**2. Methods**

#### *2.1. Data Sources*

The search strategy aimed to find published studies in MEDLINE, CINAHL, Cochrane Central, and EMBASE from December 2019 through March 2020 (Figure 1). The keywords used were: *COVID-19*, *coronavirus 2019*, *ICU surge capacity*, *nursing surge capacity*, and *strategies*. The filters applied included "humans", "last 10 years", and "English language". The unpublished studies were searched in ProQuest and MEDNAR.

**Figure 1.** Literature searching and recommendations' development framework.

#### *2.2. Quality Assessment of Extracted Data*

Initially, all titles and abstracts were screened independently by at least two reviewers. All full texts of the studies which passed through the initial stage were retrieved and assessed against the review inclusion criteria in detail. These eligible studies were again appraised by at least two reviewers independently using the Joanna Briggs Institute JBI Critical Appraisal Tools [15]. The JBI appraisal has different checklists to be applied against different study designs. The instrument consists of 10 items that assess the methodological quality of a study and determines the extent to which a study has addressed the possibility of bias in its design, conduct, and analysis. The results of the JBI appraisal have been taken into full account and used to inform the synthesis and interpretation of the results of the recommendations (Figure 1).

A total of 220 studies were retrieved. After reading the titles and abstracts, 150 studies were excluded. After reading the full articles, a total of 53 articles were excluded and 17 articles were included which met the inclusion criteria (Figure 2). All identified publications were collated and fed into Endnote X10 software. The evidence-based strategies issued are to support critical care nurses to manage critical patients in the intensive care unit during the COVID-19 pandemic. Four recommendations and rationales were issued by the expert panel based on evidence.
