Effects of wearing surgical masks on fraction of inspired oxygen in spontaneously breathing patients: improving safety for frontline healthcare professionals under pandemic situations.

BACKGROUND: During pandemic situations, many guidelines recommend that surgical masks be worn by both healthcare professionals and infected patients in healthcare settings. The purpose of this study was to clarify the levels and changes of oxygen concentration over time while oxygen was administered over a surgical mask. METHODS: Patients scheduled to undergo general anesthesia (n = 99) were enrolled in this study. First, patients were administered oxygen at 6 L/min via an oxygen mask over a surgical mask for 5 min. The patients removed the surgical mask and then took a 3-min break; thereafter, the same amount of oxygen was administered for another 5 min via the oxygen mask. We measured the fraction of inspired oxygen (FiO2), the end-tidal CO2 (EtCO2), and respiratory frequency every minute for 5 min, both while administering oxygen with and without a surgical mask. The FiO2 was measured at the beginning of inspiration and the EtCO2 was measured at the end of expiration. RESULTS: The FiO2 at 5 min was significantly lower when breathing with a surgical mask than that without it (mean difference: 0.08 [95% CI: 0.067-0.10]; p <  0.001). In contrast, the EtCO2 at 5 min was significantly higher when breathing with a surgical mask than that without it (mean difference: 11.9 mmHg [95% CI: 10.9-12.9]; p <  0.001). CONCLUSION: The FiO2 was lower when oxygen was administered over surgical masks than when patients did not wear surgical masks. Oxygen flow may need to be adjusted in moderately ill patients requiring oxygen administration.

Temporal changes in peripheral regional oxygen saturation associated with return of spontaneous circulation after out-of-hospital cardiac arrest: A prospective observational cohort study in Japan.

AIM: Temporal changes in cerebral regional oxygen saturation (crSO2) are useful for predicting return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients. However, little is known regarding the usefulness of peripheral regional oxygen saturation (prSO2) associated with OHCA patient outcomes. This study evaluated the association between temporal changes in prSO2 and ROSC in patients with OHCA. METHODS: This was a prospective study at two tertiary emergency centres in Japan. We evaluated the relationship between ROSC and temporal changes in crSO2 and prSO2. The rSO2 sensor was attached to the patient's forehead and upper arm, and rSO2 was continuously measured until resuscitative efforts were terminated or until the patient with sustained ROSC (>20 min) arrived at the emergency department. RESULTS: We included 145 patients with OHCA, of whom 35 achieved ROSC. Witness status (odds ratio [95% confidence interval]: 11.6 [3.13-58.1]) and ΔprSO2 (1.13 [1.06-1.24]) were significantly associated with ROSC in multiple logistic analysis. In the ROSC group, ΔprSO2 increased earlier than ΔcrSO2 during cardiopulmonary resuscitation. In the non-ROSC group, there was no significant difference between ΔcrSO2 and ΔprSO2, and neither increased before termination of resuscitation (TOR). CONCLUSION: We demonstrated for the first time that prSO2 is associated with ROSC in OHCA patients and showed that temporal changes in prSO2 could predict ROSC earlier than those in crSO2. Our findings could provide time to prepare early interventions after ROSC and assist in determining the TOR for OHCA patients in Japan. Further studies are needed to validate these findings.

Extracting Safety-II Factors From an Incident Reporting System by Text Analysis.

Introduction The use of electric health records (EHRs) has spread worldwide and has helped record huge amounts of data. However, despite accumulated data from EHRs, especially text data, the information has been underutilized. Our research questions and aims are as follows: How can an incident report system extract common themes behind incidents, good practices, improved quality, and safety based on the Safety-II/resilient healthcare approach? Methods We extracted data from the electronic incident reporting system of the Yokohama City University Medical Center between April 1, 2016 and March 31, 2018. We utilized natural language processing and text mining to extract concept categories and word patterns. We also used the incident levels as outcomes, as well as classification and regression tree analysis to obtain associated text combinations. Results A total of 17,231 cases were reported through the electronic incident reporting system in our hospital during the study period. Hospital staff has to be prepared for incidents with complex mechanisms in daily practice. The hospital staff tend to focus on individual actions rather than considering a systematic approach. Conclusion Certain combinations of professions and contents may contribute to resilient management. Studies on Safety-II management utilizing clinical information and text records are needed.

