Local or regional anesthesia is frequently used in ophthalmic surgery, especially in older patients undergoing cataract, glaucoma and anterior segment surgery. Local anesthesia is an alternative to general anesthesia, which has many risks, and it is suitable for patients with systemic comorbidities and can be used for early recovery. But, since the patient is awake during surgery, anxiety, cooperation and physiologic stability are important factors in determining the safety of the surgery and the comfort of the patient during surgery [1-3].

It is normal to experience anxiety prior to eye surgery. Patients might be afraid of pain, losing their sight, the surgery not working, or being awake during the surgery. This anxiety can trigger sympathetic reactions such as tachycardia, hypertension, and can cause restlessness or poor cooperation during surgery [4,5]. During ophthalmic surgery, even slight patient motion can disrupt the surgical field and may make surgery more challenging.

Sedation is often used as an adjunct to local anesthesia to improve comfort and cooperation. To provide anxiolysis with verbal responsiveness, spontaneous ventilation, airway reflexes and cardiovascular stability. Excessive sedation can be undesirable, as it can lead to respiratory depression, oxygen desaturation, excessive drowsiness, paradoxical agitation or sudden movement under surgical drapes [6,7]. Sedation should not be routinely given to all patients but should be tailored to the patient's anxiety, comfort and cooperation.

In local anaesthetic ophthalmic surgery, especially when sedative drugs are administered, it is important to monitor heart rate, blood pressure, oxygen saturation and patient cooperation intraoperatively. While anxiety and sedation are clinically relevant in routine ophthalmic practice, structured documentation of anxiety level, sedation requirement and intraoperative stability is often limited in high volume surgical settings.

A prospective cohort study was designed to evaluate the level of pre-operative anxiety, sedation requirement and intra-operative stability of adult patients undergoing elective ophthalmic surgery under local anesthesia in S. M. College and Hospital, Uttar Pradesh in 2008-2009.

OBJECTIVES

The objectives of the study were: first, to evaluate the level of preoperative anxiety among patients scheduled for ophthalmic surgery under local anesthesia; second, to assess the requirement and adequacy of sedation during ophthalmic surgery performed under local anesthesia; and third, to determine intraoperative stability by monitoring heart rate, blood pressure, oxygen saturation, and patient cooperation during surgery.

