Effect of thromboxane A2-receptor antagonist on bradykinin-induced bronchoconstriction in asthma.

The role of the thromboxane A2 (TxA2) receptor in bradykinin-induced bronchial responses was investigated in this study by using a selective and potent TxA2-receptor antagonist BAY u 3405. Eleven asthmatic subjects were randomized to receive 50 mg of BAY u 3405 or matched placebo in a crossover and double-blind fashion. Ninety minutes after dosing, serum was taken for drug assay, and subjects underwent provocation with bradykinin or prostaglandin D2 (PGD2) to determine bronchial responsiveness [provocative concentration of agonist required to produce a 20% fall in forced expiratory volume in 1 s from the postdiluent baseline (PC20)]. Pretreatment with BAY u 3405 caused a twofold doubling-dilution reduction in bronchial reactivity to PGD2; the geometric mean PC20 values were 0.132 (0.015-0.871) and 0.034 (0.008-0.095) mg/ml, respectively, for active and placebo days (P = 0.001). There was, however, no significant difference in PC20 values for bradykinin between active and placebo treatment days. We have demonstrated that BAY u 3405 caused a significant inhibition of bronchconstriction induced by inhaled PGD2 but had no influence on bronchial responsiveness to inhaled bradykinin. This study suggests therefore that TxA2 receptors do not play a role in bradykinin-induced bronchoconstriction in asthma.

The anesthetic management of a patient with chromosome 10qter deletion syndrome.

Terminal deletions of chromosome 10q are uncommon. The resulting syndrome includes cardiac and facial anomalies, urogenital abnormalities, limb defects, and mental retardation. Most affected infants require surgical correction of these anomalies. Presented are features inherent in the syndrome that will aid the anesthesiologist in the perioperative management of such patients.

Arterial-venous carbon dioxide tension difference during severe hemorrhage and resuscitation.

PURPOSE: To define clinically useful markers for determining the adequacy of resuscitation after hemorrhage. DESIGN: Prospective study of 20 Yorkshire swine, using an established model for hemorrhagic shock in swine. BACKGROUND AND METHODS: Clinically useful markers for assessing the adequacy of resuscitation after hemorrhage do not exist. We assess variables, such as BP and arterial blood pH. However, these variables do not correlate well with restoration of organ perfusion. In this study, 14 anesthetized swine were hemorrhaged to a mean arterial pressure of less than 25 mm Hg. After 30 mins without interventions, each animal was resuscitated with whole blood, hydroxyethyl starch, or normal saline. At baseline and during shock and resuscitation, hemodynamic variables, arterial and mixed venous blood gases, and arterial lactate concentrations were measured to determine which variables correlated most closely with the restoration of blood flow. RESULTS: The correlation between cardiac index and arterial or mixed venous pH and the correlations with arterial lactate values were poor. The correlation between cardiac index and mixed venous hemoglobin saturation also was weak (r2 = .28). Cardiac index correlated best with the arterial-venous PCO2 difference (r2 = .67) and the arterial-venous pH difference (r2 = .38). Using multiple regression, a linear correlation was established between the cardiac index and the arterial-venous pH and PCO2 differences throughout shock and resuscitation (r2 = .91). CONCLUSION: These findings suggest that the adequacy of resuscitation after hemorrhage can be assessed using paired arterial and mixed venous pH and PCO2 values.

Incidence of colonization, nosocomial pneumonia, and mortality in critically ill patients using a Trach Care closed-suction system versus an open-suction system: prospective, randomized study.

