Emergency Laparotomies and Outcomes During the COVID-19 Pandemic - a Retrospective Cohort Study
Conditions: COVID-19, Emergency General Surgery
Sponsor: Barking, Havering and Redbridge University Hospitals NHS Trust

Document date – 04/06/20 
NCT number – 133196  
IRAS number – 285260  
 
Study Title 
 
Peri-Operative Neutrophil:Lymphocyte Ratio (NLR) as a Predictor of Outcomes 
Following Emergency General Surgery During the COVID-19 Pandemic 
 
Study Design 
 
Observational study 
 
Anticipated Start Date 
 
25/05/2020 
 
Sources of Funding 
 
NIL 
 
Conflict of Interest 
 
NIL 
 
Ethical Approval 
 
The UK National Research Ethics Service decision tool1 confirmed this study 
does not require ethical approval. It has been registered locally within our 
hospital trust Research and Development team. 
 
Sponsorship and Governance 
 
An Integrated Research Application System (IRAS) form was completed 
(registration number 285260) and copies of the protocol submitted to Barking, 
Havering and Redbridge University NHST Trust (BHRUT) for sponsorship review 
and for Health Research Authority (HRA) approval. The protocol was 
subsequently submitted to clinicaltrials.gov (NCT number 133196) for 
registration. 
 
Participants/Study Population 
 
All adult patients (>17 years) undergoing emergency (general) surgery at a 
single centre (Queens Hospital, Romford, UK) regardless of COVID-19 status will 
be included. Patients will be organised into those with: 
 
a) suspected or confirmed COVID-19 (diagnosed clinically, radiologically or with 
positive viral PCR); and  
b) those for whom COVID-19 was not suspected.  

 
Diagnosis or suspicion of COVID-19 must be made between 7-days before and 
30-days after date of surgery in accordance with the COVIDsurg study criteria2. 
 
Planned Study Period 
 
Data will be collected on all patients meeting criteria undergoing emergency 
surgery on or after the date of UK lockdown due to COVID-19 (23th March 2020) 
until 22nd May 2020. If sample size is small then the end date for data collection 
will be extended. 
 
Study Questions 
 
1) Is NLR a predictor of negative outcomes in patients undergoing 
emergency general surgery? 
2) Is NLR different in COVID positive versus COVID negative patients 
undergoing emergency general surgery? 
 
Primary Outcome 
 
30-day mortality 
 
Secondary Outcomes 
 
7-day mortality 
Reoperation 
Length of stay 
Post-operative respiratory failure 
Post-operative ARDS 
Post-operative sepsis 
ITU/HDU admission 
 
Data Collection 
 
Data will be collected using a data extraction template. This will be piloted on 5 
included patients and refined as appropriate. Data will be collected from 
electronic sources including (but not limited to) BlueSpier, EPRO, Cyberlab and 
Medway. Data will include baseline patient characteristics, operation performed, 
COVID status and diagnostic method, NLR (pre-operative/day 0 (D0), D1, D2 and 
D3) and the aforementioned outcome measures.  Data will be collected for 30-
days following on from the date of surgery. 
 
Data Synthesis  
 
For dichotomous outcome measures Relative Risk (RR) will be calculated and 
significance testing completing using Chi-Squared or Fisher’s exact test 
depending on sample sizes. For continuous variables standardised mean 
difference (SMD) will be calculated and unpaired, two-tailed student’s t-tests 
used for significance testing. 

 
References 
 
1  Do I need NHS Ethics approval? http://www.hra-decisiontools.org.uk/ethics/ 
(accessed 22 May2020). 
2  Nganwa A. CovidSurg Cohort Study. Globalsurg. 
https://globalsurg.org/covidsurgcohortstudy/ (accessed 22 May2020).