Anesthetics management of a renal angiomyolipoma using pulse pressure variation and non-invasive cardiac output monitoring: A case report.

BACKGROUND: Hypovolemic shock can lead to life-threatening organ dysfunction, and adequate fluid administration is a fundamental therapy. Traditionally, parameters such as vital signs, central venous pressure, and urine output have been used to estimate intravascular volume. Recently, pulse pressure variation (PPV) and non-invasive cardiac monitoring devices have been introduced. In this case report, we introduce a patient with massive active bleeding from giant renal angiomyolipoma (AML). During emergent nephrectomy, we used non-invasive cardiac monitoring with CSN-1901 (Nihon Kohden, Tokyo, Japan) and PPV to evaluate the patient's intravascular volume status to achieve optimal fluid management. CASE SUMMARY: A 30-year-old male patient with giant AML with active bleeding was referred to the emergency room complaining of severe abdominal pain and spontaneous abdominal distension. AML was diagnosed by computed tomography, and emergent nephrectomy was scheduled. Massive bleeding was expected so we decided to use non-invasive cardiac monitoring and PPV to assist fluid therapy because they are relatively easy and fast compared to invasive cardiac monitoring. During the surgery, 6000 mL of estimated blood loss occurred. Along with the patient's vital signs and laboratory results, we monitored cardiac output, cardiac output, stroke volume, stroke volume index with a non-invasive cardiac monitoring device, and PPV using an intra-arterial catheter to evaluate intravascular volume status of the patient to compensate for massive bleeding. CONCLUSION: In addition to traditional parameters, non-invasive cardiac monitoring and PPV are useful methods to evaluate patient's intravascular volume status and provide guidance for intraoperative management of hypovolemic shock patients.

Perforation on the superior side of duodenum is a risk factor of laparoscopic primary repair for duodenal ulcer perforation.

PURPOSE: Primary repair is the standard surgical method for treating duodenal ulcer perforations, with very good results usually anticipated because of the simplicity of the associated surgical techniques. Therefore, this study aimed to analyze the risk factors that affect laparoscopic primary repair outcomes for duodenal ulcer perforation. METHODS: Between June 2010 and June 2020, 124 patients who underwent laparoscopic primary repair for duodenal ulcer perforations were reviewed. Early surgical outcomes were evaluated and risk factors for postoperative complications were assessed. RESULTS: All surgeries were performed laparoscopically without open conversion. Multivariate analysis showed that the elderly (over 70 years), and perforations that needed more than 2 stitches for closure were risk factors for overall postoperative complications. Perforations that needed more than 2 stitches and perforations on the superior side of the duodenum were major risk factors for severe postoperative complications. Severe postoperative complications occurred in 6 of the patients, and 1 of them died of multiorgan failure. CONCLUSION: Based on our results, we suggest that laparoscopic primary repair can be safely performed in duodenal ulcer perforation. However, more careful surgery and postoperative care are needed to improve the surgical outcomes of patients who need more than 2 stitches to close their perforation or who have perforations on the superior side of the duodenum.

Unilateral pulmonary hemorrhage caused by negative pressure pulmonary edema: A case report.

BACKGROUND: Unilateral pulmonary hemorrhage is typically reported in young and healthy men with upper respiratory tract obstruction during anesthesia in special situations. Negative pressure in the lungs is created, resulting in negative pressure pulmonary edema (NPPE). CASE SUMMARY: A 78-year-old male patient diagnosed with spinal stenosis was admitted to receive a unilateral laminectomy with bilateral decompression. The patient had been diagnosed with hypertension four years earlier and asthma more than 70 years earlier. We experienced a unilateral alveolar hemorrhage associated with NPPE that occurred in a longstanding asthma patient who bit the intubated endotracheal tube for a short period during posture change at the end of surgery. Because diffuse alveolar hemorrhage accompanied by NPPE was caused in this case by airway obstruction in an older patient with asthma without known risk factors, anesthesiologists should be careful not to induce airway irritation during anesthesia awakening in asthma patients. CONCLUSION: Because diffuse alveolar hemorrhage accompanied by NPPE can occur, anesthesiologists should take care not to induce airway irritation.

Surgical Outcomes and Survival Prognostic Factors for Palliative Gastrectomies in Stage IV Resectable Gastric Cancer Outlet Obstruction Patients.

PURPOSE: Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019. Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. RESULTS: There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. CONCLUSIONS: We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

The use of remifentanil to facilitate the insertion of the Cobra perilaryngeal airway.