Eighty-four intubated, mechanically ventilated patients were prospectively evaluated for incidences of colonization and nosocomial pneumonias dependent on whether they received endotracheal suctioning by an "open" suction method vs. "closed" suction (Trach Care Closed Suction System) method. Results show that closed suctioning is associated with a significant (67% vs. 39% p less than .02) increase in colonization compared with open suctioning. However, difference in the incidence of nosocomial pneumonia was not significantly (26% vs. 29%) different between closed and open suctioning. Differences in severity of illness (Acute Physiology and Chronic Health Evaluation II and Therapeutic Intervention Scoring System), age, sex, presence of NG tubes, use of H2 antagonists or antacids, use of antibiotics, and history of smoking were all nonsignificant. Survival analysis demonstrated that the probability of survival without developing nosocomial pneumonia was greater among closed-suctioning patients vs. open-suctioned patients (p less than .03). This study shows that suctioning performed via the Trach Care closed-suction system increases the incidence of colonization but not the incidence of nosocomial pneumonia, and may actually decrease mortality when compared with open-suction systems.

Value of a screening fetal heart rate tracing in the latent phase of labor.

We studied the value of a screening fetal heart rate (FHR) tracing obtained on 405 women in the latent phase of labor on presentation to the labor-and-delivery suite. All pregnancies were at term and had a cephalic presentation. Thirty-two women in the sample studied underwent a cesarean section for fetal distress. Using that end point, a screening FHR tracing in the admitting room had a sensitivity of 57%, specificity of 98%, positive predictive value of 75% and overall efficiency of 95%. One- and five-minute Apgar scores and thick meconium staining of the amniotic fluid were also examined. While no statistically significant differences were found (P less than .2 for Apgar score and less than .06 for meconium), there was a trend that might have been significant if more women had been studied. A screening FHR tracing on all women at term in the latent phase of labor will identify the majority of those who will develop fetal distress in labor. Women with an abnormal screening tracing should be admitted to the hospital and the fetal status evaluated further.

Intrapartum, intranasal cocaine use and acute fetal distress. A case report.

Intrapartum, intranasal cocaine was used for relief of labor pains by a healthy woman with an uncomplicated pregnancy. Fetal hypoxemia and distress followed the event. A causal relationship between the intrapartum use of cocaine and the fetal distress was postulated. Cocaine abusers could benefit from hospitalization early in labor for close surveillance and monitoring, thus avoiding exposure to cocaine and its unpredictable systemic effects.

Cerebral electrophysiologic effects of resuscitation with hypertonic saline-dextran after hemorrhage.

When brain injury accompanies hemorrhage, resuscitation with hypertonic saline (HS) improves intracranial pressure (ICP) and elastance; however, its effect on brain function after a traumatic or ischemic insult has not been assessed. This study compares the electrophysiologic response to hemorrhage and resuscitation with 7.5% NaCl + 6% dextran (HSD), 6% hetastarch (HE), or 0.9% NaCl (NS) using somatosensory evoked potentials (SSEP). Resuscitation with HE resulted in a better return of electrocortical function than with either HSD or NS (SSEP grade 2.0 +/- 0.2 for HE vs. 3.2 +/- 0.3 for HSD and 2.9 +/- 0.3 for NS; p less than .01). SSEP response correlated closet with mean arterial pressure (MAP) (r = -.53). There was no correlation between the SSEP response and cardiac index (r = .06) or ICP (r = -.04). HSD blunted the usual early increase in ICP after fluid infusion, and resulted in a lower ICP throughout resuscitation. However, the restoration of MAP and cerebral perfusion pressure (CPP) after HSD infusion was poor. The vasodilatory properties of hypertonic saline have been well described, both in the systemic and in the pulmonary vascular bed. While these characteristic usually are cited as advantages of this solution, in the case of ischemic cerebral dysfunction, this diminished vascular tone prevents early restoration of the MAP and CPP. The result is suboptimal electrocortical recovery after hemorrhage.

A comparison of the cerebral and cardiovascular effects of complete resuscitation with isotonic and hypertonic saline, hetastarch, and whole blood following hemorrhage.

