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Biomedical subjects

M A Stokes

Publications and source records attributed to M A Stokes.

At least 19 recordsLinked to original sources
PubMed2003

Quality in paediatric anaesthesia: a pilot study of interdepartmental peer review.

A pilot to assess a process of interdepartmental peer review of paediatric anaesthetic departments in the United Kingdom was undertaken. Departments were assessed in relation to the standards which should characterise anaesthetic departments throughout the country. Examples of good practice and areas for further development were identified. Peer review visits were conducted by teams which included medical and non-medical members. The importance of the inclusion of lay people in such visits is being increasingly recognised. All of those who participated in the process felt their time had been usefully spent, and they were enthusiastic for the process to continue.

Anesthesia↗
PubMed2001

The effect of repeated pulses of light at the same time on period responses of the rat circadian pacemaker.

A consequence of simple velocity-based models is that, in response to light pulses, the circadian period should adjust inversely to phase. In addition, because of the interaction of circadian period and phase response, earlier circadian period changes should modify later circadian period changes. The literature contains few mentions of response curves of circadian period responses following light pulses. Rats were exposed to four pulses of light (60 minutes, 1000 lux) at the same circadian time, a minimum of 26 days apart; we assessed period responses and possible bias in the period-response curve. Modulation of circadian period following light-induced phase responses was examined by assessing the period of running wheel activity onset. Phase and circadian period were not consistently found to share an inverse relationship. Moreover, biases in initial period tended to be increased by the experimental protocol regardless of circadian time of pulse. Rats with a short initial (high-velocity) period had a lengthened period, while rats with a long initial period (low velocity) tended to have a reduce period. However, rats with a long initial period were phase delay biased, not phase advance biased. These results do not support a simple velocity model of the pacemaker.

Animals↗
PubMed2000

Nodal rhythm and bradycardia during inhalation induction with sevoflurane in infants: a comparison of incremental and high-concentration techniques.

We studied heart rate and rhythm changes during sevoflurane inhalation induction in 60 healthy, unpremedicated infants. Patients were allocated randomly to receive an incremental (2% sevoflurane, increased every four to six breaths by 2% increments, to 8%) or high-concentration induction technique (8% sevoflurane from the outset). The ECG was recorded for 330 s (30 s pre- and 300 s postinduction) using a mini-Holter device (Recollect Dual Channel, Hertford Medical) and later analysed by an independent observer. Twelve patients developed nodal rhythm (six in each group), but no other dysrhythmias were recorded. The onset of nodal rhythm was associated with bradycardia (< 80 bpm) in seven out of 12 cases, and occurred significantly earlier in the high-concentration group (median 123 (range 99-139) s versus 164 (127-138) s). Its duration was similar in both groups (62 (2-84) s versus 90 (20-167) s). These findings highlight the importance of using continuous ECG analysis when studying volatile anaesthetic agents in young children.

Anesthesia, Inhalation↗
PubMed1999

Bladder exstrophy in a neonate at risk of transient myasthenia gravis: a role for remifentanil and epidural analgesia.

Infants born to mothers with myasthenia gravis may exhibit a transient form of the disease, with similar sensitivity to non-depolarizing neuromuscular blocking drugs. We report the case of an infant at risk who required major surgery when 48 h old for closure of bladder exstrophy. A combined epidural-general anaesthetic technique, with remifentanil supplementation, enabled us to avoid unnecessary neuromuscular blocking drugs and prolonged intensive care, which had been anticipated. The potential benefits of remifentanil and epidural analgesia in neonates are discussed.

Analgesia, Epidural↗
PubMed1999

The effect of multiple pulses of light on the circadian phase response of the rat.

Multiple pulses of light administered to humans have been reported to result in type 0 phase responses. These results suggest the underlying pacemaker to be nonsimple. At present, results with this type of protocol have only been reported for humans. Therefore, multiple pulses of light were administered to rats. Rats were exposed to one, two, three, or four pulses of light for 5 h (1000 lux) at successive 24-h intervals. Results did not suggest a type 0 phase response. Nonetheless, results with a second, third, or fourth light exposure were not fully predictable from a phase response curve derived from a single light pulse.

Animals↗
PubMed1998

Children who withdraw consent for elective surgery.

Parents and legal guardians have authority to consent to medical treatment on behalf of minors. Recently, the concept of emerging competence has been popularized, whereby a child may achieve sufficient understanding and maturity to enable him/her to make a wise choice in his/her own interests. Although there are undoubted merits in involving children in their medical treatment, the ultimate legal authority for consent rests with parents and guardians acting on the advice of doctors and in the child's best interests. We describe two cases in which children withdrew their consent to elective surgery, despite the help and encouragement of their parents and doctors. Surgery was cancelled rather than use force to induce anaesthesia. In practice, it seems that a child must demonstrate a greater maturity and understanding to refuse medical treatment than to agree to it. Some advice is given to clinicians facing similar situations.

Adolescent↗
PubMed1996

Pathological changes associated with short-term nasal intubation.

In order to define the incidence and anatomical site of nasal damage following nasotracheal intubation, we investigated 100 consecutive patients undergoing dental extractions under general anaesthesia. Patients were questioned pre-operatively about the physiological function of their noses and examined by anterior rhinoscopy for anatomical abnormalities. Examinations were repeated postoperatively, looking specifically for haemorrhage, mucosal tears and septal and turbinate disruption. Minor bruising was common (54%) and most frequently involved mucosa overlying the inferior turbinate and adjacent septum. In two cases bruising involved the middle turbinate. There was no relationship between the number of attempts at intubation and subsequent damage. