Faculty Bibliography

OBJECTIVE: To determine the incidence of withdrawal of life-sustaining treatment in various groups of patients in a mixed intensive care unit (ICU). DESIGN: Observational retrospective. SETTING: University hospital mixed medical, neurological, neurosurgical and surgical ICU. PATIENTS: All patients admitted to the ICU between 1 November 2006, and 31 October 2007. RESULTS: 1,353 Patients were admitted to our ICU between 1 November 2006, and 31 October 2007. During this period, 218 (16.1%) patients died in the ICU, 10 of which were excluded for further analysis. In 174 (83.7%) of the remaining 208 patients, life-sustaining treatment was withdrawn. Severe CNS injury was in 86 patients (49.4%) being the reason for withdrawal of treatment, followed by MODS in 67 patients (38.5%). Notably, treatment was withdrawn in almost all patients (95%) who died of CNS failure. Patients who died in the ICU were significantly older, more often admitted for medical than surgical reasons, and had higher SOFA and APACHE II scores compared with those who survived their ICU stay. Also, SOFA scores before discharge/death were significantly different from admission scores. Of the 1,135 patients who survived their ICU stay, only 51 patients (4.5%) died within 28 days after ICU discharge. CONCLUSIONS: In 83, 7% of patients who die in the mixed ICU life-sustaining treatment is withdrawn. Severe cerebral damage was the leading reason to withdraw life-sustaining treatment.

There are relatively few institutions that have developed clinical data warehouses, containing patient data from the point of care. Because of the various care practices, data types and definitions, and the perceived incompleteness of clinical information systems, the development of a clinical data warehouse is a challenge. In order to deal with managerial and clinical information needs, as well as educational and research aims that are important in the setting of a university hospital, Erasmus Medical Center Rotterdam, The Netherlands, developed a data warehouse incrementally. In this paper we report on the in-house development of an integral part of the data warehouse specifically for the intensive care units (ICU-DWH). It was modeled using Atos Origin Metadata Frame method. The paper describes the methodology, the development process and the content of the ICU-DWH, and discusses the need for (clinical) data warehouses in intensive care.

INTRODUCTION: Esophagectomy with gastric tube reconstruction is characterized by high postoperative morbidity rates. Recently it was shown that decreased sublingual microvascular blood flow (MBF) preoperatively was associated with increased rate of complications after abdominal surgery. Similar observations in severely septic patients could be treated with dobutamine, independent of cardiac output. Based on these considerations we hypothesized that sublingual MBF derangements are more likely to be found in patients undergoing high risk surgery such as esophagectomy, and if present, might be prevented with administration of low dose dobutamine. METHODS: In this single-centre, prospective, double-blinded study, we randomized 20 patients admitted to the Intensive Care Unit following esophagectomy with gastric tube reconstruction into two groups. The intervention group (D) received a small dose of dobutamine (2.5 mug/kg/min) directly postoperative until two days postoperatively, whereas the placebo group (P) received a similar volume of saline. A subset of patients undergoing pancreaticoduodenectomy surgery was included as control group (C) for comparison with the study group. Sublingual MBF was determined one day prior to surgery until two days postoperatively. RESULTS: At the first postoperative day, patients in the esophagectomy/placebo group (P), showed a significant lower microvascular flow index, perfused vessel density and proportion of perfused vessels compared to baseline (p < 0.001) and the pancreaticoduodenectomy group (C) (p < 0.001). Administration of dobutamine significantly prevented the overall decrease in microvascular blood flow the first postoperative day. CONCLUSION: Postoperative sublingual MBF is markedly impaired in esophagectomy patients compared to patients who underwent a pancreaticoduodenectomy and could be prevented by early administration of a small dose dobutamine.

INTRODUCTION: We studied whether the choice of timing of discussing organ donation for the first time with the relatives of a patient with catastrophic brain injury in The Netherlands has changed over time and explored its possible consequences. Second, we investigated how thorough the process of brain death determination was over time by studying the number of medical specialists involved. And we studied the possible influence of the Donor Register on the consent rate. METHODS: We performed a retrospective chart review of all effectuated brain dead organ donors between 1987 and 2009 in one Dutch university hospital with a large neurosurgical serving area. RESULTS: A total of 271 medical charts were collected, of which 228 brain dead patients were included. In the first period, organ donation was discussed for the first time after brain death determination (87%). In 13% of the cases, the issue of organ donation was raised before the first EEG. After 1998, we observed a shift in this practice. Discussing organ donation for the first time after brain death determination occurred in only 18% of the cases. In 58% of the cases, the issue of organ donation was discussed before the first EEG but after confirming the absence of all brain stem reflexes, and in 24% of the cases, the issue of organ donation was discussed after the prognosis was deemed catastrophic but before a neurologist or neurosurgeon assessed and determined the absence of all brain stem reflexes as required by the Dutch brain death determination protocol. CONCLUSIONS: The phases in the process of brain death determination and the time at which organ donation is first discussed with relatives have changed over time. Possible causes of this change are the introduction of the Donor Register, the reintroduction of donation after circulatory death and other logistical factors. It is unclear whether the observed shift contributed to the high refusal rate in The Netherlands and the increase in family refusal in our hospital in the second studied period. Taking published literature on this subject into account, it is possible that this may have a counterproductive effect.

