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Biomedical subjects

G Hocking

Publications and source records attributed to G Hocking.

18 recordsLinked to original sources
PubMed2006

Epidural abscesses.

Until recently epidural abscess was considered a rare, almost theoretical, complication of central nerve block, but anecdotal reports suggest that this is no longer the case. Thus a review of the risk factors, pathogenesis, clinical features and outcome of this condition is appropriate, the primary aim being to make recommendations on best anaesthetic practice to minimize the risk of this serious complication. A search of EMBASE(c), PUBMED(c) and MEDLINE(c) databases from 1966 to September 2004 was performed using several strategies, supplemented by reference list screening. Spontaneous epidural abscess is rare, accounting for 0.2-1.2 cases per 10,000 hospital admissions per year. Estimates of the incidence after central nerve block vary from 1:1,000 to 1:100,000. Risk factors (compromised immunity, spinal column disruption, source of infection) are present in the majority of patients, whether the condition is spontaneous or associated with central nerve block. Presentation is vague, fever and back pain usually preceding neurological deficit. Diagnosis requires a high index of suspicion and modern imaging techniques. Treatment involves early surgical drainage to prevent permanent deficit and high dose parenteral antibiotics chosen with bacteriological advice. Primary prevention depends on proper use of full aseptic precautions. Epidural abscess can be a catastrophic consequence of central nerve block. Early diagnosis will minimize permanent damage, but primary prevention should be the aim. There is a need for a large survey to indicate the true incidence to better inform the risk-benefit ratio for central nerve block.

Anesthesia, Epidural↗
PubMed2004

Comparison of plain and hyperbaric solutions of ropivacaine for spinal anaesthesia.

BACKGROUND: Preliminary work has shown that ropivacaine provides spinal anaesthesia of shorter duration than bupivacaine, and may be of particular use in the day-case setting. However, there are few data comparing the actions of plain and hyperbaric solutions of this drug. METHODS: Forty ASA grade I-II patients undergoing elective perineal surgery under spinal anaesthesia were randomized to receive 3 ml ropivacaine 5 mg ml(-1), either in plain solution or with glucose 50 mg ml(-1). The extent and duration of sensory and motor block, pulse rate, blood pressure, and time to mobilization were recorded. RESULTS: Two patients (one per group) were withdrawn because of total block failure. There were significant differences in median time to onset of sensory block at T10 (plain 10 min; hyperbaric 5 min; P<0.01), median maximum extent (plain T8; hyperbaric T4; P<0.05), and median duration of sensory block at T10 (plain 25 min; hyperbaric 115 min; P<0.001). However, median times to complete regression of both sensory (270 vs 240 min; P<0.05) and motor (180 vs 120 min; P<0.001) block were longer in the plain group. Patients therefore mobilized sooner in the hyperbaric group (218 [n=16] vs 286 min [n=17]; P<0.01). All the hyperbaric blocks were adequate for surgery, but three patients receiving plain ropivacaine required general anaesthesia. CONCLUSION: Addition of glucose 50 mg ml(-1) to ropivacaine 5 mg ml(-1) increases the speed of onset, block reliability, duration of useful block for perineal surgery, and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of L1.

Adult↗
PubMed2002

Efficacy and safety of sedation with propofol in peribulbar anaesthesia.

PURPOSE: To evaluate the efficacy and safety of a sub-anaesthetic dose of propofol for reducing patient recall of peribulbar block in eye surgery. METHODS: A retrospective analysis of patients scheduled for elective cataract extraction or trabeculectomy using peribulbar anaesthesia with an intravenous bolus of propofol to provide sedation during the administration of the block. The dose of propofol was based on age and body weight. Patients' vital signs were monitored with continuous pulse oximetry and blood pressure measurements. Efficacy of sedation was assessed by recording patient's recall of the anaesthetic block after 8-10 min. RESULTS: Data from 2043 patients were analysed. The dose of propofol used ranged from 15-75 mg. Propofol was effective in abolishing recall in 87.5% of the patients studied. Only four patients required airway support but no major systemic side effects were encountered. CONCLUSIONS: A single sub-anaesthetic dose of propofol prior to administering peribulbar block is effective in reducing recall of the injection and safe without major systemic side effects.

