Search PubMed⌕ Search

Biomedical subjects

R G Hahn

Publications and source records attributed to R G Hahn.

At least 109 records · Page 6Linked to original sources
PubMed1996

Dextran 70 and blood loss during transurethral resection of the prostate.

BACKGROUND: Dextran is an effective plasma expander but also a potential anticoagulant. This article attempts to establish the clinical significance of any increased intra-operative blood loss associated with the use of dextran 70 during transurethral resection of the prostate (TURP). METHODS: The blood loss was measured in used irrigating fluid by a photometer in 800 patients undergoing TURP. In 154 of them, 500-1,000 ml of 6% dextran 70 was given for volume replacement. A regression model was used to test for interactions between the use of dextran and the operative parameters that correlated independently with the blood loss. RESULTS: The bleeding varied between 10 and 3,825 ml (median 323). Operative parameters correlating to the blood loss were: weight of the prostatic resectate, operating time, irrigating fluid absorption, and systolic arterial blood pressure. The result of this regression analysis indicated that dextran did not increase the blood loss. Neither did the prostatic weight and operating-time-corrected blood loss increase when dextran was infused. CONCLUSION: There was no indication that dextran 70 given within the recommended dose range increases the blood loss during TURP.

Aged↗
PubMed1996

Serum levels of endometrial proteins during transcervical resection of the endometrium.

OBJECTIVE: To study the potential for dissemination of endometrial tissue substances during transcervical resection of the endometrium (TCRE). DESIGN: Prospective study. SETTING: One university and two county hospitals. PARTICIPANTS: Forty-eight women with dysfunctional bleeding. INTERVENTIONS: The serum levels of two endometrial proteins, insulin-like growth factor binding protein-1 (IGFBP-1) and placental protein 14 (PP14), were measured before and every 10 min during the operations. Blood loss was also measured by a photometer together with absorption of the irrigating fluid containing glycine 1.5% and ethanol 1% by expired-breath tests, and serum sodium and volumetric fluid balances. MAIN OUTCOME MEASURES: Linear correlations between changes in IGFBP-1 and PP14 during TCRE and operating parameters such as operating time, blood loss and fluid absorption. RESULTS: The baseline levels of IGFBP-1 were normal but PP14 could only be detected in one third of the patients, which was due, in part, to pre-operative treatment with danazol. The highest levels of IGFBP-1 and PP14 during surgery correlated positively with the baseline concentrations. Fluid absorption (median 405 ml, range 0-2177) was the only surgical factor associated with increasing serum levels of endometrial proteins. CONCLUSION: Absorption of the solution used to irrigate the uterus is associated with dissemination of endometrial products in the bloodstream during TCRE.

Adult↗
PubMed1996

Irrigating fluid absorption from the intact uterus.

OBJECTIVE: Absorption of irrigating fluid may occur through severed blood vessels during endometrial resection. We studied whether irrigating fluid can also be absorbed through the undamaged uterus. PARTICIPANTS: We studied 25 women, aged 28-46 years (mean 38 years), who underwent elective laparoscopic sterilisation under general anaesthesia. INTERVENTIONS: In 15 women blue-stained irrigating fluid containing glycine 1.5% and ethanol 1% was applied to the uterine cavity under increasing pressure. Laparoscopy was employed to see when fluid emerged from the Fallopian tubes. Another 10 women had their Fallopian tubes clamped before the fluid pressure was raised, and systemic absorption was detected by measuring the serum glycine concentration. RESULTS: Passage of fluid through the Fallopian tubes occurred in 14 of the 15 patients at a uteroabdominal pressure gradient of 40 mmHg (n = 4), 80 mmHg (n = 4), 120 mmHg (n = 3), and 160 mmHg (n = 3), respectively. The fluid passage rate ranged between 0.5 and 13 (mean 6.4) ml min-1. Of the women with clamped Fallopian tubes, 8 of 10 showed an increase in the serum glycine level of 60% at a pressure gradient of 160 mmHg, and of 120% at 200 mmHg. CONCLUSIONS: Uterotubal and transendometrial passage of small to moderate amounts of irrigating solution occurred frequently at the intrauterine fluid pressures normally used during endometrial resection.

Absorption↗
PubMed1996

Pathology of the heart after overhydration with glycine solution in the mouse.

Glycine solution, which is widely used for irrigation in endoscopic surgery, has recently been suspected to have acute or subacute cardiotoxic properties. Therefore, the hearts of 46 mice that survived an intravenous infusion of 0.21/kg glycine 1.1%, 1.5% or 2.2% were examined for pathological alterations between 2 h and 7 weeks after the infusions. Half the animals developed extensive dilatation of the interstitium. Hypoxic events were evidenced by leakage of myoglobin from myocytes in 32 animals and correlated with dilatation of the interstitium. Focal necrosis with an inflammatory cell reaction and replacement of the myocardial tissue with granulation and fibrous tissue were observed after five glycine infusions. Pathological changes were mild or absent in five mice given mannitol solution and in three to which no infusion was given.

