MRI after removal of central venous access device reveals a high number of asymptomatic thromboses in children with haemophilia.

Central venous access devices (CVADs) are often required in children with haemophilia to secure venous access for prophylactic treatment or immune tolerance therapy. Complications of CVADs include infections, thrombosis and mechanical problems. This study sought to determine the outcome of the vessels by magnetic resonance imaging (MRI) in children with haemophilia and to assess risk factors for development of catheter-related deep venous thrombosis (DVT). After the removal of CVAD an MRI of the chest and neck was performed to 20 boys with haemophilia who each had 1-3 (total number 27) CVADs placed. MRI revealed DVT in five children (25%). As their CVADs were functional at the time of the removal, the DVTs were clinically silent. However, there had been suspicion of DVT leading to replacement of the CVAD in one case. All the children with DVT had their CVADs inserted initially below the age of 1 year. The clinical signs of mild post-thrombotic syndrome (PTS) were common: dilated chest wall veins were observed in 11 (55%) children and were associated with DVT in three cases. Arm circumference discrepancy was observed in one child with DVT. No correlation between the duration or number of CVADs and DVT was detected. None of the patients had subjective symptoms of PTS. Silent DVT is a common complication of CVAD. Catheter insertion at a young age seems to predispose to thrombosis. The long-term consequences of the DVTs remain unknown.

Transdermal fentanyl therapy for pains in children with infantile neuronal ceroid lipofuscinosis.

We used infantile neuronal ceroid lipofuscinosis (INCL), in which deterioration of the central nervous system is extremely rapid, to study constant release of an opioid for pains of central origin in a metabolic disease. The effect of a transdermal fentanyl patch was studied in five children with INCL. In two of them, measurements of 17 fentanyl serum concentrations and also visual analogue pain scale were obtained during a 15-day study period. Low doses of transdermal fentanyl usually provided good pain relief for the first two days, but not for the third day, of the three-day patch change interval. Pain relief of this type seems mandatory for pains mostly of central origin.

Pain medication during terminal care of children with cancer.

The purpose of this study was to evaluate the need for pain medication and the adequacy or inadequacy of the analgesia achieved, in children with cancer who died while in terminal care. Of the 100 pediatric patients with cancer treated at the Children's Hospital, University of Helsinki, Finland, who died during 1987-1992, 70 died while in terminal care. The underlying diseases were leukemia (N = 25), solid tumors (N =24), and brain tumors (N = 21). Of these children, 60% were treated at home, 29% at hospital, and 11% at both. The assessment of pain during terminal care was retrospective and included analysis of the patients' records and a structured interview of the two parents separately. In total 62 children (89%) received regular pain medication, with a mean duration of 17 days in children with leukemia, 58 days in those with solid tumors, and 66 days in those with brain tumors. Medication was usually started with anti-inflammatory drugs, then changed to oral opioids when deemed necessary, and finally to parenteral opioids. Parenteral morphine was administered to 40 children, to 30 as a continuous infusion through a central venous line. The dose of morphine was 0.8 mg/kg/day at the start and was increased to 4.9 (range, 0.2-55) mg/kg/day. Of the 62 children who received regular pain medication, the majority (81%) had adequate analgesia. In 19%, analgesia had been suboptimal. In conclusion, the vast majority of children with cancer need regular pain medication while in terminal care. This can be administered adequately at home, even if continuous intravenous infusions are required.

Haemodynamic responses during general anaesthesia for renal transplantation in patients with and without hypertensive disease.

Haemodynamic changes in 81 patients undergoing surgery for renal transplantation were studied. They were allocated to three groups depending on whether or not they had chronic hypertension and which drugs were used to control it. The patients in Group I (N = 18, 22%) were normotensive and were not receiving antihypertensive therapy, those in Group II (N = 21, 26%) were taking beta-blockers and those in Group III (N = 42, 52%) both beta-blockers and vasodilating agents. Antihypertensive medication was continued as prescribed until surgery. No anticholinergic premedication was given. All patients received a standardized anaesthesia which included thiopentone, fentanyl, vecuronium and isoflurane. Mean arterial blood pressure and mean heart rate were lowest in Group I compared with the other groups immediately before induction, following vecuronium and thiopentone administration, and after tracheal intubation (P less than 0.05). After the 10-min induction period, blood pressure and heart rate values did not differ between the groups. Although before and during surgery and anaesthesia central venous pressure did not differ between the groups, CVP was higher in Group I postoperatively compared with the other groups (P less than 0.05). No serious anaesthesia-related complications occurred.

Effects of oral clonidine premedication on concentrations of cortisol and monoamine neurotransmitters and their metabolites in cerebrospinal fluid and plasma.

