Extracorporeal immunoadsorption from whole blood based on the avidin-biotin concept. Evaluation of a new method

This study of 36 rats with rat colon adenocarcinoma transplants was carried out to investigate the efficacy of a new method of whole blood immunoadsorption (WBIA) in removing biotinylated monoclonal antibodies (MAbs) directly from unseparated blood, in order to increase 'the tumor/normal-tissue uptake ratio', as compared with extracorporeal immunoadsorption (ECIA) of antibodies from plasma. Compared with the ECIA system, the overall volume of the WBIA system (comprising only a pump, an adsorption column, a drop-chamber and tubings) was less (3.6 vs. 6.2 ml), and procedure duration 2 h less. The 17 rats undergoing the WBIA procedure, started 12 h after i.v. injection of 4.0-4.5 MBq 125I-BR96-biotin, manifested neither hemolysis nor any other complication; no signs of organ edema were found at dissection; whole body and blood radioactivity values were reduced by 51% and 89.5%, respectively. The WBIA method was as effective as ECIA, but technically simpler, safer and more reliable.

Transient radicular irritation after bupivacaine spinal anesthesia

BACKGROUND AND OBJECTIVES

Transient radicular irritation (TRI) has been described to occur following spinal anesthesia with hyperbaric 5% lidocaine. The authors recently used only isobaric or hyperbaric 0.5% bupivacaine for spinal anesthesia. All patients who had spinal anesthesia for various kinds of surgery were interviewed after the operation to discover the possibility of TRI following bupivacaine spinal anesthesia.

METHODS

The study included 226 patients. Isobaric 0.5% bupivacaine was given to 116 patients and hyperbaric 0.5% bupivacaine to 110. The local anesthetic was chosen according to the expected duration of surgery. All patients were interviewed by an anesthesiologist 24 hours after spinal anesthesia, and after 1 week the patients were asked to return a written questionnaire. If pain not associated with operation was noted, the patients were interviewed by phone.

RESULTS

One 48-year-old woman reported TRI after spinal anesthesia (saddle block) with hyperbaric 0.5% bupivacaine in the 24-hour interview. Her spinal anesthetic was performed in a sitting position and the anal surgery in a lithotomy position. In the 1-week questionnaire (response rate 92%), none of the other patients fulfilled our criteria for TRI.

CONCLUSIONS

In spite of one case of TRI, the authors consider bupivacaine to be safe for spinal anesthesia. The association of the sitting and lithotomy positions to the restricted distribution of hyperbaric solution and consequent TRI warrants further studies.

Enhanced radioimmunotargeting of 125I-labeled L6-biotin monoclonal antibody (MAb) by combining preload of cold L6 MAb and subsequent immunoadsorption in rats

The present study investigates whether tumor:normal tissue uptake ratios of radiolabeled monoclonal antibodies can be further improved by a combination of extracorporeal immunoadsorption (ECIA) and preload with unlabeled idiotypic monoclonal antibody. Athymic rats, heterotransplanted with human lung carcinoma under the kidney capsule (SR tumor) and i.m. (IM tumor), were divided into four study groups: controls, ECIA, preload, and combined preload+ECIA. The preload+ECIA procedure reduced the whole-body and plasma activity by 48 and 89%, respectively. After such combined procedure, the uptake of 125I-labeled L6-biotin in SR tumors was unchanged, while the uptake in normal tissues was considerably reduced. Tumor (T):bone marrow ratio was then increased by 17.5 times (after ECIA) and by 4.5 times (24 h after ECIA). Similar enhancements were achieved for T:liver and T:kidney ratios. For the IM tumors, the ratios were not as high as for SR tumors. The effects on T:normal ratios of preload+ECIA in combination were synergistic. The combined procedure resulted both in an increased uptake and prolonged persistence of 125I-labeled L6-biotin in the SR tumors and also in a reduction of corresponding uptake values in organs critical for radiation.

The effect of skin incision followed by alfentanil on catecholamine levels and on the T-wave amplitude of ECG during isoflurane anaesthesia

