Cataract surgeons can manage a patient’s pain and anxiety during phacoemulsification through a wide variety of anesthetic techniques. These can be used alone or in combination with a variety of sedation modalities, with the anesthesia delivered through intra- or periocular injections or topically as drops or gels. When surgeons opt for conscious sedation, it is often administered intravenously or sublingually. Sedatives, anxiolytics, hypnotics and opiate analgesics are given via oral, sublingual or intravenous sedation.
In the United States and Canada, conscious sedation is not mandatory, yet the majority of cataract surgeries are performed using neuroleptic anesthesia under the supervision of an anesthesiologist. Internationally, research finds significant variation in anesthesia management strategies.1 These variations should come as no surprise.
While many studies2-4 have shown that local anesthesia alone without conscious sedation is sufficient for adequate pain control during cataract surgery, others conclude that local anesthesia alone is not sufficient in managing patient pain and anxiety and that surgeons were more likely to express dissatisfaction with topical/local anesthesia alone.5-7
Then there’s the cost issue. The findings in this study have implications for cost-containment in modern health-care delivery. Performing the procedure without IV sedation may reduce those associated with personnel, disposables and drugs. A cost analysis study8 published in 2001 found that the most cost-effective anesthesia management strategy in cataract extraction was a combination of oral sedation and an ocular block, without an anesthesiologist present ($16.47). The most expensive method involved intravenous sedation and topical anesthesia, with an anesthesiologist present throughout the operation ($324.72). No standards or clinical practice guidelines for the choice of sedation during phacoemulsification currently exist, and the decision relies entirely on the preference of the patient, ophthalmologist, anesthesiologist or administrators where the surgery is performed.
This is the first systematic review and meta-analysis to synthesize the literature on non-intravenous sedation methods vs. intravenous sedation use when comparing the primary outcomes of patient pain and perioperative complications. Our study has the potential to impact resource allocations in both publicly and privately funded environments.
A WORD ON OUR METHODS
We performed this systematic review in accordance with the recommendations of the Cochrane Collaboration9 and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)10 statement.
We searched the following databases using a comprehensive search strategy: Medline (OVID), Embase (OVID), Cochrane Library (Wiley), BIOSIS Previews (Thomson-Reuters), Web of Science (Thomson-Reuters) and CINAHL (EBSCO). Grey literature was explored by searching dissertations, theses, reports, conference proceedings and clinical trials as well as ophthalmology-specific meetings. The review included randomized control trials with a study population of healthy adults (ages 18+) clinically diagnosed with cataracts and undergoing phacoemulsification. We compared intravenous conscious sedation to local anesthetic techniques and sublingual sedation. The primary outcomes were patient pain perception and perioperative complications. Included studies were in English with no restrictions on the geographic location of the study; articles published prior to 1995 were excluded. We conducted data analysis using STATA 13. All values are in U.S. dollars.
A total of 4,541 articles were retrieved and imported into Covidence; duplicate article removal then resulted in 2,920 articles for level one abstract screening. Level two full text screening consisted of 428 articles. A total of 10 randomized control trials11-19 (895 participants) were included in the systematic review and meta-analysis. The PRISMA diagram demonstrating the selection process is displayed in Figure 1 (page 48).
Patient pain perception
Figure 2 (page 50) displays the forest plot of a random effects meta-analysis comparing pain perception with intravenous sedation vs. no intravenous sedation. IV sedation was significantly associated with a decrease in pain (SMD = -0.86 with 95% CI of -1.49 to -0.23, p=0.0008, i2=94.8%, p<0.001) when compared to all other methods grouped together (no sedation with topical anesthesia and/or intracameral anesthesia, and oral sedation).
Meta-analysis for pain perception (SMD)
We performed a sub-group analysis, grouping studies by non-intravenous sedation method used (Figure 3, page 50). Eight studies compared intravenous sedation with local anesthesia to local anesthesia only; two studies compared intravenous sedation with local anesthesia to oral sedation with local anesthesia. The analysis revealed that IV sedation with local anesthesia was significantly better than local anesthesia alone at controlling pain perception; however, we found no significant difference in perceived pain between IV or oral sedation methods.
Perioperative complication rate
We extracted quantitative data to analyze complication rates when comparing intravenous sedation to non-intravenous methods. The forest plot for the risk of complications with a correction factor of 0.5 is displayed in Figure 4 (below). Our findings: intravenous sedation was not significantly associated with an increase in ocular or systemic complications (RR= 0.99 with 95% CI 0.97 to 1.02, p=0.704, i2=0%), and there was no difference in risk between the two groups.
Intravenous sedation significantly reduces pain during cataract extraction when compared to no sedation. We conducted a weighted mean difference meta-analysis to highlight the clinical significance of this finding and found that intravenous sedation reduced pain by approximately 10%.
The subgroup analysis suggests that oral sedation and intravenous sedation techniques may be equivalent in terms of pain control. Eighteen patients in the IV sedation group had perioperative complications compared to 14 in the non-intravenous group; the meta-analysis indicated no difference in risk between the two groups. Given equivalent effects on pain control and no difference in risk of complications, it is evident that non-intravenous sedation strategies may be a feasible alternative to the more invasive and resource-intensive intravenous methods.
These results have potential cost implications in both publicly and privately funded environments, as the use of intravenous sedation requires considerable resources: equipment, medication, nurse anesthetists and the presence of anesthesiologist. Further, obtaining intravenous access itself is a source of pain and anxiety for the patient.20,21 But added costs can result from augmented anesthetic techniques that reduce pain at the needle entry site.22 According to a 2001 cost analysis study,8 oral sedation cost $16.47 USD per procedure, while IV sedation was estimated at $324.72 per procedure. These values have likely increased since.
