Prophylactic use of midazolam or propofol at the end of surgery may reduce the incidence of emergence agitation after sevoflurane anaesthesia.

Sevoflurane is associated with a high incidence of emergence agitation in children. Midazolam and propofol have been examined with the aim of reducing emergence agitation after sevoflurane anaesthesia. However the effect of both drugs on emergence agitation is still controversial. Therefore we designed this study to measure the effect of midazolam or propofol at the end of surgery on emergence agitation during the recovery period. One hundred and one children, aged one to 13 years, undergoing strabismus surgery were enrolled in this randomised double-blind study. Anaesthesia was induced and maintained with sevoflurane in N2O/O2. Children were randomly assigned to receive midazolam 0.05 mg/kg (group M, n = 35), propofol 1 mg/kg (group P, n = 31) or saline (group S, n = 35). A four-point scale was used to evaluate recovery characteristics upon awakening and during the first hour after emergence from anaesthesia. The incidence of emergence agitation in group M was 42.9% (15/35), in group P 48.4% (15/31) and in group S 74.3% (26/35). The incidence of emergence agitation in groups M and P was significantly less than in group S. The emergence time was prolonged for patients in groups M and P compared to group S. There was no significant difference in the incidence of emergence agitation or in emergence times between the groups P and M. We conclude that propofol or midazolam administration before the end of surgery may be effective in reducing the incidence of emergence agitation in children undergoing strabismus surgery under sevoflurane anaesthesia.

Control of the haemodynamic response to surgical stimuli in semi-closed circuit or closed circuit anaesthesia using a multifunctional anaesthesia system.

This study compared the ability of the Zeus multifunctional anaesthesia system to control haemodynamic response to surgical stimulation in semi-closed (SCA) or closed circuit anaesthesia (CCA) modes. Fifty patients undergoing gynaecological surgery were randomly assigned to SCA or CCA. Anaesthesia was induced with 2 mg propofol and 0.9 mg/kg rocuronium, intravenously, and maintained using sevoflurane (minimum alveolar concentration [MAC], 1.0) using 2 l/min oxygen plus 2 l/min nitrous oxide (SCA 4 l/min group) or 50% oxygen plus 50% nitrous oxide (CCA group). An increase in mean arterial pressure (MAP) > 20% above baseline in response to surgical stimulation provoked a stepwise increase in sevoflurane (1.3 MAC and then 1.6 MAC), followed by fentanyl 1 pg/kg intravenously (rescue drug). The time required for MAP to return to within 10% of baseline was significantly shorter in the CCA group (6.4 +/- 3.6 min) compared with the SCA 4 l/min group (10.2 +/- 6.0 min). The percentage of patients requiring fentanyl was significantly greater in the SCA 4 l/min group than in the CCA group. In conclusion, CCA controlled acute haemodynamic responses to surgical stimuli more successfully and rapidly than SCA 4 l/min, using a multifunctional anaesthesia machine.

The effect of increasing operating room capacity on day-of-surgery cancellation.

Several studies have been conducted to evaluate the utilisation of the operating room, a fixed resource, in terms of conditions that prevent day-of-surgery cancellation due to deficient operative capacity. In this study, we surveyed the causes and overall rates of elective surgery cancellation and then compared the number of cancellations that occurred before and after the installation of additional operating rooms. We surveyed all patients undergoing elective surgery for 100 days prior to and after the installation of additional operating rooms. The causes for cancellations were divided into six categories: departmental issues, abnormal laboratory results, patient denial, inadequate preparation, over-booking and other issues. The departmental causes were further divided into four categories: ward overflow, scheduling date errors, unavailable surgeons and other issues. The number of overall cancelled cases and scheduled cases increased following the increase in operating room capacity, although this increase was not statistically significant. However; the cancellation ratio rose significantly after the operating room capacity was increased. The primary reasons for cancellation prior to the increase in operating room capacity were departmental issues, over-booking and abnormal laboratory data, in that order. After the operating room capacity was increased, the primary reasons for cancellation were departmental issues, abnormal laboratory data and over-booking, in that order Taken together the results of this study indicate that increased operating room capacity can prevent cancellation due to over-booking. However; the numbers of cancellations due to ward overflow exceeded the numbers of cancellations that occurred as a result of over-booking. In conclusion, increasing the operating room capacity is not an appropriate option for preventing the cancellation of operations.

Evaluation of corrected flow time in oesophageal Doppler as a predictor of fluid responsiveness.

BACKGROUND: Corrected flow time (FTc) by oesophageal Doppler is considered to be a 'static' preload index. We evaluated the ability of FTc to predict fluid responsiveness and compared this with the abilities of other preload indices, such as pulse pressure variation (PPV), central venous pressure (CVP), and left ventricular end-diastolic area index (LVEDAI). METHODS: Twenty neurosurgical patients were studied. After induction of anaesthesia, FTc, PPV, LVEDAI, CVP, and stroke volume index (SVI) were measured before and 12 min after fluid loading with 6% hydroxyethyl starch solution (7 ml kg(-1)). Responders and non-responders were defined as those patients with an SVI increase >or= 10% or < 10% after fluid loading, respectively. Pearson's correlation was used to assess correlations between changes in SVI and initial haemodynamic variables. Receiver operating characteristic (ROC) curves were constructed and compared to evaluate the overall performance of preload indices (FTc, PPV, LVEDAI, and CVP) in terms of predicting fluid responsiveness. RESULTS: FTc and PPV before fluid loading differed between responders (n = 11) and non-responders (n = 9), and correlated with changes in SVI (r = -0.515 and r = 0.696, respectively), which was opposite to that observed for CVP or LVEDAI. Areas under ROC curves for FTc [0.944 (SD 0.058)] and PPV [0.909 (0.069)] were significantly greater than those for CVP [0.540 (0.133), P < 0.001] and LVEDAI [0.495 (0.133), P < 0.001]. The optimal threshold value given by ROC analysis was 357 ms for FTc. CONCLUSIONS: In this study, FTc predicted fluid responsiveness. However, FTc should be used in conjunction with other clinical information.

