Temporal and geospatial trends of pediatric cancer incidence in Nebraska over a 24-year period.

BACKGROUND: Data from the Surveillance, Epidemiology, and End Results (SEER) revealed that the incidence of pediatric cancer in Nebraska exceeded the national average during 2009-2013. Further investigation could help understand these patterns. METHODS: This retrospective cohort study investigated pediatric cancer (0-19 years old) age adjusted incidence rates (AAR) in Nebraska using the Nebraska Cancer Registry. SEER AARs were also calculated as a proxy for pediatric cancer incidence in the United States (1990-2013) and compared to the Nebraska data. Geographic Information System (GIS) mapping was also used to display the spatial distribution of cancer in Nebraska at the county level. Finally, location-allocation analysis (LAA) was performed to identify a site for the placement of a medical center to best accommodate rural pediatric cancer cases. RESULTS: The AAR of pediatric cancers was 173.3 per 1,000,000 in Nebraska compared to 167.1 per 1,000,000 in SEER. The AAR for lymphoma was significantly higher in Nebraska (28.1 vs. 24.6 per 1,000,000; p = 0.009). For the 15-19 age group, the AAR for the 3 most common pediatric cancers were higher in Nebraska (p < 0.05). Twenty-three counties located >2 h driving distance to care facilities showed at least a 10% higher incidence than the overall state AAR. GIS mapping identified a second potential treatment site that would alleviate this geographic burden. CONCLUSIONS: Regional differences within Nebraska present a challenge for rural populations. Novel use of GIS mapping to highlight regional differences and identify solutions for access to care issues could be used by similar states.

Detection of small implanted tumors growing during repeated magnetic resonance imaging of the rabbit liver: application of an interpretation model.

PURPOSE: To apply experimentally and further develop a new image interpretation model based on repeated imaging and aimed at improving assessments of technical efficacy and diagnostic accuracy in the detection of small lesions. MATERIAL AND METHODS: VX2 carcinoma was implanted in the liver of 14 rabbits as two 1.1-1.7 mm3 cores. Magnetic resonance imaging was performed before and 4 days after implantation and then every second day up to the 14th to 20th day. One T2-weighted sequence (TSE T2) and three T1-weighted sequences (SE T1, GE T1, and TFL T1) were used. Interpretation was performed stepwise: three readers independently interpreted image sequences chronologically (step 1). Tumors were included at the last examination (step 2). By concurrent interpretation of repeated examinations, the earliest day at which tumors became visible and tumor size were recorded (step 3). Records were corrected (step 4) and autopsy was performed (step 5). Two procedures for use in calculating repeated detection rates of tumors with different magnetic resonance imaging sequences are presented and discussed. RESULTS: Of 40 macroscopic tumors, 34 were included. They were mainly small (size range SE T1: 1-3mm, TSE T2: 1.5-5 mm) when they became visible as determined at step 3, which was consistently earlier than observed at step 1. TSE T2, SE T1, and GE T1 did not differ significantly regarding earliest day of detection (step 3), while TFL T1 revealed the tumors later. The initial repeated detection rates were higher with TSE T2 than with the other sequences. Frequency of false positives varied over time, indicating fluctuating criteria for reporting tumors. CONCLUSION: A theoretical image interpretation model previously described proved to be applicable for detection of experimental liver tumors. The model was improved by introducing calculations of repeated detection rates for initial image interpretation using an imaging reference standard.

Spinal anaesthesia: comparison of plain ropivacaine 5 mg ml(-1) with bupivacaine 5 mg ml(-1) for major orthopaedic surgery.

BACKGROUND: Ropivacaine provides effective spinal anaesthesia for total hip arthroplasty. This study was designed to compare the efficacy and safety of plain ropivacaine with plain bupivacaine for spinal anaesthesia in patients undergoing total hip arthroplasty. METHODS: Sixty-six patients, ASA I or II, were randomized to receive an intrathecal injection of one of two local anaesthetic solutions. Group R (n=32) received 3.5 ml of ropivacaine 5 mg ml(-1) (17.5 mg). Group B (n=34) received 3.5 ml of bupivacaine 5 mg ml(-1) (17.5 mg). The onset and duration of sensory block at dermatome level T10, maximum upper and lower spread of sensory block and the onset, intensity and duration of motor block were recorded, as were safety data. RESULTS: Onset of motor and sensory block was rapid with no significant differences between the two groups. The median time of onset of sensory block at the T10 dermatome was 2 min (range 2-5 min) in Group R and 2 min in Group B (range 2-9 min). The median duration of sensory block at the T10 dermatome was 3.0 h (range 1.5-4.6 h) in Group R and 3.5 h (2.7-5.2 h) in Group B (P<0.0001). The median duration of complete motor block (modified Bromage Scale 3) was significantly shorter in the ropivacaine group compared with the bupivacaine group (2.1 vs 3.9 h, P<0.001). CONCLUSIONS: Intrathecal administration of either 17.5 mg plain ropivacaine or 17.5 mg plain bupivacaine was well tolerated and an adequate block for total hip arthroplasty was achieved in all patients. A more rapid postoperative recovery of sensory and motor function was seen in Group R compared with Group B.

