Prevention of Oxygen Desaturation in Morbidly Obese Patients During Electroconvulsive Therapy: A Narrative Review.

In general, preoxygenation is performed using a face mask with oxygen in a supine position, and oxygenation is maintained with manual mask ventilation during electroconvulsive therapy (ECT). However, hypoxic episodes during ECT are not uncommon with this conventional method, especially in morbidly obese patients. The most important property of ventilatory mechanics in patients with obesity is reduced functional residual capacity (FRC). Thus, increasing FRC and oxygen reserves is an important step to improve oxygenation and prevent oxygen desaturation in these individuals. Head-up position, use of apneic oxygenation, noninvasive positive pressure ventilation, and high-flow nasal cannula help increase FRC and oxygen reserves, resulting in improved oxygenation and prolonged safe apnea period. Furthermore, significantly higher incidence of difficult mask ventilation is common in morbidly obese individuals. Supraglottic airway devices establish effective ventilation in patients with difficult airways. Thus, the use of supraglottic airway devices is strongly recommended in these patients. Conversely, because muscle fasciculation induced by depolarizing neuromuscular blocking agents markedly increases oxygen consumption, especially in individuals with obesity, the use of nondepolarizing neuromuscular blocking agents may contribute to better oxygenation in morbidly obese patients during ECT.

Effect of endotracheal tube lubrication on cuff pressure increase during nitrous oxide exposure: a laboratory and prospective randomized controlled trial.

BACKGROUND: We previously demonstrated that lubrication of an endotracheal tube (ETT) cuff with K-Y™ jelly strongly and significantly inhibited the increase in cuff pressure during nitrous oxide (N2O) exposure in vitro. However, in our previous study, we identified critical differences between some influential factors, such as the amount of lubricant retained on the cuff, and studied temperature differences between laboratory and clinical conditions. Therefore, it remained unclear whether this effect holds true in clinical settings. METHODS: We first sought to study how changes in the amount of K-Y™ jelly and temperature influence the inhibitory effects of the lubricant on the increase in N2O-induced cuff pressure in vitro. Furthermore, we aimed to determine whether the application of K-Y™ jelly inhibits the increase in ETT cuff pressure during general anesthesia using N2O in adult patients. RESULTS: In the laboratory studies, we found that K-Y™ jelly inhibited the cuff pressure increase dose-dependently when the dose of K-Y™ jelly was varied (P = 0.02), and that such an inhibitory effect decreased with an increase in the studied temperature (P = 0.019). In the clinical study, lubrication with K-Y™ jelly slightly, but significantly, delayed the increase in ETT cuff pressure during general anesthesia with N2O (P = 0.029). However, the inhibitory effect in the clinical settings was smaller than that in vitro. CONCLUSIONS: Lubrication of the ETT cuff with K-Y™ jelly may delay the increase in cuff pressure during general anaesthesia with N2O. However, the clinical significance of this effect may be limited. TRIAL REGISTRATION: UMIN Clinical Trials Registry: UMIN000031377 on March 1, 2019.

K-Y™ jelly inhibits increase in endotracheal tube cuff pressure during nitrous oxide exposure in vitro.

BACKGROUND: The increase in endotracheal tube cuff pressure due to nitrous oxide diffusion is a well-known risk during general anesthesia using nitrous oxide. We hypothesized that lubricating endotracheal tube cuffs with K-Y™ Jelly might inhibit the increase in cuff pressure that occurs during exposure to nitrous oxide. METHODS: We used two types of endotracheal tube cuffs: one made from ultrathin polyurethane (PU) and another made from conventional polyvinyl chloride (PVC). Using a pediatric trachea model, which consisted of an acrylic cylinder with an internal diameter of 12 mm, we measured changes in the cuff pressure during nitrous oxide exposure in size 5.0-mm internal diameter endotracheal tubes with each type of cuff, with and without lubrication with K-Y™ Jelly. RESULTS: During nitrous oxide exposure, the increase in cuff pressure was significantly lower in the lubricated cuffs than in the non-lubricated cuffs in both types of cuffs (PVC, P < 0.0001; PU, P < 0.0001). However, the cuff compliance in the trachea model was unaffected by lubrication in both types of cuffs. CONCLUSIONS: Lubrication of endotracheal tube cuffs with K-Y™ Jelly may effectively delay the increase in cuff pressure that occurs during general anesthesia using nitrous oxide.

Effect of head position on the success rate of blind intubation using intubating supraglottic airway devices.