This study has identified crucial gaps in the literature, which will guide future research, allowing researchers and clinicians to generate better conclusions regarding the most effective sedation method for phacoemulsification. OM
- Nørregaard J, Schein O, Bellan L, et al. International variation in anesthesia care during cataract surgery: results from the International Cataract Surgery Outcomes Study. Arch Ophthalmol. 1997;115:1304-1308.
- Shammas HJ, Milkie M, Yeo R. Topical and subconjunctival anesthesia for phacoemulsification: prospective study. J Cataract Refract Surg. 1997;23:1577-1580. http://www.ncbi.nlm.nih.gov/pubmed/9456419 . Accessed July 12, 2017.
- Gupta SK, Kumar A, Kumar D, Agarwal S. Manual small incision cataract surgery under topical anesthesia with intracameral lignocaine: study on pain evaluation and surgical outcome. Indian J Ophthalmol. 2009;57:3-7. http://www.ncbi.nlm.nih.gov/pubmed/19075400 . Accessed July 12, 2017.
- Kershner RM. Topical anesthesia for small incision self-sealing cataract surgery. A prospective evaluation of the first 100 patients. J Cataract Refract Surg.1993;19:290-292. http://www.ncbi.nlm.nih.gov/pubmed/8487176 . Accessed July 12, 2017.
- Fernandes M, Souza R, Vasconcelos G, Ribeiro K, Andrade B, Fernandes C. Assessing patient satisfaction with cataract surgery under topical anesthesia supplemented by intracameral lidocaine combined with sedation. Arq Bras Oftalmol. 2013;76:345-349.
- Aydin, ON Kir E, Ozkan SB, Gursoy F. Patient-controlled analgesia and sedation with fentanyl in phacoemulsification under topical anesthesia. J Cataract Refract Surg. 2002;28: 1968-1972.
- Dogan R, Karalezli A, Sahin D, Gumus F. Comparison of Sedative Drugs Under Peribulbar or Topical Anesthesia During Phacoemulsification. Ophthalmic Surgery, Lasers, and Imaging. 2012;43:121-127.
- Reeves SW, Friedman DS, Fleisher LA, Lubomski LH, Schein OD, Bass EB. A decision analysis of anesthesia management for cataract surgery. Am J Ophthalmol. 2001;132:528-536.
- The Cochrane Collaboration. Cochrane Handbook for Systematic Reviews of Interventions. (Higgins J, Green S, eds.). Wiley-Blackwell; 2008.
- Moher D, Liberati A, Tetzlaff J, Altman DG, Grp P. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Phys Ther. 2009;89:873-880.
- Aydin ON, Kir E, Özkan SB, Gürsoy F. Patient-controlled analgesia and sedation with fentanyl in phacoemulsification under topical anesthesia. J Cataract Refract Surg. 2002;28:1968-1972.
- Inan ÜÜ, Sivaci RG, Ermis SS, Öztürk F. Effects of fentanyl on pain and hemodynamic response after retrobulbar block in patients having phacoemulsification. J Cataract Refract Surg. 2003;29:1137-1142.
- Laube T, Krohner H, Franke GH, Brockmann C, Steuhl KP. Clorazepate dipotassium versus midazolam for premedication in clear corneal cataract surgery. J Cataract Refract Surg. 2003;29:1956-1961.
- Habib NE, Mandour NM, Balmer HGR. Effect of midazolam on anxiety level and pain perception in cataract surgery with topical anesthesia. J Cataract Refract Surg. 2004;30:437-443.
- Leidinger W, Schwinn P, Hofmann HM, Meierhofer JN. Remifentanil for analgesia during retrobulbar nerve block placement. Eur J Anaesthesiol. 2005;22:40-43.
- Akgul A, Aydin ON, Dayanir V, Sen S, Ugur B, Kir E. Usage of remifentanil and fentanyl in intravenous patient-controlled sedo-analgesia. J Turkish Soc Algol. 2007;19:39-46.
- Erdurmus M, Aydin B, Usta B, Yagci R, Gozdemir M, Totan Y. Patient comfort and surgeon satisfaction during cataract surgery using topical anesthesia with or without dexmedetomidine sedation. Eur J Ophthalmol. 2008;18:361-367.
- Santiago AEQ, Issy AM, Sakata RK. Effects of preoperative intravenous clonidine in patients undergoing cataract surgery: a double-blind, randomized trial. J Ophthalmol. 2014;2014:1-5.
- Chen M, Hill GM, Patrianakos TD, Ku ES, Chen ML. Oral diazepam versus intravenous midazolam for conscious sedation during cataract surgery performed using topical anesthesia. J Cataract Refract Surg. 2015;41:415-421.
- Arendt-Nielsen L, Egekvist H, Bjerring P. Pain following controlled cutaneous insertion of needles with different diameters. Somatosens Mot Res. 2006;23:37-43.
- Zilinsky I, Bar-Meir E, Zaslansky R, Mendes D, Winkler E, Orenstein A. Ten commandments for minimal pain during administration of local anesthetics. J Drugs Dermatol. 4:212-216. http://www.ncbi.nlm.nih.gov/pubmed/15776779 . Accessed Nov. 6, 2017.
- Strazar AR, Leynes PG, Lalonde DH. Minimizing the Pain of Local Anesthesia Injection. Plast Reconstr Surg. 2013;132:675-684.