Two-handed facemask technique effectively causes hyperventilation in electroconvulsive therapy: an observational study.

BACKGROUND: Electroconvulsive therapy (ECT) remains the mainstay treatment option for patients with psychiatric diseases, such as severe depression. Although various anesthetic techniques provide adequate therapeutic seizures, hyperventilation is a useful adjunct to augment seizure duration and improve seizure quality. We investigated how to efficiently use a facemask to accomplish protocolized hyperventilation and evaluate its effect on ECT seizure. METHODS: We studied 60 patients aged ≥18 years who underwent ECT. The patients were divided into two groups according to the technique of facemask ventilation used: the one-handed (n = 30) and two-handed (n = 30) groups. Following anesthesia induction under preoxygenation conditions, hyperventilation induced hypocapnia in the one-handed facemask group with manual bag ventilation was compared to that in the two-handed facemask group with assisted pressure-controlled ventilation. Ictal and peri-ictal electroencephalogram parameters and cardiovascular responses were monitored and compared between the one-handed and two-handed groups. RESULTS: The two-handed technique demonstrated better electroencephalogram regularity and minimized cardiovascular stress compared to the one-handed technique. These conclusions come from the fact that the one-handed technique induced a substantial volume of leaks around the facemask (201.7 ± 98.6 mL/breath), whereas minimal leaks (25.8 ± 44.6 mL/breath) with stabler and higher ventilation rate led to greater inhaled minute ventilation in the two-handed group (the one-handed group, 9.52 ± 3.94 L/min; the two-handed group, 11.95 ± 2.29 L/min; p <  0.005). At the end of ECT treatment, all parameters of blood pressure and heart rate increased significantly in both groups equally, with lower SpO2 and more ST-segment depression on the electrocardiogram in the one-handed group. Comparing baseline values before anesthesia, ECT treatment significantly depressed ST-segment in both groups, while the degree of depression in ST-segment increased significantly in the one-handed group compared to that in the two-handed group. CONCLUSIONS: End-tidal carbon dioxide monitoring for hyperventilation can reliably ensure hypocapnia only in the two-handed group. In ECT, the two-handed technique assisted by pressure-controlled ventilation is an effective and practical method for hyperventilation to induce adequate therapeutic seizures. While, the two-handed group with sufficient preoxygenation did not cause more cardiovascular stress than the one-handed group. TRIAL REGISTRATION: UMIN Clinical Trials Registry 000046544, Date of registration 05/01/2022.

Factors affecting prolonged time to extubation in patients given remimazolam.

PURPOSE: To analyze the cause of prolonged recovery from general anesthesia with remimazolam. METHODS: We studied 65 patients under general anesthesia with remimazolam. According to time to extubation, patients were divided into short period (SP) (n = 34, < 15 min) and long period (LP) (n = 31, ≥ 15 min) groups. Variables affecting time to extubation such as age, sex, height, body weight, body mass index (BMI), plasma albumin concentration, ASA class, duration of surgery, and total duration of general anesthesia, and total dose of remimazolam were compared between SP and LP groups. At the end of remimazolam infusion and upon extubation, predictive remimazolam concentrations were calculated using pharmacokinetic/pharmacodynamic three compartment modeling. RESULTS: LP group showed significantly higher BMI, older age, and lower plasma albumin concentration compared with those of SP group. Logistic regression analysis showed that the probability of time to extubation of ≥ 15 min was higher in patients with BMI greater than 22.0 kg/m2 (AUC 0.668, 95% CI 0.533‒0.803), ages older than 79.0 years (AUC 0.662, 95% CI 0.526‒0.798), and plasma albumin concentrations lower than 3.60 g/dl (AUC 0.720, 95% CI 0.593‒0.847). LP group showed significantly lower predicted remimazolam concentration than SP group upon extubation despite no difference in concentration between both groups at the end of infusion. Pharmacological analysis estimates that LP group is more sensitive to remimazolam than SP group through amplified responses. CONCLUSIONS: Lower remimazolam doses should be considered for the overweight patients, elderly, and those with lower plasma albumin concentration.

An outcome study of adult in-hospital cardiac arrests in non-monitored areas with resuscitation attempted using AED.

