Feasibility and utility of the use of real time random safety audits in adult ICU patients: a multicentre study

PURPOSE

The two aims of this study were first to analyse the feasibility and utility (to improve the care process) of implementing a new real time random safety tool and second to explore the efficacy of this tool in core hospitals (those participating in tool design) versus non-core hospitals.

METHODS

This was a prospective study conducted over a period of 4 months in six adult intensive care units (two of which were core hospitals). Safety audits were conducted 3 days per week during the entire study period to determine the efficacy of the 37 safety measures (grouped into ten blocks). In each audit, 50% of patients and 50% of measures were randomized. Feasibility was calculated as the proportion of audits completed over those scheduled and time spent, and utility was defined as the changes in the care process resulting from tool application.

RESULTS

A total of 1323 patient-days were analysed. In terms of feasibility, 87.6% of the scheduled audits were completed. The average time spent per audit was 34.5 ± 29 min. Globally, changes in the care process occurred in 5.4% of the measures analysed. In core hospitals, utility was significantly higher in 16 of the 37 measures, all of which were included in good clinical practice guidelines. Most of the clinical changes brought about by the tool occurred in the mechanical ventilation and haemodynamics blocks. Multivariate analyses demonstrated that changes in the care process in each block were associated with the core hospital variable, staffing ratios and severity of patient disease.

CONCLUSIONS

Real time safety audits improved the care process and adherence to the clinical practice guidelines and proved to be most useful in situations of high care load and in patients with more severe disease. The effect was greater in core hospitals.

Assessment of the environmental fate and effects of azilsartan, a selective antagonist of angiotensin II type 1

In this paper the results of a thorough evaluation of the environmental fate and effects of azilsartan are presented. Azilsartan medoxomil is administered as a pro-drug for the treatment of patients with essential hypertension. The pro-drug is converted by hydrolysis to the active pharmaceutical ingredient azilsartan. Laboratory tests to evaluate the environmental fate and effects of azilsartan medoxomil were conducted with azilsartan and performed in accordance with OECD test guidelines. The predicted environmental concentration (PEC) in surface water was estimated at 0.32 μg L(-1) (above the action limit of 0.01 μg L(-1)), triggering a Phase II assessment. Azilsartan is not readily biodegradable. Results of the water sediment study demonstrated significant shifting of azilsartan metabolites to sediment. Based on the equilibrium partitioning method, metabolites are unlikely to pose a risk to sediment-dwelling organisms. Ratios of the predicted environmental concentrations (PECs) to the predicted-no-effect concentrations (PNECs) did not exceed the relevant triggers, and the risk to aquatic, sewage treatment plant (STP), groundwater and sediment compartments was concluded acceptable. A terrestrial assessment was not triggered. Azilsartan poses an acceptable risk to the environment.

Elimination of piperacillin and tazobactam by renal replacement therapies with AN69 and polysulfone hemofilters: evaluation of the sieving coefficient

BACKGROUND/AIM

Piperacillin-tazobactam is commonly used to treat infections in ICU patients. Controversial data have been published about the sieving/saturation coefficient (Sc/Sa) of piperacillin during continuous renal replacement therapies (CRRT). The objective was to evaluate the Sc/Sa of piperacillin-tazobactam during continuous venovenous hemofiltration (CVVH) and continuous venovenous hemodialysis (CVVHD) using AN69 and polysulfone.

METHODS

Ringer lactate, BSA-containing Ringer lactate and plasma were circulated at 150 ml/min. The ultrafiltrate/dialysis flow was kept at 1,500 ml/min. A bolus was injected and samples were taken. Drugs were measured using HPLC. Sc/Sa was calculated according to standard formula.

RESULTS

Free passage of drugs through the membranes was reported with protein free solutions. In the presence of proteins the Sc/Sa lowered and correlated to protein free fraction. Polysulfone had a significantly higher permeability than AN69 during CVVH.

CONCLUSION

Drug binding to albumin contributes to the decrease of the Sc/Sa of piperacillin but it does not completely justify the in vivo value obtained by some authors.