Animals↗
PubMed1996

Origin of intravascular fluid recruited by vasodilatation during epidural anaesthesia.

Arterial hypotension during induction of epidural anaesthesia is caused by peripheral vasodilatation and promotes intravascular fluid distribution. The excess fluid in the blood may result from either diffusion across the capillaries or enrichment of the fluid that is routinely infused intravenously to prevent severe hypotension. These alternatives were assessed in 40 urology patients who received 10 ml kg-1 of Ringer acetate solution without or with 0.5% glucose during onset of epidural anaesthesia. The result shows that arterial hypotension (systolic pressure down by > 25%) promoted mild dilutional hypoglycaemia when the infusion was glucose-free (-6% in hypotensive vs. +2% in normotensive) and hyperglycaemia when glucose was given (+15% in hypotensive vs. +7% in normotensive). The consistent deviation of the blood glucose level towards the concentration of the infused fluid suggests that the excess intravascular fluid associated with epidural-induced hypotension is derived directly from the ongoing infusion rather than by transcapillary transport.

Aged↗
PubMed1996

Large-sized bladders reduce intravesical pressure and fluid absorption during TURP using the suprapubic trocar.

We studied whether the height of the irrigating fluid bags above the operating table and the capacity of the bladder influence intravesical pressure and fluid absorption during transurethral resection of the prostate (TURP) when evacuation is performed with Reuter's trocar. For this purpose, the intravesical pressure was recorded continuously, and the fluid absorption was measured by the ethanol method during 30 TURP procedures. The bags were placed between 60 and 95 cm above the operating table, and the bladder capacity was measured before surgery started. The results show that the bladder capacity, but not the bag height, correlated with the intravesical pressure and the fluid absorption. Large-sized bladders were associated with lower pressures and smaller absorption. Rapid absorption (>30 ml/min) occurred at a maximum pressure of 2-3 kPa and a mean pressure of between 1 and 2 kPa. In conclusion, the size of the bladder is important to the intravesical pressure and to the fluid absorption during TURP when using the suprapubic trocar.

Absorption↗
PubMed1996

Early detection of 'endometrial resection syndrome'.

We report a patient who developed symptoms of fluid overload after having absorbed 3 litres of irrigating fluid during transcervical resection of the endometrium. Four methods were used to measure the absorption at 10-min intervals throughout the operation. There were strong intercorrelations between the results of these monitoring methods, which consisted in breath ethanol analyses and measurements of the serum sodium and glycine concentrations and of the volumetric fluid balance. However, the ethanol method was easiest to perform and provided immediate results. This monitoring gave the operating team as much as 45 min to prevent further absorption before it became large enough to elicit a transcervical endometrial resection syndrome.

Absorption↗
PubMed1996

Morphological and X-ray microanalytical changes in mammalian tissue after overhydration with irrigating fluids.

We compared morphological changes in the heart, brain, liver and kidneys after giving 100 ml/kg of 5 irrigating fluids by intravenous infusion to 30 rabbits. Glycine 1.5% and 1.0%, both with ethanol 1% as a tracer for absorption, received the highest scores for tissue swelling and were sometimes followed by focal necrosis and an inflammatory cell reaction in subendocardial areas of the heart. Three rabbits died shortly after infusion of glycine 1.5% + ethanol 1%, the deaths being preceded by bradycardia and an irregular cardiac rhythm. This solution also lowered the intracellular potassium and chlorine content as shown by X-ray microanalysis of myocardial cells. Mannitol 3% + ethanol 1% produced the most favorable outcome in our evaluation, with the lowest scores for tissue swelling, while sorbitol 2% + mannitol 1% and normal saline took intermediate positions.

Animals↗
PubMed1995

Ultrastructural changes following overhydration with irrigating fluids.

We studied ultrastructural alterations caused by intravenous infusion of 150 ml/kg of irrigating fluid containing mannitol and/or sorbitol in 15 rabbits. The osmolality of the solutions varied between 165 and 350 mosmol/kg. Specimens for electron microscopic examination were obtained from the kidney, brain and lung. Regardless of the choice of solute, the hypo-osmotic solutions caused damage to kidney and brain tissue by inducing marked interstitial and cellular oedema. No such changes were observed after administration of isosmotic irrigating fluid. We conclude that ultrastructural changes following overhydration with irrigating fluid vary with the osmolality of the solution but not with the choice of solute. Moreover, the consistent absence of tissue damage in the lungs suggests that the lung is not a primary target organ for the "TUR syndrome".

