Comparisons of the vertical one-handed chest compressions according to the rescuer's handedness.

OBJECTIVE: The vertical one-handed chest compression (OHCC) technique has demonstrated superior compression power and chest compression depth (CCD) compared to conventional OHCC. This study aimed to determine if a rescuer's handedness influences the CCD during the vertical OHCC. METHODS: This prospective randomized crossover simulation trial included 59 medical doctors. Each performed a 2-min single-rescuer cardiopulmonary resuscitation (CPR) on a pediatric manikin using the vertical OHCC, once with the dominant hand (Test 1) and once with the non-dominant hand (Test 2). CPR parameters were recorded in real-time via sensors in the manikin, and the compression force exerted by each hand was measured using a force plate. RESULTS: The mean and adequate CCD did not differ significantly between Test 1 and 2 (mean depth: 52 mm (interquartile range [IQR]: 49-57) in Test 1 vs. 52 mm (IQR: 49-57) in Test 2, P = 0.625; adequate depth: 97% (IQR: 37-100) in Test 1 vs. 92% (IQR: 51-99) in Test 2, P = 0.619). The mean compression force was significantly greater in the dominant hand compared to the non-dominant hand (23.1 kg ± 4.9 in dominant hand vs. 21.7 kg ± 4.1 in non-dominant hand, P < 0.001). Other parameters showed no significant differences between Tests 1 and 2. CONCLUSIONS: While vertical OHCC with a dominant hand generated greater force, the rescuer's handedness did not affect the CCD during the vertical OHCC.

Purification and Molecular Docking Study on the Angiotensin I-Converting Enzyme (ACE)-Inhibitory Peptide Isolated from Hydrolysates of the Deep-Sea Mussel Gigantidas vrijenhoeki.

The objective of this study was to prepare an angiotensin I-converting enzyme (ACE)-inhibitory peptide from the hydrothermal vent mussel, Gigantidas vrijenhoeki. The G. vrijenhoeki protein was hydrolyzed by various hydrolytic enzymes. The peptic hydrolysate exhibited the highest ACE-inhibitory activity and was fractionated into four molecular weight ranges by ultrafiltration. The <1 kDa fraction exhibited the highest ACE inhibitory activity and was found to have 11 peptide sequences. Among the analyzed peptides, KLLWNGKM exhibited stronger ACE inhibitory activity and an IC50 value of 0.007 µM. To investigate the ACE-inhibitory activity of the analyzed peptides, a molecular docking study was performed. KLLWNGKM exhibited the highest binding energy (-1317.01 kcal/mol), which was mainly attributed to the formation of hydrogen bonds with the ACE active pockets, zinc-binding motif, and zinc ion. These results indicate that G. vrijenhoeki-derived peptides can serve as nutritional and pharmacological candidates for controlling blood pressure.

Effects of vertical compression during pediatric cardiopulmonary resuscitation using the one-handed chest compression technique.

OBJECTIVE: The posture of the rescuer while performing the one-handed chest compression (OHCC) has not yet been evaluated. This study aimed to investigate the effect of vertical compression during pediatric cardiopulmonary resuscitation (CPR) using the OHCC technique. METHODS: This was a prospective randomized crossover simulation trial. A total of 42 medical doctors conducted a 2-min single-rescuer CPR using the conventional OHCC (Test 1) or vertical OHCC (Test 2) technique on a pediatric manikin. The chest compression and ventilation parameters were measured in real time during the experiments using sensors embedded in the manikin. In addition, the compression force of each technique was measured using a force plate. RESULTS: The average and adequate chest compression depth (CCD) were significantly higher in Test 2 than in Test 1 (average depth: 54.0 mm (interquartile range [IQR]: 48.5-56.0) in Test 2 vs. 49.0 mm (IQR: 40.0-54.0) in Test 1, P < 0.001; adequate depth: 99.0% (IQR: 36.3-100.0) in Test 2 vs. 52.0% (IQR: 0.0-98.0) in Test 1, P < 0.001). The average force of compression was also significantly higher in vertical OHCC than that in conventional OHCC (25.7 kg ± 4.4 in vertical OHCC vs. 24.5 kg ± 4.2 in conventional OHCC, P < 0.001). The ventilation parameters were not significantly different between Tests 1 and 2. CONCLUSIONS: The vertical OHCC could provide a deeper and more adequate CCD compared with the conventional OHCC, and the advantages of the vertical OHCC originate from the superiority of the compression force.