BACKGROUND: To evaluate the effect of head position on the performance of intubating supraglottic airway devices, we compared the success rate of blind intubation in the head-elevated and the pillowless head positions with the LMA Fastrach and the air-Q, and the change of glottic visualization through the air-Q. METHODS: We assigned 193 patients to two groups according to the device used and subgrouped by head position used for intubation: Fastrach/pillowless, Fastrach/head-elevated, air-Q/pillowless, and air-Q/head-elevated. Blind intubation through the Fastrach or the air-Q was attempted up to twice after induction of general anesthesia. Before the attempt at blind intubation with the air-Q, the percentage of glottic opening (POGO) score was also fiberscopically evaluated at the outlet of the device in both head positions in a cross-over fashion. RESULTS: The Fastrach significantly facilitated blind intubation compared with the air-Q in both the pillowless and head-elevated positions: 87.2% in Fastrach/pillowless vs 65.9% in air-Q/pillowless (P=.048), 90% in Fastrach/head-elevated vs 53.7% in air-Q/head-elevated (P<.001). The head-elevated position did not significantly affect the success rate of blind intubation for either device (P=.97 in Fastrach, P=.37 in air-Q). Although the head-elevated position significantly improved the POGO score from the median (10-90 percentile) 60% (0-100%) in the pillowless position to 80% (0-100%) (P=.008), it did not contribute to successful blind intubation with the air-Q. CONCLUSION: Although the head-elevated position improved glottic visualization in the air-Q, the head position had minimal influence on the success rate of blind intubation with either the Fastrach or the air-Q.

Effects of sniffing position for tracheal intubation: a meta-analysis of randomized controlled trials.

BACKGROUND: The purpose of this meta-analysis was to validate the efficacy of the sniffing position in the performance of intubation with direct laryngoscopy. METHODS: We searched MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and Web of Science. Six randomized controlled trials comprising 2759 adult participants were analyzed. The DerSimonian-Laird method was used to calculate pooled relative risk (RR) and the 95% confidence interval (CI) of Cormack-Lehane classification, Intubation Difficulty Scale, success rate of the first intubation, and weighted mean difference of intubation time. RESULTS: Compared with the other head positions, the sniffing position did not improve glottic visualization, success rate of the first intubation, or intubation time. However, the sniffing position was significantly associated with better Intubation Difficulty Scale compared with the simple head extension position. (RR,1.28; 95% CI, 1.15-1.42; p<0.0001) CONCLUSIONS: Although patients do not benefit from the sniffing position in terms of glottic visualization, success rate of the first intubation, or intubation time, the sniffing position can still be recommended as the initial head position for tracheal intubation because the sniffing position provides easier intubation conditions.

Isoflurane impairs learning and hippocampal long-term potentiation via the saturation of synaptic plasticity.

BACKGROUND: General anesthesia induces long-lasting cognitive and learning deficits. However, the underlying mechanism remains unknown. The GluA1 subunit of AMPAR is a key molecule for learning and synaptic plasticity, which requires trafficking of GluA1-containing AMPARs into the synapse. METHODS: Adult male rats were exposed to 1.8% isoflurane for 2 h and subjected to an inhibitory avoidance task, which is a hippocampus-dependent contextual fear learning paradigm (n = 16 to 39). The in vitro extracellular field potential of hippocampal synapses between the Schaffer collateral and the CA1 was evaluated using a multielectrode recorder (n = 6 per group). GluA1 expression in the synaptoneurosome was assessed using Western blotting (n = 5 to 8). The ubiquitination level of GluA1 was evaluated using immunoprecipitation and Western blotting (n = 7 per group). RESULTS: Seven days after exposure to 1.8% isoflurane for 2 h (Iso1.8), the inhibitory avoidance learning (control vs. Iso1.8; 294 ± 34 vs. 138 ± 28, the mean ± SEM [%]; P = 0.002) and long-term potentiation (125.7 ± 6.1 vs. 105.7 ± 3.3; P < 0.001) were impaired. Iso1.8 also temporarily increased GluA1 in the synaptoneurosomes (100 ± 9.7 vs. 138.9 ± 8.9; P = 0.012) and reduced the GluA1 ubiquitination, a main degradation pathway of GluA1 (100 ± 8.7 vs. 71.1 ± 6.1; P = 0.014). CONCLUSIONS: Isoflurane impairs hippocampal learning and modulates synaptic plasticity in the postanesthetic period. Increased GluA1 may reduce synaptic capacity for additional GluA1-containing AMPARs trafficking.

Comparison of intubation performance between the King Vision and Macintosh laryngoscopes in novice personnel: a randomized, crossover manikin study.