Adult↗
PubMed2001

Airway obstruction with cricoid pressure and lateral tilt.

We studied the effect of cricoid pressure and lateral tilt on airway patency during ventilation by facemask in a simulated obstetric setting. The lungs of 50 patients were ventilated by facemask and Guedel airway using a Nuffield Penlon 200 ventilator and Bain system with standard settings. Expired tidal volumes and peak inspiratory pressures were recorded for 10 breaths in each of four combinations: supine with no cricoid pressure, supine with cricoid pressure, 15 degrees lateral tilt with no cricoid pressure and 15 degrees lateral tilt with cricoid pressure. The timing of cricoid pressure was randomised and blinded to all observers. In both supine and tilted positions, cricoid pressure produced a reduction in tidal volume (p < 0.001) and an increase in peak inspiratory pressure (p < 0.001). Cricoid pressure with lateral tilt did not produce any additional airway obstruction to that in the supine position. Complete airway obstruction (tidal volume < 200 ml) resulted on three occasions, all with cricoid pressure applied.

Adolescent↗
PubMed2000

A single sub-anaesthetic dose of propofol to reduce patient recall of peribulbar block.

We audited a total of 1233 patients scheduled for elective cataract extraction or trabeculectomy using peri-bulbar anaesthesia. A bolus of propofol provided sedation to cover insertion of the block. During an initial two-year period we collected data on the amount of propofol used to sedate 481 patients. Multiple linear regression analysis was then used to obtain an equation to link the dose used to age and weight in those who were adequately sedated. The dose of propofol in milligrams was calculated as 56 + 0.25 x weight (kg) - 0.53 x age (yrs). We subsequently assessed the effectiveness of this formula at abolishing recall of the injections whilst not compromising the airway on a further 752 patients. This simple regime was effective at abolishing recall of the block in 78.6% of the patients studied and avoids the cost and logistic implications of more complicated drug delivery systems. Use of the formula does not significantly alter the incidence of recall compared to sedation provided by an experienced ophthalmic anaesthetist. We hope it will provide a guide for more junior anaesthetists to obtain the satisfactory sedation level that comes with experience.

Age Factors↗
PubMed1999

Battlefield analgesia: an advanced approach.

We present an advanced battlefield analgesia protocol that is designed to provide the maximum benefit for the greatest number of patients using the minimum of resources. During the development we considered logistics, drug pharmacology and safety, aetiology of the pain and the experience of the expected administrator. Analgesia is only considered after the "ABCD" criteria of the Primary Survey have been satisfied. The analgesics administered range from enteral nonopioids through to intravenous opioids based dynamically upon the Visual Analogue Score (VAS). We suggest this protocol could be used by healthcare workers who may not have been trained in acute pain management but are called to administer analgesia to the serviceman in pain.

Algorithms↗
PubMed1998

Better drug history taking: an assessment of the DRUGS mnemonic.

To improve drug history taking before anaesthesia, we have previously suggested a checklist with the mnemonic DRUGS (Doctor, Recreational, User, Gynaecological, Sensitivities). We have now tested this mnemonic in 1053 patients admitted for surgery, comparing the results with the information obtained in the original clerking. Use of the mnemonic yielded additional information in 621 patients (59%). Drugs which had gone unrecorded in routine clerking were detected in 24% of patients on medication. Of 199 patients with high alcohol intake, this feature had been recorded in only 38 (19%). Unprescribed medicines, being taken by 158, had been noted in only 31 (20%). Of women taking oral contraceptives or hormone replacement therapy, more than two-thirds had not given this information. Sensitivities had been recorded accurately in 100 patients but the mnemonic yielded relevant information in a further 85. On this evidence, use of the simple DRUGS mnemonic improves drug history taking in anaesthetic practice.

Aged↗
PubMed1998

First record of trypanosomes in Tasmanian bandicoots.