A simulation study of high-flow versus normal-flow three-way stopcock for rapid fluid administration in emergency situations: A randomised crossover design.

BACKGROUND: Initial fluid resuscitation is presumed to be important for treating shock in the resuscitation phase. However, little is known how quickly and easily a physician could perform a rapid infusion with a syringe. OBJECTIVES: We hypothesised that using a high-flow three-way stopcock (HTS) makes initial fluid resuscitation faster and easier than using a normal-flow three-way stopcock (NTS). METHODS: This was a simulation study with a prospective, nonblinded randomised crossover design. Twenty physicians were randomly assigned into two groups. Each participant used six peripheral intravenous infusion circuits, three with the HTS and the others with the NTS, and three cannulae, 22, 20, and 18 gauge (G). The first group started with the HTS first, while the other started with the NTS first. They were asked to inject the fluid as quick as possible. We compared the time until the participants finished rapid infusions of 500 ml of 0.9% saline and the practitioner's effort. RESULTS: In infusion circuits attached with the 22G cannula, the mean difference using the HTS and the NTS (95% confidence interval [CI]) was 16.30 ml/min (7.65-24.94) (p < 0.01). In those attached with the 20G cannula, the mean difference (95% CI) was 23.47 (12.43-34.51) (p < 0.01). In those attached with the 18G cannula, the mean difference (95% CI) was 42.53 (28.68-56.38) (p < 0.01). CONCLUSIONS: This study revealed that the push-and-pull technique using the HTS was faster, easier, and less tiresome than using the NTS, with a statistically significant difference. In the resuscitation phase, initial and faster infusion is important. If only a single physician or other staff member such as a nurse is attending or does not have accessibility to any other devices in such an environment where medical resources are scarce, performing the push-and-pull technique using the HTS could help a physician to perform fluid resuscitation faster. By setting up the HTS instead of the NTS from the beginning, we would be able to begin fluid resuscitation immediately while preparing other devices.

Two cases with intra-aortic balloon pumping use for severe septic cardiomyopathy.

Cases: Septic cardiomyopathy is defined as a reversible left ventricular systolic dysfunction. Patients with severe septic cardiomyopathy have a high mortality rate, even if they receive conventional therapy. For those patients, previous reports showed intra-aortic balloon pump (IABP) efficacy. We report two rare cases with IABP introduction leading them to drastic improvement, and survival from severe septic cardiomyopathy. Case 1 is a 78-year-old woman diagnosed with renal calculus pyelonephritis, septic shock, and septic cardiomyopathy. Case 2 is a 62-year-old man diagnosed with pneumonia, septic shock, and septic cardiomyopathy. Outcome: In both cases, despite conventional therapy for cardiomyopathy, including high-dose catecholamine therapy, shock was not reversed, and the IABP was inserted. Circulatory status was improved after the introduction of the IABP. Conclusion: Our findings suggest that an IABP can be useful for salvaging patients with septic cardiomyopathy who do not respond to conventional therapy.

Low tidal volume ventilation with low PEEP during surgery may induce lung inflammation.

BACKGROUND: Compared to conventional tidal volume ventilation, low tidal-volume ventilation reduces mortality in cased of acute respiratory distress syndrome. The aim of the present study is to determine whether low tidal-volume ventilation reduces the production of inflammatory mediators in the lungs and improves physiological status during hepatic surgery. METHODS: We randomly assigned patients undergoing hepatectomy into 2 groups: conventional tidal-volume vs. low tidal-volume (12 vs. 6 mL•kg(-1) ideal body weight) ventilation with a positive end-expiratory pressure of 3 cm H2O. Arterial blood and airway epithelial lining fluid were sampled immediately after intubation and every 3 h thereafter. RESULTS: Twenty-five patients were analyzed. No significant changes were found in hemodynamics or acid-base status during the study. Interleukin-8 was significantly elevated in epithelial lining fluid from the low tidal-volume group. Oxygenation evaluated immediately after admission to the post-surgical care unit was significantly worse in the low tidal-volume group. CONCLUSIONS: Low tidal-volume ventilation with low positive end-expiratory pressure may lead to pulmonary inflammation during major surgery such as hepatectomy. TRIAL REGISTRATION: The effect of ventilatory tidal volume on lung injury during hepatectomy that requires transient liver blood flow interruption. UMIN000021371 (03/07/2016); retrospectively registered.

