[Pharmacokinetics and pharmacodynamics of antibiotics in intensive care]. / Pharmakokinetik und Pharmakodynamik von Antibiotika in der Intensivmedizin.

Optimized dosage regimens of antibiotics have remained obscure since their introduction. During the last two decades pharmacokinetic(PK)-pharmacodynamic(PD) relationships, originally established in animal experiments, have been increasingly used in patients. The action of betalactams is believed to be governed by the time the plasma concentration is above the minimum inhibitory concentration (MIC). Aminoglycosides act as planned when the peak concentration is a multiple of the MIC and vancomycin seems to work best when the area under the plasma vs. time curve (AUC) to MIC has a certain ratio. Clinicians should be aware that these relationships can only be an indication in which direction dosing should go. Larger studies with sufficiently high numbers of patients and particularly severely sick patients are needed to prove the concepts. In times where all antibiotics can be measured with new technologies, the introduction of therapeutic drug monitoring (TDM) is suggested for ICUs (Intensive Care Unit). The idea of a central lab for TDM of antibiotics such as PEAK (Paul Ehrlich Antibiotika Konzentrationsmessung) is supported.

[Bleeding during central venous catheterization : Cannot intubate, cannot ventilate due to massive cervical hematoma]. / Blutung bei ZVK-Anlage : "Cannot intubate, cannot ventilate" durch massives zervikales Hämatom.

Central venous catheterization is an invasive procedure which can be associated with severe complications. These include in particular unsuccessful arterial puncture and vascular injuries, which in addition to loss of blood can lead to massive soft tissue swelling. A 63-year-old female patient developed massive cervical bleeding during ultrasound-guided internal jugular vein puncture and the rapidly enlarging hematoma led to compromisation of the airway. A cannot intubate, cannot ventilate situation developed and the subsequent hypoxia led to cardiac arrest that was only resolved after emergency surgical tracheotomy during cardiopulmonary resuscitation.

[Fatal hyperpyrexia in an adolescent patient with severe burns after a traffic accident]. / Letale Hyperpyrexie bei einem jugendlichen Schwerbrandverletzten nach Verkehrsunfall.

After a motorcycle accident a 16-year-old patient suffered severe burns to 40.5 % of the total body surface area (TBSA) of which 37 % were deep subdermal burns. After tangential and partly epifascial necrosectomy, Integra® was used as a temporary dermis replacement material for the lower extremities, combined with extensive negative pressure wound therapy (NPWT). In the further course of the treatment the patient developed uncontrollable hyperpyrexia with a fatal outcome. Possible influencing factors, such as the dermis replacement material combined with NPWT over large areas as well as the differential diagnoses propofol infusion syndrome, heatstroke and malignant hyperthermia are discussed.

Case-based update: primary intraventricular brain abscess in a 10-year-old child.

BACKGROUND: Intraventricular abscesses are very rare and usually result from secondary rupture of a brain abscess. In the few published cases, clinical presentation was subacute and different pathogens were found. The diagnosis might be mistaken as an intraventricular tumor. CASE REPORT: This is a case of a 10-year-old girl suffering from cyanotic heart disease that was presented with subacute onset of headache, vomiting, and some signs of inflammation. Symptoms lead to early brain imaging (CT/MRI) demonstrating left ventricular horn lesion affecting adjacent brain structures. Neuroradiologists suspected an intraventricular tumor, but cardiac history and signs of inflammation led to lumbar puncture and evidence of CNS infection, and intraventricular abscess was suspected. Navigated aspiration was performed, and multi-sensitive Eikenella corrodens was cultivated. Broad antibiotic treatment and dexamethasone were initiated, and symptoms disappeared. Follow-up imaging demonstrated gradual regression of the intraventricular abscess. The girl underwent regular professional teeth cleaning which was discussed as possible cause of infection. CONCLUSIONS: Although an isolated intraventricular abscess is a very rare event, typical predisposing cardiac history together with central nervous symptoms and an intracranial contrasting mass should always lead to the differential diagnosis of a brain abscess and be biopsied first. E. corrodens is a typical organism of the mouth flora, but a rare cause for a brain abscess. Harmless teeth cleaning procedures may cause hematogenic spread and lead to CNS infections, e.g., in patients with predisposing diseases. To our knowledge, there are only six previous reports of primary intraventricular brain abscess.

