Optimal Management of the Conscious Patient Undergoing Intraocular Surgery*

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KEITH W. McNEER AND ARTHUR JAMPOLSKY

mary position, and no change in horizontal deviation in up-gaze. W e have had two cases of appropriately indicated unilateral tenotomy of the superior oblique, which was followed by a gradually increasing overaction of the superior oblique in the fellow previously normal eye. This observation bears an interesting relationship to a similar circumstance involving a unilateral overaction of the inferior oblique associated with an esodeviation, wherein a unilateral weakening of an overacting inferior oblique muscle occasionally results in a gradually increasing overaction of a previously normal fellow inferior oblique in the previously normal eye. CONCLUSION

T h e presence of a markedly overacting superior oblique muscle is a predictor of a satisfactory postoperative return of function of an underacting antagonist inferior oblique muscle. W h e n there is an indicated surgical weakening of the overacting superior oblique muscle, one may expect a return of function of the underacting inferior oblique muscle, as well as a satisfactory amelioration of the over-all incomitance and A-pattern. SUMMARY

1. Underaction of the inferior oblique muscle, when associated with a marked overaction of the antagonist superior oblique, is probably a consequence of the overacting superior oblique.

2. A weakening procedure of the overacting superior oblique (if not contraindicated) may be expected to result in a normalization of the inferior oblique vertical rotatory capability, with marked improvement of over-all comitance ( A - p a t t e r n ) . 3. Horizontal muscle surgery alone (for a horizontal deviation) ameliorates the underaction of the inferior oblique muscle, but does not significantly improve the over-all comitance ( A-pattern ) . 4. Inferior oblique underaction may be considered a consequence of the overacting antagonist superior oblique muscle (probably with a significant acquired component), if the superior oblique overaction is marked and an agonist-antagonist muscle relationship exists. O n e may expect a significant improvement in both the under and overacting muscles, with surgical alteration directed at weakening the overacting superior oblique muscle. This agonist-antagonist oblique muscle relationship is to be differentiated from Brown's superior oblique tendon sheath syndrome, wherein there is a marked underaction of the inferior oblique, with little or no superior oblique overaction. This anomaly (probably congential) probably involves a mechanical anomaly of the structures adjacent to the superior oblique tendon, and exhibits the positive forced duction test of the inferior oblique muscle (inability manually to rotate the globe up and i n ) . Clay and Webster Streets (15).

OPTIMAL MANAGEMENT OF T H E CONSCIOUS UNDERGOING INTRAOCULAR M A R T I N W. LIVINGSTON, York New

Today, as in the past, most intraocular surgery is done on a conscious patient following regional or local anesthesia. 1 This type of procedure is relatively atraumatic, * From the Anesthesia Department, New York Eye and Ear Infirmary.

PATIENT

SURGERY* M.D.

usually of short duration and, after adequate regional anesthesia, should be without pain to the patient. Intraocular surgery is delicate and must be precise. Hence, it is rather unique in that success to a great degree can be jeopardized

MANAGEMENT OF THE CONSCIOUS PATIENT

by a poor state of the patient. A quiet and relaxed subject is an absolute requirement for consistently successful intraocular surgery. Coughing, retching or certain movements at a critical time may preclude a successful operation and possibly result in blindness of the eye being operated upon. Nevertheless aside from the obtaining of medical clearance and the administration of a more or less routine dose of preoperative sedation, too little attention is usually paid to the general management and supervision of the patient during the operation. Although most procedures go well, many ophthalmologists are not fully satisfied with doing eye surgery on the conscious patient following regional or local anesthesia,1 and an increasingly large proportion of patients are given sleep-producing drugs for intraocular surgery. At the New York Eye and Ear Infirmary during the past 10 years the proportion of patients being given general anesthesia for intraocular surgery has increased from 5% to over 50%. What are some of the factors responsible for this change ? Although a patient is usually given a standard dose of barbiturate and narcotic to produce tranquility, one of three situations may ensue during surgery. Depending on when and how much medication was given, the patient may be relaxed and optimally sedated, he may be apprehensive and undersedated, or he may be sleeping and oversedated. The patient is then placed on the flat operating table by an orderly or nurse. There is usually little or no elevation of his head. The scrub nurse directs him to look up, drops a topical anesthetic in each eye, washes his face and paints it with an antiseptic. She then covers him from head to toe with the surgical drapes, the only exposed area being the eye to be operated upon, on which a spotlight is now focused. Some indefinite time later the surgeon enters the room, surveys his patient through the three-inch hole in the drape, admonishes him not to move and to remain quiet, and proceeds to operate.