PURPOSE: The King Vision laryngoscope is a newly developed video laryngoscope. We conducted a simulation study to evaluate the efficacy of the King Vision in novice personnel. METHODS: Thirty-one registered nurses with no previous experience with tracheal intubation were enrolled. Participants made 6 consecutive attempts at intubation of the manikin's trachea with a Macintosh laryngoscope (MAC) and the King Vision with channeled blade (KVC) and non-channeled blade (KVNC) in a randomized cross-over fashion. The Grading Scale of Intubation Difficulty (GSID) was rated on a 5-point scale. RESULTS: Overall median (range) intubation times (sec) were 16.9 (8.0-60.0) with the MAC, 20.5 (7.2-60.0) with the KVC, and 60.0 (11.0-60.0) with the KVNC. The KVNC required significantly longer intubation time compared with the MAC or the KVC (p < 0.001). Success rate with the KVNC was 47.3 %, which was significantly inferior to that with the MAC (91.4 %) or KVC (86.6 %). Median GSID was 2 (range 1-5) with the KVC and 3 (1-4) with the MAC, which were both significantly lower than the 4 (2-5) with the KVNC (p < 0.001). Esophageal intubation with the MAC occurred in 18 of 186 attempts, whereas no incidents of esophageal intubation occurred with the KVC or KVNC. CONCLUSION: The KVC facilitated intubation by novice personnel without incidence of esophageal intubation. However, intubation times, success rates, and GSID scores were similar to the values obtained with the MAC. These findings suggest that the KVC, but not the KVNC, could be used as an alternative device for intubation by novice personnel.

Bumetanide, an inhibitor of cation-chloride cotransporter isoform 1, inhibits γ-aminobutyric acidergic excitatory actions and enhances sedative actions of midazolam in neonatal rats.

BACKGROUND: It has been shown that γ-aminobutyric acid exerts excitatory actions on the immature brain due to the increased expression of Na(+)-K(+)-2Cl(-) cotransporter isoform 1. The authors sought to clarify whether midazolam, a γ-aminobutyric acid-mimetic hypnotic agent, causes neuronal excitation that can be blocked by bumetanide, a selective inhibitor of Na(+)-K(+)-2Cl(-) cotransporter isoform 1. Furthermore, the authors examined whether bumetanide potentiates the sedative effects of midazolam in neonatal rats. METHODS: The authors measured the effects of midazolam with or without bumetanide on the cytosolic Ca(2+) concentration ([Ca](2+)(i)) in hippocampal slices (n=3 in each condition) from rats at postnatal days 4, 7, and 28 (P4, P7, and P28) using fura-2 microfluorometry. Neuronal activity in the hippocampus and thalamus after intraperitoneal administration of midazolam with or without bumetanide was estimated by immunostaining of phosphorylated cyclic adenosine monophosphate-response element-binding protein (n=12 in each condition). Furthermore, the authors assessed effects of bumetanide on the sedative effect of midazolam by measuring righting reflex latency (n=6 in each condition). RESULTS: Midazolam significantly increased [Ca](2+)(i) in the CA3 area at P4 and P7 but not at P28. Bumetanide inhibited midazolam-induced increase in [Ca](2+)(i). Midazolam significantly up-regulated phosphorylated cyclic adenosine monophosphate-response element-binding protein expression in a bumetanide-sensitive manner in the hippocampus at P7 but not P28. Bumetanide enhanced the sedative effects of midazolam in P4 and P7 but not P28 rats. CONCLUSION: These results suggest that γ-aminobutyric acid A receptor-mediated excitation plays an important role in attenuated sedative effects of midazolam in immature rats.

Truncal Blocks for Emergency Laparotomy in a High-Risk Patient: A Case Report and Literature Review.

In critically ill patients undergoing laparotomy, both general anesthesia (GA) and central neuraxial block (CNB) may pose significant risks. Peripheral truncal blocks have been reported to provide effective postoperative analgesia following laparotomy. However, there are a limited number of reports describing this technique as surgical anesthesia for laparotomy. An 86-year-old man with non-specific interstitial pneumonia under home oxygen therapy and aortic valve stenosis was diagnosed with an incarcerated inguinal hernia. Because of these comorbidities, both GA and CNB were considered relatively contraindicated. Thus, we chose an ultrasound-guided transverse abdominis plane block and ilioinguinal/iliohypogastric block supplemented with neuroleptanesthesia as surgical anesthesia for emergency laparotomy. The surgery was uneventful using this technique. Truncal blocks supplemented with titrated intravenous sedatives/analgesics could be an alternative in high-risk patients undergoing laparotomy in whom both GA and CNB are considered relatively contraindicated.