Is transient lumbar pain after spinal anaesthesia with lidocaine influenced by early mobilisation?

BACKGROUND: The aetiology of transient lumbar pain (TLP) after spinal anaesthesia has generated much interest. Many theories have been discussed. Early ambulation has been suggested as one plausible theory for developing TLP. METHODS: A total of 107 patients scheduled for inguinal hernial repair under spinal anaesthesia (20 mg/ml hyperbaric lidocaine) were randomised to either early or late ambulation: the early ambulation (group A), as early as possible after total regression of spinal block or the late mobilisation (group B) bedridden for more than 12 h. The clinical course and duration of operation were monitored. Assessments 4, 8 and 12 h after spinal anaesthesia were performed with respect to wound pain, nausea, tiredness and eventual symptoms of TLP were recorded. The patients also kept a diary about any symptoms once daily day 1-3 at home. A telephone follow-up was performed at day 5-7. RESULTS: Our results showed an incidence of TLP of 23% in all patients. No difference was recorded between early and late mobilisation patients, 12 and 13 patients, respectively. CONCLUSION: Early ambulation does not seem to increase the risk of developing TLP.

Methods for detecting residues of cleaning agents during cleaning validation.

Cleaning validation procedures are carried out in order to assure that residues of cleaning agents are within acceptable limits after the cleaning process. Cleaning agents often consist of a mixture of various surfactants which are in a highly diluted state after the water rinsing procedure has been completed. This makes it difficult to find appropriate analytical methods that are sensitive enough to detect the cleaning agents. In addition, it is advantageous for the analytical methods to be simple to perform and to give results quickly. In this study, four different analytical methods are compared: visual detection of foam, pH, conductivity measurements, and analysis of total organic carbon (TOC). TOC was used as a reference method when evaluating the other three potential methods. The analyses were performed on different dilutions of the cleaning agents Vips Neutral, RBS-25, Debisan and Perform. The results demonstrated that the most sensitive method for analysis of Vips Neutral, Debisan and Perform is visual detection of foam, by which it is possible to detect concentrations of cleaning agents down to 10 micrograms/mL. RBS-25 was not detected below 200 micrograms/mL, probably because it is formulated with low-foaming surfactants. TOC analysis is less sensitive but has the advantage of being a quantitative analysis, while visual detection of foam is a semi-quantitative method. Visual detection of foam is easy to perform, gives a quick result, and requires no expensive instrumentation. The sensitivity of each method was found to be dependent upon the type of cleaning agent that was analyzed.

Can local anesthesia be recommended for routine use in elective knee arthroscopy? A comparison between local, spinal, and general anesthesia.

Local anesthesia (LA) for outpatient knee arthroscopy is not a standard procedure at most hospitals. To evaluate the LA technique for knee arthroscopy on medically healthy patients, this study compared 3 anesthesia techniques. Four hundred patients were randomized to either local (n = 200), general (n = 100), or spinal (n = 100) anesthesia. Evaluated outcomes included the patient's subjective view of the procedure, and nausea and pain at rest and during active movement. All variables were recorded perioperatively and postoperatively. In addition, the performing surgeon's opinion of the degree of patient pain and the technical difficulty of the procedure were noted. Three hundred forty-two patients completed the study. In the group receiving local anesthesia (n = 180) the median visual analog scale pain score during surgery was 6 mm (mean, 17.5; SD, 23.2; range, 0 to 100 mm). Twenty-one LA patients would have preferred another form of anesthesia. In 29 patients, LA was not considered as the optimal anesthesia by the performing surgeon. Eight LA patients agreed with the surgeon that the anesthesia method used was not optimal, of these patients, 5 had synovitis (3%). In 5% of the LA patients there were technical problems. Thus, this study shows that elective knee arthroscopy can be performed under local anesthesia in 92% of the patients from a technical point of view. Excluding patients who do not choose local anesthesia and those who have hypertrophic synovitis preoperatively, knee arthroscopies can be performed as safely and effectively under local anesthesia as under any other form of anesthesia. For most patients, local anesthesia can be recommended as the standard procedure for outpatient knee arthroscopy.

