To use critical thinking to identify patient safety concerns, you need to adopt a systematic and proactive approach that involves four steps: assessing the patient, environment, and situation; analyzing the data and information collected; acting on the analysis with interventions; and appraising the actions taken. During assessment, use your senses, clinical knowledge, and tools such as vital signs, lab tests, and assessment scales to observe and monitor the patient's condition. For analysis, use your reasoning, judgment, and critical thinking skills to identify patterns, trends, gaps, discrepancies, and potential problems. When acting on the analysis, plan and implement appropriate actions based on your findings with your decision-making, problem-solving, and clinical skills. Finally when appraising the actions taken review and reflect on the results achieved with your evaluation, feedback, and critical thinking skills to determine if further actions are needed.