BACKGROUND: Many clinicians have probably used subjective, unscientific methods for dose reduction to avoid overdose in elderly patients. The aim of this study was to compare several dosing schedules of intravenous dexmedetomidine (DEX) to identify the appropriate dosing schedule within the therapeutic dose range for adequate sedation of elderly patients under spinal anesthesia. METHODS: After administration of spinal anesthesia, a loading dose of DEX was injected over 10 min in three groups with the following dosages: group A, 1.0 μg/kg of actual body weight; group B, 1.0 μg/kg of ideal body weight (IBW); and group C, 0.8 μg/kg of IBW. Then, a maintenance infusion (0.5 μg/kg of each BW/h) was administered. The bispectral index score (BIS), the time required to reach BIS 80, airway obstruction score, and the occurrence of bradycardia were recorded. RESULTS: The changes in the BIS among the groups over time were found to have statistically significant differences (P < 0.001). The times required to reach BIS 80 were 6.1 ± 5.3 min, 5.0 ± 3.6 min, and 11.0 ± 8.6 min in groups A, B, and C, respectively (P < 0.001). The airway obstruction score and the frequency of bradycardia did not have statistically significant differences among the groups. CONCLUSIONS: An initial loading dose of DEX that is 0.8 μg/kg of IBW over 10 min, followed by an infusion rate of less than 0.5 μg/kg of IBW/h may be adequate for sedation in elderly patients receiving spinal anesthesia.
Aged* ; Airway Obstruction ; Anesthesia, Spinal* ; Appointments and Schedules* ; Body Weight ; Bradycardia ; Dexmedetomidine* ; Humans ; Ideal Body Weight

BACKGROUND: Many clinicians have probably used subjective, unscientific methods for dose reduction to avoid overdose in elderly patients. The aim of this study was to compare several dosing schedules of intravenous dexmedetomidine (DEX) to identify the appropriate dosing schedule within the therapeutic dose range for adequate sedation of elderly patients under spinal anesthesia. METHODS: After administration of spinal anesthesia, a loading dose of DEX was injected over 10 min in three groups with the following dosages: group A, 1.0 μg/kg of actual body weight; group B, 1.0 μg/kg of ideal body weight (IBW); and group C, 0.8 μg/kg of IBW. Then, a maintenance infusion (0.5 μg/kg of each BW/h) was administered. The bispectral index score (BIS), the time required to reach BIS 80, airway obstruction score, and the occurrence of bradycardia were recorded. RESULTS: The changes in the BIS among the groups over time were found to have statistically significant differences (P < 0.001). The times required to reach BIS 80 were 6.1 ± 5.3 min, 5.0 ± 3.6 min, and 11.0 ± 8.6 min in groups A, B, and C, respectively (P < 0.001). The airway obstruction score and the frequency of bradycardia did not have statistically significant differences among the groups. CONCLUSIONS: An initial loading dose of DEX that is 0.8 μg/kg of IBW over 10 min, followed by an infusion rate of less than 0.5 μg/kg of IBW/h may be adequate for sedation in elderly patients receiving spinal anesthesia.
Aged* ; Airway Obstruction ; Anesthesia, Spinal* ; Appointments and Schedules* ; Body Weight ; Bradycardia ; Dexmedetomidine* ; Humans ; Ideal Body Weight

BACKGROUND: In this study, we assessed the 50% effective concentration (EC50) of sevoflurane for reducing a rocuronium-induced reaction, based on the Dixon's up-and-down method. We also assessed the 50 and 95% effective end-tidal concentration of sevoflurane (ETsev), based on the probit regression curve of the probability of nonwithdrawal reaction. METHODS: We conducted a prospective, double-blind study in 23 males and 24 females. After using 2.5% thiopental sodium (4 mg/kg), anesthesia was induced in the patients. The patients then inhaled sevoflurane with 5 vol% in 6 L/min of oxygen. When the target ETsev was achieved, a nurse injected the intubating dose of rocuronium (0.6 mg/kg) for 5-10 s under the free flow of intravenous fluid. After the nurse evaluated the response, the nurse recorded the maximum heart rate during 30 s and the mean arterial pressure after rocuronium injection. RESULTS: Based on Dixon's up-and-down method, the EC50 of sevoflurane was 2.5 alpha 0.5 vol% in males and 2.5 alpha 0.3 vol% in females. The probit regression curve of the probability of nonwithdrawal reaction showed that in males the 50% effective ETsev was 2.4 vol% (95% confidence interval [CI], 1.5-3.1 vol%) and the 95% effective ETsev was 3.5 vol% (95% CI, 2.9-11.0 vol%); in females, the 50% effective ETsev was 2.4 vol% (95% CI, 2.1-2.7 vol%) and the 95% effective ETsev was 3.0 vol% (95% CI, 2.7-4.5 vol%). CONCLUSIONS: The inhalation of sevoflurane during the induction period may provide a simple and reliable means of reducing rocuronium-induced reactions without adverse hemodynamic changes. There was no significant difference between males and females.
Adult* ; Anesthesia ; Arterial Pressure ; Double-Blind Method ; Female ; Heart Rate ; Hemodynamics ; Humans ; Inhalation ; Male ; Oxygen ; Prospective Studies ; Thiopental

