Ascending arterial blood flow velocities during cardiac diastole in critical care patients--a characteristic flow pattern with a bad prognosis

AIM

Pulsed Doppler ultrasound is a standard noninvasive investigation to measure the velocity and pulsatility of blood flow within the major intracranial and organ-supplying arteries in critical care patients. The normal arterial flow pattern in organ-supplying vessels is characterised by a systolic-diastolic forward flow which is caused by the aortic "Windkessel" function and the low peripheral resistance of the parenchymatous organs. A variety of well known pathological conditions may cause a change of the vascular characteristics within the perfused organs which are diagnosed by the typical changes of the flow pattern in the supplying arteries. In the cardiac diastole, however, there is always a slow decrease of the flow velocity which is terminated by the onset of the following systole.

METHOD AND RESULTS

We report on 11 patients investigated by Doppler ultrasound during their stay in our intensive care unit. All these patients presented a markedly different flow pattern measured in their intra- and/or extracerebral vessels. This very distinctive flow pattern is characterised by a diastolic ascent of the arterial flow velocity and is caused by an excessively increased venous pressure within the draining veins of the affected organs. All patients died due to (multiple) organ failure.

CONCLUSION

It is of major importance to be aware of the rare but very characteristic flow pattern described here because of the poor prognosis associated with it.

Intravenous immunoglobulin therapy for resistant ocular Behçet's disease

AIMS

The present report was aimed at finding out whether gammaglobulin could have a role in treating ocular Behçet's disease (BD) refractory to accepted medical therapy.

METHODS

Six eyes of four patients with ocular BD refractory to steroids and cyclosporin A were treated with a course of intravenous gammaglobulin and followed up for their response to treatment.

RESULTS

All six eyes of all four patients showed good response to gammaglobulin therapy.

CONCLUSION

Gamma globulin may have a role in treating refractory ocular BD. A wide range of controlled studies with longer follow up is needed to substantiate this impression.

Pharmacokinetic and clinical evaluation of serious infections in premature and newborn infants under therapy with imipenem/cilastatin

Efficacy and pharmacokinetic parameters of imipenem/cilastatin (I/C) were investigated in a retrospective evaluation in 104 premature and newborn infants. Patients enrolled in this investigation constituted a particularly high risk group with extreme prematurity, perinatal asphyxia and amnion infection as well as various malformations. In 15 of the 104 infants serum concentrations were measured for drug monitoring and determination of optimal total daily dosage. A total daily dose of 50 mg/kg birth weight for premature and newborn infants divided into two doses led to imipenem peak concentrations of 17.7 mg/l +/- 9.2 mg/l (range: 1.95-38.05) and trough levels were 2.35 mg/l +/-1.02 (range 2.34-10.88) in premature infants. Imipenem peak concentrations of 20.6 +/- 10.8 (range 3.94-32.3) and trough levels of 0.43 +/- 0.17 (range 0.16-0.94) were measured in newborns. The half-life of elimination was 3.3 h and 1.86 h, respectively. Six of the 104 treated patients died, five of them of causes unrelated to infection. Seizures occurred in 8.9% of patients during therapy with I/C compared with 5.8% of a large survey of premature and newborn infants in our intensive care unit (ICU). However, the severity of illness of these two groups cannot be compared. I/C can be expected to constitute effective therapy in premature and newborn infants with serious nosocomial infections even after failure of other broad spectrum antibiotics.

Multiple retinal arteriolar occlusions associated with coexisting primary antiphospholipid syndrome and factor V Leiden mutation

PURPOSE

To investigate a case of a young woman with both primary antiphospholipid syndrome and factor V Leiden mutation who developed multiple retinal arteriolar occlusions.

METHOD

Case report of a 25-year-old woman with history and laboratory tests confirming the diagnosis of both primary antiphospholipid syndrome and factor V Leiden mutation who presented with blurred vision in both eyes.

RESULTS

Multiple retinal arteriolar occlusions were observed in both of her eyes. The patient was treated first with heparin and then with warfarin.

CONCLUSIONS

Primary antiphospholipid syndrome and factor V Leiden mutation, as well as other forms of thrombophilia, should be considered in the differential diagnosis of unexplained retinal vascular occlusions. The coexistence of several thrombophilic disorders may carry a particularly high risk for thrombotic manifestations.

