Impaired eye protection mechanisms have been observed in patients admitted to the intensive care unit (ICU) with decreased level of consciousness, especially under mechanical ventilation. But eye health is maintained by eyelid function, tear secretion and prevention of corneal dryness [1, 2]. Tears help to moisturize and protect the eyes by having antimicrobial substances as well as frequent blinking [3]. As a result, in these patients, following the loss of the blinking reflex and keeping the eyes open, there is a possibility of dryness and tissue scarring. There is corneal epithelium and other superficial ocular disorders [1].
Another risk factor for superficial eye disorders (SED) in these patients is the use of muscle relaxants and sedatives that affect the eye muscles and lead to blink reflex disorder and complete closure of the eyes, resulting in faster evaporation of tears. Other drugs (antihistamines, atropine, etc.) and prolonged eye closure cause hypoxia, hypercapnia and slow repetition of blinks and dryness and damage to the eye, all due to reduced tear production [3]. It should be noted that in these patients, the use of ventilation with positive pressure and firm fixation of the endotracheal tube leads to increased venous pressure, followed by increased intraocular pressure and conjunctival edema and increases the chances of eye disease. On the other hand, patients admitted to the ICU often suffer from fluid imbalance, which increases capillary permeability leading to edema and eye damage [3]. Studies have shown that 60 % of patients who have endotracheal tubes in whom eyelids do not close completely are at risk for ocular complications [4].
Ocular complications that occur in patients admitted to the ICU range from a mild conjunctival infection to severe corneal injury such as corneal ulcers and even corneal perforation followed by permanent eye damage. Among these, the most ocular complications identified in the intensive care unit were contact keratopathy (3.5–60 %), chemosis (conjunctival swelling) (9 -80 %) and microbial keratitis [3]. Also, the prevalence of corneal ulcers in the ICU is estimated at 22–33 % [3, 5] and lagophthalmos occurs in 75 % of these patients, (there is no complete closure of the eye) [1].
Inpatient care in the ICU needs to support all body systems; however, in these patients, the greatest focus of nursing care is on life-threatening problems. As a result, this factor can reduce the attention of the health care team to other parts of the body, including the eyes [1, 4]. As in one study, eye care(EC) was not performed in 62 % of patients [4]. Due to the possibility of ocular complications in intensive care patients, the principles of EC are necessary and important. A review of studies shows that the same EC method does not exist in ICUs and there are differences in these methods. On the other hand, various methods are used in different centers for EC, but in most cases, their effects have not been studied [4]. One of the common EC methods in the ICU is rinsing the eyes with normal saline solution in patients with decreased level of consciousness, but various EC methods have been reported that can be used with eye ointments such as tetracycline, gentamicin, methyl cellulose, liposuction ointment, simple eye closure, use of polyethylene coating, use of swimming goggles, paraffin gas and artificial tear drops [4]. Different opinions have been reported about the effectiveness of these methods, so that in the method of closing the eyes, although it reduces epithelial changes, but there is a risk of eyelid damage and increased patient anxiety [6]. Or the use of eye ointments is more effective in reducing corneal abrasions than closing the eyes [7] and are more effective in reducing contact keratopathy than hydrogel dressings [8]. A review study also suggests the use of polyethylene coating as an effective method to prevent keratopathy in patients admitted to the ICU compared to other care [3] and also polyethylene coatings in the prevention of corneal abrasions are more effective than eye drops and ointments [7, 9].
Due to the importance of EC in the ICU, it is necessary for nurses to use accurate and evidence-based methods in EC for these patients [3, 5]. Despite the different methods of EC, ICU nurses need to have a proper evaluation of the performance and effectiveness of EC methods [4] .Therefore, the implementation of a comprehensive, complete and accurate care protocol can be one of the most effective methods of EC in the ICU. The aim of this study was to determine the effect of implementing an EC protocol on the incidence of SED in patients admitted to the ICU.
Methods
This study was a crossover clinical trial conducted in the ICU of Shahid Rahnemoun Hospital, Yazd, Iran. Inclusion criteria were: hospitalization in the ICU with a decrease in the maximum level of consciousness [8], corneal surface health in the initial examination, and required mechanical ventilation and sedation. Exclusion criteria were: patients with facial and ocular trauma that impede ocular care and history of ocular problems (ocular diseases, infections, trauma, chronic lagophthalmos, allergic eye diseases and use of ocular medications). Also, the criteria of blink reflex recovery, discharge or transfer from the ICU, death of the patient before this period, and the patient’s unwillingness to continue were considered as the criteria for attrition. Patients were selected by purposive sampling method and the sample size was determined with S1 = 2.2), s2 = 0.86,, 1-α = 95 %, (1-β = 80 % using the following formula and taking into account the attrition rate of 20 % of samples as 32 people in each group.
$$n=\frac{{\left({Z}_{1-\frac{\alpha }{2}}+{Z}_{1-\beta }\right)}^{2}\left({\delta }_{1}^{2}+{\delta }_{2}^{2}\right)}{{\left({\mu }_{1}-{\mu }_{2}\right)}^{2}}$$
Data collection tools included demographic data form (age, sex, level of education, reason for hospitalization, medical history) and clinical data form (diagnosis, Glasgow coma criterion, history of cardiac or renal disease, Richmond Agitation Sedation Scale, eyelid condition, mechanical ventilation, levels of ocular surface impairment, and duration of ventilation. Also data were collected by grading for eyelid position, conjunctival edema and corneal changes. All three criteria are standard and their validity and reliability have been confirmed [1, 10]. Demographic and clinical data were collected based on the patient’s record and the assessment of eyelid condition and superficial eye disorders and the severity of chemosis in the pre-study stages. They were observed and recorded by researchers in the second to seventh days of the study.
At the beginning of the study, two EC methods were taught to ICU nurses. Also, important points to be reminded were: compliance for suctioning lung secretions in relation with EC including tracheal suctioning on one side of the bed with eyes covered, eye covering during oral and open endotracheal suctioning for patients with respiratory infection and close endotracheal suctioning and suction catheter was not passed across the face. It should also be noted that if the patient’s eye was infected or blinked, the eye should not be covered (grade 1 eyelid condition, mild sedation with occasional blinking). Also they were taught the necessary measures to reduce or prevent conjunctival edema by raising the head of the bed and checking the stiffness of the airway fixator band. Then, during the initial examination with fluorescein staining and using ophthalmoscope blue light filter and corneal surface health confirmation, patients were included in the study according to the inclusion criteria. It should be noted that patients with fluorescein test were not included in the study. For this group of patients, ophthalmological consultation was requested to be treated. In order to perform the procedures, after giving the necessary explanations on how to conduct the study and its objectives and conditions, a written consent was obtained from the patient’s companion. Then, in patients for the right eye (control), routine care including rinsing the eyes with sterile gauze impregnated with normal saline was performed in each shift, and if the eye remained open, the patient’s eyelid was kept horizontally closed with anti-allergic adhesive. For their left eye (test), was performed based on the EC protocol at study of " Making a Difference in Eye Care of the Critically Ill Patients” [3] .
This study was registered in the clinical trial registration system on (13.11.2019) with registration number [IRCT20140307016870N5].Permission was obtained from the Ethics Committee of Shahid Sadoughi University of Medical Sciences .Also, written consent was obtained from the Patient guardian.
Data analysis was performed using SPSS16. Descriptive statistics used included absolute and relative frequency, mean, standard deviation and median. The inferential statistics used included Chi-square, Cochran and McNemar with 95 % confidence interval.