BACKGROUND: The use of remifentanil before propofol administration facilitates the insertion of the Laryngeal Mask Airway. We designed the present study to determine whether remifentanil would also create more suitable conditions for providing Cobra Perilaryngeal airway (CobraPLA) insertion when administered with propofol. METHODS: Both remifentanil and propofol were given as effect-site target-controlled infusions. There were four groups of 25 patients each. The propofol effect-site concentration was set at 6 microg/mL in all groups. Group R1 received a target effect-site remifentanil concentration of 1 ng/mL, Group R2 received remifentanil at 2 ng/mL, Group R3 received remifentanil at 3 ng/mL, and Group R4 received remifentanil at 4 ng/mL before the induction of anesthesia with propofol. The ease of insertion of CobraPLA was graded by the following 3-point scale: Grade 1, excellent, no response to CobraPLA insertion; Grade 2, acceptable, gagging or swallowing with insertion of CobraPLA; Grade 3, poor, unable to open mouth or biting upon insertion of CobraPLA. RESULTS: The most patients ranked as excellent for the first CobraPLA insertion (Grade 1) were found in Group R4, which was significantly higher than Groups R1 and R2 (P < 0.01), whereas no significant difference was found when compared with Group R3. The duration of apnea showed a significant dose-related increase (P < 0.01), especially between Group R2 (median 2.95 min) and R3 (median 7.9 min), but there was no significant difference between Groups R3 and R4. The incidence of hypotension in Group R4 within 1 min after insertion of CobraPLA was significantly more than for Groups R1 and R2 (P < 0.01). No significant differences could be found between the incidence of hypotension between Group R3 and the other groups. The incidence of hypertension at 1 min postinsertion was significantly more common in Groups R1 and R2 than Groups R3 and R4 (P < 0.01). CONCLUSION: An effect-site concentration of remifentanil of 2 ng/mL provides excellent conditions for insertion of the CobraPLA on the first attempt with minimal hemodynamic perturbations and a shorter duration of apnea.

Ultrasound-guided greater occipital nerve block with botulinum toxin for patients with chronic headache in the occipital area: a randomized controlled trial.

BACKGROUND: Ultrasound-guided greater occipital nerve (GON) block has been frequently used to treat various types of headaches, and botulinum toxin has recently begun to be used in patients with headache. Our study presents the long-term effect of botulinum toxin on GON block using ultrasound in patients with chronic headache in occipital area. METHODS: Patients with occipital headache were divided into two groups (bupivacaine: BUP group [n = 27], botulinum toxin: BTX group [n = 27]), and ultrasound-guided GON block was performed at the C2 level. GON was detected with ultrasound and distance from GON to midline, from the skin surface to GON, and size of GON were measured in both groups. Visual analogue scale (VAS) scores and Likert scale were assessed at pretreatment and at 1, 4, 8, and 24 weeks after treatment in both groups. RESULTS: The distance from GON to midline was 18.9 ± 4.4 mm (right) and 17.3 ± 3.8 mm (left). The depth from the skin was 12.9 ± 1.5 mm (right) and 13.4 ± 1.6 mm (left). GON size was 3.1 mm on both sides. The VAS score and patient satisfaction score (Likert scale) in 4, 8, and 24 weeks after injection were superior for the BTX than the BUP group. CONCLUSIONS: Ultrasound-guided GON block using BTX is effective in reducing short-term and long-term pain in patients with chronic headache in the occipital area.

Comparison of the GlideScope and the McGrath method using vascular forceps and a tube exchanger in cases of simulated difficult airway intubation.

BACKGROUND: A "difficult airway" can be simulated with an extrication collar, which restricts cervical motion and mouth opening. The purpose of this study is to compare the efficacy of the GlideScope and the McGrath in difficult airway simulation. METHODS: Patients were randomized using computer-generated numbers and were placed into the GlideScope group or the McGrath group. The total intubation time was defined as the time measured from when the anesthesiologist picks up the device to the time at which three successive end-tidal CO2 values are acquired after intubation. RESULTS: There was no significant difference in total intubation time between the two groups (73.0 ± 25.3 sec vs. 72.3 ± 20.9 sec, P = 0.92). The success rates of the first intubation attempt did not differ between the two groups (82.8% vs. 83.3%, P = 0.95). CONCLUSIONS: Our results suggest that there are no significant differences in the intubations with GlideScope and McGrath using vascular forceps and tube exchangers in difficult intubation scenarios.