Forty-two healthy male patients (aged 19-40 years), undergoing orthopaedic surgery under spinal anaesthesia (3 ml isobaric 0.5% bupivacaine), were given clonidine 4.5 micrograms kg-1 orally either 2 (Group I, n = 10) or 4 (Group II, n = 10) hours before the operation, diazepam 0.15 mg kg-1 orally (Group III, n = 10) or a placebo tablet (Group IV, n = 12) 2 h before the operation. Plasma concentrations of cortisol, noradrenaline (NA), adrenaline (A), 3,4-dihydroxyphenylglycol (DHPG) and dihydroxyphenylacetic acid (DOPAC) were assayed from venous blood samples just before premedication and just before the spinal block. Cerebrospinal fluid (CSF) concentrations of cortisol, tryptophan, 5-hydroxyindoleacetic acid and catecholamine metabolites were assayed from a sample taken before the spinal block. The plasma NA concentrations of the patients in the groups receiving clonidine decreased clearly compared with the other groups (P less than 0.05). The NA metabolite DHPG was also lower in Groups I and II than in Group III (P less than 0.05) after premedication. Plasma A concentrations were lower in Groups I and III than in Group IV (P less than 0.05). The CSF concentrations of the different substances were similar in all groups. In Group I the sensory blockade lasted significantly longer than in Group III (P less than 0.05) and the mean duration of motor blockade was longer in Group I than in Groups III and IV (P less than 0.05). Two patients in both clonidine groups developed bradycardia (heart rate less than 45 min-1) requiring atropine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular responses caused by the combination of lidocaine and vecuronium in the induction of general anaesthesia.

Fentanyl, vecuronium and enflurane may cause bradyarrhythmias during anaesthesia. Lidocaine administered before endotracheal intubation may interact synergistically with these agents. In this randomized and double-blind study, lidocaine 1 mg kg-1 (24 patients) or saline (20 patients) was given, immediately after glycopyrrolate 5 micrograms kg-1, fentanyl 1.5 micrograms ml-1 and thiopentone 3-5 mg kg-1, together with vecuronium 0.1 mg kg-1 as a rapid i.v. injection to healthy (ASA 1) surgical patients. Enflurane 0.8% was included in the inhaled gases 10 min and enflurane 1.6% 25 min after lidocaine administration. The plasma concentrations of lidocaine rose to a mean level of 3.1 micrograms ml-1 (maximum 7.1 micrograms ml-1) which may affect the electrical conduction at various sites in the heart. There were no statistically significant differences in arterial blood pressures or heart rates during anaesthesia between the groups. The incidence of junctional rhythm was 7/24 patients in the lidocaine group and 5/20 patients in the saline group. Three patients in the lidocaine group, and two patients in the control group developed junctional rhythm immediately after intubation. The plasma concentrations of vecuronium were unaffected by lidocaine. The ratio of the unbound lidocaine to plasma protein bound lidocaine was at the expected level and did not differ significantly 2 and 10 min after the injection.

Oral premedication with clonidine: effects on stress responses during general anaesthesia.

The effect of clonidine (4.5 micrograms kg-1) on haemodynamics and hormonal stress responses was evaluated in 21 female patients undergoing breast surgery. The standardized general anaesthesia included diazepam as premedicant, thiopentone, enflurane, N2O, fentanyl and vecuronium. Venous plasma concentrations of noradrenaline, adrenaline, growth hormone, vasopressin, and cortisol were assayed at various times before, during and after surgery. Clonidine attenuated the sympathoadrenal response; arterial blood pressure and heart rate increases in association with intubation were lower in clonidine-premedicated patients. Noradrenaline levels were lower throughout and 3 h after surgery in the clonidine group (P less than 0.05). Adrenaline levels were lower in this group 2 min after intubation (P less than 0.05). Growth hormone, vasopressin and cortisol plasma levels were increased at the end of and after surgery, with no differences between the groups. In spite of the effect on sympathoadrenal response, clonidine did not have any significant additive anxiolytic effect. Statistically significant differences were not found as to need for postoperative analgesics.

Effect of clonidine on haemodynamic responses to endotracheal intubation and on gastric acidity.

Sixty-three patients (ASA 1-2), scheduled for elective surgery under general anaesthesia, were randomly given either oral clonidine (225-375 micrograms) + diazepam (5 15 mg), cimetidine (300 mg the night before and 300 mg in the morning) + diazepam or only diazepam for premedication. Anaesthesia was induced with thiopentone and maintained with N2O + O2 (70:30), enflurane and fentanyl. Vecuronium bromide was used as a muscle relaxant. The sleep dose of thiopentone was significantly smaller in the patients pretreated with clonidine than in the other groups. The mean maximal increase in heart rate was lowest in the clonidine-pretreated patients, but there were no significant differences in the mean arterial pressure changes associated with intubation. Before and just after intubation and in the recovery room, the arterial pressures were lowest in the patients pretreated with clonidine. During anaesthesia, marked bradycardia (less than or equal to 45 beats min-1) did not occur more often when clonidine was used, but in the recovery room there were statistically significantly more patients with bradycardia in the clonidine group than in the other groups. On the electrocardiogram (ECG) during the endotracheal intubation, the incidence of bigeminy was higher in the diazepam patients (5/20) than in the cimetidine patients (2/20) and the clonidine patients (0/23). There were significantly more gastric content samples with a pH above 2.5 in the cimetidine group than in the other groups, and clonidine patients did not differ from diazepam patients in this respect. The high incidence of bradycardia with the concomitant hypotension may limit use of this drug to highly selected patients.

Bradycardia associated with the use of vecuronium. A comparative study with pancuronium with and without glycopyrronium.

One hundred and twenty patients undergoing anaesthesia for elective surgery received either pancuronium or vecuronium for muscle relaxation. Within each of these two groups, half were given glycopyrronium and the remainder an inert placebo. The incidence of bradycardia or bradydysrhythmias was higher in the group having vecuronium compared with those given pancuronium. Glycopyrronium afforded protection against undesirable vagal activity.