A comparison of 50, 100 and 200 mg of intra-articular pethidine during knee joint surgery, a controlled study with evidence for local demethylation to norpethidine.

Pethidine (meperidine) is a compound with both local anaesthetic and opioid agonist properties. We have in a recent study demonstrated that pethidine could be an interesting alternative to prilocaine in arthroscopy with local anaesthetic technique. Therefore, we investigated, in a controlled randomized double-blind study, the effect of three doses of pethidine compared with a standard local anaesthetic, in patients subjected to arthroscopic knee joint surgery. Ten patients in each group received 50 mg (P50), 100 mg (P100), 200 mg (P200) of pethidine or prilocaine (5 mg/ml) + adrenaline (4 mg/ml) (PC), injected intra-articularly (i.a.) before surgery. We measured pain intensity and discomfort during arthroscopy and pain intensity at rest and at movement, nausea and tiredness for 3 days post-operatively at regular intervals using the VAS-technique. We also measured the concentration of pethidine and its demethylated metabolite, norpethidine, in plasma by collecting blood samples at 20, 40, 60, 80, 140 and 200 min following injection, and in synovial fluid which was collected through the arthroscope at the start and the end of the surgery. It was found that significantly more patients in the P50 group (n = 6) needed general anaesthesia due to intense pain than those in the P100 group (n = 1), P200 group (n = 0) or the PC group (n = 1). The PC group required significantly more analgesics and had a significantly higher calculated total sum of pain scores at movement post-operatively, than the other three groups. The P200 group more often reported tiredness post-operatively than the other three groups. We conclude that 100 or 200 mg pethidine i.a. produces satisfactory anaesthesia for surgery. There was a rapid transfer of pethidine from synovial fluid to plasma, resulting in plasma levels earlier reported to produce centrally mediated effects, such as analgesia and tiredness. We found much higher concentrations of norpethidine in the synovial fluid than in plasma, suggesting a local demethylation in the knee joint tissues. This site of drug oxidation has not earlier been demonstrated neither in vitro nor in vivo. The results suggest that pethidine given i.a. in the dose range of 50 to 200 mg results in analgesia due to both peripheral and central mechanisms. The significant systemic uptake of pethidine can cause unwanted side-effects.

Intrathecal administration of sameridine to patients subjected to arthroscopic knee joint surgery.

BACKGROUND: Sameridine, a new substance with both local anesthetic and opioid effects, was administered intrathecally for the first time to humans, i.e. in patients subjected to arthroscopic knee joint surgery. METHOD: A dose-escalating (10, 15, 20 and 25 mg), open study was performed in 33 patients. Only two patients were included in the 25 mg group. RESULTS: Sameridine provided good quality of surgical anesthesia in all patients except those receiving 10 mg. The maximum level of sensory block, Th5-Th7, was reached within 30 min with a median duration of 3.6-3.9 h. The motor block was more profound with increasing dose, but never lasted longer than the sensory block. The influence on heart rate and blood pressure was minor and atropine and ephedrine were needed in four patients. No clinically significant ECG-changes were detected and no arrhythmias were recorded. Oxygen saturation and respiratory rate did not decrease in a clinically significant way and were not affected by concomitant morphine given i.v. postoperatively. There were few side-effects, the most frequent being mild pruritus (10/33). CONCLUSION: Sameridine provided clinically adequate anesthesia for the patients receiving the doses of 15, 20 and 25 mg. Further studies are needed to evaluate the substance and it is of great interest to clinically investigate the opioid component with respect to postoperative analgesia.

Diagnostic efficacy of MnDPDP in MR imaging of the liver. A phase III multicentre study.