OBJECTIVES: To investigate the outcomes of patients with in-hospital cardiac arrest (IHCA) who underwent cardiopulmonary resuscitation (CPR) using an automated external defibrillator (AED) in non-monitored areas. Additionally, to detect correlated factors associated with rate of return of spontaneous circulation (ROSC) and survival rate, among collected data. METHODS: This study included 109 patients. After investigating patient characteristics and resuscitation-related factors, the correlated factors associated with ROSC rates and survival rate were analyzed using univariate and multivariate analyses. RESULTS: The rate of survival to hospital discharge was 21.1%. CPR with AED performed since 2013 was associated with a higher ROSC rate (adjusted odds ratio [AOR] 3.24, 95% confidence interval [CI]: 1.21 to 9.52, p < 0.05), but not with the survival rate after ROSC. Tracheal intubation was significantly associated with a higher ROSC rate (AOR 3.62, 95% CI: 1.27 to 11.7, p < 0.05) and a lower survival rate after ROSC (hazard ratio 6.6, 95% CI: 1.2 to 43.3, p < 0.05). Dysrhythmia as the cause of cardiac arrest and intensive care unit (ICU) admission after ROSC were associated with higher survival rates (hazard ratio 0.056, 95% CI: 0.004 to 0.759, p < 0.05, and hazard ratio 0.072, 95% CI: 0.017 to 0.264, p < 0.0001, respectively). CONCLUSIONS: The factors associated with ROSC rate and those associated with the survival rate after ROSC were different. Although initial shockable rhythms on AED were not associated with the survival rate, dysrhythmia as the etiology of cardiac arrest, and ICU admission were significantly associated with higher survival rates after ROSC.

[Tracheal Resection and Primary Anastomosis for Adenoid Cystic Carcinoma Using an Extracorporeal Membrane Oxygenation].

We report a case of tracheal resection and primary anastomosis for adenoid cystic carcinoma using an extracorporeal membrane oxygenation (ECMO). A 45-year-old female was referred to our hospital because of a tracheal tumor that occupied most of the tracheal lumen. In case of airway obstruction by the tracheal tumor during anesthesia and operation, we decided to use ECMO before induction of general anesthesia. Under secure respiratory control using ECMO, tracheal resection and primary anastomosis was performed. Since histopathological examination revealed microscopically positive results at the surgical margin, postoperative adjuvant radiation therapy( 60 Gy/30 Fr) was conducted. Although a tracheal tumor is a relatively rare neoplasm, careful planning and a treatment strategy are necessary with special emphasis on the location and size of tumor. In this case, ECMO made a substantial contribution to secure respiratory control during surgery.

Is using an open-reservoir cardiopulmonary bypass circuit after 6 days on standby safe?

OBJECTIVES: To investigate the sterility and biocompatibility of a stored open-reservoir cardiopulmonary bypass circuit maintained on standby. METHODS: A total of four cardiopulmonary bypass circuits were assembled, primed and left to recirculate. One unit was placed in a positive-pressure operating room and the other three were placed in the intensive care unit. The primed solutions, which employed Ringer's acetate, hydroxyethylated starch and hydrate steroid, were sampled after 0, 24, 48, 72, 96, 120 and 144 h in all cardiopulmonary bypass circuits to measure the bacteria count, endotoxin count and chemical substances within the primed solution. Chemical substances were detected by assessing the following: the total organic carbon by the combustion oxidation infrared spectrometry, and molecular weight spread by gel permeation chromatography. The environments were left unattended and were uncovered during the storage period to mimic the clinical scenario. RESULTS: There were no bacteria in any of the primed solutions, and only very minute concentrations of endotoxins were detected, both in the operating room and in the intensive care unit. The total organic carbon concentration was slightly more concentrated in the 144-h samples when compared with that in the 0-h samples. However, the molecular weight spread of the 0-h sample was identical to that in the 144-h sample. DISCUSSION: With regard to the presence of bacteria and endotoxins, we noted that the hardshell reservoirs in the cardiopulmonary bypass circuit were effectively sealed and not invaded by bacteria. With regard to the presence of chemical substances, we noted that an increase in total organic carbon concentration was caused by bedewing, and that there was no release of chemical substances such as a polymer-coating agent, or other molecular materials in the primed solution. CONCLUSIONS: There was no contamination or release of chemical substances in 6-day old cardiopulmonary bypass circuits maintained on standby, confirming that they are safe to use in terms of sterility and biocompatibility.

Rocuronium-sugammadex use for electroconvulsive therapy in a hemodialysis patient: a case report.