Hemorrhagic shock and closed head injury often accompany severe trauma. Hypertonic saline may be beneficial in these patients, but few have examined its properties when sufficient volume is infused to achieve sustained resuscitation. Solutions of 6% NaCl (HS), 0.9% NaCl (NS), 6% hetastarch (HE), and whole blood (WB) were used to resuscitate swine in hemorrhagic shock (MAP less than 30 mm Hg). The endpoint of resuscitation was normal oxygen delivery (DO2). Measurements of intracranial pressure (ICP), cerebral perfusion pressure (CPP), and intracranial elastance (ICE) were made in the absence and presence of an epidural mass, created by inflating an epidural balloon. HS resuscitation resulted in a lower ICP [5 +/- 1 versus 9 +/- 2 (HE), 17 +/- 3 (NS), and 10 +/- 3 (WB) mm Hg; p = 0.016], and normalization of CPP throughout resuscitation. Animals resuscitated with NS had a lower CPP by the end of resuscitation [CPP = 45 +/- 4 for NS group, versus 63 +/- 4 (HE), 66 +/- 4 (HS), and 63 +/- 5 (WB) mm Hg; p = 0.009]. ICE fell markedly in the HS group, [a decrease of 12 +/- 2 vs. a rise of 5 +/- 3 (HE), 2 +/- 3 (NS), and 6 +/- 3 (WB) mm Hg/ml; p = 0.0005]. This improvement was even more dramatic in the presence of an epidural mass [a fall of 21 +/- 3 vs. no change (HE, WB) and a rise of 4 +/- 3 (NS) mm Hg/ml; p = 0.0005]. For hemorrhage accompanied by severe head injury, resuscitation with HS may benefit victims by decreasing ICP and diminishing the effects of an intracranial mass.

A comparison of the effects of suxamethonium, atracurium and vecuronium on intracranial haemodynamics in swine.

Sixteen Yorkshire swine weighing 15-20 kg were studied to compare the effects of suxamethonium, atracurium and vecuronium on intracranial pressure (ICP), heart rate (HR), arterial blood pressure (BP), and cerebral perfusion pressure (CPP) in swine with normal or elevated ICP. In each animal an intracranial pressure-volume curve was produced by the inflation of an epidural balloon. The baseline ICP (Po), the ICP at the inflection point (Pi) and on the steep portion (Pmax) of the pressure-volume curve were identified and the balloon volumes recorded. The animals were assigned to receive either suxamethonium 1.0 mg/kg, atracurium 0.6 mg/kg, vecuronium 0.2 mg/kg, or saline placebo intravenously at three conditions: First, with the epidural balloon deflated Po, next at Pi, then at Pmax. Neither atracurium, vecuronium, nor placebo produced any statistically significant effect on HR, BP, ICP, or CPP at any baseline level of ICP. Suxamethonium produced an early fall in ICP (0.8 +/- 0.3, 2.6 +/- 1.0 and 3.5 +/- 1.3 mmHg at Po, Pi and Pmax respectively: P = .0005) followed by a rapid rise above the pre-infusion level (1.8 +/- 0.6, 2.8 +/- 0.6 mmHg, and 2.2 +/- 0.5 mmHg at Po, Pi and Pmax respectively: P = .0005). A fall in BP coupled with the rise in ICP resulted in a fall in CPP (5.8 +/- 2.3, 6.1 +/- 1.2, and 6.3 +/- 1.8 mmHg at Po, Pi and Pmax respectively: P = .0005). Although the fall in CPP was not large, in the presence of elevated ICP, where CPP already is marginal, such a decrease may compromise cerebral blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaginal delivery after cesarean section.

We retrospectively analyzed 194 pregnancies in women with a history of previous cesarean section (CS) who were offered a trial of labor. We offered every woman a trial of labor as long as she did not have a known previous classical scar. One hundred fifty-one women delivered vaginally (79%), 24 women had multiple uterine scars. Multiple gestations and breech presentation were not considered a sole indication to perform CS. Fetal and maternal morbidity are presented. We conclude that women with multiple previous CS scars can safely deliver vaginally as can women with unknown uterine scars, with careful intrapartum surveillance. Although our numbers of women with breech presentation and multiple gestations are small, in the absence of significant morbidity, we continue to allow these women to labor and deliver vaginally.

