Eye Irrigation ============== þ Morgan Lens - A device like a hard contact lens with a tube to attach to IV tubing for irrigation. Very handy. þ Irrigation Direction - irrigate from the nose outward, to prevent irrigant from running through the nasolacrimal ducts into the nose and being (eventually) swallowed. þ Irrigation Fluid Choice - for pepper spray: "I have used milk as an antidote to pepper spray injury to the eyes several times in California. I put water in one eye and milk in the other eye. The individual was "blinded" from whether milk or water was put in his eye. The milk worked within one to two minutes. The water was 10-15 minutes for complete relief. I did not write up the data. This study is waiting to be done by other investigators. Perchance you. We do not have pepper spray injuries to the eye at the Brooklyn Hospital Center. BTW somehow a heaping spoonful of sugar does not seem like the substance to put in a eye that recently received pepper spray." --Barry Brenner MD PHD Vice-chairman, Research Director Department of Emergency Medicine The Brooklyn Hospital Center - >Powdered sugar is not good for the eye, but D50 will work in this situation Do you know this for a fact or is this just an hypothesis (like when I, half jokingly, suggested dissolving sucrose in sterile water for irrigation)? The study that I quoted used oral sucrose to alleviate the pain induced by capsaicin in chili peppers. Re-reading Barry's initial post, that implied that the protein content of milk was what was responsible for this effect, made me wonder, though. If so, sucrose probably works by a different mechanism in the mouth, perhaps in the same manner as it is used in neonates where it may relieve pain by increasing endorphin levels (1,2). If that's the case, I'm not so sure that irrigating the eye with it would really be effective treatment. On the other hand, it seems to me that D50 would probably be toxic to the cornea as it is so hypertonic. In any case it is not obvious to me that one can substitute dextrose for sucrose in this situation. In any case both sucrose and D50 seem like a very sticky solution (to this problem--no pun intended) to me. Nor do I, for that matter, like the idea of having my eyes irrigated with milk. --H. Louzon MD (1) Blass EM; Shah A Pain-reducing properties of sucrose in human newborns. Chem Senses, 20: 1, 1995 Feb, 29-35 To assess the characteristics of sucrose as a pain-reducing substance, crying in 72 newborn humans during and after blood collection via heel prick was determined. In the first study infants drank 2 ml of water or 2 ml of a 0.17-0.34- or 0.51-M sucrose solution 1 min prior to blood collection. In the second experiment, a delay of 30, 60, 90, 120 or 240 s was imposed between sucrose intake and the initiation of blood collection. The dose-response function for concentration was flat. The most effective time delay was 120 s. The effectiveness of the 2-min interval accords with previous findings of endogenous opioid release caused by sucrose taste. The flat dose-response function extends findings in rats and humans that the calming and pain-reducing effects of sucrose are not influenced by either concentration or volume, suggesting that the transduction from gustatory afferent to opioid-mediated efferent is of an on-off nature and not graded. (2) Haouari N; Wood C; Griffiths G; Levene M The analgesic effect of sucrose in full term infants: a randomised controlled trial [see comments] BMJ, 310: 6993, 1995 Jun 10, 1498-500 OBJECTIVE--To evaluate the effects of different sucrose concentrations on measures of neonatal pain. DESIGN--Randomised, double blind, placebo controlled trial of sterile water (control) or one of three solutions of sucrose--namely, 12.5%, 25%, and 50% wt/vol. SETTING--Postnatal ward. PATIENTS--60 healthy infants of gestational age 37-42 weeks and postnatal age 1-6 days randomised to receive 2 ml of one of the four solutions on to the tongue two minutes before heel prick sampling for serum bilirubin concentrations. MAIN OUTCOME MEASURE--Duration of crying over the first three minutes after heel prick. RESULTS--There was a significant reduction in overall crying time and heart rate after three minutes in the babies given 50% sucrose as compared with controls. This was maximal one minute after heel prick in the 50% sucrose group and became statistically significant in the 25% sucrose group at two minutes. There was a significant trend for a reduction in crying time with increasing concentrations of sucrose over the first three minutes. CONCLUSION--Concentrated sucrose solution seems to reduce crying and the autonomic effects of a painful procedure in healthy normal babies. Sucrose may be a useful and safe analgesic for minor procedures in neonates. - Dean Dobbert, writing on emed-l: "I had a patient the other day who got acid splashed in his eye at work. I irrigated his eye with a liter of normal saline, and then checked the pH. It was about 5.5. Huh, I thought, I would have thought it would be closer to 7 by now. So I irrigated his eye with another liter and checked again. Still 5.5. This isn't making sense, I thought. Maybe the pH paper is bad. I checked the pH of the saline sitting in the basin under his head, and it was 5.5. I was sure the paper was bad. For one last check, I placed a drop of dacriose eye irrigation solution on the paper. It was 7.0! So now I look at the bag of normal saline, and realize that right there, printed on the side of the bag, it says the pH is 5.6. So all this time I've been irrigating eyes with acid? I checked some of the other bags of IV fluid we carry. I found that ringer's lactate was the closest to physiologic pH, at 6.6. At the other end of the spectrum, I found that D5 1/3 NS the worst, at 4.3." "Two questions: What do you use to irrigate eyes? And secondly, why are we infusing acid into our patient's veins? If I have an