PURPOSE: To assess the diagnostic efficacy, safety and tolerability of mangafodipir trisodium (MnDPDP, Teslascan) in MR imaging of the liver. MATERIAL AND METHODS: Eighty-two patients from 4 centres underwent MR imaging with pre-contrast sequences including T1-weighted SE and GRE, and T2-weighted turbo SE sequences. MnDPDP at a dose of 5 mumol/kg b.w. was administered by slow i.v. infusion, and 20-60 min after infusion the T1-weighted SE and GRE sequences were repeated. Diagnostic efficacy was evaluated by counting the number of lesions and by evaluating whether more information for lesion characterisation was available in post-contrast images. Safety and tolerability were assessed by recording adverse events and infusion-related discomfort. RESULTS: Significantly more lesions were found in MnDPDP-enhanced T1-weighted SE and GRE images than in unenhanced images of the same sequences. More lesions were also found in these images compared with T2-weighted images at a level of marginal significance. More information was obtained from MnDPDP-enhanced images in 40 cases. Mild to moderate adverse events were experienced by 17% of the patients. CONCLUSION: MnDPDP-enhanced images can improve lesion detection in the liver and are helpful for lesion characterisation. To obtain optimal diagnostic information of liver lesions T2-weighted images are also valuable. MnDPDP is a safe contrast agent for MR imaging of liver lesions.

MnDPDP enhancement in rabbit liver after intravenous bolus injection and slow infusion.

PURPOSE: To investigate the MR-enhancing effect of mangafodipir trisodium (MnDPDP, Teslascan) in the rabbit liver in relation to dose, mode of administration and imaging window. MATERIAL AND METHODS: MnDPDP was administered to 18 rabbits at a dose of 10 mumol/kg or 20 mumol/kg, as a bolus injection or infusion. MR imaging of the liver was performed at different time intervals. RESULTS: Peak liver enhancement was typically observed 10-30 min after administration and the enhancement declined with a half-time of about 5 h. This pattern was observed in all sequences (SE 400/15, FLASH, and SE 132/10), with both doses and with both rates of administration. The peak enhancement was greater, though not significantly so after 20 mumol/kg than after 10 mumol/kg. A higher relative peak signal was observed with SE 132/10 than with FLASH or SE 400/15. CONCLUSION: A good liver imaging result was obtained after a dose of 10 mumol/kg, either bolus or infusion, 10-30 min post-contrast with heavily T1-weighted sequences.

Local anesthesia for arthroscopic surgery of the ankle using pethidine or prilocaine.

Investigation of the intraoperative and postoperative pain-reducing effect of pethidine (meperidine) as compared with local anesthetics given into the ankle joint was performed, in a comparative and double-blind fashion, in 20 patients subjected to arthroscopy of the ankle, diagnostic and surgical procedures. These patients were randomly assigned to one of two groups. Group A consisted of 10 patients receiving prilocaine 5% with adrenaline and the patients of group B received pethidine 5% with adrenaline intraarticularly. During arthroscopy, the patients reported on pain and discomfort using visual analog scales. Ratings did not differ between the two groups, but six patients would not have chosen the local anesthetic technique again. Postoperatively, all patients rated their pain and discomfort at rest and at movement (1, 2, 3, 5, 6, 8, and 24 hours and at three times during 2 following days). No differences were found between the two groups, except for pain at rest through the whole observation period when significant lower values for pethidine. There were no differences in use of analgesics between the two groups. The current study indicates that pethidine is a potential alternative to prilocaine in arthroscopy of the ankle.

Analgesia following arthroscopy--a comparison of intra-articular morphine, pethidine and fentanyl.

It has recently been reported that morphine given in low doses intra-articularly can produce significant analgesia in patients undergoing arthroscopic knee joint surgery. Data are lacking on the effect of other opioids using a local approach for drug delivery. We studied the analgesic effect of intra-articular opioids in 70 patients, divided into 7 groups, subjected to arthroscopic knee surgery in general anesthesia. The dimension of the study was based on a power of 0.8 to detect a 25% difference in pain intensity between those receiving opioids locally versus systemically (alpha = 0.05 and beta = 0.20). Following surgery, but before terminating anesthesia, the patients received one of the following combinations: 1 mg morphine intra-articularly (i.art.) + saline intramuscularly (i.m.), 10 mg pethidine i.art + saline i.m., or 10 micrograms fentanyl i.art + saline i.m. In three additional groups the three opioids were given i.m. and saline given i.art. An additional control group received saline i.art. + i.m. We did not find any significant difference between the groups considering postoperative pain intensity, need for analgesics or considering time to standing/walking or to discharge, analysing each opioid independently. There was, however, a tendency for pethidine i.art. to produce the lowest pain scores both at rest and during movement (P = 0.06). If analysing the results with regards to if opioids were given intra-articularly or systemically, not considering the type of opioid given, we did however, find a significantly lower total sum of pain scores at movement following local administration (P < 0.05). No specific side-effects were detected. We conclude that pethidine given intra-articularly merits further investigation with respect to postoperative analgesia following the activation of peripheral opioid mechanisms.

