School performance in cholesteatoma-operated children in Denmark: a nationwide population-based register-study

Conclusion Cholesteatoma in childhood had no long-term effect on school performance for the majority who completed lower secondary school. Aim To investigate whether individuals operated on for cholesteatoma in childhood have impaired school performance in adolescence. Methods All children born in Denmark between 1986-1991 with cholesteatoma surgery performed before the age of 15 years were included (cholestetaoma group). A control group consisting of a 5% random sample of all children born in Denmark during the same period was used for comparison. Final marks (average, mathematics, Danish, and English) achieved upon completion of lower secondary school (9th grade; age 15 or 16 years) were compared between groups. Results A total of 549 individuals met the inclusion criteria for the cholesteatoma group and 15 106 for the control group. High parental education and female sex were strongly associated with high 9th grade marks. The cholesteatoma group did equally as well as the control group in all outcome-measures except from in English (1st foreign language), where children with ≥2 cholesteatoma surgeries scored 0.26 marks lower (95% confidence interval = 0.03-0.48). In the cholesteatoma group, though, the odds ratio for not attaining a 9th grade exam was 1.33 (95% confidence interval = 1.03-1.72%) when compared with the control group.

Caudal bupivacaine supplemented with caudal or intravenous clonidine in children undergoing hypospadias repair: a double-blind study

BACKGROUND

Clonidine is used increasingly in paediatric anaesthetic practice to prolong the duration of action of caudal block with a local anaesthetic agent. Which route of administration of clonidine is the most beneficial remains unknown. We compared the effects of caudal and i.v. clonidine on postoperative analgesia produced by caudal bupivacaine after hypospadias repair.

METHODS

Forty-six children (ASA I or II) aged 24-104 months received standardized premedication with midazolam, a general anaesthetic and a caudal block with bupivacaine 0.25%, 0.5 ml kg(-1). The children were randomized in a double-blind fashion to two groups: the i.v. group received clonidine 2 micro g kg(-1) i.v. and simultaneously the same volume of saline caudally. The caudal group received clonidine 2 micro g kg(-1) caudally and a similar volume of saline i.v. After surgery, all children received acetaminophen 20 mg kg(-1) rectally or orally 6-hourly and were given a patient-controlled or nurse-controlled analgesia (PCA/NCA) pump with i.v. morphine (bolus of 25 micro g kg(-1) and an 8-min lockout period with no background infusion). Monitoring of scores for pain, sedation, motor block, and postoperative nausea and vomiting was performed by nurses blinded to the study allocations. Time to first activation of the PCA/NCA pump and 0-24 h and 24-48 h morphine consumption were also recorded.

RESULTS

Forty-four children completed the study. Age, weight and duration of anaesthesia and surgery were similar in the two groups. The median (range) time to first activation of the PCA/NCA pump was similar in the two groups: 425 (150-1440) min in the i.v. group and 450 (130-1440) min in the caudal group. The number of children not requiring postoperative morphine was four and seven respectively. Morphine consumption during 0-24 h and 24-48 h was similar between groups.

CONCLUSIONS

The analgesic effect of clonidine 2 micro g kg(-1) as an adjunct to caudal block with bupivacaine 0.25%, 0.5 ml kg(-1) is similar whether administered i.v. or caudally.

Caudal ropivacaine in infants: population pharmacokinetics and plasma concentrations

BACKGROUND

Ropivacaine is a new long-acting amino-amide local anesthetic. However, there are no data on its use in infants. In the current study, the authors investigated the pharmacokinetics of caudal ropivacaine in 30 infants younger than 12 months.

METHODS

Two groups of infants (group 1 [n = 15], aged 0-3 months; group 2 [n = 15], aged 3-12 months) were given a caudal bolus dose of 0.2% ropivacaine (2 mg/kg) and a standardized general anesthetic technique. Serial blood samples taken for up to 12 h were analyzed for total and free ropivacaine using high-performance liquid chromatography. Population pharmacokinetic modeling was performed to yield estimates of clearance, volume of distribution, and absorption rate constant. An analysis of covariates on the kinetic parameters also was made.

RESULTS

Median maximum free ropivacaine concentration was significantly higher in group 1 (99 micog/l) than in group 2 (38 microg/l) (P = 0.0002), as was the median free fraction of ropivacaine (10% vs. 5%; P = 0.01). Pharmacokinetic variables of the total population were best described by a one-compartment model with first-order absorption. Mean clearance was 0.31 l.h(-1).kg(-1) (coefficient of variation [CV], 51%), volume of distribution was 2.12 l/kg (CV, 34%), and absorption rate constant was 1.61 h(-1) (CV, 46%). Mean absorption and elimination half-lives were 0.43 and 5.1 h, respectively. Age and percentage of free ropivacaine were significant covariates for clearance. Posterior Bayesian estimates of clearance were significantly higher (38%) in older children.