Study design and setting This prospective cohort study was conducted at S. M. College and Hospital, Uttar Pradesh, during 2008–2009. Adult patients scheduled for elective ophthalmic surgery under local anesthesia were enrolled and followed from the preoperative period until completion of surgery. Study population The study included patients undergoing cataract surgery, glaucoma surgery, pterygium surgery, trabeculectomy revision, or other anterior segment procedures under local or regional ophthalmic anesthesia. Sample size and sampling technique A sample size of 120 patients was selected. As the expected proportion of patients with significant preoperative anxiety or sedation requirement was not known, a prevalence of 50% was assumed for maximum sample size estimation. Using the formula n=Z^2 pq/d^2, with Z = 1.96, p = 50%, q = 50%, and allowable error of 10%, the calculated sample size was approximately 96. After allowing for incomplete records or exclusions, the sample size was rounded to 120. Patients were recruited by consecutive sampling until the required sample size was achieved. Eligibility criteria Patients aged 18 years or older, of either sex, scheduled for elective ophthalmic surgery under local anesthesia, belonging to American Society of Anesthesiologists physical status I–III, able to respond to anxiety assessment, and willing to provide informed consent were included. Patients were excluded if they underwent emergency surgery or general anesthesia, were younger than 18 years, were unable or unwilling to provide informed consent, had cognitive impairment or communication difficulty preventing anxiety assessment, had known psychiatric illness or regular use of anxiolytics, sedatives, antipsychotics, or antidepressants, had contraindications to local anesthetic or sedative drugs, had severe uncontrolled systemic illness, required conversion to general anesthesia, or had incomplete intraoperative monitoring records. Preoperative assessment Demographic details, comorbidities, previous surgical or anesthetic exposure, ASA physical status, planned procedure, and type of local anesthesia were recorded. Baseline heart rate, systolic and diastolic blood pressure, and oxygen saturation were measured before surgery. Assessment of preoperative anxiety Preoperative anxiety was measured prior to the use of any sedative drug. Anxiety was clinically rated as none, mild, moderate or severe according to verbal expression of fear, facial expression, restlessness, repeated questioning, need for reassurance and ability to cooperate. Moderate and severe anxiety were deemed clinically significant. Local anesthesia and sedation The type of local anesthetic used was based on the procedure to be performed and institutional practice and comprised peribulbar block, sub-Tenon block, topical anesthesia, retrobulbar block, or local infiltration. Sedation was used when clinically indicated for anxiety, restlessness, discomfort, poor cooperation, or anticipated difficulty in maintaining a still operative field. The sedative drug used, indication, dose, need for additional sedation, adequacy of sedation, and adverse events were documented. Sedation was deemed sufficient if the patient was calm, cooperative, verbally responsive, and physiologically stable without respiratory compromise. Intraoperative monitoring and stability assessment Heart rate, systolic and diastolic blood pressure, oxygen saturation and patient cooperation were measured at baseline, after local anesthesia, at the beginning of surgery, at the main surgical step and at the end of surgery. Patient cooperation was rated as good, satisfactory or poor. Intraoperative stability was defined as acceptable heart rate, blood pressure, oxygen saturation, cooperation and no major sedation-related or anesthesia-related adverse events. Outcome measures The primary outcomes were preoperative anxiety, sedation requirement, and intraoperative stability. Secondary outcomes were the relationship between anxiety and sedation requirement, intraoperative changes in vital parameters, patient cooperation, additional sedation required, and adverse events related to sedation. Statistical analysis Appropriate statistical software was used to analyze the data. Continuous variables were presented as mean ± standard deviation or median (interquartile range) as appropriate. Categorical variables were presented as frequency and percentage. The chi-square test or Fisher exact test was used to evaluate the associations between categorical variables. Independent t-test or appropriate non-parametric tests were used for between group comparisons of continuous variables. Repeated-measures or non-parametric equivalent tests were used to analyze changes in repeated intraoperative measurements as appropriate. A p-value <0.05 was considered statistically significant. Ethical considerations The study was performed with the approval of the institutional ethics committee. Written informed consent was obtained from all participants. Participation was voluntary and refusal to participate did not compromise standard treatment. Patient confidentiality was maintained. The study was observational, and all decisions regarding local anesthesia, sedation, monitoring and intraoperative management were made according to standard institutional practice and clinical judgment.

Study population and baseline characteristics

A total of 120 patients undergoing elective ophthalmic surgery under local anesthesia were included in the analysis. The mean age of the cohort was 61.8 ± 8.9 years. Men accounted for 63 (52.5%) patients and women for 57 (47.5%). Cataract surgery was the commonest procedure, performed in 92 (76.7%) patients. ASA physical status II was most frequent, seen in 71 (59.2%) patients, and peribulbar block was the commonest local anesthetic technique, used in 59 (49.2%) patients. Baseline hemodynamic parameters were within acceptable perioperative limits (Table 1).

Table 1. Baseline demographic and perioperative characteristics of the study cohort

Preoperative anxiety and sedation requirement

Preoperative anxiety was absent in 5 (4.2%) patients, mild in 46 (38.3%), moderate in 52 (43.3%), and severe in 17 (14.2%); thus, clinically significant anxiety was present in 69 (57.5%) patients. Sedation was required in 54 (45.0%) patients overall. The proportion of patients requiring sedation increased progressively across anxiety categories, from 1 (20.0%) among those with no anxiety and 8 (17.4%) among those with mild anxiety to 29 (55.8%) among those with moderate anxiety and 16 (94.1%) among those with severe anxiety (χ² = 34.44, p < 0.001) (Table 2, Figure 1).

Table 2. Association between preoperative anxiety category and sedation requirement

Pearson chi-square test used for overall association.