Effects of resuscitation guideline terminology on pediatric cardiopulmonary resuscitation.

OBJECTIVE: This study aimed to investigate the effect of resuscitation guideline terminology on pediatric cardiopulmonary resuscitation (CPR) performance. METHODS: This was a prospective randomised crossover simulation trial. A total of 32 medical doctors conducted 2-min single-rescuer CPR using the one-handed chest compression technique (OHCC) or two-handed chest compression technique (THCC) on a pediatric manikin. The participants conducted chest compressions according to the chest compression depth (CCD) target of '5 cm (Test 1)' or 'at least one third of the anterior-posterior dimension of the chest (Test 2)' in a random order. RESULTS: In both techniques (OHCC or THCC), the average CCD of Test 1 were significantly lower than those of Test 2 (OHCC: 50.0 mm [46.0-52.0 mm] in Test 1 vs. 52.0 mm [50.3-55.0 mm] in Test 2, P = 0.001; THCC: 52.0 mm [50.3-55.0 mm] in Test 1 vs. 58.0 mm [54.0-62.0 mm] in Test 2, P < 0.001). The adequacy of the chest compressions was also superior in Test 2 (OHCC: 63.0% [7.5-95.8%] in Test 1 vs. 96.5% [78.8-99.9%] in Test 2, P < 0.001; THCC: 96.5% [78.8-99.9%] in Test 1 vs. 100.0% [100.0-100.0%] in Test 2, P < 0.001). Ventilation parameters were not significantly different between Tests 1 and 2. CONCLUSIONS: Average CCD during simulated pediatric CPR according to the CCD target of '5 cm' was significantly lower than those according to the CCD target of 'at least one third of the anterior-posterior dimension of the chest'.

Renal replacement therapy is independently associated with a lower risk of death in patients with severe acute kidney injury treated with targeted temperature management after out-of-hospital cardiac arrest.

BACKGROUND: The effect of renal replacement therapy (RRT) on the outcomes of severe acute kidney injury (AKI) after out-of-hospital cardiac arrest (OHCA) is uncertain. This study aimed to evaluate the association of RRT with 6-month mortality in patients with severe AKI treated with targeted temperature management (TTM) after OHCA. METHODS: This was a retrospective analysis of a prospectively collected multicentre observational cohort study that included adult OHCA patients treated with TTM across 22 hospitals in South Korea between October 2015 and December 2018. AKI was diagnosed using the Kidney Disease: Improving Global Outcomes criteria. The primary outcome was 6-month mortality and the secondary outcome was cerebral performance category (CPC) at 6 months. Multivariate Cox regression analysis was performed to define the role of RRT in stage 3 AKI. RESULTS: Among 10,426 patients with OHCA, 1373 were treated with TTM. After excluding those who died within 48 h of return of spontaneous circulation (ROSC) and those with pre-arrest chronic kidney disease, our study cohort comprised 1063 patients. AKI developed in 590 (55.5%) patients and 223 (21.0%) had stage 3 AKI. Among them, 115 (51.6%) were treated with RRT. The most common treatment modality among RRT patients was continuous renal replacement therapy (111 [96.5%]), followed by intermittent haemodialysis (4 [3.5%]). The distributions of CPC (1-5) at 6 months for the non-RRT vs. the RRT group were 3/108 (2.8%) vs. 12/115 (10.4%) for CPC 1, 0/108 (0.0%) vs. 1/115 (0.9%) for CPC 2, 1/108 (0.9%) vs. 3/115 (2.6%) for CPC 3, 6/108 (5.6%) vs. 6/115 (5.2%) for CPC 4, and 98/108 (90.7%) vs. 93/115 (80.9%) for CPC 5, respectively (P = 0.01). The RRT group had significantly lower 6-month mortality than the non-RRT group (93/115 [81%] vs. 98/108 [91%], P = 0.04). Multivariate Cox regression analyses showed that RRT was independently associated with a lower risk of death in patients with stage 3 AKI (hazard ratio, 0.569 [95% confidence interval, 0.377-0.857, P = 0.01]). CONCLUSION: Dialysis interventions were independently associated with a lower risk of death in patients with stage 3 AKI treated with TTM after OHCA.