CONCLUSION

Total and free plasma ropivacaine concentrations after caudal ropivacaine (0.2%, 2 mg/kg) in infants were within the range of concentrations previously reported in adults and older children. Age and percentage of free ropivacaine were significant covariates of clearance.

Plasma concentrations and pharmacokinetics of bupivacaine with and without adrenaline following caudal anaesthesia in infants

BACKGROUND

The aim of this study was to determine whether the use of adrenaline 1/400000 added to 0.25% bupivacaine significantly delays the systemic absorption of the drug from the caudal epidural space in young infants.

METHODS

Fifteen infants less than 5 months of age undergoing minor lower abdominal procedures under a standardised general anaesthetic were randomised to receive a caudal block with either 0.25% plain bupivacaine 2.5 mg/kg (n=7) or bupivacaine 0.25% with 1/400000 adrenaline (n=8). Blood samples were drawn at 30, 60, 90, 180, 240 and 360 min according to the infant's weight and analysed for total and free bupivacaine concentrations using a gas chromatography-mass spectrometry (GC-MS) technique.

RESULTS

The total C(MAX) and T(MAX) were comparable in both groups. The total bupivacaine concentration at t=360 min was significantly higher in the "adrenaline" group compared to the "plain" group, i.e. a median (range) 742 ng/ml (372-1423 ng/ml) vs. 400.5 ng/ml (114-446 ng/ml), P=0.0080. The median "apparent" terminal half-life (t1/2) was significantly longer in the "adrenaline" group (363 min; range 238-537 min) compared to the "plain" group (n=6) (165 min; range 104-264 min), P=0.0087. The free bupivacaine concentrations (n=3 in both groups) ranged between 13 ng/ml and 52 ng/ml, corresponding to a percentage of free bupivacaine between 1.3% and 6.7%.

CONCLUSION

The addition of 1/400.000 adrenaline prolongs the systemic absorption of caudally administered bupivacaine in infants less than 5 months of age.

Treatment with paracetamol in infants

BACKGROUND

Paracetamol (N-acetyl-p-amino-phenol) or acetaminophen has become the most widely used analgesic and antipyretic in children. However, there is a wide discrepancy between the extent to which paracetamol is used and the limited available pharmacological data in small infants. The purpose of this article is to present a review of the current literature regarding the use of paracetamol in neonates and infants with a particular emphasis on pharmacological issues.

METHODS

A MEDLINE search (up to March 2000) was conducted to identify relevant English-language publications using paracetamol, children, infants and neonates as search terms. Additional studies were identified from bibliographies of the reviewed literature.

RESULTS

Pharmacological studies on paracetamol in infants are few. Most studies have focused on the administration of one single paracetamol dose, and the problem of cumulative toxicity with repeated dosing has not been addressed. Plasma paracetamol concentration should be 10-20 mg ml(-1) to achieve antipyretic and analgesic effects. The bioavailability of the different formulations and routes of administration vary with age. Rectal absorption is slower and more erratic than the oral; however, in the very young, rectal bioavailability is higher than in older patients. Volume of distribution seems to be age-independent, whereas clearance is reduced in neonates and particularly in preterm babies. Neonates and infants are capable of forming the reactive intermediate metabolite that causes hepatocellular damage, particularly after multiple doses. They have an immature glucuronide conjugation system, but the rate constant for the sulphation metabolic pathway is larger than in older children, and this is the most important route of metabolism.

CONCLUSIONS

The pharmacokinetics and pharmacodynamics of paracetamol differ substantially in neonates and infants from those in older children and adults; hence, dosing should be adjusted accordingly.

Pharmacokinetics and clinical efficacy of long-term epidural ropivacaine infusion in children