Development of bilateral tension pneumothorax under anesthesia in a Boerhaave's syndrome patient: a case report.

A 33-year-old male visited the emergency room with abdominal pain which developed after a vomiting episode. Based on the pneumomediastinum findings from a chest radiograph and a contrast-enhanced chest and abdominal computed tomography scan, the patient was diagnosed with Boerhaave's syndrome. Preoperative radiologic findings showed no pneumothorax or pleural effusion. Once anesthesia was administered, the patient developed near complete cardiopulmonary collapse due to a bilateral tension pneumothorax, which was treated by bilateral thoracentesis, followed by chest tube insertion. Despite a left side rupture, the damaged right lung was unable to overcome single right ventilation, so the surgery was completed via right thoracotomy. The ruptured site was treated, and the patient was transferred to the intensive care unit. We discuss the anesthetic implications of this disease and how to prevent fatal complications.

End-tidal concentration of sevoflurane for preventing rocuronium-induced withdrawal of the arm in pediatric patients.

BACKGROUND: During induction of general anesthesia, the intravenous injection of rocuronium is often associated with withdrawal movement of the arm due to pain, and this abrupt withdrawal may result in dislodgement of the venous catheter, injury, or inadequate injection of rocuronium. We performed this study to evaluate the 50 and 95% effective end-tidal concentrations of sevoflurane (ETsev) for preventing rocuronium-induced withdrawal of the arm. METHODS: We conducted a prospective double-blind study in 31 pediatric patients. After free flow of lactated Ringer's IV fluid was confirmed, anesthesia was induced in the patients by using 2.5% thiopental sodium (4 mg/kg) and sevoflurane (4 vol%) with 6 L/min of oxygen. When the target ETsev was reached, preservative-free 1% lidocaine (1.5 mg/kg) was intravenously injected during manual venous occlusion and rocuronium (0.6 mg/kg) was injected after lidocaine injection under free-flow intravenous fluid. A nurse who was an investigator and was blinded to the ETsev injected the rocuronium. The nurse evaluated the response. RESULTS: Non-withdrawal movement was observed in 5 out of 11 patients with ETsev 3.0 vol% and in 5 out of 6 patients with ETsev 3.5 vol%. By Dixon's up-and-down method, the 50% effective concentration (EC50) of sevoflurane for non-withdrawal movement at rocuronium injection was 3.1 ± 0.4 vol%. A logistic regression curve of the probability of non-withdrawal movements showed that the 50% effective ETsev for abolishing withdrawal movement at rocuronium injection was 2.9 vol% (95% confidence interval [CI] 2.4-3.8 vol%) and the 95% effective ETsev was 4.3 vol% (95% CI 3.6-9.8 vol%). CONCLUSIONS: This study showed that the 50 and 95% effective ETsev that prevent withdrawal movement at rocuronium injection are 2.9 and 4.3 vol%, respectively.

Comparison of the Proseal LMA and intersurgical I-gel during gynecological laparoscopy.

BACKGROUND: The relatively recently developed I-gel (Intersurgical Ltd., Workingham, England) is a supraglottic airway device designed for single-use that, unlike conventional LMAs, does not require an inflatable cuff. In addition, the I-gel, much like the Proseal LMA (PLMA), has a gastric drainage tube associated with an upper tube for decompression of the stomach, thereby avoiding acid reflux and decreasing the risk of pulmonary absorption. The purpose of this study was to compare PLMA and I-gel devices in patients undergoing gynecological laparoscopy based on sealing pressure before and during pneumoperitoneum, insertion time, and gas exchange. METHODS: Following Institutional Review Board approval and written informed consent, 30 adult patients were randomly allocated to one of two groups (the PLMA or I-gel group). In each case, insertion time and number of attempts were recorded. After successful insertion, airway leak pressure was measured. RESULTS: Successful insertion and mechanical ventilation with both supraglottic airway devices was achieved on the first attempt in all 30 patients, and there were no significant differences with respect to insertion time. Likewise, leak pressure did not vary significantly either between or within groups after CO(2) insufflation. In addition, differences between leak volume and leak fraction between groups were not significant. CONCLUSIONS: The results of our study indicate that the I-gel is a reasonable alternative to the PLMA for controlled ventilation during laparoscopic gynecologic surgery.

Peri-operative ketamine with the ambulatory elastometric infusion pump as an adjuvant to manage acute postoperative pain after spinal fusion in adults: a prospective randomized trial.

