively (P = 0.012). CONCLUSIONS: In the high-LM score patients, PR based anesthesia resulted in better surgical field condition for ESS than DR based anesthesia. In ESS, PR based anesthesia is considered to be helpful.
Subject(s)
Humans , Anesthesia , Anesthetics , Blood Pressure , Epistaxis , Hemorrhage , Isoflurane , Piperidines , Propofol , SinusitisABSTRACT
BACKGROUND: Pain after laparoscopy is multifactorial and different treatments have been proposed to provide pain relief. Multimodal analgesia is now recommended to prevent and treat post-laparoscopy pain. Dexamethasone is effective in reducing postoperative pain. The timing of steroid administration seems to be important. We evaluated the analgesic efficacy of preoperative intravenous dexamethasone 1 hour before versus during laparoscopic cholecystectomy with multimodal analgesia. METHODS: One hundred twenty patients aged 20 to 65 years old were allocated randomly into one of three groups (n = 40, in each). The patients in the group N received normal saline 1 hour before induction and after the resection of gall bladder. The patients in the group S1 received dexamethasone 8 mg 1 hour before induction and normal saline after the resection of gall bladder. The patients in the group S2 received normal saline 1 hour before induction and dexamethasone 8 mg after the resection of gall bladder. RESULTS: VAS scores of group S1 and S2 were lower than that of group N during 48 hours after laparoscopic cholecystectomy. There were no significant differences of VAS scores between the group S1 and the group S2. The analgesic consumption of group S1 and S2 were significantly lower than that of group N. CONCLUSIONS: A single dose of dexamethasone (8 mg) intravenously given 1 hour before induction or during operation was effective in reducing postoperative pain after laparoscopic cholecystectomy with multimodal analgesia. The analgesic efficacy of preoperative intravenous dexamethasone 1 hour before versus during surgery was not significantly different.
Subject(s)
Aged , Humans , Analgesia , Cholecystectomy, Laparoscopic , Dexamethasone , Laparoscopy , Pain, Postoperative , Urinary BladderABSTRACT
BACKGROUND: The administration of a single dose of propofol is reported to be effective in decreasing the incidence and severity of emergence agitation (EA) in children following sevoflurane anesthesia. The aim of this study was to investigate the clinical usefulness of a single dose of propofol 1 mg/kg at the end of adenotonsillectomy for reducing the incidence of EA after sevoflurane anesthesia. METHODS: Ninety children, aged 3-8 years, undergoing adenotonsillectomy were randomized into two groups: the propofol group (n = 45) and the saline group (n = 45), of which 88 children completed the study. Anesthesia was maintained with sevoflurane 2-2.5 vol% and nitrous oxide/oxygen (50%/50%). At the completion of adenotonsillectomy, the propofol group patients were given 1 mg/kg of propofol and the saline group patients were given saline 0.1 ml/kg in the same volume. The incidence of EA was assessed with Aono's four point scale and the severity of EA was assessed with pediatric anesthesia emergence delirium (PAED) scale at 5 min (T5), 15 min (T15) and 30 min (T30) after emergence. RESULTS: Of the 88 patients, the incidence of EA at T5, T15 and T30 was 61.4%, 27.3%, and 4.5% in the propofol group while in the saline group was 68.2%, 29.5%, and 9.1%, respectively. The incidence and severity of EA were not found to be significantly different between the two groups, but the scales in each group decreased significantly over time. CONCLUSIONS: The administration of propofol 1 mg/kg at the end of surgery did not have any significant effect in reducing the incidence and severity of EA in children undergoing adenotonsillectomy under sevoflurane anesthesia.
Subject(s)
Aged , Child , Humans , Anesthesia , Delirium , Dihydroergotamine , Incidence , Methyl Ethers , Propofol , Weights and MeasuresABSTRACT
Spinal muscular atrophy (SMA) in children leads to progressive muscle weakness, dysphagia, aspiration, and death. The most common and severe form of SMA is designated as type I, also known as Werdnig-Hoffman Disease or Floppy Baby syndrome. We anesthetized an 8 month-old female infant with SMA type I undergoing feeding gastrostomy. We planned to use inhalational anesthesia without muscle relaxants. Anesthesia and surgery were uneventful. We herein report a case of successful peri-operative anesthetic management for SMA type I infant with aspiration pneumonia.