Validation of Pouch Size Measurement Following the Swedish Adjustable Gastric Banding Using Endoscopy, MRI and Barium Swallow.

BACKGROUND: Pouch volume appears to be of major importance for subsequent weight loss following any gastric restriction type of surgery for morbid obesity. In order to be able to evaluate pouch volume following Swedish Adjustable Gastric Banding (SAGB), an endoscopic pouch volume classification system was designed in which pouch volume is classified in five categories. The aim of this study was to validate the endoscopic classification system using MRI and barium swallow as reference methods for pouch volume measurement. METHODS: Twenty patients (13 women and seven men) were operated for obesity with SAGB. They were investigated a mean of 3 years (6 weeks-5.5 years) after surgery and had at that time lost a mean of 60 (12-112) kg. During the same afternoon they sequentially underwent endoscopy, MRI and barium swallow with an empty stomach. RESULTS: The mean pouch volume measured with MRI was 70 ml (0-1 80 ml) and with barium swallow was 72 ml (0-1 95 ml). In 17/20 patients the volume as measured by MRI and barium swallow was in the same volume category as with endoscopy. The correlation measured according to Pearson was significant between endoscopy on one hand and MRV barium swallow both independently and together (p < 0.001). CONCLUSION: Based on these results we are confident in using our endoscopic classification system for postoperative follow-up of pouch volume.

Effects of human atrial natriuretic peptide in patients after coronary artery bypass surgery.

OBJECTIVES: To determine the effects of synthetic human atrial natriuretic peptide (ANP) on renal function, hemodynamics, and levels of vasoactive peptides when infused in the immediate postoperative period after coronary bypass surgery in patients with normal kidney function. DESIGN: A prospective, randomized, double-blind, placebo-controlled study. SETTING: The Department of Cardiothoracic Anaesthetics and Intensive Care of a university hospital. PARTICIPANTS: Thirty patients with normal kidney function scheduled for elective coronary bypass surgery. INTERVENTIONS: During the first 3 hours postoperatively, patients received an infusion of either ANP 7.5 pMol/kg/min (ANP) or vehicle alone (C). MEASUREMENTS AND MAIN RESULTS: No differences were found between the two groups in respect to sex, degree of coronary disease, preoperative medical treatment, or duration of cardiopulmonary bypass and aortic occlusion. Plasma ANP levels increased nearly 10-fold from a mean of 7.0 +/- 1.1 pMol/L in ANP and remained at baseline levels in C, (p < 0.001). In ANP, there occurred significant increases in urine flow (p < 0.001), inulin clearance (p < 0.001), filtration fraction (p = 0.007), and fractional clearance of sodium (p < 0.001) and of osmoles (p < 0.001) compared with C. During the study, no differences in mean arterial pressure, heart rate, and right atrial or pulmonary capillary wedge pressure were detected between the groups. Cardiac index decreased by 5% in ANP compared with a 9% increase in C (p = 0.027). Vasopressin levels significantly increased in C but remained at baseline levels in ANP (p = 0.031). There were no changes in levels of catecholamines or angiotensin II. CONCLUSIONS: The results of this study show that ANP increases diuresis, natriuresis, and glomerular filtration in the immediate postoperative period after coronary bypass surgery.

Adjunctive treatment of murine neuroblastoma with 6-hydroxydopamine and Tempol.

Currently available therapy for disseminated neuroblastoma affords only a 5-20% 5-year survival rate. We have attempted to design targeted chemotherapy for this disease by exploiting the dopamine uptake system on neuroblastoma cells. 6-Hydroxydopamine (6OHDA) is a neurotransmitter analogue, which generates cytolytic oxygen radicals in neuroblastoma cells that take it up. It is, however, predictably, systemically toxic, because of its spontaneous oxidation. Its toxicity is particularly severe in the sympathetic nervous system, because this tissue selectively concentrates dopamine and its analogues. Lowering the dose of 6OHDA below toxic levels prohibitively compromises its antitumor effect. To avoid both the systemic and sympathetic nervous system toxicity yet retain the antitumor efficacy of 6OHDA, we have used the antioxidant Tempol adjunctively with 6OHDA. Administration of Tempol (250 mg/kg, i.p.) 10 min prior to administration of toxic doses of 6OHDA (350 or 400 mg/kg, i.p.) resulted in a decrease in the mortality rate, sympathetic nervous system impairment, and activity impairment compared with those seen with 6OHDA alone. Tumor weights from mice administered saline or Tempol alone were 3.6 +/- 1.9 and 2.9 +/- 0.7 g, respectively. In contrast, mice administered Tempol followed by 6OHDA had an average tumor weight of 0.7 +/- 0.3 g. Tumor incidence was also reduced from 80-100% to 40%. Studies performed using electron spin resonance spectroscopy suggest that Tempol acts in this system by reacting directly with both the 6OHDA radical and, in the presence of iron, its oxidation product, the hydroxyl radical.

