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Biomedical subjects

H A Bruining

Publications and source records attributed to H A Bruining.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Fever in intensive care: keep medications in mind at all times].

In two patients, men aged 35 and 69 years admitted postoperatively to the intensive care unit, fever of unknown origin developed. One had been admitted because aspiration was suspected. He had been treated immediately with amoxicillin and clavulanic acid. The other had undergone oesophageal excision and gastric reconstruction because of oesophageal carcinoma and had been subjected to antibiotic decontamination (amphotericin B, norfloxacine en fungizone). No cause for the fever was detected, but it quickly subsided after discontinuation of the amoxicillin-clavulanic acid and the norfloxacine, respectively. When encountering fever of unknown origin in intensive care patients it is always important to think of drug fever.

Adult↗
PubMed1998

Germline mutations in the vhl gene in patients presenting with phaeochromocytomas.

It has been shown that an appreciable percentage of patients presenting with primary, apparently sporadic phaeochromocytomas may in fact have von-Hippel-Lindau (VHL) disease. In order to investigate this, we retrospectively screened 68 patients, who had been operated on for phaeochromocytomas, for the presence of germline mutations in the vhl gene. DNA was isolated from peripheral-blood leukocytes and used to screen the entire coding sequence and the intron-exon boundaries of the vhl gene for mutations, using a PCR-based SSCP strategy. When an abnormal pattern was found in the SSCP analysis, sequence analysis was carried out. We found SSC variants in the vhl gene in 8 of the 68 patients. Of 6 patients, 2 turned out to be related (an uncle and his nephew), and they carried the same mis-sense mutation: R64P. In 4 other patients, mis-sense mutations, P25L, L63P, G144Q and I147T, were also identified. None of these mutations has been described, and 3 of them (P25L, L63P and R64P) are located closer to the N terminus of the vhl protein than any reported vhl mutation. In the remaining 2 cases, the mutations were localized not in the coding sequence but in the intronic sequence (but not within splice-sites), adjacent to the exon, so they were probably not related to the disease. Our results show that a relatively high proportion (6/68, or 8.8%), though not as high as the 20% reported earlier, of patients with apparently sporadic phaeochromocytomas may carry germline mutations in the vhl gene.

Adrenal Gland Neoplasms↗
PubMed1998

[Relative adrenocortical insufficiency in intensive care patients].

Unexplained shock developed after a major vascular operation in a man aged 67 who used inhalation corticosteroids for a chronic obstructive pulmonary disease, and after pancreaticoduodenectomy in a man aged 56. Both had relative adrenocortical insufficiency, combated with corticosteroid supplementation. The condition of a relative adrenocortical insufficiency is considered to exist if a test dose of corticosteroids leads to rapid weaning from sympathicomimetics. A subnormal rise of plasma cortisol after stimulation with adrenocorticotropic hormone supports the diagnosis. Routine corticosteroid substitution in intensive care patients is inadvisable, because it enhances the risk of complications related to use of steroids.

Adrenal Cortex Hormones↗
PubMed1998

NADH videofluorimetry to monitor the energy state of skeletal muscle in vivo.

BACKGROUND: Reduction of the cellular energy state during ischemia of the limbs is an important determinant for development of necrosis. Since energy conversion in the mitochondria is based on electron transport from NADH to molecular O2, the NADH/NAD+ redox couple reflects the mitochondrial redox state and cellular O2 requirement. The applicability of NADH videofluorimetry to monitor noninvasively changes in the energy state of intact resting skeletal muscle as a function of oxygenation was investigated in a rat model. MATERIALS AND METHODS: In mechanically ventilated rats (n = 6), NADH fluorescence images of the gracilis muscle were recorded under different oxygenation conditions. Induction of anoxic and ischemic hypoxia were verified by simultaneous measurement of tissue oxygen pressure and afferent blood flow. RESULTS: Anoxic hypoxia and ischemic hypoxia increased the NADH fluorescence intensity by 46.0 +/- 15.0 and 30.8 +/- 26.4%, respectively. The response time of NADH fluorescence intensity, tissue oxygen pressure, and afferent blood flow was similar during development of anoxic and ischemic hypoxia. Upon reperfusion and reoxygenation, however, NADH fluorescence intensity changed significantly earlier than tissue oxygen pressure as measured by an oxygen needle electrode. CONCLUSION: These results demonstrate that changes in NADH fluorescence intensity reflect oxygenation changes in intact skeletal muscle in vivo. Since NADH videofluorimetry, in contrast to oxygen needle electrode measurements, noninvasively visualizes temporal and regional changes in the energy state of skeletal muscle, this technique has the potential to improve clinical evaluation of ischemia/reperfusion injury and tissue viability.

