Christopher Gast

Dr. Christopher Gast


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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10 May 2010 in Critical Care
Verified
Journal Article
Open access
PDF file
MKMarin H Kollef
Marin H Kollef
DNDilip Nathwani
Dilip Nathwani
SMSanjay Merchant
Sanjay Merchant
CGChristopher Gast
Christopher Gast
AQAlvaro Quintana
Alvaro Quintana
NKNzeera Ketter
Nzeera Ketter
Introduction: Ventilator-associated pneumonia (VAP) is associated with increased medical resource utilization, but few randomized studies have been conducted to evaluate the effect of initial antibiotic therapy. To assess medical resource utilization in patients with VAP, we conducted a pooled analysis of two prospective, randomized, open-label, multicenter, phase III studies, which also showed that doripenem was clinically noninferior to comparators. Methods: We assessed durations of mechanical ventilation, intensive care unit (ICU) stay, and hospitalization in patients with VAP who received at least 1 dose of doripenem or a comparator in the phase III studies. Comparators were piperacillin/tazobactam (study 1) and imipenem (study 2). We analyzed between-group differences in medical resource utilization endpoints by comparison of Kaplan-Meier curves with generalized Wilcoxon test and in microbiologic eradication rates by two-sided Fisher's exact test. Results: 625 patients with VAP were evaluated and received at least 1 dose of doripenem (n = 312) or a comparator (n = 313). Median durations of mechanical ventilation (7 versus 10 days; P = 0.008) and hospitalization (22 versus 26 days; P = 0.010) were shorter for doripenem than comparators; corresponding ICU stays were 12 and 13 days (P = 0.065). All-cause, overall mortality rates were similar (51/312 [16%] versus 47/313 [15%]; P = 0.648). MIC90 values against Pseudomonas aeruginosa for doripenem versus imipenem were 4 versus 16 μg/mL in study 2. P. aeruginosa was eradicated from 16/24 (67%) doripenem recipients and 10/24 (42%) comparator recipients (P = 0.147). In patients with P. aeruginosa at baseline, median durations of mechanical ventilation (7 versus 13 days; P = 0.031) and ICU stay (13 versus 21 days; P = 0.027) were shorter for doripenem; corresponding hospital stays were 24 and 35 days (P = 0.129). Conclusions: Doripenem was associated with lower medical resource utilization than comparators. Differences in antipseudomonal activity may have contributed to these findings. Trial registration: ClinicalTrials.gov number NCT00211003 (study 1) and NCT00211016 (study 2).

23 August 2024 in Vaccines
Verified
Journal Article
Open access
PDF file
LMLuis Rivera Mejía
Luis Rivera Mejía
LPLourdes Peña
Lourdes Peña
RRRicardo Walter Rüttimann
Ricardo Walter Rüttimann
CGChristopher Gast
Christopher Gast
ABAnanda S Bandyopadhyay
Ananda S Bandyopadhyay
In the context of polio eradication, novel oral polio vaccines for type 2 (nOPV2) were developed, and types 1 and 3 polioviruses are being developed. We aimed to generate trivalent oral poliovirus vaccine (tOPV) safety and immunogenicity data as a reference for comparing with novel OPV formulations. This was a single-center, open-label, phase 4 study in March 2016 in the Dominican Republic with healthy children previously vaccinated with ≥3 doses of tOPV receiving one dose of tOPV and vaccine-naïve infants receiving 3 doses of tOPV. Safety and immunogenicity were assessed. No serious adverse reactions or important medical reactions were reported. Seroconversion (SC) rates at Day 28 in children were 32.7%, 36.7%, and 46.9% for types 1, 2, and 3, respectively, and seroprotection (SP) rates 28 days after one dose increased from 89.8% at baseline to 93.9%, 98.0% to 100%, and 83.7% to 98.0% for types 1, 2, and 3, respectively. In infants, SC rates were 88.5%, 98.1%, and 96.2% for types 1, 2, and 3, respectively. SP rates at Day 84 were 93.3%, 100%, and 96.2% for types 1, 2, and 3, respectively. This information can be used as a reference to compare with novel monovalent or trivalent OPVs under development.