PubMed Health⌕ Search

Biomedical subjects

L B Svendsen

Publications and source records attributed to L B Svendsen.

At least 19 recordsLinked to original sources
PubMed2002

Bicarbonate attenuates intracellular acidosis.

BACKGROUND: This study was prompted by concern that administration of bicarbonate for correction of lactate acidosis aggravates a low intracellular pH (pHi). In healthy subjects we evaluated skeletal muscle pHi using 31P-magnetic resonance spectroscopy during 5-minute rhythmic handgrip to provoke intracellular acidosis. METHODS: Subjects were randomized to treatment with bicarbonate or saline infused intravenously in a cross-over study design with 1 h between trials. RESULTS: In response to rhythmic handgrip, muscle venous O(2) hemoglobin saturation decreased from 51 +/- 4% to 36 +/- 2% and lactate increased from 1.0 +/- 0.1 to 4.9 +/- 0.5 mmol/l with a reduction in pH from 7.43 +/- 0.01-7.23 +/- 0.01 (P<0.05). pHi decreased from 7.06 +/- 0.02-6.36 +/- 0.08 (P<0.05). Infusion of bicarbonate increased the arterial blood concentration from 26 +/- 1 to 39 +/- 1 mmol/l (P<0.05). The arterial CO(2) partial pressure decreased from 5.6 +/- 0.2 to 5.2 +/- 0.3 kPa during rhythmic handgrip, whereas it increased to 5.9 +/- 0.2 kPa (P<0.05) during infusion of bicarbonate. Bicarbonate treatment also increased pH of arterial and venous blood (7.55 +/- 0.01 vs. 7.44 +/- 0.02 and 7.31 +/- 0.01 vs. 7.23 +/- 0.02, respectively; P<0.05). In the last min of rhythmic handgrip the decrease in pHi was attenuated by the administration of bicarbonate (6.60 +/- 0.11 vs. 6.40 +/- 0.12; P<0.05). CONCLUSION: During exercise-induced metabolic acidosis, intravenous administration of bicarbonate increased the buffering capacity of blood and attenuated the decrease in intracellular muscle pH, although there was a small increase in the arterial carbon dioxide pressure.

Acidosis↗
PubMed2002

Lymphoscintigraphy using technetium-99m human serum albumin in chylothorax.

Chylous effusion is an infrequent complication of abdominothoracic surgery. When conservative therapy cannot cure the patient, surgical closure of the thoracic duct must be performed. If radiological lymphography is impossible to perform, lymphoscintigraphy with Tc-99m human serum albumin is a good alternative. Here, we present two patients who developed chylothorax after abdominothoracic surgery. Successful surgery was performed after lymphoscintigraphy had demonstrated the disruption of the thoracic duct.

Adenocarcinoma↗
PubMed2001

Cerebral blood flow velocity increases during a single treatment with the molecular adsorbents recirculating system in patients with acute on chronic liver failure.

The aim of this uncontrolled pilot study is to determine the effect of treatment with the molecular adsorbents recirculating system (MARS) on cerebral perfusion in patients with acute on chronic liver failure (AOCLF). In 8 patients (median age, 44 years; range, 35 to 52 years) admitted with AOCLF, a single 10-hour MARS treatment was performed. Hepatic encephalopathy (HE) was graded according to the Fogarty criteria. Changes in cerebral perfusion were determined by transcranial Doppler as mean flow velocity (V(mean)) in the middle cerebral artery. Arterial ammonia and bilirubin levels were monitored as a measure of the capability of the MARS to remove water-soluble and protein-bound toxins. During MARS treatment, HE grade improved in 3 patients and remained unchanged in 5 patients (P =.11). V(mean) increased from 42 cm/sec (range, 26 to 59 cm/sec) to 72 cm/sec (range, 52 to 106 cm/sec; P <.05), whereas arterial ammonia level decreased from 88 micromol/L (range, 45 to 117 micromol/L) to 71 micromol/L (range, 26 to 98 micromol/L; P <.05) and bilirubin level from 537 micromol/L (range, 324 to 877 micromol/L) to 351 micromol/L (range, 228 to 512 micromol/L; P <.05). In conclusion, cerebral perfusion is increased and levels of ammonia and bilirubin are reduced during MARS treatment in patients with AOCLF.