Intraoperative hemodynamic profile

Across the entire cohort, heart rate, systolic blood pressure, and oxygen saturation changed significantly over the intraoperative period (Friedman χ² = 181.92, p < 0.001; χ² = 302.50, p < 0.001; and χ² = 24.83, p < 0.001, respectively). When patients were grouped according to the presence of clinically significant anxiety, those with moderate or severe anxiety had significantly higher heart rate after administration of local anesthesia and throughout the procedure, and significantly higher systolic blood pressure from the post-block period onward. Oxygen saturation remained comparable between groups at all measured time points (Table 3, Figure 2).

Table 3. Intraoperative hemodynamic parameters according to clinically significant preoperative anxiety

Between-group comparisons were performed using the independent t-test.

Intraoperative cooperation, stability, and adverse events

Patient cooperation was graded as good in 85 (70.8%) patients, satisfactory in 33 (27.5%), and poor in 2 (1.7%). Overall intraoperative stability was maintained in 92 (76.7%) patients. Less than good cooperation was observed in 24 (34.8%) patients with clinically significant anxiety compared with 11 (21.6%) patients without clinically significant anxiety, while intraoperative instability occurred in 20 (29.0%) and 8 (15.7%) patients, respectively. Restlessness was also more frequent among patients with moderate or severe anxiety [19 (27.5%) vs 6 (11.8%)], although this did not reach conventional statistical significance (p = 0.061). Rates of tachycardia, hypertension, oxygen desaturation, intraoperative pain, and local anesthetic complications were low and did not differ significantly between groups (Table 4).

Table 4. Intraoperative cooperation, stability, and adverse events according to clinically significant preoperative anxiety

Pearson chi-square test was used unless expected cell counts were sparse, in which case Fisher exact test was applied.

Sedation profile among sedated patients

Among the 54 patients who received sedation, midazolam was the commonest sedative agent, used in 39 (72.2%), followed by dexmedetomidine in 9 (16.7%) and a midazolam-fentanyl combination in 6 (11.1%). Sedation was judged adequate in 47 (87.0%) patients, while 9 (16.7%) required additional dosing. Sedation-related adverse effects were uncommon and were predominantly transient, comprising transient desaturation in 3 (5.6%), excess drowsiness in 3 (5.6%), and nausea or vomiting in 1 (1.9%) patient (Table 5).

Table 5. Sedation profile among patients who required intraoperative sedation

Clinically significant preoperative anxiety was prevalent in this prospective cohort study of patients undergoing ophthalmic surgery under local anesthesia and was closely associated with sedation requirement. Over half of the patients were moderately or severely anxious, and sedation requirement was found to be directly related to the level of anxiety. This finding highlights the value of pre-operative anxiety assessment as a routine, particularly in awake ophthalmic surgery where patient cooperation is essential.

The anxiety burden seen in this cohort is similar to that reported in the literature on cataract surgery, which varies depending on the population, the tool used to measure anxiety and the timing of the assessment. Nijkamp et al. found that outcome expectations, coping style, social support and doctor-patient relationship were factors that influenced surgery-related anxiety in cataract patients [9]. Fear of visual loss, pain and uncertainty about the surgical experience were also common sources of pre-operative anxiety before cataract surgery as reported by Ramirez et al. [10]. In the current study, clinically significant anxiety was found in 57.5% of patients, which shows that psychological preparedness is still a significant part of the care of patients undergoing ophthalmic surgery under local anesthesia.

The clinical significance of the strong association between anxiety and sedation requirement is important. Sedation was required in 17.4% of patients with mild anxiety, 55.8% of patients with moderate anxiety and 94.1% of patients with severe anxiety. This graded pattern indicates that a simple pre-operative anxiety assessment could be useful to identify patients who are likely to need pharmacological anxiolysis. In a pilot study of 108 cataract surgery patients, Foggitt found that anxiety was most pertinent in the perioperative period and needed to be actively recognized prior to surgery [11]. Based on the current results, routine sedation of all patients is not warranted, and moderate and severe anxiety patients should be targeted for counselling, reassurance and, if necessary, judicious sedation.

