Nonprescription H2-receptor antagonists.

OBJECTIVE: This article reviews the use of nonprescription histamine2-receptor antagonists (H2RAs) in the management of secretory disorders of the upper gastrointestinal tract. DATA SOURCES: The scientific and consumer literature pertaining to the over-the-counter availability and therapeutic uses of H2RAs was reviewed. STUDY SELECTION: References related to safety, efficacy, comparative efficacy with antacids, and economic impact of H2RA therapy were emphasized. Additional importance was placed on information describing the pharmacist's role in nonprescription H2RA therapy. DATA EXTRACTION: Data from product package inserts as well as the scientific literature were extrapolated to provide information on indications, dosage and administration, adverse effects, drug interactions, and patient information. DATA SYNTHESIS: The literature review focused on the relative role of these agents as an alternative to traditional nonprescription treatment of self-limiting gastrointestinal conditions as well as the advice and instructions that the patient should receive. CONCLUSION: H2RAs represent a nonprescription option for the prevention and treatment of heartburn, acid indigestion, and sour stomach. They are effective and safe, but take longer to work and are more expensive than antacids. The availability of H2RAs without a prescription may reduce overall health care costs by decreasing the need for physician office visits. However, the pharmacist should counsel patients on the proper use of these products. In their role as primary care providers, pharmacists must evaluate whether the products will relieve a given patient's symptoms or whether the patient requires referral to another clinician (e.g., physician) for a more thorough examination and treatment.

The prognostic value of a risk score for necrotising enterocolitis.

Necrotising enterocolitis is the most common severe acquired gastrointestinal disorder in the neonate yet there remains disagreement on predictive and prognostic factors. A previously published risk score purports to predict infants at greater risk of the disease. Fifty-nine cases and 59 matched controls were evaluated using data from the first 24 h after birth to determine the predictive and prognostic value of the score for necrotising enterocolitis. In simple models the risk score was significantly, but inversely, associated with necrotising enterocolitis, primarily due to greater respiratory problems among controls. This finding contrary to the premise is clarified by a significant interaction of the risk score with feeding variables. Odds ratios for the risk score varied at different levels of daily feeding increments. However, the risk score was not statistically significant in any models which controlled for feeding increment and the interaction. The risk score was significantly associated with mortality among necrotising enterocolitis cases. Though the score was not statistically significant when the outcome was disease stage or surgery, trends were in the expected direction. The data suggest that the risk score itself may not be an independent predictor of necrotising enterocolitis, but may indicate infants more vulnerable to other potential risk factors and, in addition, may be related to prognosis for those who do develop necrotising enterocolitis.

Increased mortality in neonates with low thyroxine values.

Serum thyroxine values were determined prospectively over a 6-month interval in 97 newborn infants with birth weight < 2200 gm or gestational age < 37 weeks. There were 89 survivors and 8 deaths. Infants with thyroxine values of < 2.5 micrograms/dl (32.2 nmol/L) had a significantly higher mortality rate (p < 0.001) compared with infants with higher thyroxine levels. In neonates there may exist a critical thyroxine value below which there is an increased risk of mortality.

Neonatal tricuspid insufficiency with abnormal tricuspid valve treated with extracorporeal membrane oxygenation (ECMO): possible extension of ECMO use.

Extracorporeal membrane oxygenation is now an accepted method of treatment for neonatal hypoxemia due to a number of causes. We extend the indications of ECMO to hypoxemia secondary to dysplastic tricuspid valve. We report the case of a neonate with congenital dysplastic tricuspid valve who responded to ECMO.

Shigellosis in a newborn.

We report a case of neonatal shigellosis presenting with abdominal distention and shock. The literature on neonatal shigellosis is reviewed. Neonatal shigellosis should be included in the differential diagnosis of newborns presenting with shock and abdominal symptoms along with necrotizing enterocolitis, midgut volvulus, and intussusception.

Role of delayed feeding and of feeding increments in necrotizing enterocolitis.

In spite of a number of studies on necrotizing enterocolitis, there remains controversy concerning prevention regimens, especially with regard to enteral alimentation. This report is of a matched case-control study of the relationship of necrotizing enterocolitis to timing of first feeding, size of feeding volumes and increments, and a risk factor index in 59 case patients with necrotizing enterocolitis and 59 matched control patients. Comparison with control patients showed that case patients were fed earlier, received full-strength formula sooner, and received larger feeding volumes and increments. More highly stressed infants, as measured by the risk index, were more vulnerable to larger feeding increments. Among case patients there was significant correlation of age at first feeding and age at diagnosis (p < 0.0001) even after control for birth weight and risk index score, indicating that delayed feeding was related to delayed onset of disease. These analyses support the theory that earlier, more rapid feeding places stressed infants at greater risk for the development of necrotizing enterocolitis, and that infants with more severe respiratory problems are more vulnerable to such feeding practices.

Mesalamine in ulcerative colitis.

Sulfasalazine has been used for many years in the management of ulcerative colitis. As many as 20 percent of patients treated with it experience intolerable adverse effects usually attributed to its sulfapyridine component. The other active component is 5-aminosalicylic acid (5-ASA); the only 5-ASA enema preparation currently available in the U.S. is mesalamine (Rowasa, Reid-Rowell) containing 5-ASA 4 g in 60 mL. In clinical trials, mesalamine has proved efficacious in treating refractory cases of distal ulcerative colitis, proctitis, and proctosigmoiditis. Because of its high cost compared with more conventional treatment modalities, it should be reserved for cases that are either refractory or intolerant to conventional treatment.

Extracorporeal membrane oxygenation in the neonate.

ECMO is a modified heart-lung bypass system for treatment of moribund neonates. The techniques are described. Our experience with 19 patients reveals a survival rate of 79 percent. In the future, with advances in technology, ECMO may become less invisible and extended to a larger population of newborns.

Extracorporeal membrane oxygenation selection criteria: partial pressure of arterial oxygen versus alveolar-arterial oxygen gradient.

Extracorporeal membrane oxygenation (ECMO) has dramatically increased the survival rate of hypoxemic neonates who are unresponsive to maximum conventional medical therapy. Because ECMO involves multiple risks, including ligation of the right common carotid artery and right internal jugular vein, ECMO candidates should be neurologically intact neonates with a high probability of death despite maximum conventional ventilatory support. Currently, criteria based on the calculated alveolar-arterial oxygen gradient (A-aDO2) have replaced the neonatal pulmonary insufficiency index for predicting mortality and, thus, ECMO eligibility. A retrospective review of death prediction for the 26 months prior to the initiation of an ECMO program revealed a sensitivity of 67% and a specificity of 96% using the criterion of a PaO2 of less than 50 mm Hg for four hours. An equivalent A-aDO2 criterion of greater than or equal to 630 for four hours produced a sensitivity of 61% and a specificity of 96%. Prediction of mortality in neonates with sepsis was poor regardless of the criteria used. Excluding the deaths due to sepsis increased the sensitivity to 86% and 79% using criteria based on PaO2 and A-aDO2, respectively. It is concluded that the use of criteria based on PaO2 is equivalent to criteria based on A-aDO2 for predicting mortality. Criteria based on PaO2 may, however, decrease both the false-negative rate (patients with an elevated PCO2) and the false-positive rate (patients with intentionally induced hypocarbia secondary to hyperventilation alkalosis).

Unexplained fetal baseline bradycardia in congenital panhypopituitarism.

An unexplained fetal baseline bradycardia apparently not secondary to uteroplacental insufficiency is reported. Congenital panhypopituitarism was diagnosed in the neonate. A common cause of both findings is speculated and a review of possible methods for antenatal diagnosis is given.