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Magnesium levels after magnesium-containing cathartics
ABSTRACTS
that included gastrointestinal symptoms, central nervous system depression, apnea, and metabolic acidosis. No children died. Severity of symptoms correlated well with mg/kg dose. No children had permanent sequelae. Two of six adult patients had toxic reactions. One had transient central nervous system depression after unknown dosage. The other took 24 g (407 mg/kg) and presented with confusion, hematemesis, and oliguria. He developed renal failure, became comatose and septic, and died. Drug assays were negative except for ibuprofen. No patients who ingested less than 104 mg/kg, adults or children, developed toxic reactions. The authors suggest several guidelines. Drug levels are of little benefit in adults. They should be admitted if they develop any symptoms within the first four hours. Laboratory studies should include urinalysis, BUN, and creatinine. Dosage appears predictive in children. Less than 100 mg/kg ingestions are safe for home observation; 100 to 200 mg/kg ingestions may be observed at home with induced emesisi 200 to 400 mg/kg ingestions require gastric emptying, charcoal, and cathartic, and a m i n i m u m of four hours of medical observation; more than 400 mg/kg ingestions require lavage and possible admission. Treatment is supportive in all patients. Robin W Nicholson, MD
magnesium, cathartics
M a g n e s i u m levels a f t e r m a g n e s i u m containing cathartics Smilkstein M J, Steedle D, Kulig KW, et al Toxicol C/in Toxico/ 26(1&2):51-65 1988
The effect on serum m a g n e s i u m (Mg) levels of oral magnesium-containing cathartics (MgCC) as used in the treatment of suspected overdoses was studied in a proSpective, nonrandomized manner. Twenty-four cases were assigned to single- or multiple-dose MgCC groups, and Mg levels were measured by absorption spectrophotometry one and four hours after final doses. The patient's clinical course and factors thought to affect Mg absorption and elimination (eg, alcohol, emesis, and renal function) were taken into consideration. In the single-dose group baseline, one- and four-hour levels showed no significant difference. The multiple-dose group with normal baseline Mg, blood pressure, renal function, and urine output showed significantly higher levels after second and third doses in two-thirds of the cases. Highest peak levels were noted in opioid and anticholinergic drug ingestion, suggesting that gut motility may be a risk factor. A history of alcoholism showed no appreciable difference. Adverse clinical effects of hypermagnesemia were not assessed due to underlying overdoses. The authors concluded that hypermagnesemia can occur rapidly (within eight hours) after multiple-dose oral MgCC therapy, using c o m m o n l y prescribed doses. They recommended nonMg-containing cathartics if multiple doses are indicated, as adverse clini-
152/433
cal effects of hypermagnesemia are well known and pose a risk to an already compromised patient. R i e m k e M Brakema, MD
visual acuity
E f f e c t s of r o u t i n e p u p i l l a r y d i l a t i o n on f u n c t i o n a l d a y l i g h t vision O'Connor PS, Tredici TJ, Pickett J, et al Arch Ophthalmol 106:1567-1569 Nov 1988
The visual acuity of 100 patients was measured before and after pupillary dilation to determine the effects of routine dilation for fundal examination on objective and subjective functional daylight vision. Visual acuity prior to dilation was determined in each eye with the patients using their current corrective lenses. After dilation with two drops of 1% tropicamide and two drops of 215% phenylephrine, visual acuity was recorded with both eyes open. Patients were taken outside and visual acuity repeated with the patient facing and with their backs to the sun using both visual correction and disposable postmydriatic spectacles. Patients reported their subjective discomfort in all circumstances. A control group of 30 patients was examined outdoors without dilation. None in the control group was objectively impaired, while 17 had subjective discomfort. All in the study group had significant subjective discomfort, and 32 had objective visual impairment (> 20/50) without sunglasses, while 12 patients had significant discomfort and three had objective impairment with sunglasses. Because it cannot be predicted beforehand who will have subjective or objective visual impairment, patients undergoing dilation should make transportation arrangements or remain in the department until the recovery of pupillary constriction. Duncan Sauer, MD CPR, circulation, IV injections
E f f e c t of i n j e c t i o n site on c i r c u l a t i o n t i m e s during cardiac arrest Emerman CS, Pinchak AC, Hancock D, et al Crit Care Med 16:1138-1141 1988
Disagreement exists concerning the optimal site for venous administration of drugs during CPR. These authors used a canine cardiac arrest model in order to study dye circulation times and peak levels following central, femoral, and peripheral venous injections during closedand open-chest CPR. Following ind0cyamine green dye injection, blood was sampled from the proximal aorta, and concentrations were determined by using a densitometer