Cerebral oxygenation and hemodynamic measurements during craniosynostosis surgery with near-infrared spectroscopy.

INTRODUCTION: Focal pressure-related changes in brain perfusion and metabolism are discussed in single-suture craniosynostosis and brachycephalic cases (bicoronal synostosis). Raised intracranial pressure levels could be measured in some cases. In order to find possible loco-regional brain tissue changes during plastic surgery, we investigated oxygenation and perfusion parameters using non-invasive near-infrared spectroscopy (NIRS) probes. METHODS: Twenty-two consecutively operated cases (mean age 7 months) with single-suture craniosynostosis were prospectively investigated using a NIRS probe (LEA(©), O2C, white light 500-800 nm, laser NIR). Measurements for oxygen saturation (SO(2)), relative quantity of hemoglobin (rHb), blood flow, and blood flow velocity of the bilateral frontal, temporal, and parietal cortices were taken transosseously (prior to decompression) and epidurally directly after decompression as well as 15 and 30 min after decompression and before closure. RESULTS: Twenty-two patients with scaphocephaly (11), trigonocephaly (6), anterior plagiocephaly (3), and brachycephaly (2) were investigated. SO(2) was improving in all patient subgroups, showing the highest levels in the fronto-temporal region; rHb improved in scaphocephalic, trigonocephalic, and brachycephalic children. Again, the highest values were found not only in the temporal but also in the frontal region and in brachycephalic patients also in the parietal cortex. CONCLUSION: These preliminary results of a new technology for brain tissue oxygenation and blood flow measurements suggest a regional compromise of cortical metabolism and circulation in patients with craniosynostosis.

[Pyoderma gangrenosum following AICD implantation: differential diagnosis to necrotizing fasciitis]. / Pyoderma gangraenosum nach AICD-Implantation: Differenzialdiagnose zur nekrotisierenden Fasziitis.

Pyoderma gangrenosum is rarely seen in the surgical disciplines. In the described case the patient was initially diagnosed with necrotizing fasciitis and admitted to the intensive care unit suffering from septic shock. The automated implantable cardioverter defibrillator (AICD), the suspected focus for infection, had already been removed. Following weeks of broad spectrum antibiotics and wound debridement without clinical improvement the alternative diagnosis of pyoderma gangrenosum was reached. Consequently the patient was treated with immunosuppressive therapy and his condition improved rapidly such that he was ultimately discharged to rehabilitation.

Hypotension after spinal anesthesia for cesarean section: identification of risk factors using an anesthesia information management system.

OBJECTIVE: To determine risk factors for developing hypotension after spinal anesthesia for cesarean section to prevent obstetric patients from hypotensive episodes potentially resulting in intrauterine malperfusion and endangering the child. METHODS: The data from 503 women, having received spinal anesthesia for cesarean sections were investigated using online gathered vital signs and specially checked manual entries employing an anesthesia information management system. Blood pressure, heart rate, and oxygen saturation were measured throughout and hypotension was defined as either a drop in mean arterial blood pressure of >20% from baseline value or readings of <90 mmHg systolic arterial blood pressure. Thirty-two variables were studied for association with hypotensive episodes using univariate analysis and logistic regression employing a forward stepwise algorithm to identify independent variables (P < 0.05). RESULTS: Hypotension was found in 284 cases (56.5%). The univariate analysis identified the neonate's weight, mother's age, body mass index, and peak sensory block height associated with hypotension. Body mass index, age and sensory block height were detected as independent factors for hypotension (odds-ratio: 1.61 each). CONCLUSIONS: Knowledge of these risk factors should increase the anesthesiologist's attention to decide for the necessity to employ prophylactic or therapeutic techniques or drugs to prevent the neonate from any risk resulting of hypotension of the mother.

