Persistent Organic Pollutants in Austrian Human Breast Milk Collected between 2013 and 2016

Breast milk holds an immense nutritional value as it contains health-promoting substances in a unique, optimal form. Additionally, breast milk's significance extends to health and environmental protection, as it serves as an indicator of both maternal and infant exposure. In this study, breast milk samples collected in 2013 and in 2014-2016 from mothers in Vienna (Austria) were analysed for polybrominated diphenyl ethers (PBDE) and per- and polyfluoroalkyl substances (PFAS), as well as further substances which have been listed under the Stockholm Convention on Persistent Organic Pollutants (POPs) due to their persistent, bioaccumulative and toxic properties. The total concentration of the PBDE congeners in the samples (n = 18, sampled 2013) ranged from 0.055 to 52 ng/g lipid, and from 0.002 to 2.5 ng/g breast milk. In the pooled sample, the sum of PBDEs was detected at a level of 4.4 ng/g lipid. Based on the 2014-2016 study population, certain PFAS were detected in all samples (n = 40). Exposure to the sum of four specific PFAS including perfluorooctanesulphonate (PFOS), perfluorooctanoic acid (PFOA), perfluoro-n-nonanoic acid (PFNA) and perfluoro-1-hexanesulfonate (PFHxS) ranged between 0.014 and 0.12 ng/L breast milk. In the pooled sample, PFOS and PFOA were found in concentrations of 0.025 ng/g and of 0.045 ng/g, respectively. In addition, the first generation of POPs, mainly organochlorine compounds, was measured in a pooled sample of breast milk from participants sampled in 2014-2016 as part of the WHO/UNEP breast milk monitoring program and compared to the POPs measured in pooled samples collected in 1987/1988 and 1992/1993, respectively. Therefore, this paper demonstrates the effectiveness of the Stockholm Convention on POPs by comparing the Austrian results from the WHO/UNEP global breast milk study from 1987 to 2016. However, the data also show that, despite these reductions, health-relevant levels are still being reached, particularly in terms of children's health when the presence of the new generation of POPs, such as PBDEs and PFAS, in human breast milk is taken into account.

Prenatal exposure to per- and polyfluoroalkyl substances and pregnancy outcome in Austria

Per- and polyfluoroalkyl substances (PFAS) are a large group of persistent industrial chemicals that can harm reproductive health. PFAS levels were analysed to determine the current sources of exposure and possible associations between prenatal PFAS exposure and adverse pregnancy outcome. Samples from 136 mother-newborn pairs recruited between 2017 and 2019 were analysed for the presence of 31 target PFAS in maternal serum, umbilical cord serum, and placental tissue by high-performance liquid chromatography coupled to a tandem mass spectrometer. Questionnaires and medical records were used to survey sources of exposure and pregnancy outcome, including small for gestational age (SGA), fetal growth restriction (FGR), preeclampsia (PE), preterm birth, large for gestational age (LGA) and gestational diabetes mellitus (GDM). Data were analysed for individual PFAS and sum4PFAS (sum of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) serum levels) in logistic regression analyses and categorical regression analyses. Compared to data from a previous Viennese study in 2010-12, sum4PFAS levels were generally lower. Sum4PFAS serum levels of three women (2.2%) exceeded 6.9 µg/L, a level that corresponds to the recently established tolerable weekly intake (TWI) of EFSA for nursing mothers aged 35 years; in the 2010/2012 study it was 13.6%. The large contribution of unidentified extractable organofluorine (EOF) fractions to total PFAS exposure is a concern. Study site, mean maternal corpuscular hemoglobin (MCH), use of facial lotion, and owning upholstered furniture were significantly influencing maternal exposure. While no effect of sum4PFAS on pregnancy outcome could be detected, we found highest placental PFDA levels in SGA births. PFHxS levels in umbilical cord and placenta were highest in preterm births. Further studies are needed to elucidate the relationship of prenatal PFAS exposure and pregnancy outcome, in particular to confirm whether and how placental PFDA levels may contribute to an increased risk for SGA.

Consideration of pathways for immunotoxicity of per- and polyfluoroalkyl substances (PFAS)

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are of public health concern, because of their ubiquitous and extremely persistent occurrence, and depending on their structure, their bio-accumulative, mobile and toxic properties. Human health effects associated with exposure to PFAS include adverse effects on the immune system. In 2020, EFSA (the European Food Safety Authority) defined adverse effects on the immune system as the most critical effect for human health risk assessment, based on reduced antibody responses to childhood vaccines and similar effects observed in experimental animal studies. Likewise, the U.S. EPA (Environmental Protection Agency) considers PFAS-induced immunotoxicity, especially in children, as the critical effect for risk assessment. However, the mechanisms by which antibody concentrations are impacted are not completely understood. Furthermore, other targets of the immune system functions have been reported in the literature.

OBJECTIVE

The aim of this review is to explore PFAS-associated immune-related effects. This includes, relevant mechanisms that may underlie the observed effects on the immune system, immunosuppression as well as immunoenhancement, such as i) modulation of cell signalling and nuclear receptors, such as NF-κB and PPARs; ii) alteration of calcium signalling and homoeostasis in immune cells; iii) modulation of immune cell populations; iv) oxidative stress and v) impact on fatty acid metabolism & secondary effects on the immune system.

METHODS

A literature research was conducted using three databases (Web of Science, PubMed, and Scopus), which were searched in July 2021 for relevant studies published in the time frame from 2018 to 2021. In total, 487 publications were identified as potentially eligible and following expert-based judgement, articles relevant for mechanisms of PFAS induced immunotoxicity are discussed.

CONCLUSIONS

Taken together, we show that there is substantial evidence from both in vitro and in vivo experimental as well as epidemiological studies, supporting that various PFAS, not only PFOA and PFOS, affect multiple aspects of the immune system. Timing of exposure is critical, because the developing immune system is especially vulnerable to toxic insults, resulting in a higher risk of particularly adverse immune effects but also other organs later in life.

Characterization of Potential Adverse Outcome Pathways Related to Metabolic Outcomes and Exposure to Per- and Polyfluoroalkyl Substances Using Artificial Intelligence

Human exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with numerous adverse health effects, depending on various factors such as the conditions of exposure (dose/concentration, duration, route of exposure, etc.) and characteristics associated with the exposed target (e.g., age, sex, ethnicity, health status, and genetic predisposition). The biological mechanisms by which PFAS might affect systems are largely unknown. To support the risk assessment process, AOP-helpFinder, a new artificial intelligence tool, was used to rapidly and systematically explore all available published information in the PubMed database. The aim was to identify existing associations between PFAS and metabolic health outcomes that may be relevant to support building adverse outcome pathways (AOPs). The collected information was manually organized to investigate linkages between PFAS exposures and metabolic health outcomes, including dyslipidemia, hypertension, insulin resistance, and obesity. Links between PFAS exposure and events from the existing metabolic-related AOPs were also retrieved. In conclusion, by analyzing dispersed information from the literature, we could identify some associations between PFAS exposure and components of existing AOPs. Additionally, we identified some linkages between PFAS exposure and metabolic outcomes for which only sparse information is available or which are not yet present in the AOP-wiki database that could be addressed in future research.