Renal and hemodynamic effects of diltiazem after elective major vascular surgery--a potential renoprotective agent?

A postoperative study was done of the effects of an infusion of diltiazem (DTZ), 1 microgram.kg-1.min-1 after a bolus dose of 0.28 mg.kg-1 on renal function and hemodynamics in 10 patients who were operated with insertion of an abdominal aortic graft. Urine flow, glomerular filtration rate (GFR) by inulin clearance, and renal plasma flow (RPF) by PAH clearance and fractional excretion of electrolytes and osmols were measured for three periods of 20 min during infusion of DTZ, in the morning after surgery. Systemic hemodynamic studies were conducted and serum levels of catecholamines were measured. GFR increased during the initial period of DTZ infusion. There were no significant changes during the study period in any of the other parameters, compared to baseline, except for a decrease in heart rate from 84 to 77 beats per minute. The absence of a sustained increase in GFR and a natriuretic and diuretic effect may possibly be ascribed to a preexisting nonconstricted status of the renal vasculature. The authors conclude that the dose of DTZ used in this study can be safely used for further investigations to elucidate the effects of peroperative infusion of DTZ on renal function in connection with major vascular surgery.

Virus validation of plasma-derived products produced by Pharmacia, with particular reference to immunoglobulins.

Important factors to assure the safety of plasma-derived products manufactured on an industrial scale are initial screening of the source material and validation of the manufacturing process in accordance with issued EEC guidelines and US [Points to Consider'. Pharmacia's manufacturing process for immunoglobulins contains a specific virucidal step, in which lipid-enveloped viruses are effectively inactivated with a solvent/detergent (SD) combination consisting of 0.3% tri(n-butyl)phosphate and 1% Tween 80. Results from virus validation studies of scaled-down versions of Pharmacia's manufacturing process for immunoglobulins demonstrated extensive removal of relevant and model viruses. More than 5.0 logs of human immunodeficiency virus type 1 (HIV-1) were inactivated in the SD step and, in total, more than 31 logs of HIV-1 were eliminated in the steps studied. Comparison between SD treatment and heating at 60 degrees C of lipid-enveloped viruses in different protein solutions demonstrated that SD treatment is the superior procedure. Polio virus is a model often used in virus validation studies to predict effects on non-enveloped viruses. Because polio virus is more sensitive to heat than are hepatitis A virus (HAV) and human parvovirus B19, thermal inactivation studies with polio virus may result in an overestimation of the effects on HAV and B19.

Renal effects of human atrial natriuretic peptide in patients after major vascular surgery.

The effects were studied postoperatively of an infusion of atrial natriuretic peptide (ANP) 7.5 pMol.kg-1.min-1 on renal function and haemodynamics in seven patients who had been operated with insertion of an abdominal aortic graft. Urine flow, glomerular filtration rate (GFR), renal plasma flow (RPF) and excretion of electrolytes and osmoles were measured for three periods of 20 minutes during infusion of ANP, in the morning of the day after surgery. Haemodynamic studies were conducted, and serum levels of ANP, catecholamines and plasma renin activity were measured. ANP levels increased from 52 to approximately 250 pMol.L-1 during ANP infusion and decreased after infusion to a level equal to baseline. GFR increased from 92 mL.min-1 by 58, 20 and 21%, respectively. RPF was unchanged. Urine flow rate increased from 1.99 mL.min-1 by 81, 151 and 173%, respectively. Fractional clearances of sodium, chloride and osmoles were increased during the second and third ANP periods whereas fractional potassium clearance did not change during the study. There were no changes in catecholamine levels or plasma renin activity during the study. Heart rate, mean arterial pressure and calculated systemic and pulmonary vascular resistance did not change whereas reductions occurred in cardiac index, mean pulmonary artery pressure, pulmonary artery wedge pressure and mean right atrial pressure. We conclude that infusion of ANP also in the postoperative situation increases GFR, diuresis and sodium excretion.