Near infrared spectroscopy (NIRS) is a non-invasive technique that allows determination of tissue oxygenation based on spectro-photometric quantitation of oxy- and deoxyhemoglobin within a tissue. This technique has gained acceptance as a tool to monitor peripheral tissue perfusion in critically ill patient. NIRS principle is based on the use of near-infrared electromagnetic waves for qualitative and quantitative assessments of molecular factors related to tissue oxygenation. Although this technique can be apllied in any tissue, it is primarily used for monitoring peripheral oxygenation in the muscle. Parameters that are determined using NIRS can be either directly calculated or can be derived from physiological interventions, such as arterial and venous occlusions methods. Information regarding muscle oxygen saturation, muscle oxygen consumption and regional blood flow can therefore be obtained. Clinical applications of NIRS include peripheral oxygenation monitoring during resuscitation of trauma and septic shock as well as the assessment of regional microcirculatory disorders. This review provides a brief discussion of NIRS basic principles and main clinical uses of this technique, with a specific focus on studies that assess the usefulness of NIRS in intensive care and emergency patients.

INTRODUCTION: Computed tomography of the lung has shown that ventilation shifts from dependent to nondependent lung regions. In this study, we investigated whether, at the bedside, electrical impedance tomography (EIT) at the cranial and caudal thoracic levels can be used to visualize changes in ventilation distribution during a decremental positive end-expiratory pressure (PEEP) trial and the relation of these changes to global compliance in mechanically ventilated patients. METHODS: Ventilation distribution was calculated on the basis of EIT results from 12 mechanically ventilated patients after cardiac surgery at a cardiothoracic ICU. Measurements were taken at four PEEP levels (15, 10, 5 and 0 cm H2O) at both the cranial and caudal lung levels, which were divided into four ventral-to-dorsal regions. Regional compliance was calculated using impedance and driving pressure data. RESULTS: We found that tidal impedance variation divided by tidal volume significantly decreased on caudal EIT slices, whereas this measurement increased on the cranial EIT slices. The dorsal-to-ventral impedance distribution, expressed according to the center of gravity index, decreased during the decremental PEEP trial at both EIT levels. Optimal regional compliance differed at different PEEP levels: 10 and 5 cm H2O at the cranial level and 15 and 10 cm H2O at the caudal level for the dependent and nondependent lung regions, respectively. CONCLUSIONS: At the bedside, EIT measured at two thoracic levels showed different behavior between the caudal and cranial lung levels during a decremental PEEP trial. These results indicate that there is probably no single optimal PEEP level for all lung regions.