Subject(s)
Child , Female , Humans , Infant , Anesthesia , Anesthesia, General , Deglutition Disorders , Gastrostomy , Muscle Weakness , Muscles , Muscular Atrophy, Spinal , Neuromuscular Diseases , Pneumonia, Aspiration , Spinal Muscular Atrophies of ChildhoodABSTRACT
BACKGROUND: Volatile-based anesthesia resulted in a significantly reduced cilia beat frequency. This study was to evaluate the effect of bronchodilator on bronchial mucus transport (BMT) distance measured with a bronchoscope during Inhalational anesthesia. METHODS: Twenty-four adult patients undergoing elective orthopedic surgery under inhalation anesthesia using sevoflurane and nitrous oxide were included. Twenty minutes after tracheal intubation, they were manually inspired without nebulization of salbutamol (control group: n = 12) or with nebulization of salbutamol(salbutamol group: n = 12). And then a single drop of 0.02 ml methylene blue was applied to the posterior mucosal surface of the right main bronchus 5 cm away from the carina under the bronchoscope. The distance of dye movement was measured 5 min after its application. RESULTS: BMT distance and velocity of methylene blue during 5min were 6.2 +/- 3.1 mm and 1.2 +/- 0.6 mm/min in control group, and 23.3 +/- 16.6 mm and 4.7 +/- 3.3 mm/min in salbutamol group, respectively. BMT distance and velocity of methylene blue in salbutamol group were longer and faster than those in control group(P < 0.05). CONCLUSIONS: Salbutamol facilitates the transport of bronchial secretion under sevoflurane-based inhalational anesthesia in term of BMT velocity.
Subject(s)
Adult , Humans , Albuterol , Anesthesia , Anesthesia, Inhalation , Bronchi , Bronchoscopes , Cilia , Intubation , Methyl Ethers , Methylene Blue , Mucus , Nitrous Oxide , OrthopedicsABSTRACT
BACKGROUND: The selective unilateral administration of drugs into a single lung of a rat is difficult because of the small airway diameter. Therefore, a simple method for unilateral administration into rat lung is needed. METHODS: Rats were assigned to 1 of 2 groups according to the direction of the catheter used for drug administration. Anesthetized rats were intubated, and curved epidural catheters were rotated up to a maximum of 90degrees toward the left lung (group L) or right lung (group R). Bronchial catheters were then inserted via a tracheal tube and fixed. Methylene blue (0.3 ml) was injected via the epidural catheter. Additionally, to compare survival rates, rats were assigned to one of two groups according to the drug administration route. In group T, bleomycin hydrochloride (20 mg/kg) in 0.3 ml of phosphate-buffered saline (PBS) was administrated into the lung intratracheally via a tracheal tube. In group B, the same dose of bleomycin was administrated into the lung intrabronchially via a bronchial catheter, targeting the left lung. RESULTS: Gross examination revealed that targeted administration was 100% successful. Methylene blue was observed in the right lung of all rats in the R group and in the left lung of all rats in the L group. The survival rate was higher in group B than in group T. CONCLUSIONS: The intrabronchial method offers an advantage over tracheal administration as it decreases mortality and allows the administration of a drug unilaterally into a single lung or into a localized area without the need for double-lumen tubes or more invasive procedures.
Subject(s)
Animals , Rats , Bleomycin , Catheters , Drug Administration Routes , Imidazoles , Lung , Methylene Blue , Nitro Compounds , Survival RateABSTRACT
Thoracic outlet syndrome has neurologic symptoms caused by compression of brachial plexus, blood vessel symptoms are caused by compression of the artery or vein. The authors report a case of sudden decrease in blood pressure of the left arm after turning the patient from supine position to prone position. They confirmed that the patient had thoracic outlet syndrome after performing computed tomography.