Clinical Guidance for Point-of-Care Ultrasound in the Emergency and Critical Care Areas after Implementing Insurance Coverage in Korea.

Point-of-care ultrasound (POCUS) is a useful tool that is widely used in the emergency and intensive care areas. In Korea, insurance coverage of ultrasound examination has been gradually expanding in accordance with measures to enhance Korean National Insurance Coverage since 2017 to 2021, and which will continue until 2021. Full coverage of health insurance for POCUS in the emergency and critical care areas was implemented in July 2019. The National Health Insurance Act classified POCUS as a single or multiple-targeted ultrasound examination (STU vs. MTU). STU scans are conducted of one organ at a time, while MTU includes scanning of multiple organs simultaneously to determine each clinical situation. POCUS can be performed even if a diagnostic ultrasound examination is conducted, based on the physician's decision. However, the Health Insurance Review and Assessment Service plans to monitor the prescription status of whether the POCUS and diagnostic ultrasound examinations are prescribed simultaneously and repeatedly. Additionally, MTU is allowed only in cases of trauma, cardiac arrest, shock, chest pain, and dyspnea and should be performed by a qualified physician. Although physicians should scan all parts of the chest, heart, and abdomen when they prescribe MTU, they are not required to record all findings in the medical record. Therefore, appropriate prescription, application, and recording of POCUS are needed to enhance the quality of patient care and avoid unnecessary cut of medical budget spending. The present article provides background and clinical guidance for POCUS based on the implementation of full health insurance coverage for POCUS that began in July 2019 in Korea.

Recovery from acute kidney injury as a potent predictor of survival and good neurological outcome at discharge after out-of-hospital cardiac arrest.

BACKGROUND: Acute kidney injury (AKI) after out-of-hospital cardiac arrest (OHCA) is a well-known predictor for mortality. However, the natural course of AKI including recovery rate after OHCA is uncertain. This study investigated the clinical course of AKI after OHCA and determined whether recovery from AKI impacted the outcomes of OHCA. METHODS: This retrospective multicentre cohort study included adult OHCA patients treated with targeted temperature management (TTM) between January 2016 and December 2017. AKI was diagnosed using the Kidney Disease: Improving Global Outcomes criteria. The primary outcome was the recovery rate after AKI and its association with survival and good neurological outcome at discharge. RESULTS: A total of 3697 OHCA patients from six hospitals were screened and 275 were finally included. AKI developed in 175/275 (64%) patients and 69/175 (39%) patients recovered from AKI. In most cases, AKI developed within three days of return of spontaneous circulation [155/175 (89%), median time to AKI development 1 (1-2) day] and patients recovered within seven days of return of spontaneous circulation [59/69 (86%), median time to AKI recovery 3 (2-7) days]. Duration of AKI was significantly longer in the AKI non-recovery group than in the AKI recovery group [5 (2-9) vs. 1 (1-5) days; P < 0.001]. Most patients were diagnosed with AKI stage 1 initially [120/175 (69%)]. However, the number of stage 3 AKI patients increased from 30/175 (17%) to 77/175 (44%) after the initial diagnosis of AKI. The rate of survival discharge was significantly higher in the AKI recovery group than in the AKI non-recovery group [45/69 (65%) vs. 17/106 (16%); P < 0.001]. Recovery from AKI was a potent predictor of survival and good neurological outcome at discharge in the multivariate analysis (adjusted odds ratio, 8.308; 95% confidence interval, 3.120-22.123; P < 0.001 and adjusted odds ratio, 36.822; 95% confidence interval, 4.097-330.926; P = 0.001). CONCLUSIONS: In our cohort of adult OHCA patients treated with TTM (n = 275), the recovery rate from AKI after OHCA was 39%, and recovery from AKI was a potent predictor of survival and good neurological outcome at discharge.

Effect of metronome guidance on infant cardiopulmonary resuscitation.