Acute Disease↗
PubMed2001

Hemodynamic changes during a single treatment with the molecular adsorbents recirculating system in patients with acute-on-chronic liver failure.

The aim of this pilot study is to evaluate the circulatory safety of treatment with the molecular adsorbents recirculating system (MARS) by determining the effect on systemic hemodynamics of a single MARS treatment in patients with acute-on-chronic liver failure (AOCLF). In eight patients admitted with AOCLF, a single 10-hour MARS treatment was performed. Systemic hemodynamic variables were determined before and during treatment. Bilirubin and urea were monitored as measures of protein-bound and water-soluble toxins. During MARS treatment, mean arterial pressure increased from 67 +/- 9 to 76 +/- 6 mm Hg (P < .05). Systemic vascular resistance index increased from 757 +/- 134 to 884 +/- 183 dyne x s/cm(5)/m(2) (P < .05), whereas cardiac index remained constant (5.9 +/- 0.7 v 6.0 +/- 1.1 L/min/m(2)). No episode of dialysis-induced hypotension was observed. Systemic oxygen consumption remained constant (92 +/- 30 v 93 +/- 11 mL/min/m(2)). Bilirubin levels decreased from 537 +/- 192 to 351 +/- 106 micromol/L (P < .05), and urea levels, from 19.1 +/- 13.9 to 6.7 +/- 5.1 mmol/L (P < .05). In conclusion, MARS treatment proved safe in critically ill patients with no attributing side effects.

Acute Disease↗
PubMed1999

Double-stapled esophagogastric anastomosis for resection of esophagogastric or cardia cancer: new application for an old technique.

In colorectal surgery, the double-stapled technique is used extensively, because it is a fairly safe and simple procedure and is useful in relatively inaccessible areas. For these reasons, we adapted the procedure to the upper gastrointestinal tract. The present study reports our first experiences of the surgical efficacy using an esophagogastric double-stapled end-to-end anastomosis for subtotal esophagectomy and cardia resection. We retrospectively studied 31 patients treated between January 1991 and January 1997 with respect to hospital mortality, anastomotic leakage, cancer recurrence, and benign stricture rate. No hospital mortality was seen. One nonfatal anastomotic leak occurred (3%). In three patients, esophageal resection was not radical (10%). Of the remaining 28 patients, one had an anastomotic cancer recurrence (4%). Eleven of the remaining 27 patients (41%) developed a benign anastomotic stricture. All achieved normal swallowing after a median of two endoscopic dilatation procedures using TTS balloons. In conclusion, the double-stapled end-to-end anastomosis technique after resection for esophagogastric or cardia cancer is a simple and expeditious procedure, carrying an acceptable perioperative morbidity and cancer recurrence rate. Larger staplers are recommended to lower the high stricture rate observed after the usage of a 21-mm stapler in this study.

Adult↗
PubMed1998

The influence of PaO2, pH and SaO2 on maximal oxygen uptake.

