Intraoperative fluid therapy in neonates

The evidence base for the administration of intraoperative fluids in neonates is poor and extrapolated from adults and children. Differences from adults and children in physiology and anatomy of neonates inform our practice.Keywords: fluid responsiveness, fluid therapy, intraoperative, neonate

A patient's experience of a new post-operative patient-controlled analgesic technique

A patient underwent major spinal surgery, twice within a 3 week period. On the first occasion his post-operative pain was managed by conventional morphine patient-controlled analgesia (PCA). After the second procedure his pain was managed by a patient-controlled computer-assisted titration of alfentanil. This provided the opportunity to compare the efficacy of these two drug regimens in the same subject. The results showed comparable quality of analgesia and sedation and similar effects on respiration. However, the patient expressed a preference for morphine PCA.published_or_final_versio

Peri-operative administration of rectal diclofenac sodium. The effect on renal function in patients undergoing minor orthopaedic surgery

In a randomized, double-blind study, we administered placebo and diclofenac sodium 100 mg suppositories 1 h pre-operatively and on the first post-operative morning to 22 adult patients undergoing minor orthopaedic surgery. A standardized post-operative intravenous fluid regimen was instituted until oral fluids were tolerated. Renal function was assessed pre-operatively, and on the first and second post-operative days by the measurement of urine output, creatinine, urea, sodium, potassium and NAG (N-acetyl-b-D-glucosaminidase) levels and serum creatinine, urea, sodium and potassium concentrations. On the first postoperative day, the diclofenac group demonstrated a reduced urinary sodium excretion. On the second postoperative day, a reduced urinary NAG/creatinine ratio was observed in the diclofenac group when compared to placebo. We conclude that peri-operative administration of diclofenac causes changes in renal function consistent with prostaglandin inhibition on the first post-operative day but had no lasting adverse effects in this group of patients. Our results reinforce the need for caution when administering this drug in the context of pre-existing renal impairment.published_or_final_versio

The effect of premedication on oxygen saturation during the post-premedication period in 20 Chinese children undergoing elective surgery

Peri-operative continuous pulse oximetric data were studied in healthy Chinese children randomly allocated to receive either pethidine 1 mg kg-1 and atropine 0.02 mg kg-1 intramuscularly 90 min prior to surgery (n=10), or midazolam 0.5 mg kg-1 and atropine 0.02 mg kg-1 orally, 120 min before surgery (n=10). Data were collected during the night before surgery, after premedication and for 8h post-operatively. The pulse oximeter (Nellcor N-200E) output was retrospectively evaluated using Satmaster(®), a computer programme which permits storage, retrieval, signal evaluation and compilation of oximetric data. There was no significant difference in the frequency, duration, or magnitude of desaturation episodes recorded during the post-premedication period compared to the desaturation episodes which occurred in the same child during normal sleep, on the night before surgery. Furthermore, there was no significant difference in the desaturation data between the two premedicant regimens. No child recorded a genuine desaturation less than 80% for longer than 15s at any time during the study. Neither regimen significantly depressed saturation in otherwise healthy children presenting for minor surgical procedures.published_or_final_versio

The provision of NHS health checks in a community setting: an ethnographic account

Background: The UK National Health Service Health Checks programme aims to reduce avoidable cardiovascular deaths, disability and health inequalities in England. However, due to the reported lower uptake of screening in specific black and minority ethnic communities who are recognised as being more at risk of cardiovascular disease, there are concerns that NHS Health Checks may increase inequalities in health. This study aimed to examine the feasibility and acceptability of community outreach NHS Health Checks targeted at the Afro-Caribbean community. Methods: This paper reports findings from an ethnographic study including direct observation of four outreach events in four different community venues in inner-city Bristol, England and follow up semi-structured interviews with attendees (n = 16) and staff (n = 4). Interviews and field notes were transcribed, anonymized and analysed thematically using a process of constant comparison. Results: Analysis revealed the value of community assets (community engagement workers, churches, and community centres) to publicise the event and engage community members. People were motivated to attend for preventative reasons, often prompted by familial experience of cardiovascular disease. Attendees valued outreach NHS Health Checks, reinforcing or prompting some to make healthy lifestyle changes. The NHS Health Check provided an opportunity for attendees to raise other health concerns with health staff and to discuss their test results with peers. For some participants, the communication of test results, risk and lifestyle information was confusing and unwelcome. The findings additionally highlight the need to ensure community venues are fit for purpose in terms of assuring confidentiality. Conclusions: Outreach events provide evidence of how local health partnerships (family practice staff and health trainers) and community assets, including informal networks, can enhance the delivery of outreach NHS Health Checks and in promoting the health of targeted communities. To deliver NHS Health Checks effectively, the location and timing of events needs to be carefully considered and staff need to be provided with the appropriate training to ensure patients are supported and enabled to make lifestyle changes

Use of two oximeters to investigate a method of movement artefact rejection using photoplethysmographic signals