The clinical efficacy and pharmacokinetics of long-term epidural ropivacaine infusion were investigated in 18 postoperative children aged between 0.3 and 7.3 yr. A lumbar or thoracic epidural catheter was inserted after the anaesthetic induction. Sixty minutes following a bolus dose of ropivacaine 1 mg kg-1, 0.2% ropivacaine was infused at a fixed rate of 0.4 mg kg-1 h-1 for a mean of 61.3 h (range 36-96 h). Clinical evaluation comprised hourly recording of pain, sedation, motor block, nausea/vomiting, pruritus-scores, SpO2, pulse and respiratory rates, and recording of non-invasive arterial pressure every 4 h. Total and free plasma concentrations were measured by high-performance liquid chromatography at 0, 1, 6, 12, 24, 36, 48, 72 and 96 h. Analgesia was of high quality and side effects were minor. No clinical signs of local anaesthetic toxicity were seen. Total (100-3189 micrograms litre-1) and free (10-56 micrograms litre-1) ropivacaine concentrations were within the range reported to be 'safe' in previous studies in adults. Mean (95% CI) volume of distribution was 3.1 litre kg-1 (2.1-4.2 litre kg-1), total clearance was 8.5 ml kg-1 min-1 (5.8-11.1 ml kg-1 min-1), free clearance was 220 ml kg-1 min-1 (170-270 ml kg-1 min-1) and elimination half-life was 4.9 h (3.0-6.7 h).

Plasma paracetamol concentrations and pharmacokinetics following rectal administration in neonates and young infants

BACKGROUND

Despite widespread use in children pharmacokinetic data about paracetamol are relatively scarce, not the least in the youngest age groups. This study aimed to describe plasma paracetamol concentrations and pharmacokinetics of a single rectal paracetamol dose in neonates and young infants.

METHODS

Perioperatively, 17 neonates and infants < or =160 days of age received one rectal paracetamol dose (mean 23.9 mg/kg (+/-4.2 mg/kg)). Blood samples were drawn at 60, 120, 180, 240, 300 and 360 min, according to the infants' weights. Plasma paracetamol concentrations were measured by a Colorometric Assay, Ectachem Clinical Chemistry Slides (Johnson & Johnson Clinical Diagsnostics).

RESULTS

The plasma paracetamol concentrations were mainly below the therapeutic (i.e. antipyretic) range of 66-132 micromol/l and did not exceed 160 micromol/l in any infant. The mean maximum plasma concentration (Cmax) was 72.4 micromol/l (+/-33.5 micromol/l) and the time to Cmax, i.e. the mean Tmax was 102.4 min (_+59.1 min). The mean "apparent" terminal half-life (n=10) was 243.6 min (+/-114.1 min).

CONCLUSION

The absorption of rectal paracetamol (mean dose 23.9 mg/kg, +/-4.2mg/kg) in young infants <160 days is variable and often prolonged and achieves mainly subtherapeutic plasma concentrations.

Changes in adhesion molecule expression and oxidative burst activity of granulocytes and monocytes during open-heart surgery with cardiopulmonary bypass compared with abdominal surgery

Cardiac and major abdominal surgery are associated with granulocytosis in peripheral blood. The purpose of the present study was to describe the granulocyte and monocyte oxidative burst and the expression of adhesion molecules following cardiac surgery with cardiopulmonary bypass and abdominal surgery. The ability to respond with an oxidative burst was measured by means of flow cytometry using 123-dihydrorhodamine. The adhesion molecules CD11a/CD18, CD11c/CD18, CD44 were measured using monoclonal antibodies. Blood samples from eight patients undergoing open-heart surgery were taken before surgery, 1, 5, 10 and 20 min after aortic clamping, and then 1, 5, 10 and 20 min and 1, 2 and 3 h after declamping. Samples from eight patients undergoing abdominal surgery were taken before surgery, at the end of surgery, and 2 and 3 h post-operatively. A decrease in number of granulocytes and monocytes during cardiopulmonary bypass was observed. The percentage of CD11a-positive granulocytes increased from 30% pre-operatively to 75% following cardiopulmonary bypass, while CD44-positive granulocytes increased from 5% to 13%. Despite the extent of the changes, these were not significant. The oxidative burst of the granulocytes and monocytes decreased after declamping to 15% and 27% of initial values in vitro. Several hours after surgery, there was no significant difference between the two groups. These results can be explained by a granulocyte and monocyte refractory response developing subsequent to an increased per-operative oxidative burst activity, and the induction of adhesion molecules on granulocytes associated with the cardiopulmonary bypass and surgery. In conclusion, open-heart surgery with cardiopulmonary bypass was associated with a rapid and pronounced activation of leukocytes which may play a role in reperfusion injury.

Haemolysis following rapid experimental red blood cell transfusion--an evaluation of two infusion pumps

BACKGROUND

The vast majority of infusion pumps used for rapid transfusion of large amounts of blood have never been properly examined regarding their influence on the quality of the red blood cells (RBCs) infused. In this study, we evaluated the effect of two different infusion pumps on the degree of RBC destruction following rapid experimental blood transfusion.

