[Usefulness of ultrasound pre-scanning for cricothyroid membrane puncture in a patient with rupture of a pseudoaneurysm].

A 63-year-old man with von Recklinghausen disease was transported to the emergency department for swelling and pain of his right neck. Chest X-ray and computed tomography scan showed displacement of the trachea to the left by a tumor mass. Urgent airway management was required and fiberoptic intubation in awake condition was planned. First we pre-scanned cricothyroid membrane by ultrasound in a case of emergency. Regardless of several trials, his trachea could not be secured by fiberscope because of narrow pharyngeal space. Suddenly, his consciousness level and Sp(O2) went down, therefore surgical airway was required. Due to pre-scanning, emergency cricothyroid membrane puncture could be performed immediately without any complications. We recommend ultrasound pre-scanning for cricothyroid membrane puncture in a patient with suspected tracheal displacement.

The impact of relative hypotension on acute kidney injury progression after cardiac surgery: a multicenter retrospective cohort study.

BACKGROUND: Cardiac surgery is performed worldwide, and acute kidney injury (AKI) following cardiac surgery is a risk factor for mortality. However, the optimal blood pressure target to prevent AKI after cardiac surgery remains unclear. We aimed to investigate whether relative hypotension and other hemodynamic parameters after cardiac surgery are associated with subsequent AKI progression. METHODS: We retrospectively enrolled adult patients admitted to 14 intensive care units after elective cardiac surgery between January and December 2018. We defined mean perfusion pressure (MPP) as the difference between mean arterial pressure (MAP) and central venous pressure (CVP). The main exposure variables were time-weighted-average MPP-deficit (i.e., the percentage difference between preoperative and postoperative MPP) and time spent with MPP-deficit > 20% within the first 24 h. We defined other pressure-related hemodynamic parameters during the initial 24 h as exploratory exposure variables. The primary outcome was AKI progression, defined as one or more AKI stages using Kidney Disease: Improving Global Outcomes' creatinine and urine output criteria between 24 and 72 h. We used multivariable logistic regression analyses to assess the association between the exposure variables and AKI progression. RESULTS: Among the 746 patients enrolled, the median time-weighted-average MPP-deficit was 20% [interquartile range (IQR): 10-27%], and the median duration with MPP-deficit > 20% was 12 h (IQR: 3-20 h). One-hundred-and-twenty patients (16.1%) experienced AKI progression. In the multivariable analyses, time-weighted-average MPP-deficit or time spent with MPP-deficit > 20% was not associated with AKI progression [odds ratio (OR): 1.01, 95% confidence interval (95% CI): 0.99-1.03]. Likewise, time spent with MPP-deficit > 20% was not associated with AKI progression (OR: 1.01, 95% CI 0.99-1.04). Among exploratory exposure variables, time-weighted-average CVP, time-weighted-average MPP, and time spent with MPP < 60 mmHg were associated with AKI progression (OR: 1.12, 95% CI 1.05-1.20; OR: 0.97, 95% CI 0.94-0.99; OR: 1.03, 95% CI 1.00-1.06, respectively). CONCLUSIONS: Although higher CVP and lower MPP were associated with AKI progression, relative hypotension was not associated with AKI progression in patients after cardiac surgery. However, these findings were based on exploratory investigation, and further studies for validating them are required. Trial Registration UMIN-CTR, https://www.umin.ac.jp/ctr/index-j.htm , UMIN000037074.

Airway scope versus macintosh laryngoscope in patients with simulated limitation of neck movements.

BACKGROUND: Tracheal intubation in patients with suspected neck injuries should achieve two contradicting goals-sufficient laryngeal exposure and the least cervical spine movement. Because the former involves displacements of the cervical vertebrae, intubation under immobilization is widely performed today to prevent exacerbation of spinal code injuries. The unique curving blade of the Airway Scope (AWS) is designed to fit the oropharyngeal anatomy. A camera at the tip of the blade displays the view of the larynx, but unlike the direct laryngoscope, it needs no line-of-sight of the oral, pharyngeal, and tracheal axis. Our purpose is to determine whether AWS could be a suitable airway device for the intubation of patients with potential neck injury. METHODS: Thirty-six patients scheduled for surgery were randomly assigned to undergo intubation using either AWS or Macintosh laryngoscope (MLS). After general anesthetic induction, the patient's head was set in a neutral position, and an appropriately sized semi-rigid neck collar was placed. Measurements include intubation time, number of attempts, success rate, Cormack-Lehane classification, airway optimization maneuver, Intubation Difficulty Scale scores, and complications. RESULTS: Intubation time proved no statistical significance (mean ± SD, AWS, 62.9 seconds ± 26.0 seconds, MLS, 55.6 seconds ± 26.0 seconds; p = 0.42). AWS scored less in Cormack-Lehane classification (median [range], AWS I [I-I], MLS IIIa [I-IIIb]; p < 0.0001), required fewer additional airway optimization maneuvers (p = 0.0003), and scored less in Intubation Difficulty Scale scores (AWS 0 [0-1], MLS 2 [0-5]; p < 0.0001). CONCLUSIONS: In neck-immobilized patients using semi-rigid cervical collars, AWS improves laryngeal exposure and facilitates tracheal intubation. AWS may be a suitable intubation device for trauma patients.