The hemodynamic effects of severe mitral stenosis and pulmonary hypertension during labor and delivery.

Pregnancy represents a hyperdynamic state characterized by increased cardiac output, blood volume, and oxygen consumption. Valvular heart disease may blunt this response and, especially when associated with pulmonary hypertension, carries a high mortality. We report the hemodynamic variables as measured through the completion of labor, delivery and postpartum period in a woman with severe mitral stenosis and pulmonary hypertension.

Pregnancy surveillance with Doppler velocimetry of uterine and umbilical arteries.

Previous studies with Doppler velocimetry have demonstrated a strong correlation between abnormal waveforms and fetal-maternal disease. This study was designed to evaluate the potential role of Doppler velocimetry as a screening test in routine prenatal care. Two hundred fifty-five pregnant women had routine monthly Doppler (systolic/end-diastolic ratio) studies on the uterine and umbilical arteries starting in the twentieth week of gestation. When a cutoff value of 3 was used at 30 weeks for the umbilical arteries, there were 35 (13%) positive tests. In 20 of these values fell to less than 3 in the ensuing weeks and were considered false positive. The remaining 15 babies demonstrated positive clinical pathologic correlates. When a value of 2.6 was used at 26 weeks for uterine arteries, there were nine positive results, seven of which had clinical pathologic correlates. This study suggested an overall positivity rate of 7%; therefore it provides encouragement for a larger venture in which screening and impact on decision making are evaluated.

Continuous thoracic epidural analgesia for the control of pain associated with pleural sclerosis.

Successful use of nonnarcotic, thoracic epidural analgesia for the control of pain associated with pleural sclerosis was accomplished in three gynecologic oncology patients with severe respiratory compromise due to malignant pleural effusions. Excellent analgesia was obtained with no observed anesthetic complications.

Upon-admission adrenal steroidogenesis is adapted to the degree of illness in intensive care unit patients.

Adrenal function was studied in 2 groups of intensive care unit (ICU) patients with varying degrees of illness, as determined by Acute Physiological and Chronic Health Evaluation (APACHE). The 15 seriously ill patients with high APACHE scores (greater than or equal to 25) had elevated Therapeutic Intervention Scores and increased mortality compared to the 15 ill patients (APACHE, less than or equal to 10; 67% vs. 27%). Plasma cortisol, aldosterone, and androstenedione concentrations were increased in the ICU patients compared to those in normal subjects (n = 23), being greater in the seriously ill patients. Plasma dehydroepiandrosterone sulfate (DHEAS) concentrations were low in both groups of ICU patients. The ratios of aldosterone or androstenedione to cortisol were not altered, whereas the DHEAS to cortisol ratios were reduced in the ICU patients. ACTH injection elicited increases in plasma cortisol, aldosterone, and androstenedione concentrations in both groups of ICU patients, and the ratios of aldosterone and androstenedione to cortisol did not change. In the seriously ill patients, plasma DHEAS increased, so that the DHEAS to cortisol ratio did not change, whereas in less ill patients plasma DHEAS did not increase, so that the DHEAS to cortisol ratio was reduced. In this study of patients admitted to an ICU, impairment of adrenal steroid secretion appears to be specific for DHEAS. Although plasma cortisol was elevated in ill patients proportional to the degree of illness, the contribution of the concomitant decrease in DHEAS to this increase is not clear.

Uterine and umbilical artery Doppler velocimetry in postterm pregnancy.

Uterine and umbilical artery Doppler velocimetry was carried out on 149 women whose pregnancies went to 41 weeks or beyond. Flow velocity was not altered even in the presence of other signs suggestive of fetal compromise. It appears that the postdate syndrome is not associated with significant alterations in the maternal or umbilical blood flow prior to the onset of labor.