Remifentanil vs. lignocaine for attenuating the haemodynamic response during rapid sequence induction using propofol: double-blind randomised clinical trial.

This study was conducted to determine whether lignocaine or remifentanil effectively attenuate the response to endotracheal intubation during rapid sequence induction. Forty-eight patients were randomly divided into three groups: Group NS (n = 16) received normal saline 0.1 ml/kg, Group L (n = 16) received lignocaine 1.5 mg/kg, and Group R (n = 16) received remifentanil 1 microg/kg. Anaesthesia was induced with propofol 2 mg/kg after glycopyrrolate 0.2 mg IV. Each study drug was given intravenously over 30 seconds after loss of consciousness. Cricoid pressure was applied until intubation. Succinylcholine 1.0 mg/kg was administered to facilitate tracheal intubation. After intubation, the patient's lungs were ventilated with sevoflurane 1% and nitrous oxide 50% in oxygen. Mean arterial pressure and heart rate were recorded before induction, at loss of consciousness, immediately before laryngoscopy and every minute after intubation for 10 minutes. Mean arterial pressure fell following propofol in all groups. The maximum increase in mean arterial pressure in Group NS and Group L were 46% and 38% respectively above the baseline value one minute after intubation, whereas the mean arterial pressure in Group R increased only back to the baseline value. Heart rate in Group NS and Group L were increased by 27% and 33% above baseline value respectively one minute after intubation, while that in Group R was increased only to the baseline value. The results indicate that remifentanil 1 microg/kg, but not lignocaine 1.5 mg/kg, effectively attenuates the haemodynamic response to endotracheal intubation during rapid sequence induction using propofol.

Depth of a central venous catheter tip: length of insertion guideline for pediatric patients.

BACKGROUND: In pediatric patients, several studies have been undertaken to establish central venous catheter (CVC) tip optimal depth. Assessments of catheter tip position using chest radiographs may be misleading, whereas transesophageal echocardiography (TEE) has been shown to accurately monitor catheter tip placement at the superior vena cava-right atrial (SVC-RA) junction. The aim of this study was to issue a guideline for ideal catheter insertion depth, from the right internal jugular vein (IJV) using TEE to confirm the position of the catheter tip at the SVC-RA junction. METHODS: Over a 6-month period, we studied 60 right internal jugular vein catheterizations in infants and children undergoing surgery for congenital heart disease. Positions of CVC tips were confirmed to be at the SVC-RA junction by TEE. Distance from the skin puncture site to the SVC-RA junction, height, weight, and age were recorded. RESULTS: Distances measured were found to be highly correlated with patient height. The following guideline allows the CVC tip to be positioned above the RA in 97.5% of patients with an accuracy of 95%: optimal depth of insertion (cm) = 1.7 + (0.07 x height) in patients whose height is between 40 and 140 cm. CONCLUSION: The model proposed for the insertion of the CVC tip in pediatric patients could be used to prevent inadvertent catheter tip placement into the atrium.

Usefulness of the carina as a radiographic landmark for central venous catheter placement in paediatric patients.

BACKGROUND: Several reports have proposed radiographic landmarks for the proper positioning of central venous catheters (CVC). The carina is one of the proposed landmarks in adults. Here, we evaluate the possibility of using the carina as a radiographic landmark for the identification of proper positioning of the CVC tip in paediatric patients. METHODS: We studied 57 right internal jugular vein catheterizations in infants and children undergoing surgery for the treatment of congenital heart disease. After placing the CVC tip at the junction of the superior vena cava and the right atrium (SVC-RA junction) via intraoperative transoesophageal echocardiography, and by taking postoperative anterior-posterior chest radiographs, we measured the longitudinal distance from the carina to the SVC-RA junction, using the Picture Archiving and Communicating System. RESULTS: The average distance between the carina and the SVC-RA junction was 1.5 cm (95% CI 1.3-1.8 cm). No catheter tip was above the carina. Although there was no particular relationship between this distance and the patient's age, height, or weight, the distance between the carina and the SVC-RA junction tended to be more variable in younger and smaller children. CONCLUSIONS: The carina can be used as a radiographic landmark for the proper CVC tip placement in paediatric patients. If the tip of the CVC is not distal to the carina the chances are minute that it is in the right atrium.

Transfusion for a patient of cis-AB blood type undergoing a redo cardiac operation.

cis-AB, a rare ABO genotype, is the result of a mutated gene resulting in dual specific hybrid enzymes. A single-point mutation reverses the specificity of human blood group B synthesizing galactosyltransferase. This may lead to misclassification in ABO grouping and adverse transfusion reactions. Recently, the authors experienced a case of a patient with cis-AB blood type undergoing pulmonary valve replacement and tricuspid valvuloplasty. We transfused the patient with Rh+ A packed red blood cell, fresh frozen plasma and platelet concentrates without any clinically significant transfusion reactions.