OBJECTIVE: We conducted this observational study to investigate tissue oxygen saturation during a vascular occlusion test in relationship with the condition of peripheral circulation and outcome in critically ill patients. DESIGN: Prospective observational study. SETTING: Multidisciplinary intensive care unit in a university hospital. PATIENTS: Seventy-three critically ill adult patients admitted to the intensive care unit. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were followed every 24 hrs until day 3 after intensive care admission. Near-infrared spectroscopy was used to measure thenar tissue oxygen saturation, tissue oxygen saturation deoxygenation rate, and tissue oxygen saturation recovery rate after the vascular occlusion test. Measurements included heart rate, mean arterial pressure, forearm-to-fingertip skin-temperature gradient, and physical examination of peripheral perfusion with capillary refill time. Patients were stratified according to the condition of peripheral circulation (abnormal: forearm-to-fingertip skin-temperature gradient >/=4 and capillary refill time >4.5 secs). The outcome was defined based on the daily Sequential Organ Failure Assessment score and blood lactate levels. Upon intensive care unit admission, 35 (47.9%) patients had abnormal peripheral perfusion (forearm-to-fingertip skin-temperature gradient >4 or capillary refill time >4.5 secs). With the exception of the tissue oxygen saturation deoxygenation rate, tissue oxygen saturation baseline and tissue oxygen saturation recovery rate were statistically lower in patients who exhibited abnormal peripheral perfusion than in those with normal peripheral perfusion: 72 +/- 9 vs. 81 +/- 9; p = .001 and 1.9 +/- 0.7 vs. 3.2 +/- 0.9; p = .001, respectively. When a mixed-model analysis was performed over time for estimate (s) calculation, adjusted to the condition of disease, we did not find a significant clinical effect between vascular occlusion test-derived tissue oxygen saturation measurements (as response variables) and mean systemic hemodynamic variables (as independent variables): tissue oxygen saturation vs. heart rate: s (95% confidence interval) = 0.007 (-0.08; 0.09); tissue oxygen saturation vs. mean arterial pressure: s (95% confidence interval) = -0.02 (-0.12; 0.08); tissue oxygen saturation deoxygenation rate vs. heart rate: s (95% confidence interval) = 0.002 (-0.0004; 0.006); tissue oxygen saturation deoxygenation rate vs. mean arterial pressure: s (95% confidence interval) - 0.0007 (-0.003; 0.004); tissue oxygen saturation recovery rate vs. heart rate: s (95% confidence interval) = -0.009 (-0.02; -0.0015); tissue oxygen saturation recovery rate vs. mean arterial pressure: s (95% confidence interval) = 0.01 (0.002; 0.018). However, there was a strong association between tissue oxygen saturation baseline and tissue oxygen saturation recovery rate with abnormal peripheral perfusion: tissue oxygen saturation vs. abnormal peripheral perfusion: s (95% confidence interval) = -10.1 (-13.9; -6.2); tissue oxygen saturation recovery rate vs. abnormal peripheral perfusion: s (95% confidence interval) =-10.1 (-13.9; -6.2); tissue oxygen saturation recovery rate vs. abnormal peripheral perfusion: s (95% confidence interval) = -1.1 (-1.4; -0.81). Poor outcome was more closely related to abnormalities in peripheral perfusion than to tissue oxygen saturation-derived parameters. CONCLUSIONS: We found that the condition of peripheral circulation in critically ill patients strongly influences tissue oxygen saturation resting values and the tissue oxygen saturation reoxygenation rate but not the tissue oxygen saturation deoxygenation rate. In addition, changes in near-infrared spectroscopy-derived variables were independent of condition of disease and were not accompanied by any major differences in systemic hemodynamic variables.

BACKGROUND: The choice of wording in cases of suspected brain death is important. If brain death has not been proven by electrocerebral silence and by absence of spontaneous breathing in an apnoea test in a patient in intensive care, then words like 'brain dead', 'has died' and 'clinical brain death' should be avoided in conversations with the relatives of the patient. This is illustrated by three cases. CASES: The first patient was a 46-year-old woman, with thrombosis of the basilar artery; the second was a 26-year-old man who was resuscitated after a bilateral pneumothorax, but developed severe postanoxic encephalopathy; and the third patient was a 64-year-old man with a large intracerebral haemorrhage. The relatives were informed that the patient was 'brain dead' or 'deceased' based on loss of consciousness (Glasgow Coma score of 3) and absence of brain stem reflexes, but prior to the completion of the brain death protocol by electroencephalography and apnoea testing. In the first and third cases, brain death could not be proven, and the pronouncement that the patient was deceased had to be reversed. The emotional relatives refused organ donation. In the second case, death was pronounced upon loss of consciousness and absence of brain stem reflexes. The relatives refused organ donation, after which mechanical ventilation was withdrawn and the patient was declared dead for a second time based on circulatory arrest. CONCLUSION: A patient is dead after complete brain death determination or after circulatory arrest. Loss of consciousness (Glasgow Coma score of 3) and absence of brain stem reflexes lead to a state of catastrophic cerebral damage, but not to brain death. In such a situation, wording such as 'brain death', 'deceased' and 'clinical brain death' should be avoided in conversations with the relatives.

The brain dead patient is the ideal multiorgan donor. Conversely, brain death (BD) is an undesirable outcome of critical care medicine. Conditions that can lead to the state of BD are limited. An analysis showed that a (aneurysmal) subarachnoid hemorrhage, traumatic brain injury, or intracerebral hemorrhage in 83% precede the state of BD. Because of better prevention and treatment options, we should anticipate on an inescapable and desirable decline of BD. In this article, we offer arguments for this statement and discuss alternatives to maintain a necessary level of donor organs for transplantation.