Haemodynamic, ECG T-wave amplitude and plasma potassium changes and plasma catecholamine responses to skin incision followed by alfentanil were studied in 24 ASA I patients. Propofol and vecuronium were used without anticholinergics for induction of anaesthesia followed by isoflurane in 02/air. End-tidal isoflurane concentration was kept constant (0.7%) for 30 min before the skin incision. Five min after the skin incision alfentanil 30 mu g kg-1 was given. Blood samples for catecholamines and plasma potassium concentrations were drawn from right ventricle of the heart one minute before and after the skin incision and two minutes after alfentanil. Heart rate, systolic and diastolic arterial pressures increased after the skin incision (P < 0.001), and decreased after alfentanil (P < 0.001). Plasma adrenaline and noradrenaline concentrations increased slightly after the skin incision (P < 0.05 and P < 0.01, respectively). Noradrenaline levels continued to increase after alfentanil (P < 0.001) despite totally abolished haemodynamic responses to the skin incision. ECG T-wave amplitude changes, measured as R/T ratio, did not correlate to the changes in plasma catecholamine levels: both rapid increases and decreases in R/T ratio were seen. No plasma potassium changes were seen during the trial. T-wave changes, occurring in seconds after the skin incision, are probably produced by a direct catecholamine release from cardiac sympathetic nerve endings.

Conventional pneumoperitoneum compared with abdominal wall lift for laparoscopic cholecystectomy

We have compared, in a randomized study, conventional carbon dioxide pneumoperitoneum with abdominal wall lift in 25 patients undergoing laparoscopic cholecystectomy. Intra-abdominal pressure (IAP) (11 (SD 2) mm Hg vs 2.7 (9) mm Hg) (P < 0.01) and total amount of carbon dioxide used (40 (23) litre vs 9 (7) litre) (P < 0.001) were significantly less with abdominal wall lift. Pulmonary compliance was significantly greater (P < 0.01) in the abdominal wall lift group throughout operation. During the first 15 min of insufflation, arterial pressures were lower with abdominal wall lift (P < 0.05). In the conventional pneumoperitoneum group, femoral vein pressure increased (P < 0.01) and remained elevated for 3 h in the recovery room. Postoperative drowsiness was of significantly longer duration in the conventional pneumoperitoneum group than in the abdominal wall lift group (98 (46) min vs 13 (34) min) (P < 0.01). Postoperative nausea and vomiting and right shoulder pain occurred more often in patients with conventional pneumoperitoneum (P < 0.05). We conclude that the benefits of abdominal wall lift may be attributed to avoiding excessive carbon dioxide and high IAP.

Premedication with promethazine and transdermal scopolamine reduces the incidence of nausea and vomiting after intrathecal morphine

Intrathecal morphine provides effective postoperative pain relief in major orthopaedic surgery. In use, however, is associated with unpleasant side effects like nausea and vomiting. The effect of different premedications on postoperative emetic sequelae induced by intrathecal morphine was studied in a prospective, double blind study. Sixty patients scheduled for arthroplasty surgery of the lower extremity were anaesthetized with spinal anaesthesia with a combination of isobaric bupivacaine 20 mg and morphine 0.3 mg. For premedication the patients were randomised to three groups of equal size. They received either oral diazepam (5-15 mg), oral promethazine (10 mg) or a combination of promethazine and transdermal scopolamine (1.5 mg). Sixty percent of the patients with both promethazine and transdermal scopolamine were totally free from postoperative nausea and vomiting (PONV) symptoms compared to those premedicated with diazepam (40%) or promethazine alone (30%). Promethazine together with transdermal scopolamine reduced significantly the number of patients with vomiting (to 25%) and also vomiting episodes. This combination was also more efficient in reducing the incidence of nausea (to 25%) and nausea episodes than promethazine along (P < 0.05). Combination also reduced the requests for additional pain relief (P < 0.05). PONV occurred in a majority of patients during the first 12 hours of the 24 hour study period and the need for additional analgesics thereafter. The incidence of itching (50-65%) and urinary catheterisation (55-70%) was similar in all groups. In conclusion, the combination of oral promethazine and transdermal scopolamine was most effective in reducing PONV symptoms and also reduced the need for postoperative pain treatment.

Disturbance of hepatocellular integrity associated with propofol anaesthesia in surgical patients

Propofol anaesthesia has not been associated with any hepatic consequences. We used glutathione transferase Alpha (GSTA), a very sensitive indicator of hepatocellular integrity, to evaluate the effect of propofol on the liver. Total intravenous anaesthesia was induced and maintained with propofol without any supplements in 30 female patients undergoing breast surgery. Ten healthy female volunteers given the lipid vehicle of propofol served as controls. Serum GSTA concentration was measured with a sensitive time-resolved immunofluorometric assay. Total intravenous propofol anaesthesia was stable and postoperative nausea negligible. A significant increase in GSTA from 3.1 micrograms.l-1 (mean baseline) to 10.0 micrograms.l-1 (mean peak) was noted after propofol infusion, indicating subclinical disturbance in hepatocellular integrity. No change in aminotransferases and no clinical signs of hepatotoxicity were observed. A small increase in GSTA from 2.4 micrograms.l-1 (mean baseline) to 4.1 micrograms.l-1 (mean peak) was observed during lipid infusion. We detected a subclinical disturbance in hepatocellular integrity after propofol anaesthesia for breast surgery. The mechanisms of hepatocellular impairment are not clear but the lipid vehicle of propofol alone does not explain it.

Occurrence and clinical features of sensitization to Pityrosporum orbiculare and other allergens in children with atopic dermatitis

One hundred and nineteen consecutive cases of children with atopic dermatitis aged 4-16 years (73 girls) from a pediatric dermatology outpatient clinic were included in a study of atopic sensitization. Structured interviews and clinical investigations were performed. IgE antibodies to common inhalant allergens, Pityrosporum orbiculare, Candida albicans, Tricophyton rubrum and Staphylococcus aureus were detected. Specific IgE antibodies frequently occurred to pollens, animal epithelia, C. albicans, house dust mites and moulds, whereas specific IgE antibodies to potential skin allergens were less prevalent. Twenty-six children (21.8%) had IgE antibodies to P. orbiculare, 14 (11.8%) to T. rubrum and 3 (2.5%) to S. aureus. Atopic dermatitis in children with one or several RAST positivities was worse, with a more chronic course, higher total eczema score, more frequent distribution in the head-neck-face regions and more itch compared to the children without serum detectable IgE antibodies. Severe itch disturbing nightly sleep was the only clinical feature that characterised P. orbiculare-positive cases. Allergy to P. orbiculare appears to be of little importance in early childhood atopic dermatitis but is likely to carry a poor prognosis.

ECG T-wave amplitude changes during thiopentone induction with or without alfentanil

The T-wave amplitude of ECG is thought to reflect the sympathetic tone of the heart but anaesthesia studies on this topic are rare. Haemodynamic and ECG T-wave amplitude changes were studied during induction of anaesthesia in 24 ASA I-II patients. Twelve patients were given alfentanil 30 micrograms kg-1 at induction while physiologic saline was given to the rest (control). Thiopentone was then administered at the rate of 5 mg s-1 until eyelash reflex disappeared. Vecuronium 0.1 mg kg-1 was given thereafter. No anticholinergics were used. The lungs were ventilated with 40% oxygen in air. Haemodynamic parameters and T-wave amplitude were measured before induction, before intubation, 30 s, 3 min and 5 min after intubation. A significantly higher amount of thiopentone was needed to abolish the eyelash reflex in the control group than in the alfentanil group (P < 0.001). There were no changes in heart rate (HR) in the alfentanil group during the trial. Systolic and diastolic arterial pressures (SAP and DAP) were continuously below the preinduction levels in the alfentanil group. After baseline HR, SAP and DAP were significantly higher in the control group than in the alfentanil group at each data point. T-wave amplitude flattened significantly (P < 0.001) after intubation in the control group while no significant changes were seen in the alfentanil group. T-wave flattening correlated to the increases in HR (P < 0.01) and SAP (P < 0.01). Three control patients with flattened T-wave had a transient bigeminia period after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythrocyte counts in the cerebrospinal fluid associated with continuous spinal anaesthesia

Continuous spinal anaesthesia technique can be associated with peridural haemorrhage due to blood vessel damage caused by the needle or the catheter. We studied whether thrombosis prophylaxis or anticoagulation medications increase the risk of subarachnoid haemorrhage when continuous spinal anaesthesia is used. Twenty arthroplasty patients received low-molecular-weight heparin preoperatively and twenty-two vascular surgery patients received heparin (100 IU kg-1) peroperatively; eight of the latter patients were on regular preoperative antiplatelet medication. Twenty-four prostate surgery patients, not exposed to heparin or other drugs affecting coagulation, served as controls. A 22-gauge spinal catheter was used and bupivacaine was injected through the catheter. Within the following 24 hours, 4-5 cerebrospinal fluid samples were collected for erythrocyte counts. In the arthroplasty and the vascular group there were five patients each and in the control group seven patients with more than 100 x 10(6) l-1 erythrocytes in at least one of the samples. The highest erythrocyte count was 23900 x 10(6) l-1 in a control patient. The 24-hour sample was blood-tinged (erythrocytes > 1000 x 10(6) l-1) in two patients in the arthroplasty group, in one patient in the vascular group and in four patients in the control group. In spite of the haemorrhages detected in this study, no related neurological symptoms or other serious consequences were observed. The risk of subarachnoid haemorrhage was not increased by drugs affecting coagulation.