Determination of ceftazidime and cefepime in plasma and dialysate-ultrafiltrate from patients undergoing continuous veno-venous hemodiafiltration by HPLC

We have developed and validated a new, rapid and reproducible HPLC method for the determination of cefepime and ceftazidime in plasma and dialysate-ultrafiltrate samples obtained from intensive care unit (ICU) patients undergoing continuous veno-venous hemodiafiltration (CVVHDF). The method for plasma samples involved protein precipitation with acetonitrile, followed by washing with dichloromethane to remove apolar lipophilic compounds. Dialysate-ultrafiltrate samples did not require any preparation. Separation was performed on a muBondapak C18 (30 cm x 3.9 mm x 10 microm) with UV detection. The mobile phase contained acetate buffer: ACN and was delivered at 2 ml/min. The coefficients of determination of the calibration curves were always > or = 0.998 and R.S.D.% of the response factors <10%. The intra and inter-assay precision and accuracy of the quality controls (QC) and limit of quantification (LOQ) were satisfactory in all cases. Plasma and dialysate-ultrafiltrate samples were stable at -20 and -80 degrees C for 2 months and also after three freeze/thaw cycles. Dialysate-ultrafiltrate samples were stable in the chromatographic rack for 24h at room temperature, but we recommend storing processed plasma samples at 4 degrees C until the analysis. The described method has proved to be useful to give accurate measurements of ceftazidime and cefepime in samples obtained from patients undergoing CVVHDF.

Emergence of a glomus-like body in the human yolk sac: a microanatomical analysis of its structure

Since the last decade the Yolk sac (YS) has been a topic of increasing interest due to the growing use of high-resolution sonography in early determination of pregnancy. Human YS shape and diameter are indicators of viability of pregnancy during the early embryonic period. Nevertheless, the major interest concerns the vital function it plays in early embryo growth and development. Two compartments are recognized in this organ: the yolk sac proper and the vitelline stalk. In this study we report the identification and partial characterization of a glomus-like body in the wall of the secondary YS in humans. A detailed structural description is also presented on the time course of formation of this new structure, at precisely sequential stages between 4-8 wk post-conception. The significance of this new compartment on the YS function is analyzed. Light and scanning electron microscopy were used to investigate the microstructure of the YS and the vitelline stalk during the first 8 wk of development. Ten YSs were collected from embryos (aged between 24-50 days) obtained from emergency salpingectomies due to tubal ectopic pregnancy. From 5 wk onward a new structure was observed in the YS located near the apex of the pear-shaped yolk vesicle and closed to the connecting stalk. We designate this differentiation as glomus-like body. This structure is 1-1.5 mm long and merged from a pocket-like structure of the extraembryonic splanchnic mesoderm of the YS wall. It likely represents an area of convergence of the vascular network of the YS wall. Our findings underline the remarkable complexity of the human secondary yolk sac during early development. The detailed description of the microanatomy of this vital organ is of theoretical and practical interest in order to unravel the mechanisms used by the yolk sac to transport nutrients to the embryo.

Chromosomal abnormalities in fetuses with open neural tube defects: prenatal identification with ultrasound

OBJECTIVES

To determine the prevalence of chromosomal abnormalities in fetuses with open neural tube defects (NTD) undergoing prenatal chromosome analysis. The role of prenatal ultrasound in detecting those with an underlying chromosomal abnormality was also investigated.

METHODS

Over a 6-year period, 144 fetuses with open NTD underwent prenatal chromosome analysis between 12 and 37 weeks of gestation, as part of a prospective, multicenter prenatal diagnosis and counseling program in Chile. This population included 66 fetuses with spina bifida, 46 with acrania/anencephaly, 21 with cephalocele and 11 with iniencephaly. A confident prenatal diagnosis was made in 143 fetuses (99%) and confirmed postnatally in all cases.

RESULTS

An underlying chromosomal abnormality was diagnosed in 10 fetuses (7%), six with spina bifida, three with cephalocele and one with craniorachischisis. The prevalence of chromosomal abnormality varied according to the defect present in the fetus, with a 14% (3/21) prevalence among those with cephalocele, 9% (6/66) among those with spina bifida and 2% (1/57) among those with lethal defects such as acrania, anencephaly or iniencephaly. Karyotype results revealed trisomy 18 in seven cases, trisomy 13 in two and mosaicism for a marker chromosome in one. Prenatal ultrasound before the procedure showed that all chromosomally abnormal fetuses had additional findings. The prevalence of chromosomal abnormality in fetuses with spina bifida and cephalocele was higher when chromosome analysis was performed at or before 24 weeks of gestation in comparison to those performed after 24 weeks (5/31 (16%) vs. 4/56 (7%), respectively). However, this difference did not reach statistical significance, probably due to the small number of cases.

CONCLUSIONS

A significant number of fetuses with open NTD are chromosomally abnormal. Although prenatal chromosome analysis should be considered in all cases, prenatal ultrasound seems effective in identifying those fetuses with an underlying chromosomal abnormality.