BACKGROUND: In this study, we assessed the effectiveness of ketamine as an alternative to non-steroidal anti-inflammatory drugs (NSAID), to manage acute postoperative pain after spinal fusion when given intravenously via a patient-controlled analgesia (PCA) pump in which the dose was proportional to that of fentanyl. METHODS: Forty patients undergoing 1-2 level spinal fusion were enrolled in this study. Patients were intraoperatively randomized into two groups to receive intravenous PCA consisting either of fentanyl 0.4 µg/ml/kg (control group) or fentanyl 0.4 µg/ml/kg with ketamine 30 µg/ml/kg (ketamine group) after intravenous injection of a loading dose. The loading dose in the control group was fentanyl 1 µg/kg with normal saline equal to ketamine volume and in the ketamine group it was fentanyl 1 µg/kg with ketamine 0.2 mg/kg. The verbal numerical rating scale (NRS), fentanyl and ketamine infusion rate, and side effects were evaluated at 1, 24, and 48 hours after surgery. RESULTS: There were no significant differences in patient demographics, duration of surgery and anesthesia or intra-operative opioids administration. We did not find any significant differences in the mean infusion rate of intraoperative remifentanil or postoperative fentanyl or in the side effects between the groups, but we did find a significant difference in the NRS between the groups. CONCLUSIONS: Based on our results, we conclude that a small dose of ketamine (0.5-2.5 µg/kg/min) proportional to fentanyl is not only safe, but also lowers postoperative pain intensity in patients undergoing spinal fusion, although the opioid-sparing effects of ketamine were not demonstrated.

Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy.

BACKGROUND: Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the cardiovascular responses in patients who are undergoing gynecological laparoscopy. METHODS: Sixty female patients were randomly allocated to one of two groups, (the VCV or PCV groups). In the VCV group, baseline ventilation of the lung was performed with volume-controlled ventilation and a tidal volume of 10 ml/kg ideal body weight (IBW). In the PCV group, baseline ventilation of the lung using pressure-controlled ventilation was initiated with a peak airway pressure that provided a tidal volume of 10 ml/kg IBW and an upper limit of 35 cmH(2)O. The end-tidal CO(2), the peak airway pressures (P(peak)), the compliance, the airway resistance and the arterial oxygen saturation were recorded at T1: 5 minutes after insertion of the laryngeal airway, and at T2 and T3: 5 and 15 minutes, respectively, after CO(2) insufflation. RESULTS: The P(peak) at 5 minutes and 15 minutes after CO(2) insufflation were significantly increased compared to the baseline values in both groups. Also, at 5 minutes and 15 minutes after CO(2) insufflation, there were significant differences of the P(peak) between the two groups. The compliance decreased in both groups after creating the pneumopertoneim (P < 0.05). CONCLUSIONS: Our results demonstrate that PCV may be an effective method of ventilation during gynecological laparoscopy, and it ensures oxygenation while minimizing the increases of the peak airway pressure after CO(2) insufflation.

The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction without muscle relaxation.

STUDY OBJECTIVE: To determine the most suitable effect-site concentration of remifentanil during lightwand intubation when administered with a target-controlled infusion (TCI) of propofol at 4.0 µg/mL without neuromuscular blockade. DESIGN: Prospective study using a modified Dixon's up-and-down method. SETTING: Operating room of an academic hospital. PATIENTS: 28 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for minor elective surgery. INTERVENTIONS: Anesthesia was induced by TCI propofol effect-site concentration to 4.0 µg/mL, and the dose of remifentanil given to each patient was determined by the response of the previously tested patient using 0.2 ng/mL as a step size. The first patient was tested at a target effect-site concentration of 4.0 ng/mL of remifentanil. If intubation was successful, the remifentanil dose was decreased by 0.2 ng/mL; if it failed, the remifentanil dose was increased by 0.2 ng/mL. Successful intubation was defined as excellent or good intubating conditions. MEASUREMENTS AND MAIN RESULTS: The remifentanil effect-site concentration was measured. The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction using 2% propofol target effect-site concentration to 4 µg/mL was 2.16 ± 0.19 ng/mL. From probit analysis, the effect-site concentration of remifentanil required for successful lightwand intubation in 50% (EC50) and 95% (EC95) of adults was 2.11 ng/mL (95% CI 1.16-2.37 ng/mL) and 2.44 ng/mL (95% CI 2.20-3.79 ng/mL), respectively. CONCLUSION: A remifentanil effect-site concentration of 2.16 ± 0.19 ng/mL given before a propofol effect-site concentration of 4 µg/mL allowed lightwand intubation without muscle relaxant.

