Jacob Chen

Dr. Jacob Chen

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2020 in eClinicalMedicine
Verified
Journal Article
Open access
YMYasmin Maor
Yasmin Maor
DCDaniel Cohen
Daniel Cohen
NPNir Paran
Nir Paran
TITomer Israely
Tomer Israely
VEVered Ezra
Vered Ezra
JCJacob Chen
Jacob Chen
We assessed outcome of patients with moderate and severe COVID-19 following treatment with convalescent plasma (CP) and the association with IgG levels in transfused CP. A prospective cohort study. Primary outcome was improvement at day 14 defined as alive, not on mechanical ventilation, and moderate, mild, or recovered from COVID-19. Antibody levels in CP units were unknown at the time of treatment. IgG against the spike protein S1 was subsequently measured by ELISA. Neutralizing antibodies titers were determined in a subset. Outcome was assessed in relation to the mean antibody level transfused to the patients (≤4.0 versus >4.0). Of 49 patients, 11 (22.4%) had moderate, 38 (77.6%) had severe disease, 28 were ventilated. At day 14, 24 (49.0%) patients improved, 9 (18.4%) died, and 13 (26.5%) were ventilated. In 14/98 (14.3%) CP units IgG was < 1.1 (cutoff calibration) and in 60 (61.2%) ≤4.0. IgG level and neutralizing antibody titer were correlated (0.85 p < 0.001). In patients receiving ≤4.0 antibody levels, 11/30 improved (36.7%) versus 13/19 (68.4%) in patients receiving >4.0 odds ratio (OR) 0.267 [95% confidence interval (CI) 0.079–0.905], P = 0.030. In patients diagnosed >10 days prior to treatment, 4/14 (22.4%) improved in the ≤4.0 antibody group, versus 6/7 (85.7%) in the >4.0 antibody group, OR 0.048 (95% CI, 0.004–0.520), P = 0.007. No serious adverse events were reported. Treatment with CP with higher levels of IgG against S1 may benefit patients with moderate and severe COVID-19. IgG against S1 level in CP predicts neutralization antibodies titers.

Verified
Journal Article
Open access
PDF file
Moran AmitMoran Amit
Moran Amit
ASAlex Sorkin
Alex Sorkin
JCJacob Chen
Jacob Chen
BCBarak Cohen
Barak Cohen
DKDana Karol
Dana Karol
ABAvi Benov
Avi Benov
Knowledge of the outcomes of critically ill patients is crucial for health and government officials who are planning how to address local outbreaks. The factors associated with outcomes of critically ill patients with coronavirus disease 2019 (Covid-19) who required treatment in an intensive care unit (ICU) are yet to be determined. Methods: This was a retrospective registry-based case series of patients with laboratory-confirmed SARS-CoV-2 who were referred for ICU admission and treated in the ICUs of the 13 participating centers in Israel between 5 March and 27 April 2020. Demographic and clinical data including clinical management were collected and subjected to a multivariable analysis; primary outcome was mortality. Results: This study included 156 patients (median age = 72 years (range = 22–97 years)); 69% (108 of 156) were male. Eighty-nine percent (139 of 156) of patients had at least one comorbidity. One hundred three patients (66%) required invasive mechanical ventilation. As of 8 May 2020, the median length of stay in the ICU was 10 days (range = 0–37 days). The overall mortality rate was 56%; a multivariable regression model revealed that increasing age (OR = 1.08 for each year of age, 95%CI = 1.03–1.13), the presence of sepsis (OR = 1.08 for each year of age, 95%CI = 1.03–1.13), and a shorter ICU stay(OR = 0.90 for each day, 95% CI = 0.84–0.96) were independent prognostic factors. Conclusions: In our case series, we found lower mortality rates than those in exhausted health systems. The results of our multivariable model suggest that further evaluation is needed of antiviral and antibacterial agents in the treatment of sepsis and secondary infection.

1 February 2017 in Shock
Verified
Journal Article
Closed access
PDF file
JCJacob Chen
Jacob Chen
XWXiaowu Wu
Xiaowu Wu
JKJeffrey Keesee
Jeffrey Keesee
BLBin Liu
Bin Liu
DDDaniel N. Darlington
Daniel N. Darlington
ACAndrew P. Cap
Andrew P. Cap
We have recently shown that human whole blood stored at 4°C maintains hemostatic and platelet function. In this study, we compared restoration of hemodynamic, metabolic and hemostatic function after limited resuscitation with rat fresh whole blood, rat stored whole blood, or Lactated Ringers in traumatized rats. Rat whole blood was stored for 10 days at 4°C for evaluation of hemostatic function. Polytrauma was performed on isoflurane-anesthetized Sprague–Dawley rats (350–450 g) by damage to the intestines, liver, right leg skeletal muscle, and right femur fracture, followed by 40% hemorrhage. At 1 h, rats were resuscitated (20%) with either fresh whole blood (FWB), stored whole blood, 4°C for 7 days (SWB), Lactated Ringers (LR), or nothing. Blood samples were taken before and 2 h after trauma and hemorrhage to evaluate metabolic and hemostatic function. Whole blood stored for 10 days showed a significant prolongation in prothrombin time (PT) and activated partial thromboplastin time (aPTT), and fall in fibrinogen concentration, but no change in Maximum Clot Firmness or speed of clot formation. Platelet function was maintained until day 7 in storage, than fell significantly. Polytrauma and hemorrhage in rats led to a fall in arterial pressure, plasma bicarbonate, fibrinogen, and platelet function, and a rise in plasma lactate, PT, aPTT, and creatinine. Resuscitation with either FWB or 7 day SWB, but not LR, returned arterial pressure, plasma lactate and plasma bicarbonate to levels similar to control, but had no effect on the fall in fibrinogen or platelet function, or the rise in PT, aPTT, or creatinine. Hemostatic and platelet function of rat whole blood stored at 4°C is preserved for at least 7 days in vitro. Low volume resuscitation with SWB or FWB, but not LR, restores hemodynamic and metabolic function, but not the coagulopathy after severe trauma and hemorrhage.