BACKGROUND: Recently, rocuronium with subsequent use of sugammadex was proposed for electroconvulsive therapy (ECT) as an alternative to succinylcholine. Because sugammadex is cleared via the kidney with no metabolism, it is unknown that rocuronium-sugammadex use is safe in hemodialysis patients who received ECT. CASE PRESENTATION: In this case report, we used rocuronium with subsequent administration of sugammadex in a 69-year-old female, hemodialysis patient, scheduled for ten ECT sessions for severe major depression. In the initial eight sessions, we tested the feasibility of rocuronium-sugammadex use for ECT. During the series of four ECT sessions, we measured plasma concentrations for the sum of sugammadex and sugammadex-rocuronium complex and observed whether possible residual sugammadex affected muscle relaxation during subsequent sessions of ECT. The results showed the feasibility of rocuronium-sugammadex use as muscle relaxants for ECT in patients undergoing hemodialysis. However, an accumulation of sugammadex did occur even after two sessions of hemodialysis, and residual sugammadex decreased the effect of the rocuronium given in the subsequent ECT sessions. Rocuronium-sugammadex was successfully utilized as muscle relaxants for ECT in this patient. CONCLUSIONS: Our experience in this case may indicate that if succinylcholine is contraindicated, rocuronium-sugammadex can be an alternative method for muscle relaxation during ECT in patients undergoing hemodialysis. When this rocuronium-sugammadex procedure is used, the effect of residual sugammadex after hemodialysis on the subsequently administered rocuronium should be considered.

[Rapid Rise of Trans-oxygenerator Pressure Gradient Accompanied by Rapid Decrease of Platelet Counts During Open-heart Surgery].

A 77-year-old male patient with 2-vessel coronary artery disease and previous myocardial infarction underwent on-pump coronary artery bypass grafting (CABG). Following systemic heparinization, cardiopulmonary bypass using heparin coated circuit was started. Ten minutes after starting the cardiopulmonary bypass, the trans-oxygenerator pressure gradient rapidly increased accompanied by a rapid decrease of platelet counts. Emergency replacement of cardiopulmonary bypass circuit with a non-heparin coated one was performed because the development of heparin induced thrombocytepenia (HIT) was strongly suspected. On-pump CABG was accomplished as planned, and the postoperative course was uneventful. HIT might be ruled out as HIT specific antibodies were not detected in the intraoperative serum samples.

Urinary retention occurring one week after spinal anesthesia: a case of Elsberg syndrome.

PURPOSE: We describe a case of urinary retention caused by viral sacral myeloradiculitis (Elsberg syndrome) that occurred one week after spinal anesthesia. The differential diagnosis of urinary retention after spinal anesthesia is discussed. CLINICAL FEATURES: A 76-yr-old male patient presented for operative removal of a right testicular hydrocele under spinal anesthesia. Anesthesia and surgery were uneventful, and he was discharged on the fifth postoperative day. Two days after discharge, he developed intermittent anal pain and voiding difficulty and was readmitted to hospital on the tenth postoperative day. He subsequently developed urinary retention, incontinence of feces, and difficulty in defecation. Magnetic resonance imaging showed no epidural hematoma, abscess, or other lesions in the spinal column, cauda equina, or spinal cord. Neurological examination showed dysesthesia in the perineal region and loss of the anal reflex and bulbocavernosus response, which indicated sacral (S4-5) radiculopathy or a lesion of the conus of the spinal cord. A cerebrospinal analysis showed slight elevation of protein without pleocytosis. After neurologic consultation, herpetic sacral myeloradiculitis was suspected and intravenous acyclovir was administered along with large doses of methylprednisolone and immunoglobulin. The symptoms gradually resolved, and the difficulty in voiding resolved 19 days after initiation of the treatment. The patient was discharged 23 days after the start of the treatment without any other complications. CONCLUSION: This case suggests that Elsberg syndrome is important in the differential diagnosis of urinary retention after spinal anesthesia and should be discriminated from other anesthesia-related complications.

[Loss of anesthesia records during network failure of anesthesia management information system: a case of malfunction of backup system].

We report a case of an accidental loss of anesthesia records through network failure of an anesthesia information management system (AIMS). The backup data were not kept in the anesthesia workstations or the server during the failure. Accordingly, anesthesia records of five patients were lost for one hour. Our AIMS has a network redundancy where the server keeps anesthesia monitoring data via two pathways: one via the monitoring server to the AIMS server and the other via anesthesia workstation to the server. Despite the redundant pathways, transient power failures of network switches caused interruptions in both pathways. Our case indicates that, to improve the robustness of the AIMS as electronic medical records, every network apparatus of AIMS, should be supplied with an uninterrupted power supply. Furthermore, each anesthesia workstation should function independently as an anesthesia record keeping client when network failure occurs.

A case of coronary artery spasm caused by manipulation of the neck: heart rate variability analysis.