[Anesthetic management of a patient with SAPHO syndrome: a case report].

We report a case of SAPHO syndrome accompanying progressive osteoarthritis. In this 43-year-old woman, difficult intubation was expected due to unilateral hyperostosis of the mandible and spinal degeneration. As far as we know, anesthetic management of this disease has not been reported. Therefore we made an anesthetic plan based on spinal degenerative disease which was considered to have similar problems of intubation and the case was managed without problems. As this syndrome is a progressive disorder, careful perioperative management is required each time.

Cardiovascular monitoring in patients with hypertrophic obstructive cardiomyopathy in a prone position: A report of 2 cases.

Supine positioning in patients with hypertrophic obstructive cardiomyopathy (HOCM) can affect their preload, afterload, and heart rate, potentially leading to cardiovascular collapse. Here, we report the successful anesthetic management of two patients with HOCM who underwent spinal surgery in a prone position. The approximate values of the systemic vascular resistance index (SVRI) were continuously calculated without measuring the central venous pressure. Intraoperative monitoring of the SVRI estimates may be helpful in patients with HOCM so as to avoid cardiovascular collapse when monitoring with both transesophageal echocardiography and a central venous catheter is clinically inappropriate.

Perioperative Management During the COVID-19 Pandemic: Strategies at Three General Hospitals in Japan and a Narrative Review.

Coronavirus disease 2019 (COVID-19) has rapidly spread globally ever since the virus was first identified in December 2019 in Wuhan, China. Despite efforts to accelerate the supply of COVID-19 vaccines worldwide, the global pandemic has continued. Polymerase chain reaction (PCR) test is currently considered the gold standard for the diagnosis of COVID-19. However, the rate of false-negative PCR for COVID-19 has been reported to be over 10%. Furthermore, an asymptomatic period can last up to 14 days following the infection. Under these circumstances, standard anesthetic practice, surgery scheduling, and approaches to appropriate management of the operating room to protect both patients and medical personnel against COVID-19 transmission need to be reviewed and appropriately modified. In this review, based on our institutional experiences along with the guidelines reported elsewhere, we propose safer and more effective perioperative management amidst the COVID-19 pandemic.

Intraocular pressure during robotic-assisted laparoscopic prostatectomy: a prospective observational study.

BACKGROUND AND OBJECTIVES: Although previous reports have shown intraocular pressure changes during robotic-assisted laparoscopic prostatectomy, they did not discuss the time course of changes or the timing of the largest change. We conducted this study to quantify pressure changes over time in patients assuming the steep Trendelenburg position during robotic-assisted laparoscopic prostatectomy. METHODS: Twenty-one men were enrolled. Intraocular pressure was measured before anesthesia induction in the supine position (T0); 30 (T1), 90 (T2), and 150 minutes after assuming the Trendelenburg position (T3); and 30 minutes after reassuming the supine position (T4). End-tidal carbon dioxide and blood pressure were also recorded. To compare intraocular pressure between the time points, we performed repeated-measures analysis of variance. A mixed-effects multivariate regression analysis was conducted to adjust for confounding factors. RESULTS: The mean (standard deviation) intraocular pressure was 18.3 (2.4), 23.6 (3.0), 25.1 (3.1), 25.3 (2.2), and 18.1 (5.0) mmHg at T0, T1, T2, T3, and T4, respectively. The mean intraocular pressure was higher at T1, T2, and T3 than at T0 (p < 0.0001 for all). There was no significant difference between T0 and T4, and between T3 and T2 (p > 0.99 for both). CONCLUSIONS: The Trendelenburg position during robotic-assisted laparoscopic prostatectomy increased intraocular pressure. The increase was moderate at 90 minutes after the position was assumed, with the value being approximately 7 mmHg higher than the baseline value. The baseline intraocular pressure was restored at 30 minutes after the supine position was reassumed. TRIAL REGISTRATION: UMIN ID 000014973 DATE OF REGISTRATION: August 27, 2014.

C-arm fluoroscopy for tracheal intubation in a patient with severe cervical spine pathology.

Tracheal intubation is challenging in patients with severe cervical spine pathology. In such cases, awake fiberoptic intubation is the gold standard and safest option for tracheal intubation. However, this technique requires the patient's understanding and cooperation, and therefore, may be contraindicated in patients with refusal or poor tolerance. Herein, we report successful orotracheal intubation in a patient with limited mouth opening and severe cervical spine rigidity under general anesthesia using an extraglottic airway device and a gum-elastic bougie under C-arm fluoroscopic guidance.