This study was conducted to investigate the effect of metronome guidance on the performance of infant cardiopulmonary resuscitation (CPR). A total of 36 medical doctors conducted a 2-min single rescuer CPR with the two-finger technique (TFT) or two-thumb encircling hands technique (TT) on an infant manikin without metronome guidance (baseline test). After completing the baseline test, the participants were assigned to either a "guidance group" or "non-guidance group." The guidance group performed CPR with a high-pitched sound at 110 beats/min from a metronome (test 2), while the non-guidance group performed 2-min CPR without metronome guidance (test 1). Comparison between the results of tests 1 and 2 showed that the ratio of adequate chest compression rate was significantly different in both the TFT (73% [34-93] vs. 98% [95-99], P < 0.001) and the TT (53% [32-79] vs. 99% [98-100], P = 0.010). Other parameters including average depth and the ratio of adequate depth were not significantly different between tests 1 and 2 in both the TFT and TT.Conclusion: Metronome guidance improves the adequacy of chest compression rate during infant CPR without affecting chest compression depth in both the TFT and TT.Trial registration: Clinical Research Information Service, KCT0002735 What is Known: • The rate of chest compressions can be optimized by the use of metronome guidance in pediatric cardiopulmonary resuscitation (CPR). • An adverse effect of deteriorating chest compression depth was found while using a metronome guidance during adult CPR simulations. What is New: • The metronome guidance improved the adequacy of the chest compression rate during infant CPR without affecting other parameters including average depth and the ratio of adequate depth in both the two-finger chest compression technique and two-thumb encircling hand technique.

Comparison between modified and conventional one-handed chest compression techniques for child cardiopulmonary resuscitation: A randomised, non-blind, cross-over simulation trial.

AIM: Chest compression depth (CCD) decreases significantly when performing one-handed chest compression (OHCC). We modified OHCC posture to increase CCD as follows: first, the axis of the compression hand was adjusted to the compression area; second, the opposite hand was wrapped around the elbow of the compression arm. This study compared modified OHCC with conventional OHCC for child cardiopulmonary resuscitation. METHODS: A total of 46 health-care providers performed 2 min of continuous chest compression using conventional OHCC (trial 1) and modified OHCC (trial 2) in a random order on a 5-year-old-sized child manikin lying on a bed. Chest compression parameters were assessed with an accelerometer and analysed by comparing the mean values of 30-s segments. RESULTS: The average CCD decreased significantly in all segments in both trials (trial 1 (segments 1-4): 40.9 ± 5.6 mm, 39.4 ± 6.6 mm, 38.0 ± 6.9 mm, 36.7 ± 7.3 mm, P < 0.001; trial 2 (segments 1-4): 42.3 ± 5.4 mm, 41.2 ± 6.2 mm, 40.1 ± 6.8 mm, 39.0 ± 6.9 mm, P < 0.001). However, the average CCD in trial 2 was significantly greater in all segments than that in trial 1 (segments 1-4: P = 0.016; P = 0.009; P = 0.004; P = 0.001). The average chest compression rates were comparable in all segments in both trials. CONCLUSION: By modifying OHCC posture, a deeper mean CCD could be maintained for 2 min than by using conventional OHCC.

Development and Evaluation of a New Chest Compression Technique for Cardiopulmonary Resuscitation in Infants.

We designed the newly developed flexed two-finger chest compression technique for cardiopulmonary resuscitation (CPR) in infants to increase the quality of chest compression by considering the advantages and disadvantages of the two-thumb encircling hand technique and conventional two-finger technique. The aim of the study is to compare the performance of the flexed two-finger technique and the currently used two-thumb technique or two-finger technique for infant CPR. A total of 42 doctors conducted 2-min single-rescuer CPR on a cardiac arrest infant model using the two-thumb technique followed, in a random order, by the two-finger technique and the flexed two-finger technique. Although the ratio of the adequate compression depth was highest in the two-thumb technique, followed by the flexed two-finger technique and two-finger technique (100% [98-100] vs. 99% [80-100] vs. 76% [42-95], respectively, P < 0.001), the hand-off time of the two-thumb technique was significantly longer than in the two-finger technique and flexed two-finger technique (31 s [28-35] vs. 29 s [27-32] vs. 29 s [26-32], respectively, P < 0.001). The number of total chest compressions of the two-thumb technique was significantly lower than in the two-finger technique and flexed two-finger technique (150 [148-159] vs. 159 [149-173] vs. 162 [150-172], respectively, P < 0.001). The newly developed chest compression technique could provide adequate compression depth without increasing the hand-off time during single-rescuer infant CPR.Trial registration: Clinical Research Information Service, KCT0002730.