Fetal MRI of the central nervous system: clinical relevance.

OBJECTIVE: Specific conditions of the mother sometimes reduce the quality of ultrasound. In these cases, fetal magnetic resonance imaging (MRI) can be performed after gestational week (GW) 18. Interpretation of subtle disorders or malformations becomes safe not before GW 23. Clinical development of children with central nervous system (CNS) disorders is not predictable with imaging alone. Statistical evidence and personal experience of the medical team are essential in counseling, but optimized imaging is helpful in being more precise. The value of fetal MRI (fMRI) is evaluated. MATERIALS AND METHODS: Twenty-five pregnant women (30.5 +/- 4.5 years) were investigated by additional fMRI. TECHNIQUE: Breath-hold technique with T2 half-Fourier acquisition single-shot turbo spin-echo and T1 FLASH-2D images in three dimensions with field of view of 350 x 400 mm. All cases have been correlated with postnatal MRI, ultrasound, and clinical follow-up. RESULTS: In all fetuses, diagnostic MRI was performed 3-10 days after ultrasound between GW 22 and 34 (GW 26.1 +/- 3.6). Sedation was not necessary. In eight cases of suspicious ultrasound, fMRI confirmed ultrasound findings. In 13 cases, additional diagnoses or exclusions of suspected findings could be established. Complete revision of diagnosis was realized in four cases. Findings could be confirmed by postnatal MRI in 11 patients. The clinical course was not predictable in cases with ambivalent prognosis. CONCLUSIONS: Prenatal diagnosis of CNS pathologies should result in parental counseling. Sufficient diagnostic information, statistical data, and experience of the involved professionals are essential. These results show that in detecting congenital CNS abnormalities fMRI is superior to ultrasound and should be considered in difficult cases.

[Anesthesiological co-diagnosis "difficult intubation": effects on the reimbursement situation of a university hospital]. / Anästhesiologische Nebendiagnose "schwierige Intubation" : Auswirkung auf die Erlössituation eines Universitätsklinikums.

OBJECTIVE: Within the German diagnosis related groups (G-DRG) system, the accurate coding of the co-morbidity "failed or difficult intubation (T88.4)" may be relevant with respect to reimbursement. In this study, the impact of this typical anesthesia co-morbidity on revenues of an university hospital was investigated. METHODS: The computerized records of 21,204 anesthesia procedures from the year 2005 were scanned for failed or difficult intubations. The results were checked for accordance with the coding recommendation of the Medical Service of the Health Insurance Funds (MDK) with respect to the co-morbidity T88.4. For all valid cases, the DRG, the diagnosis code and the co-morbidity codes were retrieved from the hospital information system. Subsequently all cases were regrouped with the GetDRG grouper (Fa. GEOS), taking the co-morbidity T88.4 in account. RESULTS: Out of the 21,204 patients, 12,261 were intubated for general anesthesia. A failed or difficult intubation according to the definition of the expert group of social medicine was documented in 276 anesthesia cases (2.3%). In 31 cases the coding of the co-morbidity T88.4 led to an increase in revenue by grouping the case in a different DRG. Using the base rate of the year 2005 (EUR 3,379.66), the surplus in basic points of 17.093 resulted in an additional reimbursement of EUR 57,768.53. CONCLUSION: With this study it was shown that the consequent coding of the co-morbidity T88.4 during anesthesia can lead to increased reimbursement. A prerequisite is the accurate documentation and coding by the attending anesthetist.

[Scoring systems for daily assessment in intensive care medicine. Overview, current possibilities and demands on new developments]. / Intensivmedizinische Scoringsysteme zur täglichen Anwendung. Ubersicht, aktuelle Möglichkeiten und Anforderungen an Neuentwicklungen.