Animals↗
PubMed1998

In vitro and in vivo Raman spectroscopy of human skin.

Noninvasive techniques that provide detailed information about molecular composition, structure, and interactions are crucial to further our understanding of the relation between skin disease and biochemical changes in the skin, as well as for the development of penetration enhancers for transdermal drug administration. In this study we present in vitro and in vivo Raman spectra of human skin. Using a Raman microspectrometer, in vitro spectra were obtained of thin cross sections of human skin. They provided insight into the molecular composition of different skin layers. Evidence was found for the existence of a large variation in lipid content of the stratum corneum. A simple experimental setup for in vivo confocal Raman microspectroscopy of the skin was developed. In vivo Raman spectra of the stratum corneum were obtained at different positions of the arm and hand of three volunteers. They provided evidence for differences in the concentration of natural moisturizing factor at these positions.

Dermis↗
PubMed1998

A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings.

OBJECTIVE: The purpose of this study was to assess and compare the humidification, heating, and resistance properties of three commercially available heat-moisture exchangers (HMEs). To mimic clinical conditions, a previously validated, new, realistic experimental set-up and measurement protocol was used. DESIGN: Prospective, comparative experimental study. SETTING: Surgical Intensive Care Unit, University Hospital of Rotterdam. MATERIALS: An experimental set-up consisting of a patient model, measurement systems, and ventilator and three different HME types. INTERVENTIONS: The air flow, pressure in the ventilation circuit, pressure difference over the HME, and partial water vapour pressure and temperature at each side of the HMEs were measured. Measurements were repeated every 30 min during the first 2 h and every hour up to 24 h for each HME at six different ventilator settings. The mean inspiratory and maximum expiratory resistance, flow-weighted mean absolute humidity and temperature outputs, and humidification and heating efficiencies of HMEs were calculated. MEASUREMENTS AND RESULTS: The Dar Hygroster had the highest humidity output, temperature output, humidification efficiency, and heating efficiency values throughout the study (32.8 +/- 21. mg/l, 32.2 +/- 0.8 degrees C, 86.3 +/- 2.3%, and 0.9 +/- 0.01%, respectively) in comparison to the Humid-Vent Filter (25.3 +/- 3.2 mg/l, 31.9 +/- 0.8 degrees C, 72.2 +/- 5.3%, 0.9 +/- 0.02%, respectively) and the Pall Ultipor BB100 breathing circuit filter (23.4 +/- 3 mg/l, 28.3 +/- 0.7 degrees C, 68.8 +/- 5.9%, 0.8 +/- 0.02%, respectively). The inspiratory and expiratory resistance of the HMEs remained below clinically acceptable maximum values (2.60 +/- 0.04 and 2.45 +/- 0.05 cmH2O/l per s, respectively). CONCLUSION: The Dar Hygroster filter was found to have the highest humidity and temperature output of all three HMEs, the Humid-Vent filter had a satisfactory humidity output only at low tidal volume flow rate and minute volume settings, whereas the Pall Ultipore BB 100 never achieved a sufficient humidity and temperature output.

Hot Temperature↗
PubMed1998

Bioavailability of ciprofloxacin after multiple enteral and intravenous doses in ICU patients with severe gram-negative intra-abdominal infections.