No abstract available.
Anesthesia, Epidural* ; Diuresis*

BACKGROUND: Although acute tolerance to opioids, especially to remifentanil, has been demonstrated consistently in animal studies, the results of clinical trials in humans are controversial. The aim of this study was to determine whether intraoperative infusions of remifentanil used as an adjuvant in general anesthesia result in acute tolerance, an event manifested by increased postoperative pain and a higher opioid requirement than usual. METHODS: Sixty patients who underwent surgery under general anesthesia for spinal fusion were randomly assigned to receive sevoflurane-nitrous oxide-oxygen (group SO, n = 20), sevoflurane-remifentanil-nitrous oxide-oxygen (group SR, n = 20), or propofol-remifentanil-oxygen (group PR, n = 20) in a double-blinded manner. All patients within 1 hour after induction received PCA (fentanyl 0.4 microg/kg/ml and ondansetron 16 mg) administered intravenously at a basal infusion rate of 1 ml/h, after being intravenously injected with a loading dose of fentanyl (1 microg/kg). Data for fentanyl requirement, verbal Numerical Rating Scale (NRS) pain score at rest, and presence of nausea or vomiting were collected at 1, 24, and 48 hours after surgery. RESULTS: We did not find any significant difference in postoperative PCA fentanyl requirements, NRS or side effects among the groups. CONCLUSIONS: Remifentanil as an adjuvant to sevoflurane or propofol in general anesthesia for adults having surgery for spinal fusion does not appear to cause acute opioid tolerance or hyperalgesia in patients. However, further studies are needed to elucidate whether sevoflurane and propofol exert a clinically significant effect on opioid-induced tolerance or hyperalgesia and whether this effect is related to the age of the patient, the dose and duration of remifentanil given and the intensity of pain experienced postoperatively.
Adult ; Analgesia, Patient-Controlled ; Analgesics, Opioid ; Anesthesia, General ; Animals ; Fentanyl ; Humans ; Hyperalgesia ; Methyl Ethers ; Nausea ; Ondansetron ; Pain, Postoperative ; Passive Cutaneous Anaphylaxis ; Piperidines ; Propofol ; Spinal Fusion ; Vomiting

A 21-year-old woman with a 4 cm enhancing cystic renal mass in the left moiety of a horseshoe kidney was treated through a retroperitoneal laparoscopic approach. The tumor was excised completely with cold scissors, and renal parenchyma suturing with a surgical bolster was done with Vicryl 2-0 sutures. Choosing the proper approach according to the location of the lesion and the surgeon's experience with both approaches are of importance in laparoscopic surgery in horseshoe kidney cases. A preoperative kidney computed tomography angiography was helpful for understanding the complex renal vasculature.
Angiography ; Cold Temperature ; Female ; Humans ; Kidney ; Laparoscopy ; Nephrectomy ; Polyglactin 910 ; Sutures ; Young Adult

BACKGROUND: The greater occipital nerve (GON) block has been frequently used for different types of headache, but performed with rough estimates of anatomic landmarks. Our study presents the values of the anatomic parameters and estimates the effectiveness of the ultrasound-guided GON blockade. METHODS: The GON was detected using ultrasound technique and distance from external occipital protuberance (EOP) to GON, from GON to occipital artery and depth from skin to GON was measured in volunteers. Patients with occipital headache were divided into two groups (ultrasound-guided block: group S, conventional blind block: group B) and GON block was performed. The same parameters were measured on group S and VAS scores were assessed at pretreatment, 1 week and 4 weeks after treatment on both groups. RESULTS: The GON had distance of 23.1 +/- 3.4 mm (right) and 20.5 +/- 2.8 mm (left) from EOP to GON. Its depth below the skin was 6.8 +/- 1.5 mm (right) and 7.0 +/- 1.3 mm (left). The distance from GON to occipital artery was 1.5 +/- 0.6 mm (right) and 1.2 +/- 0.6 mm (left) in volunteers. Initial VAS score of group S and group B patients were 6.4 +/- 0.2 and 6.5 +/- 0.2. VAS score of 4 weeks after injection were 2.3 +/- 0.2 on group S and 3.8 +/- 0.3 on group B (P = 0.0003). CONCLUSIONS: The parameters measured in this study should be useful for GON block and ultrasound-guided blockade is likely to be a more effective technique than blind blockade in occipital headache treatment.
Anatomic Landmarks ; Arteries ; Follow-Up Studies ; Headache ; Humans ; Nerve Block ; Skin