Scoring systems are a fixed element of modern diagnostics and are integrated in the diagnosis-related groups (DRG) billing system as well as quality assurance projects. The ongoing developments require classification according to the terms of use in order to maintain an overview of the numerous systems available. In the area of intensive care medicine scoring systems can be divided into admission scores and progress scores, whereby the scores for daily assessment can be further subdivided into five categories, depending on the target criteria: objective description of the grade of organ dysfunction, progression in intensive care therapy, evaluation of the degree of nursing care, determination of outcome/mortality risk, and grouping of patient collectives for clinical trials. In future developments it will be necessary to generate new strategies to adequately describe the progress of a patient. Not only will mortality be challenged as a target criterion but also the handling of missing data and the simplification of reality by categorization practised so far that can be found in all established scoring systems as far as calculation of predictive values regarding a defined result.

Impact of different sampling strategies on score results of the Nine Equivalents of Nursing Manpower Use Score (NEMS).

OBJECTIVE: Prospective observational study to assess the impact of two different sampling strategies on the score results of the NEMS, used widely to estimate the amount of nursing workload in an ICU. METHODS: NEMS scores of all patients admitted to the surgical ICU over a one-year period were automatically calculated twice a day with a patient data management system for each patient day on ICU using two different sampling strategies (NEMS(individual): 24-hour intervals starting from the time of admission; NEMS(8 a.m.): 24-hour intervals starting at 8 a.m.). RESULTS: NEMS(individual) and NEMS(8 a.m.) were collected on 3236 patient days; 687 patients were involved. Significantly lower scores were found for the NEMS(8 a.m.) (25.0 +/- 8.7) compared to the NEMS(individual) (26.1 +/- 8.9, p < 0.01); the interclass correlation coefficient (ICC) was good but not excellent: 0.78. The inter-rater correlation between the two NEMS scores was high or very high (kappa = 0.6-1.0) for six out of nine variables of the NEMS. CONCLUSIONS: Different sampling strategies produce different score values, especially due to the end of stay. This has to be taken into account when using the NEMS in quality assurance projects and multi-center studies.

Examining the influence of maternal bradycardia on neonatal outcome using automated data collection.

BACKGROUND: Due to the increasing number of caesarean sections, we investigated the influence of maternal bradycardia during general and regional anaesthesia on seven standard paediatric outcome parameters using our online recorded data. METHODS: Data from 1154 women undergoing caesarean section were investigated prospectively. Bradycardia was defined as a heart rate below 60 beats/min. The matched-pairs method was used to evaluate the impact of bradycardia on Apgar scores at 1, 5, and 10 min, umbilical artery pH and base excess, admission to paediatric intensive care unit, and seven-day mortality. Matched references were automatically selected among all patients from the data pool according to anaesthetic technique, sensory block height, urgency, maternal age and body mass index. Stepwise regression models were developed to predict the impact of intra-operative bradycardia on outcome variables with differences between matched pairs assessed using univariate analysis. RESULTS: Bradycardia was found in 146 women (12.7%) for whom a control could be matched in 131 cases (89.7%). Mean 5-minute Apgar score was 9.2+/-1.1 for study patients and 9.3+/-1.1 for controls. pH and base excess were not significantly different between groups. In cases of urgent surgery, neonates had an increased risk of 1.8 (95% CI 1.36-2.44, P<0.01) for an Apgar score

A 21-year-old female with a third ventricular tumor.

A 21-year-old female presented with a 2-months history of tinnitus, vertigo and nausea. On magnetic resonance imaging of the brain, she demonstrated a small contrast-enhancing mass in the posterior part of the third ventricle. Intraoperatively, the tumor showed a close relationship to the choroid plexus of the third ventricle. Histopathology revealed a benign schwannoma of World Health Organization grade I. To our knowledge, only 9 cases of intraventricular Schwann cell tumors have been published so far. Most of these tumors were benign schwannomas, except for 2 cases of malignant peripheral nerve sheath tumors. The tumor of our patient is the first reported schwannoma of the third ventricle. The origin of intraventricular Schwann cell tumors is unknown. They may arise from autonomic perivascular nerves in the choroid plexus or from ectopic neural crest-derived cells. Histologically, intraventricular schwannoma needs to be distinguished from other spindle cell tumors, in particular pilocytic astrocytoma and fibroblastic meningioma.