BACKGROUND: Few data are available on the pharmacokinetics of multiple enteral dosing of ciprofloxacin in critically ill intensive care patients and none for those with severe gram-negative intra-abdominal infections (GNIAI). OBJECTIVE: To determine the bioavailability of enteral ciprofloxacin in tube-fed intensive care patients with severe GNIAI. DESIGN: A randomized crossover study. SETTING: University-based medical center. PATIENTS: 5 critically ill intensive care patients with GNIAI and an estimated creatinine clearance > 25 ml/ min who received continuous tube feeding. INTERVENTIONS: Multiple doses of enteral 750 mg b.i.d. versus 400 mg b.i.d.i.v. ciprofloxacin. MEASUREMENTS: The calculated 12-h area under the serum concentration versus time curve after 750 mg b.i.d. enteral dosing was equivalent to that after 400 mg b.i.d.i.v. The mean bioavailability of enteral dosing was 53.1% [95% confidence interval (CI) 43.5-62.8]. In seven additional patients, the mean serum steady-state concentration at 2 h after enteral administration was 3.9 microg/ml (95% CI 1.9-5.9), not significantly different from that found in the crossover study (p = 0.4). CONCLUSIONS: In tube-fed intensive care patients with severe GNIAI, the bioavailability of enteral ciprofloxacin is adequate.

Adult↗
PubMed1998

Prognostic importance of gram-negative intestinal colonization preceding pancreatic infection in severe acute pancreatitis. Results of a controlled clinical trial of selective decontamination.

OBJECTIVES: To establish, firstly, whether gram-negative (re)-colonization of the gut leads to an increased risk of gram-negative pancreatic infections and whether this event is time-related and, secondly, whether the difference in the quantity and quality of micro-organisms colonizing the digestive tract influences morbidity and mortality. DESIGN: Prospective analysis of the results of systematic semi-quantitative cultures of several body areas taken from patients with severe acute pancreatitis, during a controlled multicenter trial of adjuvant selective decontamination. SETTING: Surgical intensive care units of 16 hospitals. PATIENTS: A total of 2,159 semi-quantitative cultures from the oropharynx, rectum and pancreatic tissues taken from 90 patients were analyzed. INTERVENTIONS: Surveillance cultures from the oropharynx and rectum were taken on admission and repeated twice weekly and from the (peri)-pancreatic devitalized tissues (i. e. necrosis) at every relaparotomy and from drainage. MEASUREMENTS AND RESULTS: All gram-negative pancreatic infections were preceded by intestinal colonization with the same micro-organisms. The risk of developing a pancreatic infection following gram-negative intestinal colonization (15/42 patients) was significantly higher as compared to patients without gram-negative colonization (0/10 patients) (p < 0.001) or to patients in whom E. coli was the only intestinal micro-organism cultured (0/30 patients) (p < 0.001). The occurrence of intestinal E. coli did not increase the risk of pancreatic infection. Gram-negative colonization of the rectum and oropharynx significantly correlated with the later development of pancreatic infection: relative risks 73.7 (p < 0.001) and 13.6 (p < 0.001), respectively. However, when both areas were evaluated simultaneously, the rectum was more significant (p < 0.001). The severity of intestinal intestinal colonization until the moment of pancreatic infection showed an increase in time in all 15 patients. In 11 of 15 patients (73%) these infections occurred within 1 week following the first isolation from the digestive tract. Gram-negative intestinal colonization was associated with a 3.7 fold increased mortality risk (p = 0.004). CONCLUSIONS: Gram-negative intestinal colonization, E. coli excepted, is an early prognostic parameter in patients in whom pancreatic infection has not yet occurred and represents a significantly increased risk of pancreatic infections and mortality.

Actuarial Analysis↗
PubMed1998

Effect of L-NAME, an inhibitor of nitric oxide synthesis, on plasma levels of IL-6, IL-8, TNF alpha and nitrite/nitrate in human septic shock.