Annals of Emergency Medicine
18:4 April 1989
that included gastrointestinal symptoms, central nervous system depression, apnea, and metabolic acidosis. No children died. Severity of symptoms correlated well with mg/kg dose. No children had permanent sequelae. Two of six adult patients had toxic reactions. One had transient central nervous system depression after unknown dosage. The other took 24 g (407 mg/kg) and presented with confusion, hematemesis, and oliguria. He developed renal failure, became comatose and septic, and died. Drug assays were negative except for ibuprofen. No patients who ingested less than 104 mg/kg, adults or children, developed toxic reactions. The authors suggest several guidelines. Drug levels are of little benefit in adults. They should be admitted if they develop any symptoms within the first four hours. Laboratory studies should include urinalysis, BUN, and creatinine. Dosage appears predictive in children. Less than 100 mg/kg ingestions are safe for home observation; 100 to 200 mg/kg ingestions may be observed at home with induced emesisi 200 to 400 mg/kg ingestions require gastric emptying, charcoal, and cathartic, and a m i n i m u m of four hours of medical observation; more than 400 mg/kg ingestions require lavage and possible admission. Treatment is supportive in all patients. Robin W Nicholson, MD
magnesium, cathartics
M a g n e s i u m levels a f t e r m a g n e s i u m containing cathartics Smilkstein M J, Steedle D, Kulig KW, et al Toxicol C/in Toxico/ 26(1&2):51-65 1988
The effect on serum m a g n e s i u m (Mg) levels of oral magnesium-containing cathartics (MgCC) as used in the treatment of suspected overdoses was studied in a proSpective, nonrandomized manner. Twenty-four cases were assigned to single- or multiple-dose MgCC groups, and Mg levels were measured by absorption spectrophotometry one and four hours after final doses. The patient's clinical course and factors thought to affect Mg absorption and elimination (eg, alcohol, emesis, and renal function) were taken into consideration. In the single-dose group baseline, one- and four-hour levels showed no significant difference. The multiple-dose group with normal baseline Mg, blood pressure, renal function, and urine output showed significantly higher levels after second and third doses in two-thirds of the cases. Highest peak levels were noted in opioid and anticholinergic drug ingestion, suggesting that gut motility may be a risk factor. A history of alcoholism showed no appreciable difference. Adverse clinical effects of hypermagnesemia were not assessed due to underlying overdoses. The authors concluded that hypermagnesemia can occur rapidly (within eight hours) after multiple-dose oral MgCC therapy, using c o m m o n l y prescribed doses. They recommended nonMg-containing cathartics if multiple doses are indicated, as adverse clini-
152/433
cal effects of hypermagnesemia are well known and pose a risk to an already compromised patient. R i e m k e M Brakema, MD
visual acuity
E f f e c t s of r o u t i n e p u p i l l a r y d i l a t i o n on f u n c t i o n a l d a y l i g h t vision O'Connor PS, Tredici TJ, Pickett J, et al Arch Ophthalmol 106:1567-1569 Nov 1988
The visual acuity of 100 patients was measured before and after pupillary dilation to determine the effects of routine dilation for fundal examination on objective and subjective functional daylight vision. Visual acuity prior to dilation was determined in each eye with the patients using their current corrective lenses. After dilation with two drops of 1% tropicamide and two drops of 215% phenylephrine, visual acuity was recorded with both eyes open. Patients were taken outside and visual acuity repeated with the patient facing and with their backs to the sun using both visual correction and disposable postmydriatic spectacles. Patients reported their subjective discomfort in all circumstances. A control group of 30 patients was examined outdoors without dilation. None in the control group was objectively impaired, while 17 had subjective discomfort. All in the study group had significant subjective discomfort, and 32 had objective visual impairment (> 20/50) without sunglasses, while 12 patients had significant discomfort and three had objective impairment with sunglasses. Because it cannot be predicted beforehand who will have subjective or objective visual impairment, patients undergoing dilation should make transportation arrangements or remain in the department until the recovery of pupillary constriction. Duncan Sauer, MD CPR, circulation, IV injections
E f f e c t of i n j e c t i o n site on c i r c u l a t i o n t i m e s during cardiac arrest Emerman CS, Pinchak AC, Hancock D, et al Crit Care Med 16:1138-1141 1988
Disagreement exists concerning the optimal site for venous administration of drugs during CPR. These authors used a canine cardiac arrest model in order to study dye circulation times and peak levels following central, femoral, and peripheral venous injections during closedand open-chest CPR. Following ind0cyamine green dye injection, blood was sampled from the proximal aorta, and concentrations were determined by using a densitometer
Annals of Emergency Medicine
18:4 April 1989