[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.

Usability and performance of a wearable tele-echography robot for focused assessment of trauma using sonography.

Focused Assessment with Sonography for Trauma (FAST) is widely used as a first lifesaving step for patients suffering from internal bleeding. Because it may take a long time to transport such patients to a hospital, a wearable and portable tele-echography robot that a paramedic can attach to the patient has been developed. In the current study, experiments were conducted to evaluate the usability and performance of attached FAST. The proposed robot must be attached to 4 areas to perform FAST. The time required for attachment and the positions of attachment completed by 9 non-medical staff members, as well as the time it took for the FAST to reach a medical doctor, were measured. The echo images obtained when the patient's body was in motion were evaluated by a medical doctor. The robot could be attached to all 4 areas within approximately 5min, and the maximum gap was 4.8cm. This indicates that a paramedic who has received training in emergency medical care should be able to attach the robot to a patient quickly and accurately. Additionally, it was confirmed that the robot could be used to complete FAST under a doctor's control within 9min and that the extracted echo images were suitable for FAST. A comparison of the results with current ambulance transportation time confirmed that FAST could be completed approximately 14min before the patient reached the hospital. The results of the current study indicate that the robot is worth using, is suitable for FAST, and will be effective in emergency medical care.

Airway scope laryngoscopy under manual inline stabilization and cervical collar immobilization: a crossover in vivo cinefluoroscopic study.

BACKGROUND: Direct laryngoscopy along with manual inline stabilization (MIS) is currently the standard care for patients with suspected neck injuries. However, cervical collar immobilization is more commonly performed in the prehospital environment, and its early removal is necessary before intubation. We hypothesized that if usability of Airway Scope (AWS) in a difficult airway could also bring merits to intubation under cervical collar immobilization, unnecessary risk caused by the removal of a neck collar may be prevented. METHODS: In this crossover study, 30 consenting patients presenting for surgery were assigned to undergo intubation using AWS. Neck was stabilized manually and by a neck collar in a random order before laryngoscopy was performed by the same anesthesiologist. Measurements include interincisor distance (IID), success rate, intubation time, and fluoroscopic examination of the upper and middle cervical spine. RESULTS: IID was notably narrower after application of a neck collar (mean ± SE: MIS, 19 mm ± 1 mm; collar, 10 mm ± 1 mm; p < 0.01). One and 9 failures were encountered in MIS and collar groups, respectively (p = 0.012). Intubation time proved no statistical significance. Extension of craniocervical junction was observed in both groups, but occipitoatlantal joint was significantly more extended in collar group (median [range]: AWS, 10-degree angle [-1 to 20-degree angle]; collar, 14-degree angle [5 to 26-degree angle]; p < 0.01). DISCUSSION: AWS laryngoscopy under cervical collar immobilization fails to meet our expectation. Intubation failed in 30% of the cases in collar group whereas only 3.3% of the cases in MIS group. Significant difference of mouth opening limitation is probably the major reason, as 7 of 9 failed cases in collar group had IID <10 mm. This was insufficient to insert the 18-mm blade of AWS. In addition, occipitoatlantal joint suffered a greater extension when wearing a neck collar. Differences in the method to stabilize the neck may be the reason. CONCLUSION: When compared with cervical collar immobilization, AWS laryngoscopy along with MIS seems to be a safer and more definite method to secure airway of neck-injured trauma patients because it limits less mouth opening and upper cervical spine movement.

Tracheal intubation using Airway Scope in two patients with difficult airway during cardiopulmonary resuscitation.

The Airway Scope AWS-S100 (AWS, Pentax, Tokyo), a rigid video laryngoscope with integrated tube guidance that has recently become commercially available, helped the authors to establish airways in two patients with in-hospital cardiopulmonary arrest, after failed attempts to intubate the patients using the Macintosh laryngoscope (that only commanded the Cormack-Lehane grade 4 glottic views), the laryngeal mask airway, and even surgical cricothyroidotomy for the second case. This showed the utility of the AWS in the management of difficult airway cases even in emergency settings.

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.

High tidal volume ventilation induces lung injury after hepatic ischemia-reperfusion.