Ozone as oxidizing agent for the total oxidizable precursor (TOP) assay and as a preceding step for activated carbon treatments concerning per- and polyfluoroalkyl substance removal

Several thousands of highly persistent per- and polyfluoroalkyl substances (PFAS) exist and it is therefore challenging to analytically determine a larger spectrum of these compounds simultaneously in one sample. It is even more difficult to efficiently remove mobile PFAS in wastewater treatment plants (WWTPs) to protect the receiving waters. The total oxidizable precursor (TOP) assay is an approach that enables the detection of the total PFAS content in a sample via oxidation of precursors, followed by subsequent analysis of the perfluoroalkyl acid (PFAA) concentration before and after oxidative processes. Activated carbon combined with a preceding ozonation step is considered a promising tool for the removal of micropollutants but considering PFAS removal efficiencies in effluents for this process combination more information is required. The focus of the study was to implement and assess the TOP assay with ozone as oxidizing agent to estimate the total PFAS content in a WWTP effluent. Additionally, granular activated carbon (GAC) and powdered activated carbon (PAC) with a preceding ozonation step was tested for the removal efficiencies for 22 PFAS. For the TOP assay the obtained accordance in molarity using spiked tap water as quality control was 95.2% (15 mg O₃/L) and 99.1% (6 mg O₃/L). Applying the TOP assay, an estimated total PFAS content of 840 ng/L was determined in the respective effluent, which was 91.1% higher than obtained by target PFAS analysis, implying the presence of unknown precursors not included in common monitoring. While all treatment techniques that included ozone or a preceding ozonation step solely transformed precursors and long-chain perfluoroalkyl acids (PFAA, i.e., >C9) to shorter congeners, PAC was the only tested water treatment application that was able to remove 19.3% of the total PFAS molarity.

Extractable Organofluorine Analysis in Pooled Human Serum and Placental Tissue Samples from an Austrian Subpopulation-A Mass Balance Analysis Approach

Embryos and fetuses are of major concern due to their high vulnerability. Previous studies demonstrated that human exposure to per- and polyfluoroalkyl substances (PFAS) may be underestimated because only a limited number of known PFAS can be measured. This investigation studied the total PFAS exposure by measuring the extractable organofluorine (EOF) in pooled maternal serum, placental tissue, and cord serum samples (total number of pooled samples: n = 45). The EOF was analyzed using combustion ion chromatography, and the concentrations of known PFAS were determined using ultraperformance liquid chromatography coupled with a tandem mass spectrometer. Using a mass balance analysis approach, the amount of unknown PFAS was estimated between the levels of known PFAS and EOF. The EOF levels ranged from 2.85 to 7.17 ng F/mL (21 PFAS were quantified) in the maternal serum, from 1.02 to 1.85 ng F/g (23 PFAS were quantified) in the placental tissue, and from 1.2 to 2.10 ng F/mL (18 PFAS were quantified) in the cord serum. An average of 24, 51, and 9% of EOF is unidentified in the maternal serum, placental tissue, and cord serum, respectively. The results show that the levels of unidentified EOF are higher in the placental tissue, suggesting accumulation or potential transformation of precursors in the placenta.

Comparison of extraction methods for per- and polyfluoroalkyl substances (PFAS) in human serum and placenta samples-insights into extractable organic fluorine (EOF)

Since the detection of per- and polyfluoroalkyl substances (PFAS) in humans and different environmental media in the last two decades, this substance group has attracted a lot of attention as well as increasing concerns. The fluorine mass balance approach, by comparing the levels of targeted PFAS after conversion to fluorine equivalents with those of extractable organic fluorine (EOF), showed the presence of unidentified organofluorine in different environmental samples. Out of the thousands of PFAS in existence, only a very small fraction is included in routine analysis. In recent years, liquid chromatography coupled with tandem-mass spectrometry (LC-MS/MS) has demonstrated the ability to analytically cover a wide spectrum of PFAS. In contrast, conventional extraction methods developed 10 to 15 years ago were only evaluated for a limited number of PFAS. The aim of the present study was to evaluate the advantages and disadvantages of three different extraction methods, adapted from the literatures without further optimization (ion-pair liquid-liquid extraction, solid-phase extraction (SPE), using hydrophilic-lipophilic (HLB) or weak anion exchange (WAX) sorbents), for human biomonitoring of 61 PFAS in serum and placental tissue samples. In addition, levels of EOF were compared among these extraction methods via spiked samples. Results showed that performance, in terms of recovery, differed between the extraction methods for different PFAS; different extraction methods resulted in different EOF concentrations indicating that the choice of extraction method is important for target PFAS and EOF analysis. Results of maternal serum samples, analyzed in two different laboratories using two different extraction methods, showed an accordance of 107.6% (± 21.3); the detected perfluoroalkyl acids (PFAAs) in maternal and cord serum samples were in the range of 0.076 to 2.9 ng/mL.

Graphical abstract

Robotic-assisted laparoscopic repair of rectovesical fistula after Hartmann's reversal procedure

The case is of a 59-year-old male with history of severe ischemic colitis following emergent intervention for a ruptured infrarenal aortic aneurysm who subsequently underwent left hemicolectomy, partial proctectomy, and Hartmann colostomy. The patient later underwent reversal of the Hartmann colostomy with diverting ileostomy. The surgery was complicated by a right ureteral and posterior bladder injury that resulted in a large rectovesical fistula involving the right hemitrigone and right ureteral orifice. An attempt to repair the rectovesical fistula at an outside facility was unsuccessful. Then, he underwent a robotic-assisted laparoscopic repair of rectovesical fistula, including simple prostatectomy, excision of rectovesical fistulous tract, rectal closure, peritoneal and omental flap interposition, bladder neck reconstruction, vesicourethral anastomosis and right ureteral reimplantation. There were no intraoperative or postoperative complications, and the patient was discharged at postoperative day 4; cystoscopy at 6-week follow-up demonstrated a successful closure of the fistula, at which time the ureteral stents were removed.

Definitive seton management for transsphincteric fistula-in-ano: harm or charm?