[Follow-up of TIPSS by color-coded duplex sonography using an ultrasonic signal enhancer. First results]

A study was performed to determine the visualization of the transjugular intrahepatic portosystemic stent shunt (TIPSS) and the detection of stenosis by the use of a capillary transversing signal enhancer. In 37 patients 37 colour-coded duplex sonographies were performed before and after intravenous injection of the ultrasound signal enhancer Levovist (Schering, Berlin). The examinations were evaluated using a four-category score. Special attention was paid to the detection of stenoses in the TIPSS. Transjugular portal venograms of the same day were used as gold standard. The use of Levovist provided better colour and flow signals for the portal vein end of the shunt in only 9 of 37 sonograms and for the hepatic vein end of the shunt in 37 of 39 sonograms. Eleven of 13 stenoses requiring reintervention in portal venography could be correctly identified with signal enhancer. Eleven of these 13 stenoses were located in the hepatic vein end of the shunt. Ultrasound signal enhancer can significantly improve the sonomorphological visualization especially of the hepatic vein end of TIPSS in colour-coded duplex sonography. Stenoses which usually occur in the hepatic vein end of the shunt may be better detected.

Reduced rates of catheter-associated infection by use of a new silver-impregnated central venous catheter

A central venous catheter with a new form of silver impregnation of the internal and external surfaces was investigated for antimicrobial activity and tolerance in patients in a controlled comparative, prospective and randomized clinical study. Commercially available catheters with no antimicrobial activity were used as controls. One hundred sixty-five catheters were included in the final evaluation. All catheters were percutaneously inserted for the first time with a duration of > or = 5 days and a microbiological examination of the catheter tip. Catheter location (> 90% internal jugular vein), mean duration of catheterization (8-9 days), patients' age and diagnosis were comparable in both groups. Silver-impregnated catheter tips showed an incidence of colonization in 14.2/1000 catheter days and control catheters in 22.8/1000 catheter days. This represents a reduction of 37.7%. Catheter-associated infections were diagnosed in the silver group in 5.26/1000 catheter days and 18.34/1000 catheter days in the control group, indicating a reduction rate of 71.3% (P < 0.05, chi 2-test). No complications or side effects were documented in either group.

Assessment of hepatic perfusion in pigs by pharmacokinetic analysis of dynamic MR images

The purpose of this study was to evaluate a new method based on magnetic resonance imaging for the characterization of hepatic perfusion. In nine pigs dynamic MRI was performed before and after partial occlusion of the portal vein. The pharmacokinetic analysis of the contrast enhancement resulted in a set of parameters (amplitude, A; perfusion rate, kp; elimination rate, kappa(e1); lag time, t(lag)) of which kp was expected to correlate with hepatic perfusion. Reference measurements were done with ultrasound flow-meters and with a thermal diffusion probe (TDP). MR perfusion rate kp significantly dropped under partial portal vein occlusion from an average of 11.3 to 4.9 min(-1) (P < 0.001), while the difference in amplitude A was not significant. The correlation between kp and the TDP measurement was r = 0.89 (P < 0.001). Pharmacokinetic analysis of MRI contrast enhancement provides a non-invasive assessment of hepatic perfusion.

Severe pulmonary hypertension in a neonate caused by premature closure of the ductus arteriosus following maternal treatment with diclofenac: a case report

The administration of non-steroidal antiinflammatory drugs (NSAID) has occasionally been related to fetal and neonatal cardiopulmonary, gastrointestinal, cerebral and renal complications. This report describes a term newborn with severe persistent pulmonary hypertension due to premature closure of the ductus arteriosus following a 5 day maternal treatment with diclofenac two weeks before delivery. Pulmonary hypertension only responded to unusually high doses of inhaled NO. The treatment was necessary for 22 days suggesting structural alteration of pulmonary vasculature. The child recovered, but tricuspid regurgitation persisted, presumably because of irreversible ischemic damage of one papillary muscle. This is the first reported case of persistent pulmonary hypertension of the newborn (PPHN) in association with maternal diclofenac treatment and represents a most severe form of PPHN induced by NSAID.

MRI of pouch-related fistulas in ulcerative colitis after restorative proctocolectomy

PURPOSE

Our purpose was to determine the value of MRI in diagnosing pouch-related fistulas in patients with ulcerative colitis and to compare pulse sequences with and without contrast enhancement in their performance of visualization.