Ischemia-reperfusion not only damages the affected organ but also leads to remote organ injuries. Hepatic inflow interruption usually occurs during hepatic surgery. To investigate the influence of liver ischemia-reperfusion on lung injury and to determine the contribution of tidal volume settings on liver ischemia-reperfusion-induced lung injury, we studied anesthetized and mechanically ventilated rats in which the hepatic inflow was transiently interrupted twice for 15 min. Two tidal volumes, 6 ml/kg as a low tidal volume (IR-LT) and 24 ml/kg as a high tidal volume (IR-HT), were assessed after liver ischemia-reperfusion, as well as after a sham operation, 6 ml/kg (NC-LT) and 24 ml/kg (NC-HT). Both the IR-HT and IR-LT groups had a gradual decline in the systemic blood pressure and a significant increase in plasma TNF-alpha concentrations. Of the four groups, only the IR-HT group developed lung injury, as assessed by an increase in the lung wet-to-dry weight ratio, the presence of significant histopathological changes, such as perivascular edema and intravascular leukocyte aggregation, and an increase in the bronchoalveolar lavage fluid TNF-alpha concentration. Furthermore, only in the IR-HT group was airway pressure increased significantly during the 6-h reperfusion period. These findings suggest that liver ischemia-reperfusion caused systemic inflammation and that lung injury is triggered when high tidal volume ventilation follows liver ischemia-reperfusion.

An analysis of spoken language expression during simulated emergency call triage.

OBJECTIVES: Volunteer citizens were recruited to perform simulated emergency calls, and the expressions and content of these telephone calls were analysed to examine risk factors associated with the success or failure of communication. SUBJECTS AND METHODS: Six physicians played the role of patients who had various symptoms, such as cerebral stroke and ischaemic heart disease. Eighty-four volunteer citizens made simulated emergency calls. Physicians at a simulated call centre communicated with each caller regarding the patient's body position, respiratory condition, and cardiovascular status. Details of the telephone communications were analysed to determine if communication was successful. RESULTS: Telephone communications that resulted in the correct understanding of a simulated patient's condition were as follows: 60.2% of sessions (32/50) on whether or not a patient was breathing; 47.8% of sessions (22/46) on whether or not a patient had a pulse (carotid or radial artery); and 86.2% of sessions (56/65) on patient body position. How a simulated dispatcher verbally expressed questions was the most influential factor in the success of communication regarding respiratory condition and body position. Avoiding vague language, giving specific instructions for checking a patient, and finally reminding the caller to perform the explained procedures led to a high rate of successful communications. Various spoken expressions by simulated dispatchers in confirming patient pulse did not have any impact on the success or failure of communications. CONCLUSION: In developing a 'protocol for emergency call triage' to achieve a high rate of successful emergency communications, an analysis of expressions using simulated patients is useful.

Effect of lung-protective ventilation on severe Pseudomonas aeruginosa pneumonia and sepsis in rats.

Pneumonia caused by Pseudomonas aeruginosa carries a high rate of morbidity and mortality. A lung-protective strategy using low tidal volume (V(T)) ventilation for acute lung injury improves patient outcomes. The goal of this study was to determine whether low V(T) ventilation has similar utility in severe P. aeruginosa infection. A cytotoxic P. aeruginosa strain, PA103, was instilled into the left lung of rats anesthetized with pentobarbital. The lung-protective effect of low V(T) (6 ml/kg) with or without high positive end-expiratory pressure (PEEP, 10 or 3 cmH(2)O) was then compared with high V(T) with low PEEP ventilation (V(T) 12 ml/kg, PEEP 3 cmH(2)O). Severe lung injury and septic shock was induced. Although ventilatory mode had little effect on the involved lung or septic physiology, injury to noninvolved regions was attenuated by low V(T) ventilation as indicated by the wet-to-dry weight ratio (W/D; 6.13 +/- 0.78 vs. 3.78 +/- 0.26, respectively) and confirmed by histopathological examinations. High PEEP did not yield a significant protective effect (W/D, 4.03 +/- 0.32) but, rather, caused overdistension of noninvolved lungs. Bronchoalveolar lavage revealed higher concentrations of TNF-alpha in the fluid of noninvolved lung undergoing high V(T) ventilation compared with those animals receiving low V(T). We conclude that low V(T) ventilation is protective in noninvolved regions and that the application of high PEEP attenuated the beneficial effects of low V(T) ventilation, at least short term. Furthermore, low V(T) ventilation cannot protect the involved lung, and high PEEP did not significantly alter lung injury over a short time course.