AIM

The treatment of transsphincteric anal fistula requires a balance between eradication of the disease and preservation of faecal control. A cutting seton is an old tool that is now out of vogue for many surgeons. We hypothesized that the concept remains reliable and safe with results that exceed those reported for many of the more recently described methods.

METHOD

A retrospective review was conducted of real-time electronic health records (single institution, single surgeon) of patients presenting during the 14 years between 2001 and 2014 with a transsphincteric anal fistula who were treated with a cutting seton. Excluded were patients with Crohn's disease, fistulae related to malignancy or a previous anastomosis and patients whose fistula was treated by another method including a loose draining seton. Data collection included demographics, duration of the disease, duration of the treatment, outcome and continence.

RESULTS

In all, 121 patients (80 men) of mean age 40.2 ± 12.2 years (range 18-76) with a mean follow-up of 5.1 ± 3.3 (1-24) months were included in the analysis. The median duration of symptoms was 6 (1-84) months; 36% had failed other fistula surgery, 12% had a complex fistula with more than one track and 35% had some form of comorbidity. The median time to healing was 3 (1-18) months; 7.4% required further surgery, but eventually 98% had complete fistula healing. The incontinence rate decreased postoperatively to 11.6% from 19% before treatment with 17/121 with pre-existing incontinence resolved and 8/107 new cases developing.

CONCLUSION

Despite its retrospective non-comparative design, the study has demonstrated that a cutting seton is a safe, well tolerated and highly successful treatment for transsphincteric anal fistula and is followed overall by improved continence. The results compare very favourably with other techniques.

Prevalence and risk factors for carriage of ESBL-producing Enterobacteriaceae in Amsterdam

Objectives

The objectives of this study were to determine the prevalence of carriage of ESBL-producing Enterobacteriaceae (ESBL-E) in a representative sample of the general adult Dutch community, to identify risk factors and to gain understanding of the epidemiology of these resistant strains.

Methods

Adults enrolled in five general practices in Amsterdam were approached by postal mail and asked to fill in a questionnaire and to collect a faecal sample. Samples were analysed for the presence of ESBL-E. ESBL genes were characterized by PCR and sequencing. Strains were typed using MLST and amplified fragment length polymorphism (AFLP) and plasmids were identified by PCR-based replicon typing. Risk factors for carriage were investigated by multivariate analysis.

Results

ESBL-E were found in 145/1695 (8.6%) samples; 91% were Escherichia coli. Most ESBL genes were of the CTX-M group (bla_CTX-M-1 and bla_CTX-M-15). MLST ST131 was predominant and mainly associated with CTX-M-15-producing E. coli. One isolate with reduced susceptibility to ertapenem produced OXA-48. In multivariate analyses, use of antimicrobial agents, use of antacids and travel to Africa, Asia and Northern America were associated with carriage of ESBL-E, in particular strains with bla_CTX-M-14/15.

Conclusions

This study showed a high prevalence of ESBL-E carriage in the general Dutch community. Also, outside hospitals, the use of antibiotics was a risk factor; interestingly, use of antacids increased the risk of carriage. A major risk factor in the general population was travel to countries outside Europe, in particular to Asia, Africa and Northern America.

Electronic structure changes across the metamagnetic transition in FeRh via hard X-ray photoemission

Stoichiometric FeRh undergoes a temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) transition at ~350 K. In this Letter, changes in the electronic structure accompanying this transition are investigated in epitaxial FeRh thin films via bulk-sensitive valence-band and core-level hard x-ray photoelectron spectroscopy with a photon energy of 5.95 keV. Clear differences between the AFM and FM states are observed across the entire valence-band spectrum and these are well reproduced using density-functional theory. Changes in the 2p core levels of Fe are also observed and interpreted using Anderson impurity model calculations. These results indicate that significant electronic structure changes over the entire valence-band region are involved in this AFM-FM transition.

Efficacy of management algorithm for reducing need for sphincterotomy in chronic anal fissures

BACKGROUND

Lateral internal sphincterotomy is the most effective treatment for chronic anal fissure (CAF), but carries a risk of faecal incontinence. We aimed to analyse efficacy and acceptance of a treatment algorithm in reducing the rate of necessary sphincterotomies.

METHOD

Patients with CAF seen from 2001 to 2010 were retrospectively analysed. All patients were offered all steps of the algorithm nitroglycerine (NTG) → Botox (BTX) → surgery, unless symptoms or patient preference demanded a more aggressive treatment. Patients were followed up in clinic, and treatment was advanced if a step either failed or caused intolerable side effects.

RESULTS

Two hundred and nine patients were included in the analysis. Mean duration of symptoms was 25.6 months and mean follow up 16 months. One hundred and 41 patients started on NTG, 36 on BTX, and 31 went straight to surgery. One patient opted for no treatment. Symptoms persisted in 58 (41.1%) of 141 NTG patients. Forty-five (31.9% of NTG subset) were advanced to BTX and 13 (9.2% of subset) to surgery. Of the 81 (36 primary + 45 secondary) BTX patients (38.8% of the total), only 11 (13.6% of subset) required surgery. A total of 55 (31 primary + 24 secondary; 26.3%) patients needed surgery: two (3.6%) fissures did not heal, one patient developed an abscess, 14 (25.5%) had prolonged wound healing and two (3.6%) developed a recurrent fissure after the sphincterotomy had healed.

CONCLUSION

Our algorithm is effective in CAF and the majority of patients respond to conservative management. Only 26.3% of all patients require surgery, which is effective but also carries some temporary morbidity.

Deflection gating for time-resolved x-ray magnetic circular dichroism-photoemission electron microscopy using synchrotron radiation

In this paper, we present a newly developed gating technique for a time-resolving photoemission microscope. The technique makes use of an electrostatic deflector within the microscope's electron optical system for fast switching between two electron-optical paths, one of which is used for imaging, while the other is blocked by an aperture stop. The system can be operated with a switching time of 20 ns and shows superior dark current rejection. We report on the application of this new gating technique to exploit the time structure in the injection bunch pattern of the synchrotron radiation source BESSY II at Helmholtz-Zentrum Berlin for time-resolved measurements in the picosecond regime.

Suppression of near-Fermi level electronic states at the interface in a LaNiO3/SrTiO3 superlattice

Standing-wave-excited photoemission is used to study a SrTiO3/LaNiO3 superlattice. Rocking curves of core-level and valence band spectra are used to derive layer-resolved spectral functions, revealing a suppression of electronic states near the Fermi level in the multilayer as compared to bulk LaNiO3. Further analysis shows that the suppression of these states is not homogeneously distributed over the LaNiO3 layers but is more pronounced near the interfaces. Possible origins of this effect and its relationship to a previously observed metal-insulator-transition in ultrathin LaNiO3 films are discussed.