A comparison of the Glidescope® to the McGrath® videolaryngoscope in patients.

BACKGROUND: The Glidescope® 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® compared to the McGrath® 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.

Ultrasound-guided greater occipital nerve block for patients with occipital headache and short term follow up.

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.

Effect of ketorolac and diclofenac on the impairment of endothelium-dependent relaxation induced by reactive oxygen species in rabbit abdominal aorta.

BACKGROUND: Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in endothelium. We studied the influences of ketorolac and diclofenac on ROS effects using the endothelium of rabbit abdominal aorta. METHODS: Isolated rabbit aortic rings were suspended in an organ bath filled with Krebs-Henseleit (K-H) solution bubbled with 5% CO(2) and 95% O(2) at 37.5℃. After being stimulated to contract with phenylephrine (PE, 10(-6) M), changes in arterial tension were recorded following the cumulative administration of acetylcholine (ACh, 3 × 10(-8) to 10(-6) M). The percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS, generated by electrolysis of K-H solution, were used as the control and experimental values, respectively. The aortic rings were pretreated with ketorolac or diclofenac at the same concentrations (10(-5) M to 3 × 10(-4) M), and the effects of these agents were compared with the effects of ROS scavengers: catalase, mannitol, sodium salicylate and deferoxamine and the catalase inhibitor, 3-amino-1,2,4-triazole (3AT). RESULTS: Both ketorolac and diclofenac maintained endothlium-dependent relaxation induced by ACh in a dose-related manner inspite of ROS attack (P < 0.05 vs. control value). The 3AT pretreated ketorolac (3 × 10(-3) M) group was decreased more significantly than un-pretreated ketorolac (P < 0.05). CONCLUSIONS: These findings suggest that ketorlac and diclofenac preserve the endothelium-dependent vasorelaxation against the attack of ROS, in a concentration-related manner. One of the endothelial protection mechanisms of ketorolac may be hydrogen peroxide scavenging.

Comparison of volume-control and pressure-control ventilation during one-lung ventilation.

BACKGROUND: We hypothesized that pressure control ventilation allows a more even distribution in the lung and better maintenance of the mean airway pressure than is achieved with volume control ventilation. We try to compare the effect of pressure control ventilation (PC) with that of volume control ventilation without an end-inspiratory pause (VC) during one-lung ventilation (OLV) in an anesthetized, paralyzed patient for performing thoracopic bullectomy of the lung. METHODS: We ventilated 20 patients with VC and PC after the insertion of a thoracoscope in continual order for, at least for 15 minutes, for each, VC and PC procedure. At the end of VC and PC, the respiratory mechanics, gasometrics, and hemodynamic parameters were measured and collected. RESULTS: We found no significant differences between VC and PC except for the peak inspiratory airway pressure (PIP), the mean airway pressure and the arterial oxygen partial pressure (PaO2). The PIP was significantly decreased from 27.0 +/- 6.0 cmH2O (VC) to 21.8 +/- 5.4 cmH2O (PC). The mean airway pressure was significantly increased from 8.6 +/- 1.6 cmH2O (VC) to 9.4 +/- 2.0 cmH2O (PC), and the PaO2 was significantly increased from 252.9 +/- 97.3 mmHg (VC) to 285.2 +/- 103.8 mmHg (PC). CONCLUSIONS: If PC allows mechanical ventilation with the same tidal volume and respiratory rate as VC during OLV, then PC significantly increases the PaO2 but this is not clinically significant, and the PC significantly decreases the PIP, which induces barotrauma or volutrauma when the PIP is excessively high.

Awareness during general anesthesia due to the unlock position of the vaporizer : A report on two cases.

Awareness with recall after general anesthesia is a relatively infrequent occurrence and this awareness is often associated with significant adverse psychological sequelae, including posttraumatic stress disorder. The occurrence of awareness is often the consequence of the light anesthetic techniques with using minor anesthetic agents. Because the locking lever of the Penlon Sigma Delta Anesthetic vaporizer (sevoflurane) was at the unlock position, disconnection happened between the anesthetic machine and the vaporizer (the Selectatec(R) vaporizing system). In our two cases, the inhalation agents were not supplied and awareness with recall was identified after surgery. We recommend to check the concentration of the inhalation agents by monitoring the concentration of using endtidal inhalation agents and to measure the hypnotic level of anesthesia via the bispectral index (BIS) and the auditory evoked potential (AEP).