Effect of intraperitoneal bupivacaine on pain after laparoscopic cholecystectomy

The effect of intraperitoneal bupivacaine on postoperative pain was studied in 60 ASA 1-2 patients undergoing elective laparoscopic cholecystectomy. The patients were randomly selected (20 patients in each group) to receive in double-blind fashion 100 mo of either plain 0.15% bupivacaine (150 mg.100 ml-1) or the same solution with adrenaline (1.5 micrograms ml-1), or the same volume of saline into the right subdiaphragmatic space at the end of surgery. The patients were kept in the Trendelenburg's position for 20 min after the instillation. Venous blood samples for the determination of bupivacaine plasma concentrations were drawn up to 180 min. Plasma bupivacaine concentrations peaked at 30 min (highest individual value 2.6 micrograms ml-1) after instillation. Bupivacaine concentrations were significantly lower in the bupivacaine-adrenaline group. During the follow-up no difference between the groups occurred as to the time to first demand of analgesia, severity of postoperative pain, amount of consumed analgesics during 7 days, and length of hospitalization. In all groups, 30-45% of the patients complained of right shoulder pain. After the first 24 hours, pain at rest and during moving was reported as mild and was managed with oral ketoprofen. It is concluded that postsurgical intraperitoneal instillation of 150 mg bupivacaine in 100 ml of saline had no effect on pain after laparoscopic cholecystectomy.

Haemodynamic and catecholamine responses to induction of anaesthesia and tracheal intubation in diabetic and non-diabetic uraemic patients

We have studied cardiovascular and catecholamine responses to induction of anaesthesia and tracheal intubation in 13 patients with diabetic nephropathy, in 12 patients with uraemia of other origin and in 12 ASA I control patients. All uraemic patients were undergoing renal transplantation. Cardiovascular autonomic function tests indicated that severe autonomic neuropathy was common in the diabetic patients; less severe impairment of autonomic function was found in the non-diabetic uraemic patients. The systolic pressor response to intubation was greater in diabetic uraemic patients than in the other groups (P < 0.05). Both uraemic groups had higher plasma catecholamine concentrations than the ASA I patients both before and after induction of anaesthesia. The increased plasma concentrations of catecholamines in the uraemic patients may be a result of impaired clearance of catecholamines and higher sympathoadrenal activity needed to maintain cardiac function. The normal systolic pressor response to tracheal intubation in the uraemic patients indicates that the capacity of the cardiovascular system to respond to a stressful stimulus was preserved in these patients also, in spite of autonomic neuropathy. The greater response in the diabetic group may be caused by increased sensitivity to catecholamines and loss of autonomic control.

QT dispersion and autonomic function in diabetic and non-diabetic patients with renal failure

We have studied 13 patients with diabetic nephropathy and 13 patients with uraemia of other origin undergoing renal transplantation, and 12 control patients undergoing general surgery. QTc dispersion and maximum QTc interval were calculated from the 12-lead ECG, and cardiovascular autonomic function tests were performed. QTc dispersion was significantly greater in diabetic (mean 100 (SD 37) ms) and non-diabetic (51 (17) ms) uraemic patients than in control patients (29 (10) ms), and it differentiated the groups better than maximum QTc. In diabetic patients, severe autonomic neuropathy was common. In other uraemic patients less severe disturbances in autonomic function were found. In diabetic uraemic patients, increased QTc dispersion and severe autonomic neuropathy may indicate high risk for cardiac arrhythmias. In our opinion, QTc dispersion and autonomic function tests may give valuable information on perioperative risks.

Comparison of propofol/alfentanil anaesthesia with isoflurane/N2O/fentanyl anaesthesia for renal transplantation

Total intravenous anaesthesia (TIVA) with propofol and alfentanil was compared with balanced anaesthesia (BA) in 30 uraemic patients undergoing renal transplantation. TIVA (n = 15) was induced with propofol and alfentanil and maintained with propofol and alfentanil infusions, which were started immediately after induction. Thereafter the infusion rates were adjusted as needed. Ventilation was with oxygen in air. BA (n = 15) was induced with thiopentone and fentanyl and maintained with isoflurane/N2O/fentanyl. Vecuronium was used for muscle relaxation in both groups. Mean infusion rates for propofol and alfentanil were 10 +/- 1.8 mg kg-1 h-1 and 70 +/- 9 micrograms kg-1 h-1, respectively. To control hypertension during TIVA, larger amounts of propofol and alfentanil were needed and slower recovery was observed than in previous studies in ASA 1-2 patients. Also, significantly more vecuronium was needed during TIVA than during BA (P < 0.05). The recovery parameters were similar in both groups, except for the occurrence of nausea, which was less after TIVA. In conclusion, TIVA had no clinical advantages over BA.