Prevalence of methicillin-resistant Staphylococcus aureus and risk factors for carriage in Dutch hospitals

To evaluate the actual burden of methicillin-resistant Staphylococcus aureus and determine risk factors for carriage and infection, we performed a prevalence survey with a nested case-control study among inpatients in Dutch hospitals. The prevalence of carriage was 0.94 cases per 1,000 inpatients, and the prevalence of infection was 0.21 cases per 1,000 inpatients. Professional contact with livestock and a stay in a foreign hospital were associated with carriage.

Cloaca-like deformity with faecal incontinence after severe obstetric injury--technique and functional outcome of ano-vaginal and perineal reconstruction with X-flaps and sphincteroplasty

OBJECTIVE

Surgical technique and outcomes report.

SUMMARY BACKGROUND DATA

Three to eight per cent of vaginal deliveries are complicated by third- or fourth- degree perineal lacerations, resulting in a cloaca-like deformity in up to 0.3%. These three-dimensional defects result in often debilitating incontinence and symptoms similar to a rectovaginal fistula because of the lack of the distal rectovaginal septum.

METHOD

Between 2001 and 2006, 12 women (median age 37, range 20-57) with faecal incontinence and a postobstetric-injury-associated cloaca-like deformity underwent an ano-vaginal and perineal reconstruction with X-flaps and sphincteroplasty without primary faecal diversion.

RESULTS

The patients presented 13.0 +/- 2.9 years (range 0.5-29 years) after the obstetric injury. The median Cleveland Clinic Florida faecal incontinence score was 16 (range 12-19). In addition, one patient complained of vaginal discharge, another of dyspareunia. All patients had an open rectovaginal communication with a large anterior sphincter defects (mean 160.2 +/- 22.8 degrees, range 113-180). Resting/squeeze pressures were 28.0 +/- 4.4/63.2 +/- 8.1 mmHg, respectively. Pudendal neuropathy was present in five patients. The median length of hospital stay after surgery was 5.3 +/- 0.7 days. Three patients experienced a postoperative rectovaginal fistula, two of which closed spontaneously, whereas the third required faecal diversion and a bulbocavernosus flap. After surgical follow-up of 9.8.3 +/- 2.8 months and long-term follow-up of 38.9.0 +/- 6.9 months, all the patients were satisfied with regards to overall function, continence and cosmetic result.

CONCLUSION

Cloaca-like deformity resulting from severe obstetric injury is often not given appropriate attention. Reconstruction of the original anatomy is complex but achieves good results and does not require a prophylactic faecal diversion.

The prognostic impact of the time interval to recurrence for the mortality in recurrent colorectal cancer

OBJECTIVE

The risk of a cancer recurrence has been correlated with the stage of the primary tumour at the time of presentation. However, once a recurrence has developed, the primary tumour stage may not be the determining prognostic factor anymore. The objective of this study was (i) to evaluate the association between the recurrence interval and the outcome of the recurrence, and (ii) to determine whether that interval was affected by the use of adjuvant radiation and/or chemotherapy.

METHOD

This retrospective study analysed 212 patients who developed recurrent colorectal cancer from 1987 to 1993. Primary parameters such as age, gender, primary tumour site and stage, and use of postoperative adjuvant treatment were correlated with the recurrence interval, the type and site of the recurrence (i.e. locoregional vs distant metastases), and the outcome. Uni- and multivariate analysis was used to compare the recurrence interval and survival between different subgroups as defined by risk factors.

RESULTS

The mean time between the primary and the recurrent tumour was 25 months (range 1-252 months) with 82% of the recurrences developing within 3 years after surgery. The recurrence interval was inversely correlated with the initial tumour stage. Poor survival was associated with a short recurrence interval (less than 12 months) and a distant recurrence site. Even after adjusting for the initial tumour stage, the use of adjuvant treatment did not prolong the interval, i.e. delay the onset of recurrent cancer.

CONCLUSION

The recurrence interval of colorectal cancer is a prognostic factor. However, the use of adjuvant therapy did not prolong that interval.

Nosocomial infections in a Dutch neonatal intensive care unit: surveillance study with definitions for infection specifically adapted for neonates

The incidence of nosocomial infection in neonatal intensive care units (NICUs) is high compared with other wards. However, no definitions for hospital-acquired infection are available for NICUs. The aim of this study was to measure the incidence of such infections and to identify risk factors in the NICU of the VU University Medical Center, which serves as a level III regional NICU. For this purpose, a prospective surveillance was performed in 1998-2000. We designed definitions by adjusting the current definitions of the Centers for Disease Control and Prevention (CDC) for children <1 year of age. Birth weight was stratified into four categories and other baseline risk factors were dichotomized. Analysis of risk factors was performed by Cox regression with time-dependent variables. The relationship between the Clinical Risk Index for Babies (CRIB) and nosocomial infection was investigated. Furthermore, for a random sample of cases, we determined whether bloodstream infection and pneumonia would also have been identified with the CDC definitions. Seven hundred and forty-two neonates were included in the study. One hundred and ninety-one neonates developed 264 infections. Bloodstream infection (N=138, 14.9/1000 patient-days) and pneumonia (N=69, 7.5/1000 patient-days) were the most common infections. Of bloodstream infections, 59% were caused by coagulase-negative staphylococci; in 21% of neonates, blood cultures remained negative. In 25% of pneumonias, Enterobacteriaceae were the causative micro-organisms; 26% of cultures remained negative. Compared with the Nosocomial Infections Surveillance System (NNIS) of the CDC, our device utilization ratios and device-associated nosocomial infection rates were high. The main risk factors for bloodstream infection were birth weight [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.45-2.17] and parenteral feeding with hospital-pharmacy-produced, all-in-one mixture 'Minimix' (HR 3.69, 95%CI 2.03-6.69); administration of intravenous antibiotics (HR 0.39, 95%CI 0.26-0.56) was a protective risk factor. The main risk factors for pneumonia were low birth weight (HR 1.37, 95%CI 1.01-1.85) and mechanical ventilation (HR 9.69, 95%CI 4.60-20.4); intravenous antibiotics were protective (HR 0.37, 95%CI 0.21-0.64). In a subcohort of 232 very-low-birthweight neonates, the CRIB was not predictive for infection. With the CDC criteria, only 75% (21/28) of bloodstream infections and 87.5% of pneumonias (21/24) would have been identified. In conclusion, our local nosocomial infection rates are high compared with those of NICUs participating in the NNIS. This can be partially explained by: (1) the use of our definitions for nosocomial infection, which are more suitable for this patient category; and (2) the high device utilization ratios.