METHODS

Divided into 2 groups according to age, 30 u of SAGM RBCs were infused through an experimental transfusion model by either a manual roller pump (MRP) or a pressure infusor pump (PIP). Fresh (i.e stored for 8-11 d) RBCs, 20 u, and 10 u of older (i.e. stored for 25-33 d) RBCs were randomly allocated to infusion with either of the two pumps. The rate of infusion was as fast as possible with the MRP, and with the PIP adjusted with an external applied pressure of 300 mm Hg. RBC samples collected before and after infusion were analyzed for total haemoglobin, free haemoglobin, haematocrit, total free potassium, lactate dehydrogenase (LDH) and the percentage of haemolysis. The time spent for each transfusion was measured by a stop watch.

RESULTS

Following infusion, a marginal increase (i.e. considerably below 0.8%) in the percentage of haemolysis and LDH content was seen with both pumps. This increase was only statistically significant when RBCs stored for 8-11 d were used (P = 0.002 for both parameters). Irrespective of the age of the RBCs, no differences between the two pumps could be detected. Compared to the PIP, infusion with the MRP could be accomplished significantly faster, i.e. median 5.9 ml/s (5.2-6.4 ml/s) versus 2.9 ml/s (2.5-3.2 ml/s), (P < 0.0001).

CONCLUSIONS

Both the pumps used in this study are safe alternatives for rapid transfusion of RBCs; however, with MRP this can be accomplished approximately twice as fast as with the PIP.

The peri-operative cytokine response in infants and young children following major surgery

The peri-operative cytokine response was studied in 13 infants and young children undergoing major surgery. All children were anaesthetized with a combined general and epidural anaesthetic technique, followed by post-operative epidural analgesia with bupivacaine and fentanyl. Blood samples were taken before and after surgery, 24 h post-operatively, and finally, when the children were mobilized and had regained gastrointestinal function. Plasma samples were analysed for tumour necrosis factor-alpha, interleukin-1 alpha, interleukin-1 beta, interleukin-6, interferon-gamma, interleukin-10 and the interleukin-1 receptor antagonist. The cytokine responses were highly variable. Overall, no significant changes between pre- and post-operative plasma concentrations were found. Tumour necrosis factor-alpha and the interleukin-1 receptor antagonist were detectable in all children, and a trend towards an early increase in the interleukin-1 receptor antagonist levels at the end of surgery was seen. The other cytokines were only detectable at low concentrations among a minority of children. In conclusion, this study showed highly variable peri-operative cytokine responses in infants and young children undergoing major surgery.

[Persistent pulmonary hypertension in newborn infants]

On the basis of a review of the literature, a survey is presented concerning persistent pulmonary hypertension of the newborn. In this article the authors focus on the pathophysiology, diagnostic criteria and treatment, including mechanical ventilation, pharmacological vasodilation and extracorporal membrane oxygenation. Particular emphasis is placed on the treatment of the condition with inhaled nitric oxide. Nitric oxide is a selective pulmonary vasodilator and able to improve ventilation/ perfusion mismatching in cases where there is an affection of the pulmonary parenchyma. Data from randomized trials with close long-term follow-up is necessary before routine nitrogen oxide treatment can be recommended.

[Sedation and analgesia in ventilator-treated children]

Ventilator-treated children often require sedation in order to facilitate the ventilation. Sedatives alone or in combination with analgesics are commonly used for this purpose. In some cases, however, the addition of a neuromuscular blocking agent (NMB) may be necessary. In this article a survey is presented regarding both pharmacological and non-pharmacological means of improving the ventilator treatment in ventilated children. The most commonly employed sedatives, opioids and NMB's are discussed. The authors stress that whichever drug is used, it should be administered to the children guided by its effects rather than by a rigid scheme. In that respect monitoring of the treatment is important.

[Postoperative pain relief in children]

Postoperative pain management in children has been subject to increasing interest during the last decade, but is still insufficient. A survey is presented concerning postoperative pain management in children. The value of monitoring the pain as well as the opioid side effects in children is stressed, and such methods are presented. Acute Pain Service is mentioned and the most important pharmacological aspects regarding non-steroidal anti-inflammatory drugs, paracetamol, opioids and local anaesthetics are discussed. The management of postoperative pain in neonates is reviewed separately. It is concluded that the present insufficient management of postoperative pain in children is not due to the lack of methods and techniques, but rather to lack of sufficient utilization and comprehension of the possibilities. Moreover, pain management in children should be individualised. It is also necessary to be more aware of side effects of the pharmacological treatment.