Subject(s)
Humans , Arm , Arterial Pressure , Arteries , Blood Pressure , Blood Vessels , Brachial Plexus , Glycosaminoglycans , Neurologic Manifestations , Prone Position , Supine Position , Thoracic Outlet Syndrome , VeinsABSTRACT
There are many cause of cholinesterase deficiency, including drugs, liver disease, chronic anemia, malignant states, cardiac failure, severe acute infection, surgical shock, severe burn, collagen disease and vasculitis syndromes. Vasculitis syndromes are relatively rare, and among them, Churg-Strauss syndrome (CSS) is even rarer. We report here on a case of a patient with CSS who underwent endoscopic sinus surgery under general anesthesia.
Subject(s)
Humans , Anemia , Anesthesia, General , Burns , Cholinesterases , Churg-Strauss Syndrome , Collagen Diseases , Heart Failure , Liver Diseases , Shock, Surgical , VasculitisABSTRACT
There are many causes of prolonged postoperative muscle weakness, including drugs, residual anesthetics, cerebrovascular events, electrolyte imbalance, hypothermia, and neuromuscular disease. Neuromuscular diseases are relatively rare, with the most common being myasthenia gravis and Lambert-Eaton myasthenic syndrome (LEMS). We report an unusual case in which a patient who was given a muscle relaxant during mediastinoscopy developed postoperative muscle weakness that was ultimately diagnosed as secondary to LEMS.
Subject(s)
Humans , Anesthetics , Hypothermia , Lambert-Eaton Myasthenic Syndrome , Mediastinoscopy , Muscle Weakness , Muscles , Myasthenia Gravis , Neuromuscular DiseasesABSTRACT
Breakage of epidural catheter during insertion and removal is a rare but dilemmatic complication. Although it is favorable to remove a broken catheter entrapped in tissue, there is a controversy about whether retained fragments should be managed even in asymptomatic patients. We experienced two cases of breakage of epidural catheter in patients with thoracic epidural analgesia. One case happened during removing of the entire catheter and needle together and the other, during the removal of the catheter alone. Because neurologic or infective complications were not detected until 14 days after the events, surgical interventions were withheld. In both cases, there were no sequelae on long-term follow up.
Subject(s)
Humans , Analgesia , Analgesia, Epidural , Catheterization , Catheters , Follow-Up Studies , NeedlesABSTRACT
BACKGROUND: This study was done to evaluate the effect on pain relief when acetaminophen was added to lidocaine for intravenous regional anesthesia (IVRA). METHODS: Sixty patients undergoing hand or forearm surgery received IVRA were assigned to three groups: Group C received 0.5% lidocaine diluted with 0.9% normal saline to a total volume of 40 ml (n = 20), Group P received 0.5% lidocaine diluted with intravenous acetaminophen 300 mg to a total volume of 40 ml (n = 20) and Group K received 0.5% lidocaine diluted with 0.9% normal saline plus ketorolac 10 mg made up to a total volume of 40 ml (n = 20). Sensory block onset time, tourniquet pain onset time, which was defined as the time from tourniquet application to fentanyl administration for relieving tourniquet pain and amount of analgesic consumption during surgery were recorded. Following deflation of tourniquet sensory recovery time, postoperative pain and quantity of analgesic uses in post-anesthesia care unit were assessed. RESULTS: Sensory block onset time was shorter in Group P compared to Group C (P < 0.05). Tourniquet pain onset time was delayed in Group P when compared with group C (P < 0.05). Postoperative pain and analgesic consumption were reduced in Group P and Group K compared to Group C (P < 0.001). CONCLUSIONS: The addition of acetaminophen to lidocaine for IVRA shortens the onset time of sensory block and delays tourniquet pain onset time, but not with ketorolac. Both acetaminophen and ketorolac reduce postoperative pain and analgesic consumption.