[Resistant microorganisms in patients transferred from foreign hospitals]

OBJECTIVE

To determine the prevalence of carriers of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and gentamicin-resistant Gram-negative bacilli (GGNB) in patients repatriated from foreign hospitals to The Netherlands.

DESIGN

Determination of prevalence.

METHOD

In the period May 1998-August 2001, 1167 patients were repatriated. Swab specimens, demographic data and clinical data were obtained during the transfer.

RESULTS

The prevalence of carriers of resistant microorganisms was 18.2%. MRSA was carried by 2.7% of the total repatriated group and by 4.7% of patients transferred to a Dutch hospital. Risk factors were antimicrobial treatment (odds ratio (OR): 3.4; 95% CI: 1.2-9.7), length of stay in a foreign hospital > or = 14 days (OR: 5.4; 95% CI: 2.3-12) and artificial ventilation (OR: 8.5; 95% CI: 1.8-41). VRE and GGNB were isolated from 2.7% and 14.1% of patients, respectively. Transfer from Asia or southern, south-eastern and eastern Europe were risk factors for carrying GGNB.

CONCLUSION

Carriership of resistant microorganisms was high among repatriated patients. The highest risk of GGNB was more closely associated with the country from which the patient was transferred than the antimicrobial treatment received in the foreign hospital.

Carriage of resistant microorganisms in repatriates from foreign hospitals to The Netherlands

In a prospective survey conducted between May 1998 and September 2001, the prevalence of carriage of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and gentamicin-resistant Gram-negative bacilli (GGNB) was determined in 1167 patients repatriated from foreign hospitals to The Netherlands. Swab specimens, demographic data and clinical data were obtained during transfer of the patients from the foreign hospitals. The total prevalence of carriage of resistant microorganisms was 18.2%. MRSA was carried by 2.7% of all patients, and by 4.7% of the patients repatriated to a Dutch hospital. Antimicrobial treatment (adjusted odds ratio (OR) 3.4; 95% confidence interval (CI) 1.2-9.7), length of stay in a foreign hospital of > 14 days (adjusted OR 5.4; 95% CI 2.3-12) and artificial ventilation (adjusted OR 8.5; 95% CI 1.8-41) were risk factors for carriage of MRSA. VRE and GGNB were isolated from 2.7% and 14.1% of the patients, respectively. Transfer from Asia, and southern, southeastern and eastern Europe, were risk factors for carriage of GGNB. These carriage rates were high compared to those found in patients in Dutch hospitals, where the rates are < 1% for MRSA, 2% for VRE, and 4.5% for GGNB. The highest risk of acquisition of GGNB was associated with the country from where the patient was repatriated, rather than with the antimicrobial treatment received by the individual patient in the foreign hospital.

Preoperative probability model for predicting overall survival after resection of pulmonary metastases from colorectal cancer (Br J Surg 2004; 91: 112-120)

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Ultra-sonic nebulizers as a potential source of methicillin-resistant Staphylococcus aureus causing an outbreak in a university tertiary care hospital

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) occurred on a head and neck surgical (HNS) ward of a university hospital in Amsterdam. The outbreak lasted from May 2000 until November 2000, and MRSA spread to two intensive care units. Amplified fragment length polymorphism analysis indicated that a single clone was responsible for the outbreak. Phage-typing indicated that this clone was of a type that was uncommon in The Netherlands. Strict isolation of patients, according to the Dutch national guidelines, was instituted. During the outbreak, surveillance culture specimens, from patients, healthcare workers, and the environment, were obtained at regular intervals. MRSA was found in the dust filters of nebulizers through which air from the room was filtered and subsequently humidified. These nebulizers were used to humidify tracheostomies. The dust filters were not maintained according to the guidelines. Restricted use and cleaning and disinfection of all ultra-sonic nebulizers led to termination of the outbreak. The outbreak illustrates that to terminate transmission of outbreak strains of MRSA, meticulous measures are necessary, which not only include strict isolation precautions, but also decontamination of the environment. In addition, it demonstrates the necessity of adhering to cleaning and disinfection guidelines for all medical and nursing equipment used in the hospital.

Laparoscopic splenectomy

PURPOSE

To study the safety and efficacy of laparoscopic splenectomy (LS) in patients with hematologic disorders requiring surgical intervention.

PATIENTS AND METHODS

A series of 103 consecutive adult patients underwent LS between 1992 and 1997 at our teaching hospital. Data were collected prospectively. The indications for splenectomy included idiopathic thrombocytopenic purpura (ITP), hereditary spherocytosis, autoimmune hemolytic anemia, and thrombotic thrombocytopenic purpura.

RESULTS

The mean spleen size was 14 cm (range 8.5-24 cm) and the mean weight was 263 g (range 40-210 g). Accessory spleens were detected in 12 patients with ITP and 17 patients in the study overall. In 12 patients, LS was combined with a laparoscopic cholecystectomy for gallstones. There were four conversions to open splenectomy, all for hemorrhage and all occurred in the first 50 patients. We have not converted a single patient in the last 2 years. The mean operative time was 161 minutes and was greater in the first 10 cases than the last 10. There were no deaths. Postoperative complications occurred in six patients, one necessitating a second procedure for a small-bowel obstruction. The average length of stay in the hospital was 2.5 days. After surgery, thrombocytopenia resolved in 84% of patients with ITP and anemia resolved in 92% of the patients with hereditary spherocytosis. After a mean follow-up of 38 months (range 2-565 months), four patients (6%) showed a relapse of ITP, three within 12 months of surgery.

CONCLUSIONS

Laparoscopic splenectomy can be performed safely and effectively in a teaching institution. LS in comparison with open surgery offers the same efficacy in the control of hematologic disease with the additional benefits of a minimally invasive approach. Laparoscopic splenectomy should therefore be considered the technique of choice and should prompt earlier consideration of surgery for patients with selected hematologic disorders.

