Comparison of intra-amniotic prostaglandin F2 alpha and hypertonic saline for induction of second-trimester abortion.

The efficacy and safety of intra-amniotic prostaglandin (PG) F2 alpha (25 mg repeated in six hours) and hypertonic saline (200 ml 20% NaC1) were compared in an international multicentre randomised study organised by the World Health Organisation''s prostaglandin task force. Both hypertonic saline and PGF2alpha were found to be effective in terminating second-trimester pregnancy. The main advantage of PGF2alpha however, was its greater efficacy, with significantly higher success rates in the first 48 hours. Out of 717 women given PGF2alpha 614 (85-6%) aborted within 48 hours; by 24 hours 439 (61-2%) had aborted, and by 36 hours 574 (80-1%) had aborted. Out of 796 women given hypertonic saline 641 (80-5%) aborted within 48 hours; however, by 24 and 36 hours, respectively, only 161 (20-2%) and 462 (58%) had aborted. Although PGF2alpha was associated with a somewhat higher frequency of minor side effects than hypertonic saline, notably vomiting and diarrhoea, these were within acceptable limits. Only 59 women (8-2%) in the prostaglandin group had more than four episodes of vomiting and 11 (1-5%) more than four episodes of diarrhoea. Ohter side effects occurred only occasionally. No difference was found between the two groups in the frequency of incomplete abortion or excessive bleeding.     

Induction of therapeutic abortion using either extra-amniotic prostaglandin F-2-alpha or hypertonic saline followed by oxytocin

160 women with uteri at 10-20 weeks gestation were treated with either PG(prostaglandin)F2alpha or saline solution followed by oxytocin to effect an abortion. 80 women were in each treatment group. The distribution of the patients according to age, parity, and gestation duration is tabulated. PGF2alpha was administered extraovularly in a concentration of .1 mg/ml with .7 mg being injected in the operating theater and nurses administering the rest based on response to previous injections. Administration continued for up to 30 hours. Saline was given in a volume in ml dependent on the duration of pregnancy multiplied by a factor of 10. Subcutaneous injections of oxytocin were given on subsequent days to speed the abortion. 85% of the PG patients successfully aborted without surgical dilatation of the cervix. The average dosage of PG required was 7.5 mg in 11 instillations. Side effects and complications in the PG group were minimal. 1 instillation of saline followed by 2 days of oxytocin were required to effect a 79% abortion rate in the saline group. Although the number of patients requiring surgical dilatation was the same for both groups, the procedure was much less time-consuming for the PG group. The complication rate was 26% for the saline group as compared to 14% for the PG group. The PG group required a shorter hospital stay.     

The effect of hypertonic saline on human corneal hydration.

Hydrophilic gel contact lenses, presoaked in various strength saline solutions, were held in intimate contact with the in vivo human cornea. A change in corneal water content was observed taking place against the induced osmotic gradient. Direct stimulation of some aspect of the mechanisms controlling corneal hydration is postulated, in a manner which may be similar to that previously reported for the in vitro rabbit cornea.     

Uterine injuries complicating hypertonic saline abortion

Two cases of uterine injury complicating midtrimester abortion induced by hypertonic saline are described, one with an extensive laceration of the cervix and the other with a rupture of the lower uterine segment extending into the vault of the vagina. The etiology, diagnosis and possible obstetric sequelae are discussed.     

Site of action of hypertonic saline in the canine lung.

The site of action of inhaled hypertonic saline was determined in 8- to 10-wk-old puppies by combining measurements of respiratory mechanics, made during mechanical ventilation and after midexpiratory flow interruptions, with direct measurements of alveolar pressure. Under both control conditions and after inhalation of 10% saline, we were able to partition lung mechanics into components representing the airways and tissue viscoelastic properties. Hypertonic saline challenge altered lung mechanics by increasing airway resistance and did not have any effect on elastic or viscoelastic properties of the lung.     

Behavioral characteristics in mice with brain lesions induced by hypertonic saline

Behavioral and histopathological characteristics were studied in mice treated repeatedly with hypertonic saline. In passive avoidance response using a step-through-type shuttle box, the mice treated with hypertonic saline showed shorter latency than control mice. No changes were observed in active avoidance response using a two-way-type shuttle box, spontaneous motor activity or motor function. Histopathological examination revealed marked and frequent degeneration and loss of neurons in the hippocampus as compared with animals after single treatment. The animals with severe hippocampal lesions showed impairment of passive avoidance response. The present brain lesions resulting from repeated treatment with hypertonic saline in mice are considered to be a possible model for memory disorders caused by hippocampal lesions in humans.