Subject(s)
Humans , Acetaminophen , Anesthesia, Conduction , Fentanyl , Forearm , Hand , Ketorolac , Lidocaine , Pain, Postoperative , TourniquetsABSTRACT
BACKGROUND: Similar to lipid emulsion propofol, microemulsion propofol also causes a high incidence of pain during intravenous injection. Various methods have been used to minimize the incidence and severity of pain on injection of lipid emulsion propofol. In this study, we investigated the effect of a lidocaine mixture on pain induced by microemulsion propofol injection, and sought to determine the optimal dose of lidocaine that could reduce pain on injecting a propofol-lidocaine mixture. METHODS: One hundred sixty (n = 160) patients of American Society of Anesthesiologists physical status class I or II were randomly allocated to four groups: Group A, control; Group B, 20 mg lidocaine; Group C, 30 mg lidocaine; Group D, 40 mg lidocaine. In each patient, pain on microemulsion propofol solution injection was graded as none, mild, moderate, or severe. RESULTS: The incidence of pain in groups A, B, C, and D was 97.5%, 80%, 65%, and 50%, respectively. Increasing the lidocaine dose significantly reduced pain (P < 0.05). One patient in Group D (2.5%) had moderate to severe pain, which was significantly lower than groups B (42.5%) and C (32.5%) (P < 0.05). CONCLUSIONS: The lidocaine and propofol mixture is effective in alleviating pain associated with microemulsion propofol injection. Within this dose range and in this patients population, increasing lidocaine dosage significantly reduced pain during injection of microemulsion propofol.
Subject(s)
Humans , Incidence , Injections, Intravenous , Lidocaine , PropofolABSTRACT
BACKGROUND: The advances in surgical technology, anesthesia and perioperative care have made it possible to perform laparoscopic cholecystectomy on an outpatient basis. This study was conducted to assess the analgesic effect and the adverse events of different dosing methods when using transdermal fentanyl patches (TDFPs) after laparoscopic cholecystectomy. METHODS: Sixty patients who were to undergo laparoscopic cholecystectomy under general anesthesia were divided into two groups. Group 1: 2 TDFPs that released 12microgram/h were applied after the induction of anesthesia and these 2 patches were removed after 24 hours. Group 2: 2 TDFPs that released 12microgram/h were applied after the induction of anesthesia and one patch was removed after 7 hours and the other patch was removed after 24 hours. The intensity of the postoperative pain was assessed by using a visual analogue scale (VAS) and assessing the adverse events, including dizziness, pruritus and nausea/vomiting, were recorded for 48 hours postoperatively. RESULTS: The VAS score of postoperative pain was not significantly different between the two groups at all times. The incidence of dizziness in groups I and II was 10 and 3, respectively, and the incidence of nausea/vomiting in group I and II was 4 and 0, respectively. The incidences of dizziness and nausea/vomiting in group II were significantly lower than those of group I (P < 0.05). CONCLUSIONS: A dosing method that removes half of the TDFPs (24microgram/h) after 7 hours of application caused a lower incidence of dizziness and nausea/vomiting without any significant difference of postoperative analgesic efficacy, as compared to leaving on both the TDFPs (24microgram/h) for 24 hours after laparoscopic cholecystectomy.
Subject(s)
Humans , Anesthesia , Anesthesia, General , Cholecystectomy, Laparoscopic , Dizziness , Fentanyl , Incidence , Outpatients , Pain, Postoperative , Perioperative Care , PruritusABSTRACT
BACKGROUND: The "gold standard" for proper epidural catheter positioning is a clinical response, as assessed by a pinprick test. Yet it may take time or it may be difficult to perform this test after epidural catheter placement in sedated or uncooperative patients or during general anesthesia. We assessed the usefulness of aspirating injected air via an epidural catheter as an indicator of correct epidural catheter placement. METHODS: We surveyed 200 patients who underwent surgery under general or epidural anesthesia. A Tuohy needle was inserted into the epidural space with using the hanging drop technique. After placement of the epidural catheter, 3 ml of air was injected via the catheter, and then the volume of aspirated air was measured. RESULTS: The mean volume of aspirated air was 2.3 +/- 0.7 ml (75% of the injected air volume) and this ranged from 0 to 3 ml. CONCLUSIONS: Aspiration of injected air is a simple alternative method for identifying the appropriate placement of epidural catheters in the epidural space.