METHOD

Forty-four patients with pelvic symptoms after restorative proctocolectomy underwent MRI. All 26 patients with pouch-related fistulas were treated surgically; 18 patients with pouchitis were treated conservatively. MRI was performed at 1.0 T with T1-weighted FLASH sequences before and after administration of Gd-DTPA, T2-weighted and proton density-weighted turbo SE sequences, and a T2-weighted fat saturation sequence. Images were analyzed for the presence of fistula; pulse sequences were additionally compared for best visualization on a four point scale of diagnostic confidence.

RESULTS

MRI detected 23 of 26 cases of fistulas; there were no false-positive diagnoses. Surgery revealed fistulas in three cases in which no pathology was found on MRI. Two patients had a short sinus tract at the pouch-anal anastomosis, and a third patient had a pouch-vaginal fistula. The Gd-enhanced FLASH sequence obtained the highest score, and second best was the T2-weighted fat saturation technique.

CONCLUSION

MRI is a valuable technique for diagnosing pouch-related fistulas, However, there are limitations in detection of short sinus tracts and pouch-vaginal fistulas. Highest diagnostic confidence is obtained with a Gd-enhanced FLASH sequence, which might be helpful after pelvic surgery or if the fact saturation technique is equivocal.

[Use of the ultrasound contrast medium levovist in after-care of liver transplant patients. Improved vascular imaging in color Doppler ultrasound]

INTRODUCTION

A study was carried out to determine whether an improvement in the detection of vascular signals in patients after orthotopic liver transplantation can be achieved by the use of ultrasound contrast medium in colour Doppler sonography.

MATERIAL AND METHODS

In the early postoperative follow-up of liver transplant recipients, 31 colour Doppler sonograms were obtained in 21 patients before and after intravenous injection of the ultrasound contrast agent Levovist (Schering, Berlin). A grading score with four categories was used to evaluate the sonograms with special regard to the visibility of colour and flow signals in the hepatic artery and also in the portal vein and the hepatic veins. The arterial and portal venous signals were evaluated in the hepatic portal and in the left and right lobe.

RESULTS

With contrast enhancement significantly better arterial signals were seen in 20 of 31 sonograms for the hepatic portal, in 22 for the right lobe and in 26 for the left lobe. Better portal vein signals were obtained in 17 of 31 examinations for the right lobe and in 16 for the left lobe; only little improvement was obtained for the main stem of the portal vein. For the hepatic veins there was no significant improvement.

CONCLUSIONS

Early vascular complications after liver transplantation usually occur in the hepatic arteries. With the use of contrast-enhanced colour Doppler sonography, better detection of arterial and peripheral portal signals can be achieved; peripheral portal vein branches can be helpful in finding small arteries.

Pseudolesions at T1-weighted gradient-echo imaging after administration of superparamagnetic iron oxide: comparison with portal perfusion abnormalities at CT during arterial portography

PURPOSE

To compare specific findings at T1-weighted gradient-echo (GRE) magnetic resonance (MR) imaging performed after administration of superparamagnetic iron oxide (SPIO) with nontumorous regional portal perfusion abnormalities seen at computed tomography (CT) during arterial portography (CTAP).

MATERIALS AND METHODS

The results of CTAP, MR imaging, and surgery were compared in 19 patients with liver metastases and five with benign liver tumors. MR imaging was performed by using turbo spin-echo (SE) sequences and a GRE sequence before and after infusion of SPIO.

RESULTS

At CTAP, 34 nontumorous portal perfusion defects ("straight line sign," pseudolesions) were seen. After intravenous administration of SPIO, 18 nontumorous signal intensity differences were seen on T1-weighted GRE images in corresponding locations. No corresponding nontumorous signal intensity differences were seen on unenhanced MR images. The mean signal-to-noise ratio on the SPIO-enhanced GRE images was reduced from 26.3 to 16.6 in the areas of nontumorous signal intensity differences, whereas that in areas of normal portal perfusion (normal CTAP findings) was reduced to 10.2.

CONCLUSION

Impaired portal perfusion decreased the uptake of SPIO in histopathologically normal regions of liver parenchyma. Resultant differences in signal intensity were better visualized on GRE than on turbo SE images.