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Under these circumstances, the surgeon can have but a minimum of insight into the patient's mental and physical state and is actually leaving to chance his patient's co-operation during surgery. Now let us consider the patient himself. He is generally over the age of 60 years, in the age group in which cardiopulmonary diseases, mental deterioration and kyphoscoliosis are most common and in which there is reduced tolerance to sedative drugs and to the systemic effects of regional anesthetics. Ordinarily, he may insist on elevating his head with two or more pillows. Now, at a time of stress, he may be compelled to lie flat. His head may be hyperextended or even dangling under the drapes. The drapes, pressed tightly against his nose and mouth by the towels which protect the operating area, force him to rebreath his own exhaled carbon dioxide. Hypernea and a decrease in the 20% concentration of oxygen normally available may contribute to his anxiety. The combination of oversedation and decreased oxygen availability may lead to myocardial or cerebral hypoxia. The patient and surgeon are fortunate if such an individual manifests his discomfort early in the procedure—chest pains, nausea, dyspnea, syncope or even hysteria—before the globe is opened. The conjunctivas can be hurriedly closed, the operation cancelled and the patient returned to his bed to await medical help. Fortunately these frightening symptoms do not occur often. But the consequences to patient and surgeon if the globe has already been opened are easily imagined. The influence of the awake patient on the course and outcome of intraocular surgery is largely ignored. A large proportion of complications may stem from the patient's reaction to surgery and the surgeon's reaction to the patient. Although an anesthesiologist experienced in ophthalmic surgery can safely provide optimal conditions by completely anesthetizing the patient, except for the rare individual with extreme apprehension, equally good conditions can be obtained

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in the awake patient if thought and care are given to his over-all management. The major factors involved in the management of the patient before and during surgery can be conveniently considered under six headings. 1. Health prior to surgery. The patient should be seen prior to hospitalization by his personal physician and undergo a general checkup to insure that he is in reasonable good health. If he is chronically ill, he should attain as satisfactory a state as possible by the time he enters the hospital. Such conditions as diabetes, hypertension, blood dyscrasias and congestive heart failure should be under control. Heavy drinking and smoking should be eliminated or reduced to a reasonable degree. Individuals with chronic pulmonary diseases, such as bronchitis and emphysema, should undergo prophylactic treatment before and during hospitalization. 2. Psychologic preparation of the patient, When an operation is contemplated, the patient should be told the nature of his illness and of the surgery. This will relieve his apprehension, which is a common reaction. He should have confidence in his surgeon. He should understand what to expect in the operating room. He should be told again just before surgery that the operation is relatively brief and essentially painless after a few needle pricks for the regional anesthesia. In addition, he should be made to understand that he is expected to lie quietly, without moving or coughing, and not to talk except in answer to questions or to report discomfort. 3. Medication before and during surgery. Drugs can play a major role in obviating the emotional stress and anxiety associated with surgery of the eye. They should exert their maximum effect just before and during the operation. Therefore, timing in administration is important. Oral medications are best given an hour before surgery and intramuscular medication at least 30 minutes before. There is no single standard dose of sedative medication. Narcotics, barbiturates and