Effects of sub-hypnotic doses of propofol on the side effects of intrathecal morphine

We have studied the effect of propofol on the side effects associated with intrathecal morphine in 40 patients undergoing major arthroplasty. Patients received spinal anaesthesia with plain 0.5% bupivacaine 20 mg mixed with preservative-free morphine 0.3 mg. Before injection of the local anaesthetic, the patients were allocated randomly to receive either a bolus dose of propofol 10 mg followed by an infusion of 30 mg/24 h or equal volumes of 10% Intralipid (control group). The number of patients without postoperative nausea and vomiting (PONV) was similar in both groups. However, the incidence of nausea and vomiting was lower in the propofol (13 and 22, respectively) than in the control (34 and 36) group (P < 0.01 and P < 0.05, respectively). Severe vomiting episodes were less frequent in the propofol group (1 vs 11; P < 0.05). Four patients in the propofol group and 12 patients in the control group had itching (P < 0.05). The incidence of urinary retention was similar in both groups. There was no additional sedation attributable to propofol. In conclusion, sub-hypnotic doses of propofol protected significantly against itching and had a modest effect on PONV after intrathecal morphine.

Sudden cardiorespiratory arrest after renal transplantation in a patient with diabetic autonomic neuropathy and prolonged QT interval

A 31-yr male with insulin dependent diabetes mellitus for 20 years underwent general anaesthesia for renal transplantation. During transfer from operating theatre to ICU he developed bradycardia advancing to ventricular fibrillation and had to be resuscitated. Bradycardia did not respond to atropine. Postoperative autonomic nervous function tests showed advanced autonomic neuropathy. He was found to have constantly prolonged QTc interval in his pre- and postoperative ECGs (462-503 ms). Prolongation of QTc interval could be used as a valuable predictor of postoperative cardiac complications in diabetic patients with autonomic neuropathy.

A general extracorporeal immunoadsorption method to increase tumor-to-tissue ratio

The idea of applying extracorporeal immunoadsorption (ECIA) in radioimmunodiagnosis and radioimmunotherapy has been proposed previously. The authors here report on the development of new concept using a general method for ECIA based on biotinylated MoAb adsorbed on an avidin column. Athymic rats heterotransplanted with either human melanomas or human lung carcinoma were injected with iodine-125-labeled biotinylated 96.5 or L6 MoAb, respectively. At 24 or 48 hours after the injection, ECIA was performed by pumping blood through a hollow-fiber plasma filter. The separated plasma then was passed through an absorbent (avidin-agarose) column. The whole ECIA procedure lasted for 3 hours. By this ECIA method, the tumor-to-normal tissue ratios were increased in various tissues (i.e., radiosensitive and blood rich organs) by a factor of four to five.

The effect of atropine on the T-wave amplitude of ECG during isoflurane anaesthesia

The effect of bolus dose of atropine (20 micrograms kg-1) on the R/T-wave amplitude ratio of electrocardiogram was studied in 12 patients during isoflurane anaesthesia at electroencephalogram burst suppression level (mean ET of isoflurane 1.8 vol-%). The amplitude ratio was measured before, 1, 2, 5 and 10 min after atropine. Change was measured as decibels and 95% confidence intervals were calculated. The amplitude of T-wave flattened significantly after atropine. It is concluded, that the ECG T-wave amplitude reflects the balance of sympathetic and parasympathetic nervous activity during isoflurane anaesthesia. The use of the decibel transformation and confidence intervals seems to be a relevant method to interpret changes in physiologic measures during anaesthesia.

Atropine abolishes electroencephalogram-associated heart rate changes without an effect on respiratory sinus arrhythmia during anaesthesia in humans

Heart rate fluctuates with the electroencephalogram burst suppression pattern during anaesthesia: increasing at burst onset and decreasing at suppression. Heart rate also oscillates with positive pressure ventilation. The effects of atropine on these heart rate changes were studied in 12 patients during isoflurane anaesthesia and positive pressure ventilation at a frequency of 6 cycles min-1. Four additional patients served as controls. A bolus dose of atropine (20 micrograms kg-1 intravenously) abolished the electroencephalogram-correlated heart rate changes; however, the amplitude of respiratory sinus arrhythmia was not changed after atropine. The control mechanism of the burst suppression pattern in electroencephalogram also affects parasympathetic heart rate control. The control mechanisms of respiratory sinus arrhythmia during anaesthesia with positive pressure ventilation differ from those during spontaneous breathing awake.