Influence of arterial oxygen pressure (PaO2) and pH on haemoglobin saturation (SaO2) and in turn on O2 uptake (VO2) was evaluated during ergometer rowing (156, 276 and 376 W; VO2max, 5.0 L min-1; n = 11). During low intensity exercise, neither pH nor SaO2 were affected significantly. In response to the higher work intensities, ventilations (VE) of 129 +/- 10 and 155 +/- 8 L min-1 enhanced the end tidal PO2 (PETO2) to the same extent (117 +/- 2 mmHg), but PaO2 became reduced (from 102 +/- 2 to 78 +/- 2 and 81 +/- 3 mmHg, respectively). As pH decreased during maximal exercise (7.14 +/- 0.02 vs. 7.30 +/- 0.02), SaO2 also became lower (92.9 +/- 0.7 vs. 95.1 +/- 0.1%) and arterial O2 content (CaO2) was 202 +/- 3 mL L-1. An inspired O2 fraction (F1O2) of 0.30 (n = 8) did not affect VE, but increased PETO2 and PaO2 to 175 +/- 4 and 164 +/- 5 mmHg and the PETO2-PaO2 difference was reduced (21 +/- 4 vs. 36 +/- 4 mmHg). pH did not change when compared with normoxia and SaO2 remained within 1% of the level at rest in hyperoxia (99 +/- 0.1%). Thus, CaO2 and VO2max increased to 212 +/- 3 mL L-1 and 5.7 +/- 0.2 L min-1, respectively. The reduced PaO2 became of importance for SaO2 when a low pH inhibited the affinity of O2 to haemoglobin. An increased F1O2 reduced the gradient over the alveolar-arterial membrane, maintained haemoglobin saturation despite the reduction in pH and resulted in increases of the arterial oxygen content and uptake.

Adult↗
PubMed1998

Endoscopic palliation of inoperable cancer of the oesophagus or cardia by argon electrocoagulation.

BACKGROUND: Cancer of the oesophagus and the cardia tends to present late. Palliation of dysphagia is the prospect of most of the patients. This paper reports the use of argon electrocoagulation in 83 patients with inoperable cancer strictures in the oesophagus and cardia. METHODS: The argon electrocoagulation was done by a fibre conducting electricity and argon air to the site of coagulation. After treatment the patients were allowed to take fluids and normal food the same evening or the next morning. After recanalization the patients were treated regularly every 3-4 weeks. RESULTS: Recanalization enabling passage for normal food was achieved with 1 treatment in 48 patients (58%), whereas 22 (26%) needed more than 1 treatment. In 13 patients (16%) the ability to eat normal food was not achieved. In these patients dysphagia improved at least one grade. Perforation was seen in seven patients (8%) and in 1% of treatments. Perforations were successfully treated conservatively in six of the seven patients. Sixty-three patients (76%) died during the investigation period, on average 146 days (range, 43-397 days) after diagnosis. CONCLUSION: Argon electrocoagulation offers an easy, cheap, and safe alternative to treatment with laser photocoagulation and expandable metal stents.

Aged↗
PubMed1998

Tolerance to head-up tilt and suspension with elevated legs.

OBJECTIVE: Orthostatic hypotension is usually a benign event. However, some patients are disabled by frequent syncopal events, and vertical transportation during helicopter rescue, for example, may even be fatal. Normal orthostatic tolerance is poorly defined, so we evaluated the response to 50 degrees head-up tilt. Also, the effect of leg elevation was examined in order to establish the influence of venous return, and a fatal accident associated with orthostasis is reported. METHODS: There were 79 volunteers who were subjected to 50 degrees head-up tilt, and 9 subjects performed 1 h of suspension by double strops placed around the thorax and knee bends, respectively. The time to presyncope and changes in BP, heart rate, thoracic electrical impedance, central venous pressure and central venous and muscle oxygen saturations were measured. RESULTS: Head-up tilt resulted in hypotension, bradycardia and presyncopal symptoms in 69 subjects within 1 h (87%; half time 27 min), but during suspension with elevated legs in only one subject (11%; p < 0.02). In presyncopal subjects the central blood volume was reduced as reflected by an elevated thoracic electrical impedance and reduced central venous and muscle oxygen saturations. CONCLUSIONS: During 50 degrees head-up tilt, half of 79 subjects near-fainted within 27 min, whereas elevation of the legs secured venous return to the heart and prevented presyncopal symptoms. The high rate of near-fainting in normal subjects should be taken into account during evaluation of patients with syncope, and it emphasizes the use of a position that secures venous return during transportation.

Adult↗
PubMed1997

Muscle oxygen saturation during surgery in the lithotomy position.