tranquilizers are potent drugs, and the elderly persons, who comprise the largest group of those undergoing intraocular surgery, are especially sensitive to their effects. Premedication should be minimal. Even a moderate dose may prove excessive for some individuals. There is more danger in oversedation than undersedation. Medication can always be supplemented but, once given, cannot be taken away. The object is to obtain a sedated, conscious patient in whom cortical function is present. The sleeping, snoring or unresponsive patient may give the surgeon a false sense of security. Although a sleeping patient may seem ideal, all too often complications develop as a direct result of oversedation. The oropharyngeal relaxation which produces snoring may proceed to complete respiratory obstruction, and the patient may awake with a start. Depression of cortical function may cause an animal-like response to pain and discomfort, causing the patient to react with unreasonable objections ; he may squeeze, move or cry out. Remonstrations may have no effect and physical restraint may be required. The drugs most consistent and reliable in producing sedation are the short-acting barbiturates, such as secobarbital (Seconal) or pentobarbital (Nembutal). Their effect lasts for two to four hours. The dose for a 60year-old individual is 100 mg administered orally or intramuscularly one hour before surgery. This medication is combined with an ataractic-antiemetic of intermediate potency and a minimum of ganglionic blocking activity, such as prochlorperazine (Compazine) 10 mg, or promethazine (Phenergan) 25 mg, or hydroxyzine (Vistaril) 25 mg, given intramuscularly one hour preoperatively. Age and physical status will influence dosage. A 70-year-old patient may be given only one half to two thirds these amounts. Premedication with such narcotics as meperidine (Demerol) should be reserved for surgical procedures which, despite careful regional anesthesia, may be painful.2

MANAGEMENT OF THE CONSCIOUS PATIENT Most ophthalmic operations are pain free after topical lid and retrobulbar anesthesia. Narcotics cannot be relied upon to produce sedation or euphoria.3 A substantial proportion of individuals react with dysphoria (a state of discomfort). Nausea and hypotension are common side-effects. There are some types of ocular surgery which may be painful despite careful regional anesthesia. Muscle traction during squint correction or enucleation and manipulation of the iris in acute glaucoma or of the inflamed eye may be painful. Here administration of a painrelieving narcotic prior to and during surgery is indicated. Patients with a chronic cough should be given an antitussive, such as codeine, before being sent to the operating room. Dosage of the remainder of the sedative drugs should be reduced for these individuals. If a drug dosage is individualized and small amounts of sedatives are used, a depressed patient will rarely be a problem; however, more individuals will reach the operating room undersedated and their medication should be supplemented. How is this best done? If a supplementary drug is administered intramuscularly it may be 30 or more minutes before response is significant. When that time has passed, it may be found that the estimated dose of supplementary medication was precisely correct. More often, however, the amount given was too small or too large, and the patient will either continue to be undersedated or will become depressed. Therefore, intramuscular or subcutaneous supplementation is usually unsatisfactory in the operating room. The quickest, safest and most precise method of drug administration is the intravenous technique by which the correct dosage is easily given. The drug to be used is diluted for ease of administration ; 100 mg of Nembutal or Demerol can be conveniently diluted with normal saline in a 5-cc syringe. Small amounts can be administered each

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minute or so until the patient is optimally sedated. Adequacy of sedation is evaluated by the patient's response to questioning and by respiratory rate and depth, ability to lie still and stability of pulse and blood pressure. This technique is called fractional sedation. Administration is painless since injections are into the tubing of an intravenous infusion of 5% glucose in distilled water, started when the patient is first positioned. If, during the operation, the patient becomes restless, additional increments can be similarly administered. The object, as with the initial medication, is to produce a sedated but conscious patient. The infusion, continuing through the operation, is available for administration of drugs before and during surgery; for example, a vasopressor can be given to elevate falling blood pressure or an osmolar agent, such as urea, can be administered to reduce intraocular pressure. 4. Positioning and surgical draping of the patient is usually left to an orderly or nurse. However, the posture of the patient during surgery should be the surgeon's concern. Many patients undergoing intraocular surgery are elderly. Senile kyphosis is common (fig. 1). Cardiopulmonary disabilities are common in this age group. For both anatomic and physiologic reasons, most individuals undergoing intraocular surgery prefer to have their heads elevated. For some

Fig. 1 (Livingston). Seventy-year-old man with senile kyphosis. Note that there is inadequate elevation beneath the head and shoulders and the head is hyperextended and retrocessed. The anterior neck tissues are tense and the cross-sectional diameter of the oropharyngeal airway is reduced.