Relationship between chest compression depth and novice rescuer body weight during cardiopulmonary resuscitation.

OBJECTIVE: This study determined if rescuer body weight is a major determinant of chest compression depth (CCD) among novice rescuers by analyzing the results of cardiopulmonary resuscitation (CPR) skill tests among medical students and determined the body weight threshold for those unable to achieve adequate CCD. METHODS: Retrospective analysis of CPR test results was performed. A total of 107 medical students completed the tests, which included 5 cycles of CPR. Data were collected using a ResusciAnne SkillReporter. Anthropometric data including participant body weight, body mass index, and height were also collected. The relationships between CCD and anthropometric data were evaluated by Pearson correlation coefficient. In addition, univariate linear regression analysis was used to assess the association between body weight and CCD. RESULTS: The highest positive correlation was found between CCD and body weight (r = 0.636, P < .001). Body weight correlated with CCD by as much as 40.5% (R2 = 40.5, P < .001). Using a regression model, we described the association between body weight and CCD as follows: expected CCD (mm) = 0.46 × body weight + 17.59. The regression equation shows that rescuers weighing more than 70.5 kg could achieve a CCD of 50 mm. CONCLUSIONS: Rescuer body weight is a major determinant of CCD in novice rescuers. Based on these findings, if 2 or more rescuers are available to perform CPR, chest compression should preferentially be performed by rescuers of healthy weight or overweight.

Which Fingers Should We Perform Two-Finger Chest Compression Technique with When Performing Cardiopulmonary Resuscitation on an Infant in Cardiac Arrest?

This study compared the effectiveness two-finger chest compression technique (TFCC) performed using the right vs. left hand and the index-middle vs. middle-ring fingers. Four different finger/hand combinations were tested randomly in 30 healthcare providers performing TFCC (Test 1: the right index-middle fingers; Test 2: the left index-middle fingers; Test 3: the right middle-ring fingers; Test 4: the left middle-ring fingers) using two cross-over trials. The "patient" was a 3-month-old-infant-sized manikin. Each experiment consisted of cardiopulmonary resuscitation (CPR) consisting of 2 minutes of 30:2 compression: ventilation performed by one rescuer on a manikin lying on the floor as if in cardiac arrest. Ventilations were performed using the mouth-to-mouth method. Compression and ventilation data were collected during the tests. The mean compression depth (MCD) was significantly greater in TFCC performed with the index-middle fingers than with the middle-ring fingers regardless of the hand (95% confidence intervals; right hand: 37.8-40.2 vs. 35.2-38.6 mm, P = 0.002; left hand: 36.9-39.2 vs. 35.5-38.1 mm, P = 0.003). A deeper MCD was achieved with the index-middle fingers of the right versus the left hand (P = 0.004). The ratio of sufficiently deep compressions showed the same patterns. There were no significant differences in the other data. The best performance of TFCC in simulated 30:2 compression: ventilation CPR performed by one rescuer on an infant in cardiac arrest lying on the floor was obtained using the index-middle fingers of the right hand. Clinical Trial Registry at the Clinical Research Information Service (KCT0001515).

Does accelerometer feedback on high-quality chest compression improve survival rate? An in-hospital cardiac arrest simulation.

OBJECTIVE: We investigated whether visual feedback from an accelerometer device facilitated high-quality chest compressions during an in-hospital cardiac arrest simulation using a manikin. METHODS: Thirty health care providers participated in an in-hospital cardiac arrest simulation with 1 minute of continuous chest compressions. Chest compressions were performed on a manikin lying on a bed according to visual feedback from an accelerometer feedback device. The manikin and accelerometer recorded chest compression data simultaneously. The simulated patient was deemed to have survived when the chest compression data satisfied all of the preset high-quality chest compression criteria (depth ≥51 mm, rate >100 per minute, and ≥95% full recoil). Survival rates were calculated from the feedback device and manikin data. RESULTS: The survival rate according to the feedback device data was 80%; however, the manikin data indicated a significantly lower survival rate (46.7%; P = .015). The difference between the accelerometer and manikin survival rates was not significant for participants with a body mass index greater than or equal to 20 kg/m(2) (93.3 vs 73.3%, respectively; P = .330); however, the difference in survival rate was significant in participants with body mass index less than 20 kg/m(2) (66.7 vs 20.0%, respectively; P = .025). CONCLUSIONS: The use of accelerometer feedback devices to facilitate high-quality chest compression may not be appropriate for lightweight rescuers because of the potential for compression depth overestimation. TRIAL REGISTRATION: Clinical Research Information Service (KCT0001449).