Surgery in the lithotomy position can provoke ischaemic lesions in the lower leg. We assessed lower leg oxygen saturation using near-infrared spectroscopy (NIRS) in 42 patients undergoing urinary tract surgery. Lower leg perfusion pressure was calculated as the difference of mean arterial pressure to pressure in an air bag supporting the lower leg and the hydrostatic pressure difference from the level of the lower leg to the heart. During elevation of the lower leg for 25 (3-65) min (median and range), mean arterial pressure decreased from 100 (73-125) to 77 (53-112) mmHg and the lower leg perfusion pressure dropped from 103 (80-122) to 21 (-6-65) mmHg, corresponding to a reduction in oxygen saturation of the medial gastrocnemius muscle from 68% (40-100%) to 58% (20-96%) (P < 0.01). The results demonstrate significant desaturation of the calf muscles during surgery in the lithomy position.

Adult↗
PubMed1997

Nonsurgical treatment of esophageal perforations after endoscopic palliation in advanced esophageal cancer.

BACKGROUND AND STUDY AIMS: Iatrogenic esophageal perforation during palliative endoscopic treatment in patients with incurable esophageal or cardiac cancer is a severe complication, associated with a high rate of mortality. The treatment remains controversial, since both nonsurgical and surgical treatment regimens are used. The present study describes a nonsurgical regimen. PATIENTS AND METHODS: Nine cases of perforation occurred in 142 consecutive patients referred for endoscopic palliation of dysphagia, corresponding to a perforation rate of 6%. Laser therapy was the main treatment used (argon plasma coagulation or Nd:YAG photocoagulation). RESULTS: Nonsurgical treatment was successful in six patients (75%). Two patients died (22%) as a direct result of esophageal perforation following endoscopic palliation procedures. CONCLUSION: These findings show an acceptable mortality rate using a nonsurgical treatment regimen involving broad-spectrum antibiotics, nasogastric suction, and parenteral nutrition, with pleural drainage and endoprosthesis placement in addition when indicated.

Aged↗
PubMed1997

Hereditary non-polyposis colorectal cancer: clinical features and survival. Results from the Danish HNPCC register.

BACKGROUND: Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited syndrome characterized by the development of colorectal cancer (CRC) and other carcinomas. Our aim was to evaluate tumour parameters and survival in HNPCC. METHODS: One hundred and eight Danish HNPCC patients were compared with 870 patients with sporadic colorectal cancer. RESULTS: The median age at CRC diagnosis was 41 years in the HNPCC group. HNPCC patients had significantly more carcinomas located to the right colon (68% against 49% in controls), more synchromous tumours (7% versus 1%), more metachronous CRC after 10 years (29% versus 5%), more localized carcinomas (62% versus 39%), and significantly higher crude cumulative 5-year survival (56% versus 30%). CONCLUSIONS: CRC in HNPCC behaves differently compared to sporadic cases concerning age of onset, frequency of multiple lesions, and location. The metastatic tendency is less than in sporadic CRC and the survival is better.

Adult↗
PubMed1996

Pulsed dose rate (PDR) brachytherapy of anal carcinoma.

BACKGROUND AND PURPOSE: With radiotherapy of anal carcinomas, sphincter preservation can be obtained at survival rates similar to those obtained with radical surgery. By combining external beam irradiation with interstitial irradiation, superiority over standard external irradiation has been obtained. With the introduction of pulsed dose rate equipment, where a single high activity source moves through catheters, a more individualized dose distribution and a further elimination of radiation exposure to the staff can be achieved. MATERIALS AND METHODS: Between June 1993 and November 1994, 17 patients with anal carcinoma (T1:4, T2:4, T3:6, T4:3) have been treated at the Finsen Center. The treatment consisted of three-field external irradiation 46 Gy/23 fractions with five fractions a week to the anal canal and regional pelvic lymph nodes. Seven to 33 days after completion of external irradiation, the tumorspace was given 25.2 Gy PDR brachytherapy with 42 pulses of 0.6 Gy, one pulse every hour. RESULTS: One isolated local recurrence has been noted 13 weeks after implantation. One additional local recurrence was seen in a patient with concomitant hepatic and inguinal recurrence. In three patients inguinal recurrence had occurred, two of these patients were irradiated without any further evidence of disease, and one patient with a primary advanced tumour, had local failure. So far necrosis has been observed in 13 patients within 1-49 weeks (median 16 weeks) after implantation. Eight of these patients required colostomy. No relation was observed between the number of implanted needles and the occurrence of necrosis. CONCLUSIONS: The results indicate that the treatment is highly effective, but with substantial toxicity.

