Practical outcome measures for assessing efficacy of incontinence procedures

Standard treatment for urinary incontinence in women has evolved during the past few decades. Conservative measures such as pelvic floor exercises and biofeedback may be effective and have been advocated for the past several years. However, the availability of other methods that are potentially more invasive yet efficacious provides a wider range of choices for women with urinary incontinence. With these alternatives comes opportunity and responsibility to assess how successful these treatments are. This article explores current methods of analyzing outcomes of urinary incontinence treatments.     

Practical outcome measures for assessing efficacy of incontinence procedures

Standard treatment for urinary incontinence in women has evolved during the past few decades. Conservative measures such as pelvic floor exercises and biofeedback may be effective and have been advocated for the past several years. However, the availability of other methods that are potentially more invasive yet efficacious provides a wider range of choices for women with urinary inconti-nence. With these alternatives comes opportunity and responsibility to assess how successful these treatments are. This article explores current methods of analyzing outcomes of urinary incontinence treatments.     

Study of prostaglandins and intraocular pressure in rabbits after Nd:YAG laser anterior segment procedures

Radioimmunoassay of rabbit aqueous humor one hour after Nd:YAG laser anterior capsulotomies revealed increased concentrations of 6-keto-prostaglandin F1 alpha (PGF1 alpha), and thromboxane B2 (TBB2). Coincidental rises in intraocular pressure (IOP) and aqueous humor protein were observed. These changes correlated with the laser power used. Pretreatment with topical 1% prednisolone acetate or 1% indomethacin prior to anterior capsulotomies inhibited the post laser rise in PGF1 alpha and TBB2, but did not eliminate the post laser rise in IOP. Small rises in IOP and the concentrations of aqueous PGF1 alpha, TBB2, and protein were observed after Nd:YAG laser iridectomies. These changes were not affected by prior treatment with 1% topical prednisolone acetate. Although PGF1 alpha and TBB2 are elevated after Nd:YAG laser anterior segment procedures, a causal relationship between post treatment IOP rise and PGF1 alpha or TBB2 release could not be determined.     

Anesthesia and intraocular pressure

General anesthesia has been in use for ophthalmic surgery since 1847. The subsequent predominance of local anesthetic techniques made ophthalmic anesthesia the "Cinderella of anesthesia services" until its clinical and scientific rehabilitation in the second half of this century. Precise control of intraocular tension is an accepted advantage of general anesthesia. The exercise of such control requires understanding of intraocular physiology and the effects exerted by anesthetic techniques. Hence, the impact of anesthetic drugs on intraocular pressure (IOP) must be considered when ophthalmic surgery is to be carried out under general anesthesia. Intravenous anesthetics and volatile agents reduce IOP, with the possible exception of ketamine. Underlying mechanisms include a direct effect on cerebral IOP control centers and indirect effects mediated through the balance between production and drainage of aqueous humor, general circulation and ocular muscle tone. IOP is likely to be elevated during induction and recovery. Currently suggested measures to prevent the increase in IOP associated with laryngoscopic tracheal intubation facilitated by succinylcholine include oral premedication with clonidine, intravenous administration of lidocaine 3 min prior to laryngoscopy, and anesthetic induction with propofol or narcotics. Non depolarizing neuromuscular blocking drugs either do not affect IOP or produce a slight decrease; depolarizing muscle relaxants increase IOP. It remains controversial whether this effect, which is pronounced with succinylcholine, may be reliably abolished by any concomitant medication. The new competitive relaxants atracurium and vecuronium provide stable conditions with respect to IOP and systemic circulation, combined with a rapid onset and intermediate duration of action.     

Cranio-cerebral injury and intraocular pressure

In 102 patients with cranio-cerebral trauma the intra-ocular pressure was measured. Values of the intra-ocular pressure showed a falling tendency in patients with grade-I trauma during the first 5 days. On the 30th day normal values had been regained. In grade-II and III traumata starting readings were lower and rose again about 3 days after the injury. In no case a glaucoma could be traced. In 4 patients with grade III cranio-cerebral trauma the reaction of the intraocular pressure is similar to that occurring before death.     

Timolol and postoperative intraocular pressure

We studied the effect of timolol instillation at surgery on the acute postoperative pressure rise following extracapsular cataract extraction (ECCE) and posterior chamber lens implantation. The intraocular pressure (IOP) was measured daily during the first week following surgery in 85 eyes. Timolol was instilled immediately following surgery in 34 eyes; the remaining 51 served as controls. The mean preoperative IOP was 18.7 mm Hg in the treated and control groups. The mean IOP on the first day following surgery was 20.0 mm Hg in the timolol group and 20.7 mm Hg in the control group. Twenty-six percent of the timolol group had a pressure greater than 23.0 mm Hg (mean 35.6 mm Hg); 33% of the control group had a pressure greater than 23.0 mm Hg (mean 31.0 mm Hg). The IOP in all treated and untreated patients with ocular hypertension on the first day following surgery returned to normal within three days. Timolol, therefore, had no effect on acute postoperative pressure elevation following ECCE and posterior chamber lens implantation.     

Brain death and intraocular pressure

The authors report on the behavior of the intraocular pressure of 20 patients who had sustained severe head injury. The 8 patients who retained normal intraocular pressure all survived. The 12 patients who developed intraocular hypotony all suffered brain death. Although optic disc edema was not noted in any brain-dead patients, we did find signs of fundus ischemia in most.     

Thiopental and succinylcholine: Action on intraocular pressure.

Intraocular pressure (IOP) measurements were made in a series of 92 male surgical patients, to assess the effects of timing and dosage of succinylcholine given after a standardized sleep dose of thiopental (3 mg./kg.). The major findings of this study were as follows: (1) thiopental alone lowered IOP; (2) a small (0.5 mg./kg.) dose of succinylcholine, given immediately after thiopental, returned IOP to normal; (3) a large (1 mg./kg.) dose of succinylcholine immediately after thiopental maintained the IOP at a low value; (4) if 2 minutes elapsed between thiopental and 1 mg./kg. of succinylcholine, the relaxant raised the IOP to slightly above preanesthetic control values; (5) tracheal intubation caused a significant rise in IOP, more than any effect from succinylcholine itself; (6) succinylcholine drip (0.1 percent), begun after establishment of satisfactory endotracheal halothane-nitrous oxide anesthesia, caused significant IOP elevation in 4 of 11 patients.     

麻醉与眼内压的研究进展

背景围术期眼内压（intraocular pressure,IOP）剧烈波动可以引起严重的眼部并发症,导致视野缺损甚至失明。有研究表明,围术期麻醉、手术操作及药物的使用均可导致IOP发生改变,影响眼内血供。目的系统地阐述围术期生理及麻醉常用药物对IOP影响的研究现状以及进展,为临床工作提供参考,并启发新的研究思路。内容对麻醉期间影响IOP的生理和药物因素进行综述。趋向从近期的研究可见,研究者对围术期生理及药物对IOP的影响机制进行了更为深入的探讨。