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patients, it is anatomically impossible to accommodate themselves to a flat table with little or no elevation beneath their heads. They may lie through the operation (if they can tolerate the position) with their heads hyperextended or even dangling in midair. A patient may tolerate an uncomfortable position only long enough for the operation to get well under way before objecting. Although ophthalmic surgeons prefer to operate with the patient's head in a horizontal plane, the patient need not be lying flat to achieve this position. Despite the high incidence of senile kyphosis, these individuals maintain function of the atlanto-occipital joint and can extend their heads quite well. Thus, their backs can be elevated to almost any degree and they can still extend their heads sufficiently to attain a horizontal position. A doughnut-shaped pillow to support the occiput will contribute stability to the head. A pillow beneath the knees permits flexion and relaxes the legs and the thighs. The operating table, if adjustable, should be arranged to conform to this semireclining position. Otherwise pillows should be utilized to support the back and head of the patient (fig. 2). The surgeon will find it worthwhile to check the position of his patient prior to beginning the operation. Draping of the operative field should not force the patient to rebreathe his own exhaled breath. In no case should the drapes be brought down snugly about the face and chin. Such draping produces a feeling of suffocation, either real or fancied. The combination of sedation and rebreathing into a small, closed space can produce a significant rise in inhaled carbon dioxide and a fall in blood oxygen saturation. Either of these situations can produce serious cardiopulmonary effects, as well as aggravate a patient's emotional stress. A Mayo tray, which is fixed to the side of the operating table and extends across the patient's chest, serves admirably to lift the drapes away from his nose and mouth and

Fig. 2 (Livingston). Same patient as in Figure 1 with doughnut and pillow beneath head. Note that, despite the elevation, the head can still be extended and lies in a horizontal plane. to hold the instruments as well. Such a tray does not require readjustment as the table is raised or lowered, and is a much better repository for instruments than the patient's chest. Six to 10 liters/min. of oxygen flowing from tubing fixed to the patient's chest beneath the operating drapes will insure dispersal of exhaled carbon dioxide and provide a high concentration of oxygen to the patient. Although especially indicated for elderly patients who have been sedated, oxygen insufflation beneath the drapes should be routine in every ophthalmic procedure. 5. Regional anesthesia. After draping, the administration of regional anesthesia is the first step in an ophthalmic operation and, as far as the patient is concerned, the manner in which it is done can set the stage for the remainder of the procedure. It can make him tense and straining or calm and relaxed. The patient should be alerted for the initial needle pricks, and anesthesia should be slowly and gently induced. Raising of intradermal wheals, with the needle bevel turned toward the skin, injection of anesthetic agent as the needle is advanced and proceeding from anesthetized to nonanesthetized areas will permit as painless a block as possible. Surgery should not be started until anesthesia and akinesia are fully effective. After sensory and motor nerves are blocked, the eye should be completely anesthetized and motionless if a satisfactory intraocular procedure is to be done. One im-

MANAGEMENT OF THE CONSCIOUS PATIENT portant principle of regional anesthesia is use of anesthetic agents in the minimal effective concentration for the nerve to be blocked. If mepivacaine (Carbocaine) or lidocaine (Xylocaine) is used, a 2% concentration is indicated for the retrobulbar and O'Brien nerve blocks; 1% is an adequate concentration for the Van Lint or Atkinson field-block techniques and for infiltration of the lids. A 1:200,000 concentration of epinephrine is sufficient to prolong duration of anesthesia and decrease the speed of anesthetic absorption and yet is small enough to minimize the danger of systemic reactions. Mepivacaine has the added advantage of producing prolonged anesthesia without the addition of epinephrine.4 The majority of local anesthetic reactions are not due to allergy or hypersensitivity but to absorption of large amounts of agent into the circulation within a short period of time. However, even this more common type of reaction is rare in eye surgery. 6. Monitoring of the patient (fig. 3). If the surgeon is aware of the importance of emotional preparation, comfortable positioning and draping, moderate sedation and complete regional anesthesia, his patient will almost invariably be co-operative and quiet during surgery. Attention to the factors dis-

Fig. 3 (Livingston). Eye patient prior to being draped for surgery. The following points are illustrated. (1) Patient comfortably positioned with head resting on doughnut and pillow. (2) Mayo stand to support drapes and instrument tray. (3) Intravenous infusion of 5% glucose in distilled water. Y intubing permits painless intravenous injection of drugs. (4) Oxygen flowing beneath drapes at a rate of eight to 10 liters per minute. (S) Nonoperating monitor in physical contact with patient. (6) Drugs available for supplementary medication during surgery. (7) Blood-pressure cuff. (8) Record of patient's vital signs and medication during surgery.