1 June 2020 in Transfusion
Verified
Journal Article
Open access
PDF file
RNRoy Nadler
Roy Nadler
ATAvishai M Tsur
Avishai M Tsur
MYMark H. Yazer
Mark H. Yazer
ESEilat Shinar
Eilat Shinar
TMTzadok Moshe
Tzadok Moshe
JCJacob Chen
Jacob Chen
BACKGROUND The Israeli Defense Force Medical Corps (IDF‐MC) recently implemented the use of low titer group O whole blood (LTOWB) in the airborne combat search and rescue unit (CSAR) for both military and civilian patients during transport to definitive care. LTOWB is preferentially used by the CSAR instead of red blood cell units and freeze‐dried plasma (FDP) for patients with signs of hemorrhagic shock. Ten percent of group O donors were eligible to donate LTOWB as they had anti‐A and ‐B IgM titers of <50. METHODS All patients treated by CSAR providers with LTOWB between July 2018 and June 2019 were included. RESULTS Between July 2018 and June 2019, eight patients have received 10 units of LTOWB. All patients suffered blunt injuries, 6 out of 8 (75%) of whom were due to motor vehicle accidents. Four patients (4 out of 8, 50%) received a single LTOWB unit, two patients (2 out of 8, 25%) received two units. Two pediatric patients received fewer than one unit of LTOWB. Median (range) heart rate was 130 (30‐150) bpm, median systolic blood pressure was 107 (80‐124) mmHg, and median Glasgow coma scale was 8 (on a scale of 3‐15). For four (4 out of 8, 50%) patients, LTOWB was the only blood product used for volume resuscitation. All six adult patients were treated with 1 g of tranexamic acid at the point of injury. CONCLUSIONS The CSAR has successfully implemented a LTOWB program for the pre‐hospital treatment of bleeding patients, and as its experience grows this product will be made available to other units and in civilian hospitals.

14 April 2020 in Journal of Trauma and Acute Care Surgery
Verified
Journal Article
Closed access
ATAvishai M Tsur
Avishai M Tsur
RNRoy Nadler
Roy Nadler
NTNir Tsur
Nir Tsur
ASAlex Sorkin
Alex Sorkin
TBTarif Bader
Tarif Bader
JCJacob Chen
Jacob Chen
BACKGROUND: The American College of Surgeons and the National Association of Emergency Medical Technicians advise securing a definitive airway if there is any doubt about the trauma patient's ability to maintain airway integrity. The objective of this study was to investigate the association between a success in securing a definitive airway in the prehospital setting and survival among trauma patients, in which the provider deemed a definitive airway was necessary. METHODS: The study included all trauma patients recorded in the Israel Defense Forces Trauma Registry between the years 2006 and 2018 for whom a prehospital attempt of securing a definitive airway was documented. The successful definitive airway group was defined by explicit documentation of success in either endotracheal intubation or cricothyrotomy. Logistic regression was performed to determine the association between success in securing a definitive airway and survival. RESULTS: A total of 566 (3.6%) trauma patients underwent attempts to secure a definitive airway (successful in 425 patients and unsuccessful in 141). Prehospital survival rates were similar (77.6% vs. 78.0%, p = 0.928) between the groups. Whether the definitive airway was successful did not affect the rates of prehospital survival, neither before (odds ratio, 0.98; 95% confidence interval, 0.61–1.54) nor after adjustment for the other factors (odds ratio, 0.91; 95% confidence interval, 0.55–1.46). CONCLUSION: This study was unable to find an association between a successful definitive airway in the prehospital setting and survival, even after adjustment for injury characteristics and in multiple models. Furthermore, survival rates were high among trauma patients in which the provider deemed a definitive airway as necessary yet failed in securing one. These results suggest that the liberal use of these invasive airway procedures in the prehospital setting should be reconsidered. LEVEL OF EVIDENCE: Retrospective study, lebel III.

12 November 2022 in Injury
Verified
Journal Article
Closed access
YRYuval Ran
Yuval Ran
IMIlan Y Mitchnik
Ilan Y Mitchnik
SGSami Gendler
Sami Gendler
GAGuy Avital
Guy Avital
IRIrina Radomislensky
Irina Radomislensky
JCJacob Chen
Jacob Chen