Published by Advance Educational Institute and Research Centre International Journal of Endorsing HEALTH SCIENCE RESEARCH Original Article The effect of reduced tidal volume on post percutaneous nephrolithotomy pulmonary complications: A retrospective case control study. Fakhir Yousuf 1 , Salman el Khalid 1 , Abdul Wasay Mahmood 1 , Zafar Iqbal 1 , Zehra Kazmi 2 , Waqar Hassan 1 , Shakeel Haseeb Uddin Siddique 1 & Mujeeb Ahmed Khan 1 1 The Kidney Centre, Post Graduate Training Institute, Karachi-Pakistan. 2 The Aga Khan University Hospital, Karachi-Pakistan. Abstract Background: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for large or complex renal stones. The upper pole (supra-costal access) is associated with pulmonary and cardiac complications post- operatively, owing to its proximity to the diaphragm. The prone position also causes restricted chest expansion and decreased pulmonary compliance. In this study, we aim to evaluate pulmonary complications after percutaneous nephrolithotomy by reducing the tidal volume intra-operatively and to assess the appropriate tidal volume for patients undergoing PCNL. Methodology: A retrospective chart review was performed over a period of one year (2019-2020). All patients who underwent PCNL and fulfilled the inclusion criteria were included in the study. They were divided into two groups: low tidal volume (Cases), and normal tidal volume (Controls). The records were evaluated for any pulmonary complications post-operatively, and this was compared between the two groups. Results: A total of 114 patients were included in the study. When patients with low tidal volume were compared to patients with normal tidal volume, no significant difference in pulmonary complications was observed (p-value < 0.05). Conclusion: There was no significant difference between the two groups, in terms of post-PCNL pulmonary complications, with respect to the tidal volume. Further multicenter studies can better elucidate these findings. Keywords Percutaneous Nephrolithomy, Supra-Costal Puncture, Pulmonary Complications, Risk Factors, Urolithiasis. Doi: 10.29052/IJEHSR.v9.i3.2021.296-301 Corresponding Author Email: YOUSUF58@hotmail.com Received 20/01/2021 Accepted 30/06/2021 First Published 01/09/2021 © The Author(s). 2021 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)