Animals↗
PubMed1995

Transurethral resection syndrome after transurethral resection of bladder tumours.

The transurethral resection syndrome has not previously been described after bladder surgery. This article reports four patients who developed signs of this syndrome after transurethral resection of bladder tumours (TURB). Symptoms included abdominal pain, arterial hypotension, nausea and vomiting. There was evidence in all cases that the cause was absorption of irrigating fluid by the extravascular route. Fluid absorption was detected by ethanol in two patients and the urologist noted a perforation during the third operation. The most complicated clinical course occurred in the case where there was a delay of three hours before the diagnosis was made. Medical treatment consisted of antiemetics and volume expansion of the extracellular fluid compartment as extravasation is associated with hypovolaemia. Diuretics were not given until the circulation had been restored.

Abdominal Pain↗
PubMed1995

Effect of irrigating fluids and prostate tissue extracts on isolated cardiomyocytes.

OBJECTIVES: A higher mortality probably due to myocardial infarction has been demonstrated after transurethral resection of the prostate (TURP) compared with open prostatectomy. We used an experimental model system to study the possibility that this difference might be due to cardiotoxic effects of two events that frequently occur during TURP, namely, dissemination of electrolyte-free irrigating fluid and release of prostate tissue substances by electrocutting. METHODS: Cardiomyocytes were isolated from male Sprague-Dawley rats. Cell morphology and viability were examined repeatedly during 3 hours of incubation. Control experiments were compared with 34 preparations mixed with one of five different irrigating fluids and with 28 preparations mixed with a prostate extract, either from the same rat or from patients undergoing TURP. RESULTS: Most irrigating fluids reduced the viability of the myocytes. The fraction of viable cells in the incubation mixture averaged 83% (glycine 1.5%), 88% (glycine 1.5% plus ethanol 1%), 92% (glycine 2.2%), 92% (mannitol 3% plus ethanol 1%), and 99% (sorbitol 2% plus mannitol 1%) of that found in the respective control incubations. In contrast, the prostate extracts did not decrease the viability of the cardiomyocytes. Extract from the rats even seemed to have a trophic effect. CONCLUSIONS: Our results show that electrolyte-free irrigating fluids but not prostate extracts have mild cardiotoxic properties. This opens up the possibility that fluid absorption during TURP has a devitalizing effect on the heart.

Animals↗
PubMed1995

Phase III study comparing vincristine, doxorubicin (Adriamycin), and dexamethasone (VAD) chemotherapy with VAD plus recombinant interferon alfa-2 in refractory or relapsed multiple myeloma. An Eastern Cooperative Oncology Group study.

PURPOSE: This clinical trial was designed to compare the effectiveness of vincristine, doxorubicin (Adriamycin), and dexamethasone (VAD) with VAD plus interferon alfa-2 in patients with refractory or relapsed multiple myeloma. PATIENTS AND METHODS: Between January 1990 and May 1992, 47 eligible patients with multiple myeloma who had failed one prior chemotherapeutic regimen were accrued to a multiinstitutional prospective randomized clinical trial. The trial was halted early because of poor accrual. RESULTS: After a minimum follow-up of 13 months, the objective overall response rate was 28% (25% in the VAD group, 30% in the VAD plus interferon group). The response duration and overall survival were similar for the two treatment groups, with medians of 3.6 and 8.3 months, respectively. Life-threatening or lethal nonhematologic toxicity was seen in 27%. Interferon did not appear to increase the frequency of toxic responses. CONCLUSION: This study shows no advantage to the use of interferon combined with VAD in refractory or relapsing myeloma. However, the small sample size decreased the statistical power to recognize small differences if present. Moreover, the survival data do not suggest a clear advantage to the administration of vincristine or doxorubicin as a 96-hour infusion compared with results of studies using bolus administration combined with high-dose corticosteroids.

Adult↗
PubMed1995

Continuous monitoring of irrigating fluid absorption during transurethral surgery.

We have designed an automatic detector system for noninvasive monitoring of irrigating fluid absorption during transurethral resection of the prostate. Ethanol, which is used as a tracer for the fluid, is measured in the expired breath of the patient. The breath ethanol monitor can be used both in the awake patient and during general anaesthesia. A lap-top computer controls the monitor and calculates the fluid absorption 1-3 times per min and uses the pattern of ethanol changes to indicate whether the fluid is being taken by the intra- and/or extravascular route. The monitor has been used in routine operations for one year. The interpretation of absorption routes was checked by control methods or by evaluation of the postoperative breath-ethanol curve. We found the indicated absorption to be correct in all resections with absorption large enough for the monitor to present an interpretation.

Absorption↗
PubMed1995

Eye symptoms, visual evoked potentials and EEG during intravenous infusion of glycine.