Anus Neoplasms↗
PubMed1996

Validation of transcranial near-infrared spectroscopy for evaluation of cerebral blood flow autoregulation.

The aim of the study was to evaluate a new noninvasive transcranial near-infrared spectroscopy (TNIRS) technique for determination of the lower limit of cerebral blood flow (CBF) autoregulation by comparing this technique with the standard cerebral arteriovenous oxygen saturation difference (AVDo2) method. In eight healthy volunteers, mean arterial blood pressure was increased by infusion of angiotensin and decreased by the combination of lower-body negative pressure and labetalol. For each 5-mm Hg change in mean arterial pressure, blood was sampled from the bulb of the internal jugular vein and a radial artery, and simultaneously, the oxygen saturation of hemoglobin in the brain was measured with an INVOS 3100 Cerebral Oximeter (Somanetics). The lower limit of autoregulation was then calculated by a computer using (a) AVDo2 and (b) the difference between arterial oxygen saturation and the saturation determined with the cerebral oximeter (ACDo2). The median lower limit of autoregulation determined by the two methods was 73 and 78.5 mm Hg, respectively (p > 0.05). A statistically significant correlation between relative CBF (percentage of baseline) determined with the two methods was found below the lower limit of autoregulation (1/AVDo2 = 12 + 0.8 x 1/ACDo2; r = 0.55; p < 0.001). For all the 98 pairs of saturations registered, the correlation was 0.37 (p < 0.001), the mean difference was 16%, and the limits of agreement were -2.2 and 33.8%. We conclude that the cerebral oximeter might be useful in evaluation of the lower limit of cerebral autoregulation. This method, however, is of no value for estimation of levels of global cerebral oxygen saturation.

Adult↗
PubMed1996

Hyperplastic polyposis of the large bowel. Three cases and a review of the literature.

Small hyperplastic polyps of the large bowel constitute a frequent non-neoplastic lesion, whereas large or multiple hyperplastic polyps are rare. Here we report three cases of multiple small polyps together with some large hyperplastic ones. Two of the cases had a primary carcinoma in the bowel before onset of the polyps. The neoplastic potential of the hyperplastic polyp is discussed on the basis of the most recent investigations and the three presented cases. The hyperplastic polyp does not seem to be directly involved in the adenoma-carcinoma sequence, but dysplastic changes can be found in large hyperplastic polyps. In cases of multiple hyperplastic polyps a tendency towards a more uniform distribution of the polyps throughout the large bowel is observed. Hyperplastic colonic polyps may exist as a clinical entity, and a definition based on distribution, multiplicity, size, and symptoms is proposed. Patients with multiple or large hyperplastic polyps should have colonoscopy performed at short intervals, with removal of all lesions larger than 5 mm for histologic examination.

Adenocarcinoma↗
PubMed1995

[Compartment syndrome as a postoperative complication of lithotomy position].

Surgical procedures necessitating the use of the lithotomy position can be associated with neuromuscular lesions, usually arising from compression of nerves and muscles. Compartment syndrome of the lower extremities is a grave complication which, if unrecognized, can lead to either permanent neuromuscular dysfunction or limb loss. We report two cases of compartment syndrome complicating surgery in the lithotomy position.

Adult↗