A 66-year-old man with no history of ischemic heart disease underwent cervical lymph node dissection. General anesthesia was induced and maintained with remifentanil, along with propofol. With manipulation of the neck and a subcutaneous injection of lidocaine supplemented with adrenaline before the operation, a sudden decrease in blood pressure (BP) and elevation of the ST-T segment appeared on the monitoring electrocardiogram (ECG). Ephedrine, phenylephrine, adrenaline, and nitroglycerin were administered; however, the hypotension was sustained and the ECG abnormalities progressed, along with further elevation of the ST-T segment and a complete atrioventricular block. Following an injection of atropine, the changes in ECG and BP were attenuated. Heart rate variability (HRV) was analyzed using fully recorded monitor variables, and revealed an increase in the high-frequency domain at the time of the cervical manipulation, suggesting simultaneous vagal stimulation and coronary artery spasm. We concluded that the cervical manipulation had increased the vagal tone and we note that HRV analysis was useful to interpret this coronary event.

Systolic arterial pressure variability reflects circulating blood volume alterations in hemorrhagic shock in rabbits.

Both the high-frequency component of systolic arterial pressure variability and systolic pressure variation (SPV) have been indicated to be strongly affected by respiratory effect and sensitively reflect circulating blood volume (CBV). We attempted to determine the best means reflecting CBV from various parameters using power spectrum analyses of systolic arterial pressure variability (PSSAPV) and heart rate variability (PSHRV), SPV, and pulse pressure variation during graded hemorrhaging and fluid resuscitation. Under isoflurane anesthesia and mechanical ventilation, rabbits in group S (n = 6) had hemorrhaging induced, whereas those in group H (n = 10) had hemorrhaging induced followed by fluid resuscitation. After collecting baseline data, blood was withdrawn at a rate of 1 mL.kg.min for 25 min in both groups, and data were collected at 5 min after bleeding was stopped. Furthermore, in group H, hydroxyethyl starch was continuously infused at a rate of 1 mL.kg.min for 25 min; data were collected at 5 and 60 min after fluid resuscitation. The correlations between CBV and total power (TP, 0.04-2.00 Hz), high-frequency component (0.75-1.40 Hz), and low-frequency component (0.04-0.40 Hz) of PSSAPV were more significant as compared with SPV and pulse pressure variation, whereas no correlations were noted between CBV and PSHRV. To evaluate the regression models appropriately, Akaike information criterion was used, and TP of PSSAPV showed the lowest value. We concluded that TP of PSSAPV most sensitively reflected changes of CBV and that PSSAPV was the most useful parameter for evaluation of volume status as compared with conventional circulatory parameters.

Intrathecally administered COX-2 but not COX-1 or COX-3 inhibitors attenuate streptozotocin-induced mechanical hyperalgesia in rats.

Members of the cyclooxygenase (COX) family are known to catalyze the rate-limiting steps of prostaglandins synthesis and reported to be involved in neuropathic pain. Diabetic neuropathy is a type of neuropathic pain, though it is not clear if COX is relevant to the condition. Recently, spinal COX-2 protein was found to be increasing in streptozotocin-induced rats as compared to the constitutive expression. We attempted to determine which cyclooxygenase isoforms are involved in streptozotocin-induced mechanical hyperalgesia, which was induced by a single intraperitoneal injection of 75 mg/kg of streptozotocin. Intrathecal administrations of the COX-2 inhibitors SC-58125 (7-100 microg) and NS-398 (7-60 microg), as well as a high dose (100 microg) of the COX-1 inhibitor SC-560 attenuated hyperalgesia, whereas intrathecal administrations of a low dose (10 microg) of SC-560 and the COX-3 inhibitor acetaminophen (1-7 mg) did not. Further, intrathecal administration of SC-58125 (100 microg) did not produce an analgesic effect in normal rats. These results indicate that intrathecal administration of COX-2 inhibitors has an anti-hyperalgesic effect on streptozotocin-induced mechanical hyperalgesia and we concluded that spinal COX-2 is pivotal in streptozotocin-induced hyperalgesia.

[Evaluation of the sedation level with propofol with electroencephalographic Entropy in comparison with bispectral index monitor].

BACKGROUND: Entropy, a newly available electroencephalographic monitor, demonstrates two parameters, response entropy (RE) and state entropy (SE). The aim of this study is to compare RE and SE with bispectral index (BIS) during anesthetic induction with propofol. METHODS: Fifteen patients received target controlled infusion of propofol starting at 3 microg x ml(-1). We measured RE, SE and BIS and recorded effect-site concentrations of propofol at three sedation levels: VR1; conscious state before infusion of propofol, VR2; no response to verbal command, and VR3; no response to verbal command and shaking. Spearman rank correlations and prediction probability for sedation level were analyzed. RESULTS: Effect-site concentrations of propofol at VR1, VR2, and VR3 were 0, 1.8 +/- 0.7, and 2.4 +/- 0.7, respectively. All three parameters showed significant correlations with sedation levels. Prediction probability values of SE, RE, and BIS were 0.905, 0.894, and 0.890, respectively. CONCLUSIONS: Response entropy and SE can provide similar information as BIS about the sedation level with propofol.

