Evaluation of local anesthesia techniques for small incision cataract surgery.

PURPOSE: To evaluate the surgical experiences and patient preference with 3 local anesthesia techniques for small incision cataract surgery. SETTING: Department of Ophthalmology, Hjørring Hospital, Denmark. METHODS: This prospective, randomized study included 66 patients having simultaneous bilateral cataract surgery. There were 3 test groups, each containing 2 of the following local anesthesia techniques: retro/peribulbar (RBA), sub-Tenon's (STA), or topical (TA). Each patient served as his or her own control. No medical sedation was used. Patient response to each anesthesia technique was evaluated by the surgeon based on surgical difficulties, a nurse using hand-holding tension and verbal interaction, and a visual analog pain score. Patients were also asked which of the 2 techniques they preferred and their reasons. RESULTS: No local anesthesia techniques interfered with surgery. The order of a positive pain/discomfort response during surgery was TA > STA > RBA. Significantly more pain occurred with application of RBA than with STA or TA. No postoperative pain was recorded with any method. Fifty-six percent of patients said they preferred 1 technique over the other; 16% of patients having STA would not do so again, 19% would not have TA again, and 40% would not have RBA again. The main reasons for preferring STA and TA were fear of or pain from a retrobulbar injection. The main reasons for preferring RBA were less awareness, anxiety, and surgical pain. Immediate visual recovery seemed to be of minor importance in patients' choice of an anesthesia technique. CONCLUSION: Although less discomfort/pain occurred during surgery with RBA, patients preferred STA and TA primarily because of the inconvenience or pain of the retrobulbar injection. Although medical sedation was not used in this study, the pain/discomfort ratio from surgery was not greater than in studies using intravenous sedation, indicating that the use of medical sedation should be re-evaluated.

[Treatment of severe hypovolemia with hypertonic saline]. / Behandling af svaer hypovolaemi med hypertont saltvand.

Hypertonic saline (HS) has been used since 1980 in the treatment of traumatised, hypotensive patients. Studies show more pronounced and stable increments in blood pressure and reduced mortality in various subgroups of patients treated with HS compared to isotonic fluids. When infused in the setting of hypovolaemia HS instantaneously expands plasma volume and improves central haemodynamics through increased filling pressures and direct myocardial stimulation. HS, as compared to isotonic fluids, causes precapillary vasodilation, reduction of cell oedema and decreased haematocrit and hence improves regional and capillary perfusion. Furthermore HS-infusion has been shown to attenuate reperfusion injury and restore cell function in cells damaged during hypovolaemic shock. Animal experiments as well as clinical studies on the use of HS are reviewed. A short description of the pathophysiology of acute hypovolaemic shock and exchange of fluids between body compartments is given.

[Hypertonic saline in the treatment of hypovolemia]. / Hypertont saltvand til behandling af hypovolaemi.

Following infusion of hypertonic saline, interstitial and intracellular fluids are within minutes drawn into the vascular compartment as a result of osmotic gradients. Administration of 5 ml/kg body weight hypertonic saline leads to a degree of plasma expansion corresponding to 8-12 ml/kg. Results from major randomized studies on treatment of acute hypotension demonstrate that infusion of hypertonic saline leads to improved survival. Two case reports of patients suffering from severe septicaemia are presented in which infusion of hypertonic saline (7.5%) was performed in order to stabilize haemodynamic parameters. Case report no. I illustrates the rapid plasma expanding properties of hypertonic saline and no. II the effect on central haemodynamics with increased stroke volume and cardiac index. Consequently, hypertonic saline is considered an important supplement in the treatment of severe hypovolaemic or septic shock.