Umbilical artery aneurysm: prenatal identification in three fetuses with trisomy 18

Aneurysm of the umbilical artery is an extremely rare anomaly of the umbilical cord, with only two cases being documented in the English language literature. We report three cases diagnosed prenatally by ultrasound in the third trimester, all associated with single umbilical artery and multiple structural fetal anomalies. Prenatal karyotyping revealed trisomy 18 in all three cases. Umbilical cord anomalies, although rare, are associated with significant fetal morbidity and mortality. This report identifies umbilical artery aneurysm as an additional prenatal feature of trisomy 18.

Prenatal diagnosis of solid placental masses: the value of color flow imaging

OBJECTIVES

To determine the value of color flow imaging in the prenatal differentiation of solid placental masses protruding from the fetal surface of the placenta.

METHODS

Seven pregnancies in which a large solid mass was seen on the fetal surface of the placenta were prospectively studied. Color flow imaging was used to identify vessels within the mass and the prenatal ultrasound finding correlated with placental pathology.

RESULTS

Postpartum examination of the placenta revealed four cases of chorioangioma, two cases of subchorionic thrombohematoma and one case of subamniotic hematoma. Prenatal ultrasound using color flow imaging correctly identified all cases of placental chorioangioma by the demonstration of blood flow within the mass. Conversely, absence of blood flow signals was invariably documented in both cases of subchorionic thrombohematoma and in the single case of subamniotic hematoma. Among the four cases of chorioangioma, two developed complications requiring delivery. No complications were noted in cases of avascular placental masses in this series.

CONCLUSIONS

Color Doppler ultrasound plays an important role in the prenatal evaluation of solid placental masses. This technique allows the identification of those cases at increased risk of pregnancy complications which need close monitoring throughout gestation.

Iniencephaly: prenatal diagnosis and management

Iniencephaly is a rare malformation characterized by the triad of occipital bone defect, cervical dysraphism and fixed retroflexion of the fetal head. Because of its almost invariable lethal prognosis, termination of pregnancy is commonplace when this condition is diagnosed before viability. In this report we describe eight cases of iniencephaly prenatally diagnosed by ultrasound between 18 and 28 weeks of gestation and discuss the subsequent obstetric management in a country where elective abortion is illegal. Prenatal karyotyping was performed in seven cases, revealing a normal complement in all fetuses. One pregnancy miscarried at 24 weeks. Uneventful vaginal delivery was accomplished in six of the remaining seven cases, one delivered spontaneously at 29 weeks and five were induced between 28-32 weeks due to increasing polyhydramnios. In the remaining case the pregnancy progressed to 35 weeks, at which time spontaneous labour began and an emergency Caesarean section was performed because of malpresentation. There were no survivors in this series. We conclude that, in countries were elective abortion is not allowed, women carrying an iniencephalic fetus may benefit from preterm induction of labour in order to avoid labour dystocia, maternal trauma during delivery and the risks of a Caesarean section.

Sirenomelia sequence versus renal agenesis: prenatal differentiation with power Doppler ultrasound

In order to assess the role of power Doppler ultrasound in the prenatal diagnosis of sirenomelia, prenatal findings in two fetuses with the sirenomelia sequence and in seven with bilateral renal agenesis were reviewed and compared. Both conditions were characterized by absence of renal vessels. However, the two common iliac arteries were always visualized in fetuses with renal agenesis, whereas absence of distal branching of the main abdominal vessel was a characteristic feature of sirenomelia. Power Doppler ultrasound allows expeditious identification of absent or non-functional renal arteries in fetuses with severe oligohydramnios. In addition, incorporation of power Doppler imaging to identify the aortic bifurcation could provide a diagnostic feature that could assist in the prenatal diagnosis of sirenomelia and in the differential diagnosis with other causes of bilateral renal agenesis.

Fetal prognosis in varix of the intrafetal umbilical vein

To assess the clinical significance of varix of the intraabdominal portion of the umbilical vein, we reviewed 10 cases diagnosed prenatally by ultrasonography at a median gestational age of 27 weeks. A comprehensive anatomic survey and serial follow-up scans were performed in each case. All three fetuses with associated anomalies died in utero, and prenatal karyotyping revealed that two of them had a chromosomal abnormality. In six of the seven cases with structurally normal fetuses the pregnancy proceeded uneventfully, and no neonatal complications were attributed to the umbilical vein varix. Our experience and the review of the literature revealed 42 cases with information on fetal outcome. Overall, 24% of the fetuses died, 12% had a chromosomal abnormality, and 5% developed hydrops. We conclude that fetuses with varix of the intrafetal umbilical vein should be considered at risk for poor outcome. However, if no other anomalies are present, the prognosis is generally good.