Comparison of the effects of propofol and midazolam on the cardiovascular autonomic nervous system during combined spinal and epidural anesthesia.

STUDY OBJECTIVE: To investigate the effect of propofol and midazolam on cardiac autonomic nervous system (CANS) activity during combined spinal-epidural anesthesia. DESIGN: Prospective, clinical study. SETTING: Operating room of a university hospital. PATIENTS: Forty ASA physical status I and II patients scheduled for knee surgery. INTERVENTION: Patients were randomized to receive sedation with either propofol or midazolam. MEASUREMENTS: Heart rate (HR), HR variability (HRV), systolic arterial pressure (SAP), and SAP variability (SAPV) were used for the analysis. These values were measured at the preanesthetic period, after intrathecal injection for spinal anesthesia, after sedation with propofol or midazolam, and just before the end of surgery with sedation. Cross-spectral analyses of the HR and SAP data were assessed to quantify the frequency-related coherence spectra and phase spectra. MAIN RESULTS: Spinal anesthesia itself had no effect on power spectral changes in both groups. After sedation, as for HRV, high-frequency (HF) power (HF, 0.15-0.40 Hz) did not change, whereas low-frequency (LF) power (LF, 0.04-0.15 Hz) and LF/HF, an indicator of CANS balance, significantly decreased with propofol. Further, coherence in cross-spectra presented depression in the LF band area after sedation with propofol. Before the end of surgery with sedation, LF and LF/HF in both HRV and SAPV were correlated with age in those with propofol; however, scarce relation was observed in those who received midazolam. CONCLUSIONS: Propofol was more potent than midazolam in causing CANS activity to be sympatholytic during combined spinal and epidural anesthesia and which was correlated with age only with propofol.

Positive end-expiratory pressure depressed cardiovascular autonomic nervous system activity in acute brain damaged rabbits under general anesthesia.

Artificial ventilation with positive end-expiratory pressure (PEEP) is commonly applied for brain damaged patients. However, the effect of the ventilation on brain function, including cardiovascular autonomic nervous system (CANS) activity, is not well elucidated. In order to investigate the effect of 5 cmH2O PEEP on CANS activity in brain damaged rabbits under general anesthesia, we produced acute brain damage by intracranial balloon inflation. Measurements were made before (control) and after application of PEEP, and after inflation with incremental volume of the balloon. Power spectral analyses of heart rate variability (HRV) and systolic arterial pressure variability (SAPV) were used for the assessment of CANS activity. Spectral powers in the low-frequency range of 0.04 to 0.40 Hz (LF) and high-frequency range of 0.75 to 1.40 Hz (HF) were computed, and their ratio LF/HF was assessed as the neural balance of CANS. The animals in group P were ventilated with 5 cmH2O PEEP, while those in group Z were ventilated with zero end-expiratory pressure. Colored microsphere counting was used for the assessment of brain circulation. In the results, PEEP had no effect on HRV and SAPV parameters before induction of brain damage. After inflation with incremental volume of the balloon, log (HF) and log (LF) in group P were lower than in group Z in HRV analysis, and log (LF) in group P was lower than in group Z in SAPV analysis. Microsphere counting revealed that brain blood flow was reduced during the progression of brain damage and showed a significant difference after application of PEEP between the groups. We concluded that 5 cmH2O PEEP depressed CANS activity during the progression of brain damage in rabbits and that this was partly due to aggravated brain function induced by PEEP.

[Severe hypotension after removal of pheochromocytoma in a pediatric patient].

An 8-year-old male patient with pheochromocytoma pretreated with prazocin, carteolol, and enarapril received sevoflurane general anesthesia with fentanyl. After removal of the tumor, blood pressure and urine volume decreased and ST segment in ECG was depressed. We administered dopamine and norepinephrine to increase blood pressure, but pulmonary edema became aggravated postoperatively. He was treated with noninvasive pressure support ventilation with face mask for 4 hours which was effective. His postoperative recovery was uneventful thereafter. We hypothesized that his hemodynamic deterioration was caused by sudden decrease in serum level of norepinephrine after the tumor removal, and the responsiveness to catecholamines was depressed by long exposure to norepinephrine. We conclude that we should use norepinephrine for anesthetic care even in pediatric patients as in adults.