Successful bilevel positive airway pressure therapy in a patient with amyotrophic lateral sclerosis after emergency laparotomy: A case report.

Patients with amyotrophic lateral sclerosis (ALS) present an increased risk of postoperative respiratory failure after general anesthesia. We report the case of a 71-year-old man with ALS who underwent emergency laparotomy for small bowel strangulation. After surgery, he remained intubated and was transferred to the high care unit under mechanical ventilation, due to unstable hemodynamics requiring inotropic support. On postoperative day (POD) 3, he was extubated under stable hemodynamics and respiratory status. Immediately after extubation, bilevel positive airway pressure (bilevel PAP) was prophylactically applied to prevent postoperative respiratory failure, which may have been caused by respiratory muscle fatigue, attributed to general anesthesia and surgical stress. On POD 7, bilevel PAP was smoothly weaned off because no signs and symptoms of respiratory failure were observed. On POD 10, he achieved 30 m-walk without rest. No postoperative complications were observed up to one month after surgery. Postoperative respiratory failure may lead to death in patients with neuromuscular disorder. Non-invasive ventilation (NIV) reduces respiratory muscle fatigue, resulting in easy sputum expectoration, promoting CO2 washout, and better oxygenation. Consequently, the prophylactic use of NIV to avoid postoperative respiratory insufficiency should be considered in patients with ALS after emergency operation under general anesthesia.

Bilevel positive airway pressure therapy in a patient with myotonic dystrophy and postoperative respiratory failure: A case report.

Respiratory failure is a common complication in patients with myotonic dystrophy (MD) and might be a presenting symptom in the perioperative setting. We report the case of a 59-year-old woman with MD who underwent open cholecystectomy and developed postoperative respiratory failure. Without reintubation, the patient was successfully managed with bilevel positive airway pressure (BiPAP) and was discharged uneventfully. BiPAP may be considered as an alternative for postoperative respiratory failure in patients with MD. Careful observation of patients' postoperative condition and an earlier application of BiPAP are instrumental in avoiding retracheal intubation, which may cause further serious problems in patients with MD.

Perioperative management of a pediatric patient with suspected type 1 von Willebrand disease undergoing tonsillectomy: a case report.

BACKGROUND: Von Willebrand disease (VWD) is the most common inherited bleeding disorder in humans. Coagulopathies such as VWD are evidently risk factors for post-surgical bleeding. Perioperative management of patients with VWD remains controversial and is a major clinical concern. CASE PRESENTATION: A 5-year-old girl was scheduled for tonsillectomy under general anesthesia. Preoperative laboratory tests revealed prolongation of activated partial thromboplastin time and a mild decrease in von Willebrand factor (VWF) activity. Prophylactic administration of desmopressin or VWF was not performed. During tonsillectomy, oozing from the surgical wound was uncontrollable by conventional hemostasis techniques, but complete hemostasis was ensured by plasma-derived coagulation factor VIII concentrate containing VWF. CONCLUSION: Pediatric patients with mild abnormalities in preoperative laboratory tests may have coagulopathies. Prophylactic intervention and/or the preparation of a sufficient amount of coagulation factor VIII concentrate containing VWF may be required in patients suspected of having VWD or with mild VWF deficiency.

Intravenous ephedrine abolished suspected bronchoconstriction during general anesthesia in a patient undergoing beta-adrenergic blocker therapy for hypertension.

We report a case of intravenous ephedrine administration that abolished suspected bronchoconstriction during general anesthesia in a patient undergoing beta-adrenergic blocker therapy for hypertension and who was subsequently diagnosed postoperatively as having bronchial asthma. A 54-year-old man who had childhood asthma was scheduled for laparoscopic cholecystectomy at our institution. The preanesthetic interview suggested full resolution of his childhood asthma. His capnogram showed an airway obstructive pattern immediately after the initiation of mechanical ventilation. However, after administration of ephedrine due to low blood pressure during surgery, his obstructive capnogram reverted to normal. On postoperative day 3, he was diagnosed as having bronchial asthma. Furthermore, we found that small airway obstruction as indicated in his preoperative pulmonary function test (PFT) had been overlooked. Two important points arise from this case. First, the use of beta-blockers for the treatment of hypertension in patients potentially having obstructive lung disease should be avoided. Second, clinicians should carefully check the preoperative PFT results in detail to ensure that nothing has been overlooked.