Cause analysis and prevention of exposure keratitis during general anesthesia

Wang Yongqin. Zhang Yong

(Operating Room, Tangxian People's Hospital, Tangxian, Hebei, 072350)

ABSTRACT: In general anesthesia patients, the eyelids can not be closed and corneas are easily damaged due to dryness. Exposed keratitis often occurs under the continuous and intense irradiation of shadowless lamp. The causes of exposure keratitis during general anesthesia were analyzed, and corresponding preventive measures were put forward to avoid the occurrence of exposure keratitis.

Key words: general anesthesia; exposure keratitis; causes; preventive measures

Chinese Library Classification Number: R473.76 Document Marking Code: A Article Number: 1674-490X (2012) 02-0056-02

Exposed keratitis refers to keratitis, which is caused by dry cornea, epithelial exfoliation and secondary infection, when the cornea loses the protection of eyelids and is exposed to the air. In severe cases, it can lead to corneal ulcer U. The specific manifestations are photophobia, tears, foreign body sensation and blurred vision, which bring a certain degree of pain to patients. Studies have shown that 70% of patients with general anesthesia can not completely close their eyelids. If appropriate preventive corneal protection measures are not taken, the incidence of exposure keratitis is as high as 40%-60%. Therefore, adequate attention should be paid to the prevention of intraoperative exposure keratitis.

1 Cause of occurrence

1.1 Incomplete eyelid closure

Incomplete eyelid closure is the main cause of exposure keratitis. The eyelids cannot be completely closed and the cornea loses its protective barrier.

It loses the physiological function of keeping eyes moist, leading to excessive tear evaporation, corneal dryness, epithelial cell damage mouth. During the operation, when the mask inhales oxygen, the flow of gas accelerates the evaporation of tear, leading to corneal dryness and vulnerability. Especially in some operations of head, face and neck, the continuous strong illumination of shadowless lamp and the heat it emits make the cornea dry when the eyelids are not closed properly, which is more likely to lead to the occurrence of exposure keratitis.

1.2 Muscle relaxation of anesthetics

The use of muscle relaxants during general anesthesia is another important cause of exposure keratitis. In the initial stage of general anesthesia, eyelids were closed well, but with the operation, the degree of anesthesia deepened and muscle relaxation was strengthened. Muscle relaxants could eliminate the normal closure of eyelids in some patients, and the cornea was completely or partially exposed, thus losing its normal protective effect. If the operation lasts a long time, it will cause exposure keratitis [4].

1.3 Mechanical Injury

In the process of spreading sterile sheet before operation, if the eye protection is not paid attention to, the eyelid closure is not complete, which can easily lead to the direct contact of sterile sheet with patent closure.

Closed eyelids lead to corneal damage. Many other operations often take the form of bald head, such as not protecting the eyes before the bald head, but also easy to operate.

Medium abrasion or bruise of cornea.

1.4 Use of Medical Bioglue

Biogels are alloproteins, which may cause adverse reactions such as allergies. Li Si's investigation of 14 patients with exposed keratitis after operation showed that L2 of 14 patients used the same type of medical bioglue. Therefore, caution should also be exercised in the selection and use of biogels.

1.5 Temperature and Humidity Control

During the operation, if the temperature is too high or the humidity is too low and the eyelids are not closed properly, the tear will evaporate excessively, which will cause a series of symptoms.

2 Preventive measures

2.1 Preoperative protection to ensure eyelid closure

After tracheal intubation by anesthesiologists, if the eyelids can not be closed, open the eyelids with the left index finger before disinfection, pull down the eyelids with the thumb, gently squeeze the lower eyelid conjunctiva with erythromycin eye ointment in the right hand. Put down the eyelid ointment, lift the lower eyelid with the right hand first, then loosen the upper eyelid with the left hand, cover the eyelid ointment, and then cover the sterile dressing to ensure the double eyelids. Complete closure. When applying, do not stick eyelashes and eyebrows, so as to avoid the pain caused by pulling eyebrows and eyelashes out when removing the film. After muscle relaxant withdrawal, the sterile dressing was removed before tracheal intubation, and then the ointment in the eyes of the patients was wiped off with normal saline gauze. For those with good eyelid closure at the initial stage of anesthesia, the same method should be used to make the patients'eyelids completely closed, so as to avoid cornea exposure with prolonged operation time.

2.2 Prevention of mechanical damage

During head and neck surgery, the operator should first adjust the position of the shadowless lamp after laying the aseptic sheet to reduce the strong light. Before laying the sheet, the patient's eyes should be protected and the eyes closed. If it is head surgery, before disinfection, use erythromycin eye ointment on both eyes, then paste sterile dressing on the eyelids to ensure the closure of the eyes, prevent the flow of disinfectant into the eyes, can significantly reduce the incidence of exposure keratitis; when spreading sterile sheets, gentle, avoid sterile single contact with the eyes of patients.

2.3 Careful use of bio-glue to control temperature and humidity

When using the bioglue, read the instructions carefully, fully understand its adverse reactions, patients with allergic constitution should be cautious to use, and pay attention to observation. During the operation, the temperature and humidity of the operating room should be controlled at 22 - 25 C and 40% - 60% respectively, which can effectively protect the eyes.

3 Summary

Exposure keratitis focuses on prevention, timely and effective eye protection after induction of anesthesia, close intraoperative observation and correct eye care, which can effectively reduce the occurrence of complications, thereby reducing the suffering of patients and improving the quality of care.

Reference:

[1] Yan Jiangqin