BACKGROUND: The Glidescope(R) videolaryngoscope is a new device for tracheal intubation that provides an improved view of the larynx. This study was performed to compare the Glidescope with the McGrath videolaryngoscope in terms of time to intubation (TTI) and number of attempts. METHODS: Patients were randomly allocated to one of two groups, Glidescope or McGrath group, by using computer-generated numbers. Tracheal intubation was attempted by an anesthesiologist with extensive experience using these two devices. The operator recorded ease of visualization of glottic structures based on the classification described by Cormack and Lehane. Number of failures, number of attempts and their duration, total intubation time, and events during the whole procedure were recorded. The duration of one attempt was defined as the time elapsed between picking up the endotracheal tube and verification of tracheal intubation with visualization of three expiratory carbon dioxide waveforms. TTI was defined as the sum of the duration of all intubation attempts (as many as three), excluding preoxygenation procedures. RESULTS: TTI was significantly shorter for the Glidescope(R) compared to the McGrath(R) laryngoscope (40.5 vs. 53.3 s, respectively, P < 0.05). However, glottic views obtained at intubation were similar between the two groups. Number of intubation attempts was not significantly different between the two groups (1.03 +/- 0.19 vs 1.10 +/- 0.32, respectively) (mean +/- SD). CONCLUSIONS: Study results demonstrated that the Glidescope reduced total intubation time in comparison with the McGrath, in terms of TTI in patients with normal airways.
Carbon Dioxide ; Humans ; Intubation ; Laryngoscopes ; Larynx

The Shikani Optical Stylet(TM) (SOS, Clarus Medical, USA) is another tool to facilitate tracheal intubation. It combines the benefits of a lightwand and a fiberoptic bronchoscope. We report the application of SOS in facilitating the tracheal intubation of two-person with history of difficult airway management. A 25-year-old woman with micrognathia was scheduled to undergo an exploratory laparotomy. Intubation attemps failed with a direct laryngoscope because of difficulty in her mouth opening. Although airway management was re-attempted by a laryngeal mask airway, it also failed for the same reason. Airway management was successfully performed using the SOS instead of a laryngeal mask airway. The second case was a 38-year-old woman with ankylosing spondylitis, scheduled for spinal fusion. She had difficulty in extending her neck. Intubation was successfully performed via the SOS. We believe that intubation by the SOS is a useful and readily available alternative technique for patients with difficult airways.
Adult ; Airway Management ; Bronchoscopes ; Female ; Humans ; Intubation ; Laparotomy ; Laryngeal Masks ; Laryngoscopes ; Mouth ; Neck ; Spinal Fusion ; Spondylitis, Ankylosing

Reexpansion pulmonary edema (RPE) is a rare but sometimes fatal complication of the treatment of lung collapse secondary to pneumothorax, pleural effusion, or atelectasis. We experienced a case of RPE that developed following decortication. A 46 year-old female had a decortication for pyothorax under one-lung anesthesia. There was no event during the operation and results of arterial blood gas analysis were within normal limits. After the operation, tracheal extubation was performed and 100% oxygen saturation on a pulse oximeter (SpO2) was maintained with 100% O2, (8 L/min) via mask ventilation with self-respiration. The patient, with 50% Venturi mask, was transported to the intensive care unit (ICU). On arrival at the ICU, a SpO2 of 80% was detected and arterial blood gas analysis revealed hypoxemia with acute hypercapnic respiratory acidosis. Fortunately, reexpansion pulmonary edema was detected early and intensive treatment was performed using mechanical ventilation with positive end-expiratory pressure. Tracheal extubation was performed after 1 day of mechanical ventilation. The reexpansion pulmonary edema was successfully treated and the patient recovered without any complications.
Acidosis, Respiratory ; Airway Extubation ; Anesthesia ; Anoxia ; Blood Gas Analysis ; Empyema, Pleural ; Female ; Humans ; Intensive Care Units ; Masks ; Oxygen ; Pleural Effusion ; Pneumothorax ; Positive-Pressure Respiration ; Pulmonary Atelectasis ; Pulmonary Edema ; Respiration, Artificial ; Ventilation