OBJECTIVES: We tested the effects of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, on plasma levels of interleukin (IL) IL-6, IL-8, tumor necrosis factor-alpha (TNFalpha) and nitrite/nitrate (NO2-/ NO3-) in patients with severe septic shock. DESIGN: Prospective clinical study. SETTING: Surgical intensive care unit at a university hospital. PATIENTS: 11 consecutive patients with severe septic shock. INTERVENTIONS: Standard hemodynamic measurements were made and blood samples taken at intervals before, during, and after a 12-h infusion of L-NAME 1 mg x kg(-1) x h(-1) for determination of plasma IL-6, IL-8, TNFalpha and NO2-/NO3- concentration. MEASUREMENTS AND RESULTS: Patients with sepsis had increased plasma levels of IL-6, IL-8, TNFalpha and NO2-/NO3- (p < 0.05). Plasma levels of IL-6. IL-8, and NO2-/NO- were negatively correlated with systemic vascular resistance (r = -0.62, r = -0.65, and r = -0.78, respectively, all p < 0.05). Continuous infusion of L-NAME increased mean arterial pressure and systemic vascular resistance, with a concomitant reduction in cardiac output (all p < 0.01). No significant changes were seen in levels of plasma IL-6, IL-8, and NO-/NO3- during the 24-h observation period. Plasma levels of TNFalpha were significantly reduced during L-NAME infusion compared to baseline (p < 0.05). CONCLUSIONS: NO plays a role in the cardiovascular derangements of human septic shock. Inhibition of NO synthesis with L-NAME does not promote excessive cytokine release in patients with severe sepsis.

APACHE↗
PubMed1998

The clinical relevance of the Waterlow pressure sore risk scale in the ICU.

OBJECTIVE: To evaluate whether the Waterlow pressure sore risk (PSR) scale has prognostic significance for intensive care patients. DESIGN: A prospective study. SETTING: The surgical intensive care unit (ICU) of the University Hospital Rotterdam. PATIENTS: Data were evaluated from 594 patients who had been admitted to the ICU during the year 1994. METHODS AND RESULTS: Each patient was assessed daily with respect to their Waterlow PSR score and the development of pressure sores in the sacral region. Actuarial statistical methods were used to analyse the predictive value of the risk score. When a patient had a Waterlow PSR score > 25 on admission, the risk of developing a pressure sore was significantly increased compared to patients with a PSR score < 25. After admission, the daily Waterlow PSR scores obtained were significantly associated with the risk of developing a pressure sore. For each additional point this risk increased by 23% (95% confidence interval 17 to 28%). CONCLUSIONS: The Waterlow PSR scale provides the medical and nursing staff at an early stage with reliable information about the risk patients have in developing a pressure sore.

Adolescent↗
PubMed1998

Distribution and metabolism of N(G)-nitro-L-arginine methyl ester in patients with septic shock.

OBJECTIVE: The pharmacokinetics of N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, was investigated in patients with septic shock. METHODS: Blood was sampled at intervals before, during and after 12-h infusion of L-NAME 1 mg x kg(-1) x h(-1) in nine septic shock patients for determination of plasma concentrations by high-performance liquid chromatography (HPLC). In three patients the renal clearance of the drug was determined. RESULTS: Incubation of L-NAME with plasma and blood in vitro revealed hydrolysis to N(G)-nitro-L-arginine (L-NOARG), the active inhibitor of NO synthesis. L-NOARG did not undergo further degradation. Continuous intravenous infusion of 1 mg x kg(-1) x h(-1) of L-NAME for 12 h in patients with septic shock increased blood pressure and resulted in increasing plasma concentrations of L-NOARG (Cmax 6.2 microg x ml(-1) at 12 h) whereas L-NAME concentrations reached a plateau within 1.5 h (Cmax 1.0 microg x ml(-1)). After the infusion was stopped L-NAME disappeared from the plasma rapidly (half-life 19.2 min) whereas L-NOARG concentration declined slowly (half-life 22.9 h). The calculated volume of distribution for L-NAME was 0.451 x kg(-1) body weight and 1.961 x kg(-1) for L-NOARG. The renal clearance for L-NOARG was 3.5% of total body clearance for L-NOARG, whereas L-NAME could not be detected in urine. CONCLUSION: We conclude that vasoconstriction with L-NAME in septic patients may result from hydrolysis to L-NOARG, the active inhibitor of NO synthesis. The long plasma half-life and large volume of distribution for L-NOARG suggests extensive distribution to extravascular tissues. Since renal excretion is minimal, elimination of the metabolite L-NOARG follows other pathways.