Age-related postoperative morphine requirements in children following major surgery--an assessment using patient-controlled analgesia (PCA)

To investigate if small children require less morphine for postoperative analgesia than do older children and adolescents we analysed the morphine consumption pattern of 28 consecutive children on intravenous patient-controlled analgesia (PCA) following major surgery. The median age-specific morphine requirements between 2 comparable groups of children aged 4-8 years and 9-15 years were compared. We used the Pharmacia-Deltec pump in all children and the same settings: a bolus dose of 25 microgram/kg, an 8 minutes lockout interval and no background infusion. In addition, all children received paracetamol as a supplemently to the morphine. In this study children aged 4-8 years had significantly higher total postoperative morphine requirements compared to children aged 9-15 years, i.e. 11.6 microgram/kg/hour and 7.5 microgram/kg/hour respectively (p = 0.037). Hence, we conclude that children of this age group may have a higher total postoperative morphine requirement following major surgery than older children and adolescents.

Changes in lymphocyte subpopulations and adhesion/activation molecules following endotoxemia and major surgery

Major surgery as well as endotoxin-induced sepsis is accompanied by lymphocytopenia in peripheral blood. The purpose of this study was to investigate the redistribution of lymphocyte subpopulations and adhesion/activation molecules on lymphocytes. Twenty-four rats were included in the investigation. Eight rats received an intraperitoneal injection of E. coli endotoxin (2 mg kg-1), eight rats had a sham operation performed while eight rats received isotonic saline and served as a control group. Blood samples were obtained by making an incision in the tail before and 2 and 5 h after surgery or administration of endotoxin or saline. After isolation of lymphocytes by gradient centrifugation, flow-cytometric immunophenotyping was performed using CD2, CD3, CD4, CD8, CD11/CD18, CD20, CD44 and MHC II monoclonal antibodies. Endotoxemia and surgery were both accompanied by increased serum cortisol, lymphocytopenia, and a decrease in CD2, CD3 and CD4 lymphocytes. Only endotoxemia was followed by a decrease in CD8, CD11/CD18 and CD44 lymphocytes in peripheral blood. Our results show that several of the changes in lymphocyte subpopulations following surgery and sepsis are associated with increased serum cortisol. Sepsis is, in addition, accompanied by an upregulation of adhesion receptors.

Laryngeal mask airway guided tracheal intubation in a neonate with the Pierre Robin syndrome

Endotracheal intubation in infants with the Pierre Robin syndrome may sometimes be impossible to accomplish by conventional means. To aid difficult tracheal intubation many different techniques have been described. We present a case, in which we successfully intubated a small-for-date newborn boy with the Pierre Robin syndrome by using a modified laryngeal mask airway (no. 1) as a guide for the endotracheal tube. The technique is easy to perform, less traumatic and less time-consuming than multiple attempts at laryngoscopy or blind tracheal intubation.

[Severe bronchospasm in a 1-year old child treated with halothane]

A case of severe bronchospasm in a one-year old mechanically ventilated girl which in spite of maximal conventional bronchodilatory treatment only responded to halothane inhalation is presented. The benefits and limitations of this therapy are discussed.

[Bronchodilating inhalation anesthetics in bronchial asthma and status asthmaticus]

On the basis of a review of the literature, a survey is presented concerning the use of halogenated inhalational anaesthetics (halothane, enflurane, isoflurane) in anaesthesia of asthmatic patients and in intensive care units in the treatment of status asthmaticus refractory to maximal standard therapy. Particular emphasis is placed on the bronchospasmolytic, cardiovascular and organotoxic effect of the anaesthetics. It is concluded that halogenated inhalational anaesthetics are established as bronchospasmolytics, and that their use in bronchospastic disease should be individualized to the patient and his other specific disease process.

[Patient-controlled analgesia in children]

In order to introduce intravenous patient-controlled analgesia (PCA) in children in the Department of Anaesthesiology and Intensive Care, Odense University Hospital, we evaluated the technique in 13 children following major orthopaedic or abdominal surgery. The pump (Pharmacia-Deltec, CADD-PCA) was loaded with 1 mg/ml morphine in a 50 milliliters cassette. A bolus dose of 25 micrograms/kg and a lock-out interval of eight minutes were the initial settings. The morphine dose used, pain scores and side effects were currently recorded. Ages ranged from 4-15 years (mean 10.5 years) and the method was used for a mean of 89 hours (range 57-144 hours) postoperatively. Morphine requirements averaged 9.5 microgram/kg/hour (range 5.4-15.6 microgram/kg/hour). Pain control was good and side effects were few and of minor nature. PCA is an effective and safe means of providing good quality analgesia in children.

[Aorto-esophageal fistula originating from a peptic ulcer in Barrett's esophagus]

A case of an aorto-esophageal fistula originating from a peptic ulcer in a Barrett's esophagus and which ran a fatal course is presented.