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cussed under these headings will eliminate most of the complications which stem from lack of patient co-operation, but not all. Even with the surgeon observing precautions, a patient will occasionally become unco-operative during surgery. His medication may be inadequate to control his anxiety. Syncope may stem from his emotional state or follow global massage and vagal stimulation. He may develop a cramp after lying still for too long a period. He may develop nausea because of anxiety, a fall in blood pressure, a side-reaction to one of his preoperative medications or a combination of these reactions. He may be the rare individual who has a sensitivity to the regional anesthetic agent. He may be the even more rare ophthalmic patient who is given an overdose of regional anesthetic agent. No routine will completely eliminate all complications during surgery. Early diagnosis is especially important, since treatment at the onset is simpler and more effective. ' How is the operating surgeon, concentrating on his work, to become aware of the onset of these problems? It is impossible to monitor a patient adequately and do a cataract extraction at the same time. Since the surgeon cannot monitor or treat his patient during the operation, someone else should;

■infusion

Btoocl pressure y cuff Syringe

Y adapter

Record' Moru'tor

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MARTIN W. LIVINGSTON

whether it be an anesthesiologist, or ophthalmologist or a nurse is not too important, providing the monitor is capable of evaluating the patient's vital signs and administering drugs when indicated. Complete evaluation of a patient's state during surgery includes checking the blood pressure, pulse rate, respiratory rate and depth, and skin temperature, color and moisture, as well as response to questioning. A s stated before, to permit rapid and painless administration of supplementary medication an intravenous infusion of 5% glucose in distilled water is started in the operating room prior to the beginning of surgery. If no monitor is available, it is especially important for the surgeon to be present when the patient is positioned, prepared and draped for surgery. Once the patient is covered from head to toe, it is more difficult to evaluate his condition. Advance warnings of mental stress or physiologic deterioration are usually present before the globe is opened. Early diagnosis is important because treatment is most effective at the onset of the deterioration—when the patient first shows apprehension, not when he develops complete hysteria ; when he first has nausea, not after he vomits; when his blood pressure first falls, not after he faints. I n the typical cataract extraction 10 to 15 minutes will be required to produce regional anesthesia, place lid sutures and raise a conjunctival flap. If the patient's condition is good throughout this period, he will almost invariably be calm and comfortable through the remainder of the operation. If his condition is not good, it may grow worse after the globe is opened. If the patient is markedly oversedated or seriously nauseous, the operation should be cancelled. If the patient complains of pain,

the regional anesthesia can be repeated and small amounts of an analgesic, such as meperidine, can be injected intravenously. A p prehension can be allayed with intravenous barbiturates and encouragement. Syncope can be controlled with intravenous vasopressors. I t is during this period before the globe is opened, if all is not well, that effective therapeutic steps can be taken to correct the situation with no risk to the eye or the patient. SUMMARY

Although a proportion of the complications of intraocular surgery are the result of lack of patient co-operation at the time of surgery, insufficient attention is all too often given to the factors which influence this cooperation. Some of these factors are considered under the headings of psychologic preparation, regional anesthesia, positioning and draping and sedation. Awareness of and attention to these factors will eliminate most complications caused by lack of patient co-operation but not all. Despite good overall patient management, such complications as syncope, nausea and excitement will occasionally develop during an operation. These complications should be treated at their onset when they are most responsive to therapy, and before they can influence the outcome of surgery. T h e importance of monitoring the patient during intraocular surgery has been emphasized. 218 Second Avenue

(3).

ACKNOWLEDGMENT

I wish to thank Drs. J. B. Kara, David Kimmelman and Seymour Fradin of the New York Eye and Ear Infirmary for their help in the preparation of this paper.

REFERENCES

1. Atkinson, W. S. : Anesthesia in Ophthalmology. Springfield, 111., Thomas, 1957. 2. Beecher, H. K.: Preanesthetic medication (editorial). JAMA, 157:242-243 (Jan. 15) 1955. 3. Eckenhoff, James E. : Study of narcotics and sedatives for use in preanesthetic medication. JAMA, 167:415-422 (May 24) 1958. 4. Van dam, L. D.: Local anesthetics. Clin. Pharmacol. & Therap., 3:131 (Jan.-Feb.) 1962.