Chromatography, High Pressure Liquid↗
PubMed1998

2-Methoxyisobutylisonitrile probe during parathyroid surgery: tool or gadget?

The success of parathyroid surgery is determined by the identification and removal of all parathyroid tumors. Parathyroid tumors accumulate and retain 2-methoxyisobutylisonitrile (MIBI) labeled with technetium-99m. Intravenous injection of this radiopharmacon prior to parathyroid surgery allows identification of parathyroid tumors with a hand-held gamma detector. To assess the value of this technique, a case-control study was performed with 62 patient having nuclear-guided parathyroidectomy and 60 patients having conventional parathyroid explorations. The sensitivity rates of the MIBI probe in single and multiple gland disease were 84.6% and 63.0%, respectively. Rates of success, temporary and permanent hypoparathyroidism, and injury of the recurrent laryngeal nerve were similar in patients who underwent probe-guided surgery and those who had conventional surgery. In conclusion, although the MIBI probe appears to be a valuable tool in parathyroid surgery, its use has not improved the outcome of such surgery at our institution.

Case-Control Studies↗
PubMed1998

Retroperitoneal adrenalectomy: open or endoscopic?

Conventional adrenalectomy requires relatively large incisions. To assess the value of retroperitoneal endoscopic adrenalectomy, a case-control study was performed comparing the endoscopic technique to conventional posterior adrenalectomy. All patients had adrenal tumors less than 7 cm in diameter. Endoscopic retroperitoneal adrenalectomy required more operative time (90 vs. 60 minutes, p < 0.0001) than the open approach but was associated with less blood loss (20 vs. 125 ml, p < 0.0001). Endoscopic adrenalectomy caused less pain postoperatively (p = 0.0005) and was associated with fewer complications (p = 0.035). The hospital stay was shorter after endoscopic adrenalectomy than after open adrenalectomy (p < 0.0001). In conclusion, we advocate endoscopic retroperitoneal adrenalectomy in patients with small adrenal tumors.

Adenoma↗
PubMed1998

Infections and bacteriological data after laparoscopic and open gallbladder surgery.

In two hospitals 637 patients undergoing cholecystectomy between June 1989 and June 1993 were entered into a prospective audit. The aim of this study was to determine the incidence of postoperative infections, especially wound infections, after open and laparoscopic biliary surgery and to assess the bacteriological data on these patients. The incidence of minor wound infection was 10.4% (66/637), of major wound infection 3.6% (23/637) and the overall incidence was 14% (89/637). The incidence of wound infection after laparoscopic cholecystectomy was 5.3% (10/189) and all were minor. Significant specific risk factors for developing a wound infection after laparoscopic cholecystectomy were emergency of the operation (P = 0.046) and acute cholecystitis (P = 0.014). Overall, bile cultures were positive in 22%. There were 85 patients (13.3%) with positive bile from the gallbladder. From the laparoscopically operated patients 2.8% had a positive bile culture. The predominant micro-organisms from gallbladder bile were Escherichia coli (56 isolates), Klebsiella spp. (20 isolates) and Streptococcus spp. (16 isolates). There was no relationship between positive gallbladder cultures and wound infection. The consequences of wound infections can be serious and this study showed a morbidity rate comparable with the literature. The incisions used in laparoscopic gallbladder surgery are less susceptible to major problems. This combined with the significantly lower incidence of wound infections after laparoscopic cholecystectomy suggests that routine antibiotic prophylaxis as recommended for biliary surgery in general is now questionable.

Adult↗
PubMed1998

Methicillin-resistant Staphylococcus aureus: acquisition and risk of death in patients in the intensive care unit.