Disturbance of vision is a complication that may occur from absorption of the glycine solution used to irrigate the bladder during transurethral operations. We examined for a possible dose-response relationship between glycine dose, eye symptoms and neurophysiological changes after repeated intermittent intravenous infusions of 4.4 g of glycine for up to 22 g over 1 h in 10 male volunteers. The serum glycine concentration increased from 230 +/- 75 to 5,232 +/- 1,088 mumol/l (mean +/- s.d.) during the infusions. We found an increase in diastolic arterial pressure but no significant changes in systolic pressure, heart rate or mental status. Five of the volunteers developed blurring of vision which lasted for 10-30 min. The visual evoked potentials (VEP) of these subjects showed an increase of the P100 and N70 latencies which started after no more than 4.4 g of glycine had been administered. The amplitude of the VEP was preserved and the main frequency of the EEG did not change, indicating that VEP changes were not due to cortical dysfunction. There was no dose-response relationship between glycine infusion and eye symptoms but a sub-group of volunteers responded with both visual disturbances and VEP changes.

Adult↗
PubMed1995

Ethanol monitoring of irrigating fluid absorption in transcervical resection of the endometrium.

BACKGROUND: We evaluated the precision in using ethanol to indicate and quantify absorption of irrigating fluid during transcervical resection of the endometrium. METHODS: The ethanol concentration in the expired breath, the serum sodium level, the blood loss and the volumetric fluid balance were measured over 10-min periods during 62 operations. A solution containing glycine 1.5% and ethanol 1% was used to irrigate the uterus. RESULTS: Most principles previously outlined for ethanol monitoring in transurethral prostatic surgery could also be applied in endometrial resection. In the 21 patients who showed the intravascular pattern of ethanol changes, the breath alcohol measurement corrected for absorption time predicted the volume of irrigant absorbed (up to 2,531 ml) with a standard error of 230 ml at the end of any 10-min period of absorption. Repeated measurement of serum sodium indicated intravascular fluid absorption with practically the same precision as the breath test. Extravascular absorption was found in 14 patients. In these operations, the volume of irrigant absorbed (up to 1,767 ml) could be predicted with a standard error of 92 ml from the ethanol concentration at the plateau level attained after absorption had occurred. CONCLUSION: Ethanol monitoring is precise enough to allow monitoring of irrigating fluid absorption in endometrial resection.

Abdomen↗
PubMed1995

Effects of bladder capacity and height of fluid bag on intravesical pressure during transurethral resection of the prostate.

We studied the intravesical pressure profile and the fluid absorption in 30 men undergoing transurethral resection of the prostate with the irrigating fluid bags placed 55-60, 70-75, 80-85 or 90-100 cm above the operating table. The maximum intravesical pressure, but not the mean pressure or the period of time during which there was excessive pressure (> 2 kPa), increased when the fluid bags were placed higher. The urologist consistently reached about half the possible maximum pressure as indicated by the bag height at the end of each intermittent filling of the bladder. A large bladder capacity promoted lower maximum and mean pressures and shortened the period of excessive intravesical pressure. However, neither bag height nor bladder capacity correlated with the absorption of irrigating fluid.

Absorption↗
PubMed1995

Simulated intraperitoneal absorption of irrigating fluid.

BACKGROUND: Intraperitoneal absorption of electrolyte-free irrigating fluid may occur secondary to uterine perforation during endometrial resection, but the clinical course of this complication is known from only a few case reports. METHODS: We studied symptoms, biochemical changes and the kinetics of solute equilibration over the peritoneal membrane in 10 healthy awake women who were subjected to an experimental absorption situation by receiving an intraperitoneal infusion of 25 ml/kg of a solution containing glycine 1.5% and ethanol 1% over 20 min. We also compared the use of breath ethanol and serum sodium samples to indicate the presence of irrigating fluid in the peritoneal cavity. RESULTS: All infusions caused lower abdominal pain. The solute gradients between the peritoneal pool and plasma were reduced according to mono-exponential functions with a half-time of 33 +/- 5 min for ethanol, 92 +/- 9 min for sodium, 103 +/- 9 min for potassium, and 124 +/- 10 min for amino acids (mean +/- s.e.mean). Twenty minutes after infusion, the breath ethanol level reached a plateau which could be used to predict the infused volume within +/- 15% of the true value. In contrast, the serum sodium concentration decreased slowly and was only 3.0 +/- 0.7 mmol/l below baseline at 2 hours after infusion. CONCLUSIONS: The calculated rates of transperitoneal solute equilibration can be used to assess the need for substitution of electrolytes in patients who absorb irrigating fluid into the peritoneal cavity. Measurement of ethanol in the expired breath is more useful than serum sodium to indicate the existence of such a pool.

Absorption↗