[TIPSS: 10 years of clinical experience]

To demonstrate and document 10 years of clinical experience gathered by us with TIPSS and to discuss achievements, problems and outlook.

MATERIAL AND METHODS

The analysis is based on the following parameters: portosystemic gradient; morphological delineation of the portal circulation; determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); arterial flow changes; hepatic encephalopathy; incidence of restenotic shunt occlusion and recurrent variceal bleeding.

RESULTS

Variceal filling was widely reduced by TIPSS, and significantly reduced portal liver perfusion as assessed morphologically and rheologically. However, there was an immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion did not change significantly. In TIPSS portal decompression was readily achieved, the portosystemic gradient dropping from an average of 24 mm Hg to 10.5 mm Hg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post-TIPSS period. Early mortality was 4% and early rebleeding rate 3%. The 12-month re-intervention rate based on an invasive portography follow-up protocol was 76%, and the 24-month re-intervention rate was 90%. The definite occlusion rate was below 5%. Beyond a follow-up time span of 24-months the necessity for re-intervention dropped significantly: less than one-third of our patients required some sort of re-intervention.

CONCLUSION

The concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post-TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by an invasive flow measurement results and by the clinical results. Lethality of TIPSS is low mostly as a result of a refined technique, careful patient selection, follow-up care and meticulous shunt surveillance.

Presurgical prosthetic management of the periodontal patient--a modern adhesive approach

The comprehensive management of the periodontal prosthetic patient requires that treatment be provided in a logical sequence; initial therapy, presurgical prosthetic management, surgical management of hard and soft tissue lesions, post-surgical prosthetics, followed by maintenance therapy. This article focuses on some of the most perplexing challenges encountered during the presurgical prosthetic management phase of periodontal diagnosis and therapy, including the stabilization of mobile teeth, the immediate replacement of teeth that require removal due to advanced attachment loss, and the correction of visual defects created by soft tissue loss. A number of creative treatment modalities are described that utilize silane-treated etched-glass fiber ropes and tapes (GlasSpan, GlasSpan, Inc.) for the internal reinforcement of periodontal splints and for the attachment of composite and natural tooth pontics as transitional tooth replacements. Gingival-colored composite (Gingiblend, Jeneric Pentron) and its importance as a diagnostic aid during the early stages of periodontal therapy and as an esthetic permanent restorative material are also examined.

[Experimental evaluation of dynamic MRI for quantifying liver perfusion]

Gadolinium-DTPA enhanced dynamic MR imaging is a new method for the quantification of portal bloodflow and liver perfusion. In this study we evaluated the validity of this method comparing it with thermodiffusion and dopplerflowmetry in pigs. We found a significant correlation of tissue perfusion between dMRI and thermodiffusion and of portal bloodflow between dMRI and dopplerflowmetry. Partial occlusion of the portal vene was accurately detected by dMRI. Dynamic MRI could become a valuable diagnostic method for the quantification of liver perfusion.

Overwhelming postsplenectomy infection with vaccine-type Streptococcus pneumoniae in a 12-year-old girl despite vaccination and antibiotic prophylaxis

This report describes a 12-year-old girl who developed vaccine-type pneumococcal septicemia (type 4, Danish nomenclature) 2 years after splenectomy for recurrent idiopathic thrombocytopenia despite vaccination with the 23-valent vaccine 4 weeks before surgery and antibiotic prophylaxis with penicillin V. The disease presented as high fever with shivering and vomiting followed by disseminated petechiae and a deteriorated general condition. Initial laboratory studies showed severe sepsis with leucocytopenia and thrombocytopenia, a markedly elevated CRP, and disseminated intravascular coagulation. Despite antibiotic treatment, which was initiated with clindamycin, cefotaxime and trimethoprim/sulfamethoxazole and was switched to cefotaxime and penicillin after the result of the blood culture had been obtained, the patient had to be ventilated, and hemofiltration became necessary because of acute renal insufficiency. Furthermore, she required amputation of all her toes because of severe necrosis. No type-specific pneumococcal antibody titers were detected during and after infection. It remains unclear whether the susceptibility to Streptococcus pneumoniae was due to primary failure of antibody production or a decline in antibody levels after vaccination. Patients and/or their relatives should be informed that neither vaccination nor continuous antibiotic prophylaxis can guarantee full protection against infection with S. pneumoniae in patients after splenectomy.