OBJECTIVE: To evaluate the risk of patients in intensive care units (ICU) of becoming infected with methicillin-resistant Staphylococcus aureus (MRSA) and to assess the mortality during a six week follow-up period, compared with patients who developed methicillin-sensitive S. aureus (MSSA) infection. DESIGN: Point prevalence survey. SETTING: 1417 ICU in 17 Western European countries. SUBJECTS: 10038 patients in ICU who were part in the EPIC (European Prevalence of Infection in Intensive Care) Study. MAIN OUTCOME MEASURES: Prevalence of MRSA and MSSA ICU-acquired infections, risk factors, and mortality. RESULTS: On the study day 21% of patients had ICU-acquired infections. The most commonly reported pathogen was Staphylococcus aureus (30%). Overall, 60% of strains of S. aureus were resistant to methicillin (with a wide intercountry variation). The most commonly reported MRSA infections were pneumonia and lower respiratory tract infections. The most important risk factor for MRSA was the length of stay in the ICU. MRSA infection reduced the chance of survival, particularly when it was found in lower respiratory tract infections: the risk of mortality was three times higher in patients with MRSA than in those with MSSA. CONCLUSION: Patients in ICU are at high risk of becoming infected with MRSA. The longer they stay, the higher the risk. Patients with MRSA infections are less likely to survive than those with MSSA.

Cross Infection↗
PubMed1998

Prolonged inhibition of nitric oxide synthesis in severe septic shock: a clinical study.

OBJECTIVES: Inhibitors of nitric oxide synthesis have been suggested to be of value in the treatment of hypotension during sepsis. However, earlier clinical reports only describe the initial effects of these nitric oxide inhibitors. This study was designed to examine the effects of the prolonged inhibition of nitric oxide synthesis with N(omega)-nitro-L-arginine methyl ester (L-NAME) in patients with severe septic shock. DESIGN: Prospective, nonrandomized, clinical study. SETTING: Medical-surgical intensive care unit in a university hospital. PATIENTS: Eleven consecutive patients with ongoing hyperdynamic septic shock that was unresponsive to fluid resuscitation and vasopressor therapy. INTERVENTIONS: Measurements of hemodynamic, hematologic, and biochemical variables were made before, during, and after the start of a continuous intravenous infusion of 1 mg/kg/hr of L-NAME, an inhibitor of nitric oxide synthesis, for a period of 12 hrs. MEASUREMENTS AND MAIN RESULTS: Continuous infusion of L-NAME resulted in a direct increase in mean arterial pressure from 65 +/- 3 (SEM) to 93 +/- 4 mm Hg and an increase in systemic vascular resistance from 426 +/- 54 to 700 +/- 75 dyne x sec/cm5, reaching a maximum at 0.5 hr. Pulmonary arterial pressure was increased from 31 +/- 2 to a maximum of 36 +/- 2 mm Hg at 1 hr, and pulmonary vascular resistance increased from 146 +/- 13 to a maximum of 210 +/- 23 dyne x sec/cm5 at 3 hrs. Paralleling these changes, cardiac output decreased from 10.8 +/- 0.8 to 8.7 +/- 0.7 L/min and oxygen delivery decreased from 1600 +/- 160 to 1370 +/- 130 mL/min (for all changes p < .05 as compared with the baseline value). Heart rate, cardiac filling pressures, oxygen consumption, urine production, arterial lactate concentration, and other biochemical parameters were not significantly changed by L-NAME administration (all p > .05). Arterial oxygenation was improved during L-NAME infusion, and the dosage of catecholamines could be reduced (both p< .05). Although sustained hemodynamic effects were seen, L-NAME was most effective during the early stages of administration, and the effect of L-NAME on blood pressure and vascular resistance tended to diminish throughout the continuous infusion of L-NAME. Seven of 11 patients ultimately died, with survival time ranging from 2 to 34 days. CONCLUSIONS: Nitric oxide appears to play a role in cardiovascular derangements during human sepsis. The increased blood pressure and vascular resistance values are sustained during prolonged inhibition of nitric oxide synthesis with L-NAME in patients with severe septic shock, although the hemodynamic changes are most significant in the early stages of L-NAME infusion. The high mortality rate in these patients may suggest that L-NAME has only limited effects on outcome.

APACHE↗