A simultaneous outbreak on a neonatal unit of two strains of multiply antibiotic resistant Klebsiella pneumoniae controllable only by ward closure

Two aminoglycoside-resistant strains of Klebsiella pneumoniae caused an outbreak on the neonatal unit at St Thomas' Hospital. One, which affected 18 patients, was capsular type K18 and resistant to newer cephalosporins by the production of the extended-spectrum beta-lactamase SHV-2; the other, which colonized four patients, was capsular non-typeable and did not produce extended-spectrum beta-lactamase. Both strains were probably brought into the unit by carrier patients; the probable carrier of the non-typeable strain was transferred from another hospital but was negative on a single admission screen; the probable carrier of the K18 strain was not screened on admission because he had been born at St Thomas', but his mother had been transferred from another hospital. Despite intensive efforts to control the outbreak by standard methods of hand washing, screening, patient isolation and environmental cleaning, a total of 22 neonates on the unit eventually became colonized or infected. One of three patients with bacteraemia died. A small proportion of samples of expressed breast milk, electronic thermometers and oxygen saturation probes were contaminated by the K18 strain and may have contributed to some of the cross-infection, but this did not explain the extent of the outbreak. The outbreak was controlled only by opening a temporary ward for colonized neonates and another for newly born babies, which allowed the closure and cleaning of the main neonatal unit. Multiply antibiotic resistant klebsiellas may be highly epidemic and cause serious, difficult-to-control outbreaks on neonatal units. All patients, regardless of their admission history, should be screened on admission for carriage of multiply resistant enterobacteria by a sensitive method, and units should have plans for temporary ward closure should outbreaks occur.

History of laparoscopy

The history of laparoscopic surgery demonstrates how a close interaction between technology and medical-surgical innovators permitted its ultimate development. Similar revolutions have occurred in information and communication technology and in molecular biology. Within less than 2 decades, surgical management has moved from a disease-oriented approach to one that is more patient-oriented. While the past decade was characterized by the issue of what could be accomplished laparoscopically, the future will focus on the question of which operations should really be performed by this approach.

Surgical management of ulcerative colitis

As long as our understanding of ulcerative colitis is too limited to allow a more specific, disease-targeted treatment, surgery will play an important role in the management of these patients. Careful interdisciplinary evaluation and counselling of patients with ulcerative colitis will permit to achieve the goals on an individual basis with maximum safety. Restorative proctocolectomy with an IPAA has evolved as the procedure of choice among four basic surgical options because it appears to be safe and carries a low mortality. Although the associated morbidity is not negligible, functional results are generally good and patient satisfaction is high.

Surgical management of ulcerative colitis

As long as our understanding of ulcerative colitis is too limited to allow a more specific, disease-targeted treatment, surgery will play an important role in the management of these patients. Careful interdisciplinary evaluation and counselling of patients with ulcerative colitis will permit to achieve the goals on an individual basis with maximum safety. Restorative proctocolectomy with an IPAA has evolved as the procedure of choice among four basic surgical options because it appears to be safe and carries a low mortality. Although the associated morbidity is not negligible, functional results are generally good and patient satisfaction is high.

Outbreak of Bacillus cereus infections in a neonatal intensive care unit traced to balloons used in manual ventilation

In 1998, an outbreak of systemic infections caused by Bacillus cereus occurred in the Neonatal Intensive Care Unit of the University Hospital Vrije Universiteit, Amsterdam, The Netherlands. Three neonates developed sepsis with positive blood cultures. One neonate died, and the other two neonates recovered. An environmental survey, a prospective surveillance study of neonates, and a case control study were performed, in combination with molecular typing, in order to identify potential sources and transmission routes of infection. Genotypic fingerprinting by amplified-fragment length polymorphism (AFLP) showed that the three infections were caused by a single clonal type of B. cereus. The same strain was found in trachea aspirate specimens of 35 other neonates. The case control study showed mechanical ventilation with a Sensormedics ventilation machine to be a risk factor for colonization and/or infection (odds ratio, 9.8; 95% confidence interval, 1.1 to 88.2). Prospective surveillance showed that colonization with B. cereus occurred exclusively in the respiratory tract of mechanically ventilated neonates. The epidemic strain of B. cereus was found on the hands of nursing staff and in balloons used for manual ventilation. Sterilization of these balloons ended the outbreak. We conclude that B. cereus can cause outbreaks of severe opportunistic infection in neonates. Typing by AFLP proved very useful in the identification of the outbreak and in the analysis of strains recovered from the environment to trace the cause of the epidemic.

Repetitive short-term obstructions of the common bile-pancreatic duct induce severe acute pancreatitis in the opossum

Gallstone pancreatitis is triggered by migrating stones that cause transient or continuous bile-pancreatic duct obstruction. One might hypothesize that the great clinical variability of acute pancreatitis is related to the inconsistent number and duration of a series of stone migrations. A new setting for the opossum model of acute pancreatitis was developed allowing reversible bile-pancreatic duct obstructions. We compared the effects, on the pancreas and pancreatitis severity, of repeated transient obstructions to those of continuous obstruction of varying duration. Repetitive intermittent duct obstruction in American opossums was achieved using an extraductal balloon occluder connected to a subcutaneous port system that was inflated three times for 24 hr within a five-day period. Continuous duct obstruction was achieved by duct ligation. Sham-operated animals served as controls. After one, three, or five days of continuous obstruction and at the end of the third consecutive 24-hr obstruction (day 5), animals were killed and the severity of pancreatitis was determined quantitating the extent of acinar cell necrosis, pancreatic edema, and acinar cell fragility. Three repetitive one-day periods (total 72 hr) of bile-pancreatic duct obstruction resulted in acute necrotizing pancreatitis. The severity of pancreatitis was similar to that observed after five days of continuous obstruction and was more severe than that noted after three days (72 hr) of continuous obstruction. In conclusion, these observations suggest that the pancreas is susceptible to sensitization by factors related to transient duct obstruction. A series of minor events such as repeated stone passage may thus contribute to the progression to severe pancreatitis.

Repetitive short-term obstructions of the common bile-pancreatic duct induce severe acute pancreatitis in the opossum

Gallstone pancreatitis is triggered by migrating stones that cause transient or continuous bile-pancreatic duct obstruction. One might hypothesize that the great clinical variability of acute pancreatitis is related to the inconsistent number and duration of a series of stone migrations. A new setting for the opossum model of acute pancreatitis was developed allowing reversible bile-pancreatic duct obstructions. We compared the effects, on the pancreas and pancreatitis severity, of repeated transient obstructions to those of continuous obstruction of varying duration. Repetitive intermittent duct obstruction in American opossums was achieved using an extraductal balloon occluder connected to a subcutaneous port system that was inflated three times for 24 hr within a five-day period. Continuous duct obstruction was achieved by duct ligation. Sham-operated animals served as controls. After one, three, or five days of continuous obstruction and at the end of the third consecutive 24-hr obstruction (day 5), animals were killed and the severity of pancreatitis was determined quantitating the extent of acinar cell necrosis, pancreatic edema, and acinar cell fragility. Three repetitive one-day periods (total 72 hr) of bile-pancreatic duct obstruction resulted in acute necrotizing pancreatitis. The severity of pancreatitis was similar to that observed after five days of continuous obstruction and was more severe than that noted after three days (72 hr) of continuous obstruction. In conclusion, these observations suggest that the pancreas is susceptible to sensitization by factors related to transient duct obstruction. A series of minor events such as repeated stone passage may thus contribute to the progression to severe pancreatitis.