Effectiveness and handling characteristics of a three-layer polymer dura substitute: a prospective multicenter clinical study.

OBJECT: The goal of this study was to assess the effectiveness and handling characteristics of a dura substitute composed of two outer layers of expanded polytetrafluoroethylene (PTFE) and a middle layer consisting of an elastomeric fluoropolymer. METHODS: In a prospective multicenter study, the dura substitute was implanted using a standard technique in 119 patients undergoing cranial or spinal surgery requiring duraplasty. Intraoperative assessments of the dura patch consisted of testing for cerebrospinal fluid (CSF) leakage employing the Valsalva maneuver and a surgeon's standard evaluation of the handling characteristics of the device. Postoperative assessments conducted during a mean follow-up time of 15.7 months (range 0.3-45.6 months) consisted of physical examinations, routine computed tomography (CT) or magnetic resonance (MR) imaging studies, and histological studies of any removed dura patches. The mean age of the 119 patients was 40 years (range < 1-81 years). The dura substitute was implanted cranially in 102 patients and spinally in 17. Intraoperative assessment including the Valsalva maneuver led to application of additional sutures in 17 patients. Handling features were rated very good to excellent. Postoperative clinical evaluation resulted in 79 excellent and 18 good results. Imaging studies (MR imaging studies in 69 patients and CT studies in 34 patients) showed no adhesions in 87 patients and minimal adhesions in seven patients (the dura was not visualized in nine patients). Postoperative complications occurred in 12 patients. There were six cases of CSF leakage, three cases of extradural hematoma, one case of arachnoid fibrosis after decompression of a Chiari malformation Type I, and two cases of infection. Eight (7%) of these complications were potentially related to the dura patch. CONCLUSIONS: In a large, multicenter clinical study of the use of an expanded-PTFE-containing dura substitute, the device was found to be easy to handle and implant. No serious dura patch-related intraoperative adverse events were observed. Postoperatively, there were no major sealing problems or long-term complications. In two cases the patch had to be removed due to fibrosis and infection. The three-layer polymer dura substitute appears to be safe and effective in minimizing CSF leakage and adhesion formation, and its use avoids any risk of prion disease transmission.

[Anesthesia and sleep apnea syndrome]. / Anästhesie und Schlaf-Apnoe-Syndrom.

The perioperative risk for patients with obstructive sleep apnea syndrome and the optimal anaesthesiological management of these patients have not been well elucidated. The prevalence of obstructive sleep apnea with significant symptoms is estimated to be 4% in men and 2% in women. However, in 80-95% of patients this syndrome is not sufficiently diagnosed. Thus identification of patients at risk and a thorough multidisciplinary diagnostic approach are essential for optimal perioperative management. The risk of perioperative complications, like cardiopulmonary compromise, and difficulties in airway management is elevated. The most important aspects of perioperative management include evaluation of intubating conditions, careful search for cardiopulmonary morbidity, permanent control of patient airways, sensible use of anaesthetics, sedatives, and narcotics, and strict monitoring of vital signs. If ambulatory nasal continuous positive airway pressure (CPAP) therapy has been established preoperatively, this should be continued in the perioperative period. Postoperative monitoring should be performed in an intensive care or intermediate care unit. Controlled clinical studies on the best perioperative management of patients with obstructive sleep apnea are urgently required.

Serum creatinine and perioperative outcome--a matched-pairs approach using computerised anaesthesia records.