One-handed chest compression technique for paediatric cardiopulmonary resuscitation: dominant versus non-dominant hand.

BACKGROUND: Pediatric resuscitation guidelines do not specify which hand to use for one-handed cardiopulmonary resuscitation (CPR). OBJECTIVE: To determine whether there is a difference in the quality of one-handed chest compressions (OHCCs) using the dominant versus non-dominant hand in simulated paediatric CPR. MATERIALS AND METHODS: 41 doctors took part in the study. Chest compressions were alternately performed with the dominant (test 1) and non-dominant hand (test 2) in a random order at 30 min intervals. Experiments were carried out with a 5-year-old paediatric manikin without ventilation for 2 min. Data on average compression rate (per min) and average compression depth (mm) were collected and compared. RESULTS: No significant differences were found in the average compression rate (118.0±14.3/min vs 117.3±14.5/min, p=0.610) and average compression depth (41.3±5.6mm vs 41.9±4.1mm, p=0.327) between tests 1 and 2. CONCLUSIONS: No significant difference was found in the quality of OHCCs using the dominant and non-dominant hand in simulated paediatric CPR. The study suggests there is no need for paediatric resuscitation guidelines to state a preferred hand for performing OHCC.

Comparison of chest compressions in the standing position beside a bed at knee level and the kneeling position: a non-randomised, single-blind, cross-over trial.

BACKGROUND: When rescuers perform cardiopulmonary resuscitation (CPR) from a standing position, the height at which chest compressions are carried out is raised. OBJECTIVE: To determine whether chest compressions delivered on a bed adjusted to rescuer's knee height are as effective as those delivered on the floor. MATERIALS AND METHODS: A total of 20 fourth-year medical students participated in the study. The students performed chest compressions for 2 min each on a manikin lying on the floor (test 1) and on a manikin lying on a bed (test 2). The average compression rate (ACR) and the average compression depth (ACD) were compared between the two tests. RESULTS: The ACR was not significantly different between tests 1 and 2 (120.1 to 132.9  vs 115.7 to 131.2 numbers/min, 95% CI, p=0.324). The ACD was also not significantly different between tests 1 and 2 (51.2 to 56.6 vs 49.4 to 55.7 mm, 95% CI, p=0.058). CONCLUSIONS: The results suggest that there may be no significant differences in compression rate and depth between CPR performed on manikins placed on the floor and those placed at a rescuer's knee height.

New genus of the family Laophontidae T. Scott, 1905 (Copepoda, Harpacticoida) from Hupo on the eastern coast of Korea.

Background: The Laophontidae is a very large and diverse family containing more than 320 species and 74 genera in the Harpacticoida. According to records published until recently, 25 species of 12 genera of Laophontidae were reported to appear in Korean waters. The most common laophontid species in Korean waters is Paralaophontecongenera (Sars, 1908). During research on the meiobenthic community in the subtidal zone near the Korean coast in the East Sea, we found an undescribed genus of the Laophontidae family. The character traits of this undescribed specimen of the Laophontidae family do not match any existing genus. New information: Herein, a new genus of the interstitial marine benthic copepods family Laophontidae T. Scott, 1905 is described from the subtidal zone near Hupo Harbour on the east coast of Korea. This genus was named Strictlaophonte gen. nov. and has been classified into the family Laophontidae. This was based on the presence of seven segmented female antennules, reduced antennary exopod, first endopodal segments having no inner setae from the second leg to the fourth leg and P5 with a distinct exopod that is not fused at the basis. The distinguishing features of Strictlaophonte gen. nov. are P5 exopod having only four setae, the P1 exopod having two segments and the antenna exopod having four setae. In particular, this new genus has unique characteristics in that the caudal rami are very tightly attached to each other.