Nosocomial outbreak of gentamicin-resistant Klebsiella pneumoniae in a neonatal intensive care unit controlled by a change in antibiotic policy

Between August and November 1997, a nosocomial outbreak caused by gentamicin-resistant Klebsiella pneumoniae occurred in the Neonatal Intensive Care Unit (NICU) of our hospital. Thirteen neonates became colonized and three of them became infected. Comparison of the isolates by amplified fragment length polymorphism (AFLP) revealed clonal similarity for isolates of eight neonates (homology > 90%). Cultures from environmental specimens were negative for gentamicin-resistant K. pneumoniae. A case-control study was conducted to identify risk factors associated with acquisition of gentamicin-resistant K. pneumoniae. Risk factors were low gestational age and birth weight. These neonates need more care and handling and may therefore, be more at risk of colonization. Length of stay on the NICU was significantly longer for cases, but mean time until colonization (6.3 days) was shorter than the total stay for controls (9.5 days). No single member of the medical or nursing staff was significantly more involved with cases than with controls. The outbreak was stopped by replacing gentamicin by amikacin as the antibiotic of first choice whenever the use of an aminoglycoside antibiotic was indicated.

Prospective, randomized comparison of extrapleural versus epidural analgesia for postthoracotomy pain

BACKGROUND

Thoracic epidural analgesia is considered the method of choice for postthoracotomy analgesia, but it is not suitable for every patient and is associated with some risks and side effects. We therefore evaluated the effects of an extrapleural intercostal analgesia as an alternative to thoracic epidural analgesia.

METHODS

In a prospective, randomized study, pain control, recovery of ventilatory function, and pulmonary complications were analyzed in patients undergoing elective lobectomy or bilobectomy. Two groups of 15 patients each were compared: one received a continuous extrapleural intercostal nerve blockade (T3 through T6) with bupivacaine through an indwelling catheter, the other was administered a combination of local anesthetics (bupivacaine) and opioid analgesics (fentanyl) through a thoracic epidural catheter.

RESULTS

Both techniques were safe and highly effective in terms of pain relief and recovery of postoperative pulmonary function. However, minor differences were observed that, together with practical benefits, would favor extrapleural intercostal analgesia.

CONCLUSIONS

These results led us to suggest that extrapleural intercostal analgesia might be a valuable alternative to thoracic epidural analgesia for pain control after thoracotomy and should particularly be considered in patients who do not qualify for thoracic epidural analgesia.

Synthesis and action of the cyclic AMP antagonist, prostaglandylinositol cyclic phosphate (cyclic PIP), in Dictyostelium discoideum

The cyclic AMP antagonist, prostaglandylinositol cyclic phosphate (cyclic PIP), is synthesized from prostaglandin E (PGE) and activated inositol phosphate (n-IP) in the presence of ATP by an enzyme of rat liver plasma membranes. Extracts of the slime mould Dictyostelium discoideum contain this activated inositol phosphate and D. discoideum cells convert [3H]PGE1 to [3H]cyclic PIP. This extracted polar [3H]product co-chromatographed with cyclic PIP from rat liver on gel filtration, anion exchange- and adsorption chromatography. Starving D. discoideum cells show cyclic AMP-induced oscillations, which can be inhibited by cyclic PIP (0.4 x 10(-7) M), but not by its phosphomonoester prostaglandylinositol phosphate (PIP) (1.4 x 10(-7) M). AMP and ADP at much higher concentrations (1 mM) antagonized these oscillations. The time needed for aggregation and fruiting body formation of starving D. discoideum cells is extended by cyclic PIP (1.4 x 10(-7) M) up to 3-fold, whereas its phosphomonoester (1.9 x 10(-7) M) showed a 9-fold weaker effect, and AMP and ADP even at 1 mM concentration showed no effect.

Noninvasive comprehensive characterization of renal artery stenosis by combination of STAR angiography and EPISTAR perfusion imaging

In a small fraction of patients with hypertension, the cause is stenosis of the renal artery. To date, there is no established noninvasive screening technique available to identify this population, for whom treatment with a surgical procedure or percutaneous transluminal angioplasty is often possible. In this study, the sensitivity and specificity of STAR angiography and EPISTAR perfusion imaging in characterizing renal artery stenosis were evaluated in an animal model. Qualitatively, STAR provided projection angiograms that were comparably sensitive to x-ray angiograms but obtained noninvasively. The sensitivity for detecting the stenosis was 100%. The specificity varied according to the definition of the threshold for significance, which varied 78-94%, depending on whether > 70% or > 50% diameter reduction was considered. Improvements in specificity will depend upon use of shorter echo times and higher spatial resolution. Our preliminary data indicate that EPISTAR provides sensitivity and specificity of 100% for characterizing stenosis with diameter reductions of > 70%.

Effects of cycloheximide on pancreatic endonuclease activity, apoptosis, and severity of acute pancreatitis

The factors that determine the severity of acute pancreatitis are unknown, but a close inverse correlation between that severity and the extent of acinar cell apoptosis that follows the triggering signal has been previously noted [A. M. Kaiser, A. K. Saluja, A. Sengupta, M. Saluja, and M. L. Steer. Am. J. Physiol. 269 (Cell Physiol. 38): C1295-C1304, 1995]. In the present studies, we have evaluated internucleosomal DNA fragmentation and apoptosis within the pancreas and the effects of inhibiting protein synthesis by cycloheximide (CHX) on these phenomena as well as on the severity of pancreatitis. We report the constitutive presence of a Ca(2+)- and Mg(2+)-dependent endonuclease activity within pancreatic nuclei that is dependent on continued protein synthesis. Furthermore, we have found that CHX administration reduces the extent of apoptosis but significantly worsens the severity of pancreatitis that follows ligation of the rat common bile-pancreatic duct. These observations are consistent with the hypothesis that apoptosis is a teleologically beneficial response to acinar cell injury during acute pancreatitis.