Behavior of Anesthesiology Residents in a Situation of Intravenous Route Occlusion During Syringe Pump Use in a Simulated Intensive Care Unit.

INTRODUCTION: Unintentional catecholamine flush caused by inappropriate release of an intravenous occlusion during use of a syringe pump in the intensive care unit (ICU) can have dangerous consequences in patients receiving critical care. We investigated whether anesthesiology residents understood how to deal with syringe pump occlusion in a simulated ICU setting. METHODS: We set up a mannequin that virtually simulated a sedated patient under mechanical ventilation after cardiac surgery, with epinephrine and dopamine being infused by syringe pumps to maintain blood pressure at 100/50 mm Hg. Prior to a participant entering the simulated ICU, one of the stopcocks for the catecholamine was occluded. Thereafter, the blood pressure of the mannequin dropped to 60/30 mm Hg. If the participant inappropriately released the occlusion, resulting in a catecholamine flush, an operator immediately elevated the blood pressure to 200/100 mm Hg. In the subsequent debriefing session, the simulation facilitator evaluated whether the participant could diagnose that intravenous occlusion was the cause of hypotension in this scenario. RESULTS: Sixteen anesthesiology residents participated in the study. Only 3 of 10 participants who had previous knowledge of how such situations should be handled could appropriately release back pressure. Eleven residents released the occlusion without relieving syringe pressure. After their debriefing sessions, all the participants were of the opinion that the present simulation training was impressive and useful for them. CONCLUSIONS: Anesthesiology residents might inappropriately handle a situation of intravenous occlusion in their clinical practice. It may be necessary for the manufacturers to improve the safety features of syringe pumps.

Bumetanide, an Inhibitor of NKCC1 (Na-K-2Cl Cotransporter Isoform 1), Enhances Propofol-Induced Loss of Righting Reflex but Not Its Immobilizing Actions in Neonatal Rats.

Gamma-aminobutyric acid (GABA) has been shown to induce excitation on immature neurons due to increased expression of Na+-K+-2Cl- co-transporter isoform 1 (NKCC1), and the transition of GABAergic signaling from excitatory to inhibitory occurs before birth in the rat spinal cord and spreads rostrally according to the developmental changes in cation-chloride co-transporter expression. We previously showed that midazolam activates the hippocampal CA3 area and induces less sedation in neonatal rats compared with adolescent rats in an NKCC1-dependent manner. In the present study, we tested the hypothesis that propofol-induced loss of righting reflex (LORR) but not immobilizing actions are modulated by NKCC1-dependent mechanisms and reduced in neonatal rats compared with adolescent rats. We estimated neuronal activity in the cortex, hippocampus and thalamus after propofol administration with or without bumetanide, an NKCC1 inhibitor, by immunostaining of phosphorylated cyclic adenosine monophosphate-response element binding protein (pCREB). We studied effects of bumetanide on propofol-induced LORR and immobilizing actions in postnatal day 7 and 28 (P7 and P28) rats. The pCREB expression in the cortex (P = 0.001) and hippocampus (P = 0.01) was significantly greater in the rats receiving propofol only than in the rats receiving propofol plus bumetanide at P 7. Propofol-induced LORR or immobilizing effects did not differ significantly between P7 and P28. Bumetanide significantly enhanced propofol-induced LORR (P = 0.031) but not immobilization in P7 rats. These results are partially consistent with our hypothesis. They suggest that propofol may activate the rostral but not caudal central nervous system dependently on NKCC1, and these differential actions may underlie the different properties of sedative and immobilizing actions observed in neonatal rats.

Amount of accidental flush by syringe pump due to inappropriate release of occluded intravenous line.

BACKGROUND: An unintended bolus is delivered by the syringe pump if intravenous line occlusion is released in an inappropriate manner. OBJECTIVE: The aim of this study was to measure the amount of flushed fluid when an occlusion is inappropriately released and to assess the effect of different syringe pump settings (flow rate, alarm setting, size of syringe and syringe pump model) on the flushed amount. METHODS: After the stopcock was closed, infusions were started with different model syringe pumps (Terufusion® TE312 and TE332S), different syringe sizes or at different alarm settings. After the occlusion alarm sounded, the occlusion was released and the amount of fluid emerging from the stopcock was measured. RESULTS: The bolus was significantly lower when the alarm was set at a low-pressure setting. The bolus was significantly lower with a 10-ml than a 50-ml syringe. A significant difference was seen only when a 50-ml syringe was used (TE312: 1.99 ± 0.16 ml vs. TE332S: 0.674 ± 0.116 ml, alarm High, p < 0.001). CONCLUSION: To minimize the amount of accidentally injected medication, a smaller syringe size and a low alarm setting are important. Using a syringe pump capable of reducing the inadvertently administered bolus may be helpful.