BACKGROUND AND OBJECTIVE: A study was designed to utilise the resources of our computerised anaesthesia record keeping system to assess the attributable effects of increased preoperative creatinine (> 1.3 mg dL(-1)) on outcome in patients undergoing non-cardiac surgery. METHODS: This retrospective study was based on data sets of 58 458 patients recorded with a computerised anaesthesia record keeping system over a period of 4 yr at a tertiary care university hospital. Cases were defined as patients with a preoperative creatinine > 1.3 mg dL(-1); controls (creatinine < or = 1.3 mg dL(-1)) were selected and automatically matched according to several parameters (ASA physical status, high risk and urgency of surgery, age and gender) in a stepwise fashion. Main outcome measures were hospital mortality and the incidence of intraoperative cardiovascular events. RESULTS: Three-thousand-and-twenty-eight patients (5.2%) had preoperative creatinine values > 1.3 mg dL(-1). Matching was successful for 54.5% of the cases, leading to 1649 cases (mean creatinine 3.3 +/- 2.2 mg dL(-1)) and 1649 controls (1.0 +/- 0.2 mg dL(-1)). The crude mortality rates for the cases and matched controls were 2.2% (n = 36) and 0.9% (n = 15), respectively (P = 0.003). Intraoperative cardiovascular events were found in 30.1% of the patients (n = 496) and in 28.3% of the matched controls (n = 466; P = 0.25, power = 0.46). Using logistic regression analyses a significant association between preoperative increased creatinine and hospital mortality was found (odds ratio 2.62; 95% confidence interval [1.39; 4.931). CONCLUSIONS: An increased preoperative serum creatinine in patients undergoing non-cardiac surgery is associated with an increased perioperative risk, but not with a higher incidence of intraoperative cardiovascular events.

User acceptance of an anaesthesia information management system.

BACKGROUND AND OBJECTIVE: This paper describes the user acceptance of an anaesthesia information management system at the University Hospital in Giessen, Germany, after 5 yr of routine use. METHODS: A questionnaire with 75 items was distributed to all anaesthesiologists and anaesthetic nurses of the Department of Anaesthesiology. The questions were answered anonymously on a five-point Likert scale. RESULTS: The return rate was 60% (44 physicians and 24 nurses). The results indicated that the system generally met user expectations. The respondents thought that electronic record keeping improved the quality of their work, and they did not want to switch back to paper records. Problems arose with hardware placement and software features, e.g. coding tools for diagnoses and type of surgery. The perceived quality of training strongly influenced user acceptance. CONCLUSIONS: Despite the deficits revealed by the survey, the respondents did not want to switch back to manual record keeping. A structured user survey is a useful tool for the development, adaptation and implementation of an anaesthesia information management system. A training strategy that takes the needs of the users into account is recommended.

Decompressive craniectomy in severe brain injury.

OBJECT: The goal of this study was to evaluate the therapeutic role of decompressive craniectomy in severe brain injury. METHODS AND RESULTS: Between 1996 and 1998 we treated 87 patients with severe brain injury (GCS 3-8) in our department. In 70 cases follow up data could be obtained. Mean age was 49 years (range 1-79). Initial CT scans of all patients demonstrated diffuse brain injury with generalised brain swelling and/or mass lesion. In 51 of these patients uni (n=40)- or bilateral (n=11) decompressive craniectomy was performed initially or secondarily after failure of standard treatment. In a retrospective analysis we performed statistical tests of the follow-up group. The mortality rate did not show a significant difference between the two treatment groups (p=0.802) with a slight advantage for the decompression. The log-rank-test demonstrated a non-significant improvement of the survival time for decompressed patients (p=0.632). Secondary decompression showed a significantly better survival rate and time compared to primary decompression. In all 7 pediatric cases (1-16 yrs) we performed craniectomy. 2 of them died immediately post emergency operation, 5 survived with good outcome (1 LOF). CONCLUSIONS: A slight, but non-significant benefit could be demonstrated after decompressive craniectomy in the whole patient population. In young patients decompression seems to have a more positive influence on outcome and survival.