Relationship between severity, necrosis, and apoptosis in five models of experimental acute pancreatitis

In an effort to elucidate factors that determine the severity of an attack of acute pancreatitis, we have quantitated the extent of necrosis and of apoptosis in five different models of experimental acute pancreatitis. Severe pancreatitis was induced by obstructing the opossum common bile-pancreatic duct, by administering to mice 12 hourly injections of a supramaximally stimulating dose of caerulein, and by feeding young female mice a choline-deficient, ethionine-supplemented diet. In each of these models of severe pancreatitis, marked necrosis but very little apoptosis was found. Mild pancreatitis was induced by obstructing the rat common bile-pancreatic duct and by infusing rats with a supramaximally stimulating dose of caerulein. In contrast to our findings in severe pancreatitis, mild pancreatitis was characterized by very little necrosis but a high degree of apoptosis. Our finding that the severity of acute pancreatitis is inversely related to the degree of apoptosis suggests that apoptosis may be a teleologically beneficial response to acinar cell injury in general and especially in acute pancreatitis.

Intravenous contrast medium does not increase the severity of acute necrotizing pancreatitis in the opossum

Contrast-enhanced computed tomography provides diagnostic and prognostic information in patients with acute pancreatitis. To evaluate whether contrast medium may worsen the severity of acute pancreatitis, we have used a model of necrotizing pancreatitis induced by ligating the common bile-pancreatic duct in opossums. Animals were infused with either saline or an ionic contrast agent 48 and 96 hr after induction of pancreatitis. Hyperamylasemia, pancreatic edema, acinar cell fragility, and macroscopic evidence of pancreatitis were comparable in both experimental groups. The microscopic extent of inflammation was similar in both groups, whereas acinar cell injury/necrosis was less in the contrast group. We conclude that administration of this ionic contrast agent during early stages of necrotizing pancreatitis in the opossum does not worsen the disease severity. The concept that administration of contrast medium during early stages of pancreatitis is dangerous should not be accepted until additional experimental and clinical studies support its validity.

Evaluation of necrotizing pancreatitis in the opossum by dynamic contrast-enhanced computed tomography: correlation between radiographic and morphologic changes

BACKGROUND

The ability to quantitate the extent of acinar cell necrosis with contrast-enhanced computed tomography (CT) during acute pancreatitis is uncertain.

STUDY DESIGN

Acute hemorrhagic necrotizing pancreatitis was induced in opossums by obstructing their biliopancreatic duct for up to seven days or by retrograde injection of a bile-trypsin taurocholate mixture into the opossum pancreatic duct. At selected times, groups of three animals each were examined by dynamic contrast-enhanced CT, and the abnormalities on the images were quantitated. Immediately following CT, the animals were sacrificed and the extent of necrosis was quantitated by morphometric analysis of tissue samples at the light microscope level.

RESULTS

The CT severity score as well as the degree of nonenhancement on dynamic contrast-enhanced CT were both closely correlated with the extent of acinar cell necrosis (r = 0.91 and r = 0.97, respectively).

CONCLUSIONS

The degree of pancreatic nonenhancement on dynamic contrast-enhanced CT can be used to quantitate the extent of pancreatic necrosis during acute necrotizing pancreatitis.

Spontaneous abrupt changes in the distribution of ventilation: a cause for apparent mismatching on ventilation/perfusion scintigraphy

A defect seen in the perfusion scan in a region of lung that is normally ventilated is usually interpreted as indicating pulmonary vascular disease. Since the distribution of 99Tcm macro-aggregated albumin (MAA) represents the distribution of perfusion (Q) only at the time of MAA injection, the assumption is required that the distribution of ventilation (V) remains unchanged between MAA injection and the commencement of imaging. We report the V/Q scintigraphic findings in six patients (including four children), in whom this assumption could not be sustained. Thus ventilation imaged with 81Krm was seen to change during image acquisition in lobes that showed perfusion abnormalities. In some, but not all, views the appearances were typical for pulmonary vascular disease, which might easily have been misdiagnosed if the changes in the distribution of ventilation had not announced themselves by occurring during image acquisition. A ventilation image obtained immediately before injection of 99Tcm-MAA may be useful.

Hypertensive response to raised intracranial pressure in infancy

Mean arterial pressure and intracranial pressure were measured serially in six infants with intracranial hypertension (intracranial pressure greater than 20 mm Hg), and cerebral perfusion pressure was calculated from their difference. Overall, mean arterial pressure increased with rising intracranial pressure at a mean rate of 0.20 mm Hg/mm Hg. This caused a fall in cerebral perfusion pressure with increasing intracranial pressure at a mean rate of 0.80 mm Hg/mm Hg overall, although cerebral perfusion pressure was well maintained in one infant. Thus the rise in blood pressure was usually insufficient to compensate for the increase in intracranial pressure. In infants with acute encephalopathy vigorous blood pressure support is as important as lowering intracranial pressure.

Outcome of infants shunted for post-haemorrhagic ventricular dilatation

Between April 1980 and March 1986, 19 infants underwent cerebrospinal fluid (CSF) shunting procedures for post-haemorrhagic ventricular dilatation at the Hammersmith Hospital, London. A total of 58 shunt-related procedures have been performed on these children. The major perioperative complication was seizure activity (eight children). Postoperative complications included infection (12 shunts) and blockage (29 shunts). Prophylactic antibiotics failed to prevent shunt infection. The likelihood of the first shunt failing was significantly reduced by greater weight of the infant and lower CSF protein at surgery. Long-term outcome was poor: three have died and another four are quadriplegic with severe mental retardation. Only four children are developmentally normal. These outcomes cannot be related to the shunt surgery or its complications, but correlate best with pre-operative parenchymal brain-lesions, as shown on ultrasound scans.

Non-invasive monitoring of intracranial pressure--fact or fancy?

Ladd and Wright fontanelle pressure meters were applied to the heads of 18 babies, and simultaneously the intracranial pressure was monitored directly. Increasing the force with which the meters were applied caused a linear increase in registered fontanelle pressure. No universally optimal application force could be determined. To obviate this, application force was increased until the fontanelle pressure was calibrated with directly measured intracranial pressure. Subsequent variations in intracranial pressure were significantly correlated to fontanelle pressure, but not closely enough for clinical reliability. The correlation was similar if the meter was affixed instead directly to the scalp with collodion gel, and the clinical reliability improved. Applanation fontanometers are strongly affected by variations in the method by which they are applied and may not be a reliable reflection of intracranial pressure. If directly affixed to the scalp, however, they may yield clinically useful data.

Intracranial pressure estimation by palpation of the anterior fontanelle

Simultaneous assessment of intracranial pressure by anterior fontanelle palpation and direct measurement from a cerebrospinal fluid cannula showed that mean pressure was significantly different between 'soft' (5.4 mm Hg) and 'tense' (14.0 mm Hg) fontanelles, but with considerable overlap. Normal fontanelle tone was often confirmed, whereas clinical assessment of raised intracranial pressure was unreliable.