The hemodynamic profile found in this study also reinforces the physiological relevance of anxiety. Intraoperative and surgical heart rate and systolic blood pressure were higher in patients with moderate and severe anxiety, but not at baseline. This trend suggests that the sympathetic response may be greater in anxious patients in the operating room and when local anesthesia is given. One of the risk factors for intraoperative hypertension in cataract surgery under topical anesthesia was anxiety, as determined by Guerrier et al. [12]. In the current study, although there was no significant difference between the groups in terms of discrete hypertension episodes, the consistently higher systolic blood pressure in the anxious patients is clinically significant, particularly in an elderly ophthalmic population where cardiovascular comorbidities are common.

No difference in oxygen saturation between anxiety groups and desaturation events were rare. This indicates that in the current cohort, anxiety had a bigger impact on cardiovascular parameters than on oxygenation. But there is still a need for careful monitoring, particularly if sedative drugs are given. Kojima et al. found that patients with diabetes who had cataract surgery under local anesthesia had higher systolic blood pressure and pulse rate during the surgery, which highlighted the importance of cardiovascular monitoring in patients with systemic vulnerability [13]. The prevalence of hypertension and diabetes was high in the present study and routine monitoring during surgery is necessary even for short ophthalmic surgeries.

Most sedated patients required only sedation, the most commonly used sedative agent being midazolam. This is in line with the use of benzodiazepines in anxiolysis during ophthalmic surgery. However, a few sedated patients had some transient desaturation and excessive drowsiness, and dose titration is important. Alhashemi compared dexmedetomidine with midazolam for monitored anesthesia care in cataract surgery and reported that dexmedetomidine was associated with delayed recovery and relative cardiovascular depression, and that slightly more patients were satisfied with dexmedetomidine [14]. This helps to reinforce the idea that the choice of sedative should take into account anxiolysis, cooperation, hemodynamic stability, respiratory safety, and recovery characteristics.

The sedation results also show that there is no single sedative strategy that is best for all patients. Adinehmehr et al. compared etomidate, propofol and midazolam combined with fentanyl for phacoemulsification and found acceptable sedation quality in all groups, but differences in recovery profile, hemodynamic effects, adverse events and satisfaction [15]. In the current study, sedation was tailored to clinical requirements and in 87.0% of sedated patients, adequate sedation was achieved. This helps to facilitate a pragmatic approach where the drug and dose is adjusted to the severity of the anxiety, the comorbidity profile, the length of the procedure and the level of cooperation required.

Cooperation of the patient is a key factor in ophthalmic surgery performed under local anesthesia. While good cooperation was obtained in most patients, less than good cooperation and intraoperative instability were numerically more common in patients with clinically significant anxiety. These differences were not statistically significant but are clinically plausible. A patient can be hemodynamically stable and still need frequent reassurance or move slightly, which can impact surgical flow. Cooperation should thus be recorded in addition to the important parameters in the assessment of intraoperative stability.

The results have implications for the practice of ophthalmic anesthesia. First, a short pre-operative anxiety assessment might be useful in stratifying patients prior to surgery. Second, non-pharmacological interventions like explanation, reassurance and calm communication during surgery should be routinely used. Thirdly, sedation should be targeted and titrated, especially in elderly patients and those with cardiovascular or respiratory co-morbidities. Fourth, physiological parameters and behavioural cooperation should be monitored during surgery, as both are important to assess patient stability.

There are limitations to this study. It was performed in one center, and sedation techniques may vary from center to center. Anxiety was determined by a clinical grading system and not by a validated psychometric scale, which may make it difficult to compare with studies that used formal anxiety scales. Sedation was not protocolized or randomized and therefore no conclusions can be drawn about the superiority of specific sedative agents. Variation in discomfort, duration and sedation requirement may also have been introduced by the use of different anterior segment procedures.a

Preoperative anxiety was common and strongly associated with sedation requirement during ophthalmic surgery under local anesthesia. Patients with moderate or severe anxiety showed higher intraoperative heart rate and systolic blood pressure, while oxygen saturation remained stable. Simple anxiety assessment, targeted counselling, selective sedation, and routine monitoring may improve patient comfort and intraoperative safety.

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