Effects of different sputum suction methods on intracranial pressure levels in patients with severe craniocerebral injury and mechanical ventilation

Objective To explore the effects of closed sputum suction, open-closed sputum suction and open sputum suction on intracranial pressure levels in patients with severe craniocerebral injury and mechanical ventilation when the head of bed elevated by 30°. Methods Totally 36 patients who were admitted in Beijing Tiantan Hospital, Capital Medical University from October 2016 to December 2017 and conformed to the inclusion and exclusion criteria were selected consecutively by convenient sampling. The patients received closed suction (CS) , open-closed suction (OCS) and closed suction (OS) as needed. The intracranial pressure (ICP) values shown on the intracranial pressure monitor were recorded at 2 min before, during and after suction as well as 5 min and 15 min after suction. Arterial blood was collected for blood gas analysis at 15 min before and after suction. The patients' partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) were also recorded. Results The patients intracranial pressure increased when the three different suction methods were used. ICP values for OS, OCS and CS were (20.02±4.93) , (16.00±4.82) and (16.08±4.42) mmHg, respectively (F=8.523, P 0.05) . There was no statistical difference in PaO2 and PaO2 values before and after suction using different methods (P>0.05) . Conclusions When the head of bed is elevated by 30°, OCS and CS show small effects on ICP values in patients with severe craniocerebral injury and mechanical ventilation and do not affect the effects of sputum suction. Key words: Craniocerebral injury; Intracranial pressure; Sputum suction; Mechnical ventilation; Closed suction; Open-closed suction; Open suction