Trypanosomes were observed in 38% of blood smears from southern brown bandicoots (Isoodon obesulus) and in 10% of blood smears from eastern barred bandicoots (Perameles gunnii). This is the first record of such hemoparasites in Tasmanian marsupials. There appeared to be a statistically significant size difference between trypanosomes found in the 2 bandicoot species, suggesting the possibility of 2 distinct species of parasite. There appears to be a distinction between the trypanosomes found in our temperate Isoodon species and the tropical bandicoot. Isoodon macrurus. The use of the microhematocrit method provided an effective means for concentrating trypanosomes, whereas image analysis was a more effective method than the ocular micrometer for obtaining accurate measurements.

Analysis of Variance↗
PubMed1997

Taking a 'drugs' history.

A simple, anonymous questionnaire was used to examine the depth of drug history taken from patients by a group of junior doctors. The results showed that most who replied restricted their history to prescription medicines and smoking. We feel that this is no longer sufficient and that a drug history should be expanded to include substances such as recreational drugs and over-the-counter preparations. If an allergy is reported, detailed questioning about its nature is also important since the term is often used by patients when a true allergy does in fact not exist. We present a mnemonic which can be used as an aide memoire to the various areas of importance.

Alcohol Drinking↗
PubMed1996

Leisure and occupational physical activity and risk of colorectal adenomatous polyps.

Multiple studies have shown a protective effect for physical activity on the incidence of colorectal cancer, but few have addressed its association with incident adenomas and none have investigated its association with metachronous adenomas. We interviewed 2,001 patients undergoing colonoscopy in 3 New York City practices between 1986-1988. Of these, 298 had a first diagnosis of adenomas, 506 had normal colonoscopies, 197 had metachronous adenomas and 345 had normal colonoscopies with a past history of adenomas. Subjects were queried regarding use of moderate amounts of recreational exercise (swimming, jogging, biking, racket sports and other sports) on a regular basis, and were also asked to estimate their level of physical activity. Occupational physical activity was assessed through a blinded coding of occupational titles. After adjusting for age, years of education, body mass index, total caloric intake, dietary fiber intake, dietary fat intake and years of cigarette smoking, protective effects of borderline significance were observed among males for leisure physical activity for metachronous and incident cases. Occupational physical activity was found to be significantly protective in male incident cases. Men with increased levels of either occupational or leisure activity showed a reduction for incident and metachronous cases. No effects were observed for females. Thus, in this study, both leisure and occupational physical activity were associated with a reduced risk of incident and metachronous adenomas among men but not women.

Adenoma↗
PubMed1996

Battlefield analgesia--a basic approach.

There is a requirement for a basic approach to the provision of analgesia on the battlefield using the morphine autojet. Assuming there is cardiorespiratory stability and no contraindications to opioid therapy, morphine can be administered intramuscularly to a serviceman in pain on a 2 hourly basis provided that there are no adverse effects on the respiratory rate and degree of sedation. This proven simple approach in civilian practice has the potential to be incorporated into Battlefield Advanced Trauma Life Support (BATLS) and Combat Training Regimens (CTR).

Adult↗
PubMedDate not supplied

Umbilical cord stricture and intrauterine fetal death.

Umbilical cord stricture is an uncommon but distinctive condition associated with intrauterine fetal death. Although cases have been reported periodically since the last century, there has been considerable speculation as to whether the condition is real or a postmortem artifact. In the present study, 25 cases reported since 1925 are reviewed and 8 new cases are described. Clinically, a decrease in fetal movements is usually the only symptom during the second or third trimester of pregnancy and fetal death occurs soon after. The women's age, health, and previous history have shown no link with this condition, but a higher incidence is noted in twin pregnancies. Morphologically, most infants are macerated and an extremely narrow segment of umbilical cord is usually seen at the fetal end and rarely at the placental end or in multiple sites along the cord. Absence of Wharton's jelly, stenosis, or obliteration of cord vessels at the narrow segment and intravascular cord thrombosis are the major pathological features. The findings of this study support the view that the condition can cause fetal death and alerts both pathologists and clinicians to the important features identifying this cause of perinatal wastage.

Adult↗