acidotic, dehydrated patient and I give them a liter of normal saline at a pH of 5.6, is that such a good idea?" - Harvey Louzon replied: "There is no difference in ultimate pH in eyes irrigated by different solutions (1). There may be a difference in level of comfort however. I had been using NS until a few months ago when I read (somewhere) that LR was preferable. I'll try to find the reference for you." "The amount of free [H+] in saline is very small. When added to a buffered solution such as blood it probably does not make a great deal of difference. Because of the unphysiologic ratio of [Na+] to [Cl-] in NS, however, you will sometimes observe a transient hyperchloremic metabolic acidosis when it is infused in someone who is volume depleted. This occurs because there is intense sodium retention and the predominant anion available for resorption is chloride (dilutional effect on [HCO3-]?). Restoration of volume takes precedence over pH homeostasis. A similar situation occurs during the recovery phase of DKA. A clue to this phenomenon is that the increment in bicarb is less than the decrease in the anion gap during treatment. This discrepancy implies the presence of a mixed (anion and non-anion gap) acidosis. The reason for the presence of a non-anion gap acidosis in DKA is the subject of some dispute. Some have ascribed it to intr/extra cellular exchange of lactate for chloride. In any case it is not improved by the use of a high chloride containing solution." "Along a similar vein, the use of hypertonic saline for treatment of shock has been found to produce a profound, albeit transient, hyperchloremic metabolic acidosis (2). (1) Herr RD; White GL Jr; Bernhisel K; Mamalis N; Swanson E Clinical comparison of ocular irrigation fluids following chemical injury. Am J Emerg Med, 9: 3, 1991 May, 228-31 This study tested the hypothesis that four ocular irrigating solutions were equally irritating during copious irrigation. We conducted a prospective, double-blind study of patients with chemical exposure to the eye. Each underwent cross-over irrigation with all of the following in random order: normal saline (NS), lactated Ringer's (LR), normal saline adjusted to pH 7.4 with sodium bicarbonate (NS + Bicarb), and Balanced Saline Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, TX). Compared with traditional NS and LR, NS + Bicarb tended to be more comfortable. BSS Plus was statistically superior (P less than .05) to NS and preferred over LR and NS + Bicarb. Three patients demanded discontinuance of NS or NS + Bicarb infusions. All solutions had comparable normalization of conjunctival pH and degree of injection. Alternate solutions including BSS Plus should be considered for use in those patients whose poor tolerance to normal saline threatens to delay or interrupt eye irrigation following a chemical injury. (2) Moon PF; Kramer GC Hypertonic saline-dextran resuscitation from hemorrhagic shock induces transient mixed acidosis. Crit Care Med, 23: 2, 1995 Feb, 323-31 OBJECTIVE: To evaluate the magnitude and mechanism of potential metabolic acidosis after resuscitation with 7.5% sodium chloride/6% dextran-70. DESIGN: Blinded, randomized, control trial. SETTING: Laboratory setting. SUBJECTS: Sixteen healthy Yorkshire swine. INTERVENTIONS: Anesthetized, mechanically ventilated swine underwent 90 mins of hemorrhagic hypotension (mean arterial pressure of 50 to 55 mm Hg), and a lactic acid infusion (1.5 to 2.4 mmol/kg) was given during the last 60 mins of hemorrhage to produce pretreatment acidosis. The pigs were then given either 4 mL/kg of intravenous normal saline (n = 8) or 7.5% sodium chloride/6% dextran-70 (n = 8). Groups then received isotonic lactated Ringer's solution to restore and maintain cardiac output for 120 mins. MEASUREMENTS AND MAIN RESULTS: There was no difference between groups during baseline or shock for any parameter. At the end of shock, arterial pH and base balance were below baseline values. During resuscitation, cardiac output was reached and maintained in both groups. One minute after infusion of hypertonic saline/dextran, there was a significant but transient decrease in arterial pH (from 7.407 +/- 0.015 to 7.339 +/- 0.025) and base balance (from -6.5 +/- 0.7 to -9.9 +/- 1.0 mmol/L). These changes returned to shock levels by 10 mins and then normalized to baseline levels. Hypertonic saline dextran resulted in an immediate hypernatremia, hyperchloremia, and hypokalemia, a decrease in inorganic strong ion difference (calculated as sodium plus potassium minus chloride concentrations), and no immediate change in anion gap. The normal saline group did not show an initial transient decrease in pH and base balance during resuscitation. Plasma lactate, total protein, and hemoglobin concentrations decreased equally in both groups, although they decreased more quickly with hypertonic saline/dextran. CO2 temporarily and insignificantly increased in arterial blood slightly more after the administration of hypertonic saline/dextran. By 120 mins, acid-base, electrolyte and protein changes were normalizing with hypertonic saline/dextran, while pH, base balance, and protein were decreasing below shock values in animals initially treated with normal saline. CONCLUSIONS: Hypertonic saline/dextran caused an immediate, transient acidemia, which was primarily due to a hyperchloremic, hypokalemic, metabolic acidosis with normal anion gap and decreased inorganic strong ion difference, but which was partially due to a mild transient respiratory acidosis. The acidemia was transient because of the offsetting alkalotic effects of decreasing serum protein, normalization of electrolytes, and transient nature of the increase in CO2. Lactic acidosis was not the cause of the acidemia. Over time, the acid-base status appeared to be improved more effectively with hypertonic saline/dextran than with isotonic saline resuscitation.