Oxygen haemoglobin saturations and plethysmograph signal amplitudes were recorded from two oximeters placed on the fingers and toes of 10 patients undergoing oesophagectomy, to assess a method of removing motion artefact from saturation recordings. By examining changes in the plethysmograph amplitude that preceded changes in saturation, episodes of desaturation caused by movement artefacts were removed from the data. The reliability of the method was then determined by scrutinizing two concurrent oximetric profiles from each patient. A total of 1600 h of data were evaluated. Desaturations occurring contemporaneously in both oxygen saturation profiles were presumed genuine, whereas a desaturation occurring in only one of the profiles was classified as artefactual. Our method had a sensitivity of 96%, a positive predictive power of 98% and a specificity of 60%. We modified the method to increase specificity and re-evaluated our data. We found that a useful increase in specificity was associated with a considerable decline in sensitivity.link_to_subscribed_fulltex

The Finapres 2300e finger cuff. The influence of cuff application on the accuracy of blood pressure measurement

Blood pressure measurements associated with malapplication of a finger cuff were compared with contemporaneous intra-arterial pressure data in seven volunteers to determine the influence of cuff application on the accuracy of the Finapres 2300e. Systolic readings in all cuff positions differed from arterial line data by more than the recommended standard and tight and loose cuff applications under and over-read respectively, in all subjects. The results show the Finapres to be sensitive to small degrees of finger cuff malapplication which contribute to the bias on direct arterial comparison and limit the reliability of the instrument in clinical practice.link_to_subscribed_fulltex

Preoperative and postoperative oxygen saturation in the elderly following spinal or general anaesthesia - An audit of current practice

We have compared the incidence of preoperative and postoperative oxygen desaturation in 20 elderly patients undergoing dynamic hipscrew insertion for fractured neck of femur allocated randomly to two groups to receive subarachnoid anaestnesia (SA n=10) or a general anaesthetic (GA n=10). Oximetry data were recorded during the preoperative night and the first 48 hours after surgery using Satmasfer(®). Data associated with zero amplitude signal were automatically invalidated by the software and decreases in SpO 2 which were preceded by contemporaneous changes in signal amplitude which conformed to a previously described template were assumed to be artefactual and were discarded from final data analysis. Data demonstrated a wide interpatient variability. However those patients who desaturated preoperatively continued to do so in the postoperative period. The differences between the preoperative and postoperative oximetry profiles were examined for each patient and demonstrated a significantly longer time spent with SpO 2<90% in the CA group compared with the SA group in all the recorded time periods except on the day of surgery. The SA group showed an improvement in oxygen saturation postoperatively when compared to the preoperative night spending less time with an SpO 2<85%. We conclude that the subarachnoid anaesthetic technique was associated with a lower incidence of postoperative oximetry desaturation when compared with general anaesthetic for these elderly patients undergoing repair of fractured neck of femurlink_to_subscribed_fulltex

Premedication with oral midazolam in children - An assessment of psychomotor function, anxiolysis, sedation and pharmacokinetics

We studied 30 children, aged 4 to 12 years, undergoing elective circumcision, premedicated with midazolam 0.5 mg.kg-1 and atropine 0.02 mg.kg-1 by mouth. A modified postbox test and the coding component of the Wechsler intelligence scale (WISC-R) was used to assess the preoperative effect of premedication on psychomotor function. Mood and sedation were also scored and related to serum midazolam concentrations. The children showed a significant decline in psychomotor performance 30 and 60 minutes after premedication when compared with their best unmedicated performance recorded the previous evening. This decline in psychomotor performance was only weakly associated with serum midazolam concentrations (r = 0.1). The postbox toy ratio is a suitable measurement of psychomotor performance in children because of its simplicity and ease of use in the clinical environment, although it may suffer the 'test-retest' limitations of similar types of assessment. The sedative and anxiolytic effects of midazolam provide a quiet environment for a smooth induction of anaesthesia.link_to_subscribed_fulltex

A comparison of three induction agents in paediatric anaesthesia - Cardiovascular effects and recovery

We studied 30 children undergoing circumcision randomly allocated to receive either thiopentone 4 mg.kg-1, propofol 2.5 mg.kg-1 or midazolam 0.5 mg.kg-1 (n = 10) IV over 30 seconds at induction of anaesthesia. Blood pressure and pulse rate during the first 15 minutes of induction were recorded by a Finapres 2300e and a Cardiocap CM-104, and changes from preinduction baseline compared between the three induction agents and the two recording instruments. Postoperatively, blood levels of the induction agents were measured and recovery from anaesthesia was assessed by clinical criteria, mood and sedation scores and psychomotor performance. The Cardiocap data revealed no statistically significant haemodynamic differences between the three induction agents. Finapres data demonstrated that propofol caused a greater decrease in mean arterial pressure when compared to thiopentone at one minute (P = 0.01) and the MAP remained significantly lower than midazolam at five minutes (P = 0.02), illustrating an advantage of continuous over intermittent non-invasive blood pressure monitoring. The midazolam group took longer to identify themselves compared to both the propofol (P = 0.005) and the thiopentone groups (P = 0.02), but there was no difference in the groups in time to eye-opening. Psychomotor performance on awakening was significantly worse in the midazolam group compared to the propofol (P < 0.03) and thiopentone groups (P < 0.02). Most children had recovered to 80% of their best, practised, unmedicated, preoperative performance four hours after awakening, irrespective of the induction agent administered. Drug blood levels correlated weakly with both methods of psychomotor assessment (r ≥ 0.6). Of the three induction agents, thiopentone caused the least haemodynamic perturbation on induction, and anaesthesia induced with midazolam caused the greatest psychomotor impairment on awakening. Within one hour patients in all drug groups were equally awake, co-operative and co-ordinated.link_to_subscribed_fulltex