Retinal arterial occlusion in a child with factor V Leiden and thermolabile methylene tetrahydrofolate reductase mutations

PURPOSE

To analyze the potential cause of retinal arterial occlusion in a 9-year-old child.

METHODS

Case report. Antithrombin III, protein C, free protein S, activated protein C resistance, and antiphospholipid antibodies in plasma were determined. Determination of factor V R506Q (Leiden mutation), thermolabile methylene tetrahydrofolate reductase by polymerase chain reaction, and restriction enzyme analysis were performed.

RESULTS

The patient was found to be heterozygous for factor V R506Q (Leiden mutation) and homozygous for thermolabile methylene tetrahydrofolate reductase.

CONCLUSION

Coexistence of two mild hereditary thrombophilic states may result in severe thrombotic manifestations in young people.

Continuous plasma resin perfusion for detoxification of methotrexate

Acute renal failure is a rare but very severe side-effect of methotrexate (MTX) treatment requiring extracorporeal detoxification. A new detoxification regime, consisting of a haemodiafiltration (HDF) and continuous plasma resin perfusion (PRP) over anion exchange resin column with high affinity for MTX, was used for treatment of MTX-induced acute renal failure in a 2-year-old boy with medulloblastoma. More than 99% of MTX was removed from plasma by perfusion over the resin column resulting in a marked decrease of MTX plasma half-life. No haematological complications occurred.

CONCLUSION

The use of PRP alone or in combination with HDF is a new and effective treatment strategy for extracorporeal detoxification of MTX.

Intermittent administration of furosemide versus continuous infusion in the postoperative management of children following open heart surgery

OBJECTIVE

To compare the amount of furosemide needed to fulfil defined criteria for renal output if given intermittently or as a continuous infusion and to compare the effect of these two regimens on hemodynamic variables and urine electrolyte concentrations.

DESIGN

Prospective randomized study of postoperative hemodynamically stable pediatric cardiac patients. The patients were given furosemide according to the urine output, either as an intermittent bolus injection or as a continuous infusion.

SETTING

Pediatric intensive care unit in a university hospital.

PATIENTS

The patients were randomly assigned before admission to either the intermittent i.v. or the continuous furosemide i.v. infusion group.

MEASUREMENTS AND RESULTS

Demographic and hemodynamic data were recorded for a maximum of 72 h, as were furosemide dose, urine output, and fluid and inotropic drug requirements. Forty-six patients completed the study. Maximal hourly urine output was significantly higher in the intermittent group. A significantly lower dose of furosemide in the intermittent group produced the same 24-h urine volume as in the continuous infusion group.

CONCLUSIONS

Intermittent furosemide administration may be recommended in hemodynamically stable postoperative pediatric cardiac patients because of less drug requirement. However, the high maximal urine output may cause hemodynamic problems in patients who depend on high inotropic support.

Lokale Thrombolyse im Kindesalter nach kardiochirurgischen Eingriffen mit niedrig dosiertem rt-PA

Unmittelbar postoperativ auftretende Thrombosen in aorto-pulmonalen Shunts stellen bei Kindern mit zyanotischen Herzfehlern eine schwierige therapeutische Situation dar, da zum einen die Abhängigkeit der Lungendurchblutung vom Blutfluß im Shunt rasche Therapiemaßnahmen erfordert, andererseits aber eine systemische thrombolytische Therapie wegen der Gefahr einer lebensbedrohlichen thorakalen Blutung kontraindiziert ist.

Wir haben bei 7 Patienten mit 8 Thrombosen eine lokale thrombolytische Therapie mit rt-PA durchgeführt. Trotz der sehr niedrigen Dosis von 0,1-0,25 mg/ kg/Bolus konnten wir 5 der 8 Thrombosen vollständig auflösen und eine operative Revision dadurch vermeiden. Therapieversagen war bei einem Patienten durch das Thrombusalter, bei den beiden anderen durch eine chirurgische Stenose im Shunt bedingt. Bei einer Patientin sahen wir eine therapiebedingte Blutung, zwei Patienten entwickelten schwitzende Shunts im Sinne einer Perigraft-reaktion.

Bei lokaler Applikation stellt die thrombolytische Therapie mit rt-PA aufgrund unserer bisherigen Erfahrungen eine gute Alternative zur sofortigen operativen Revision des Shunts dar.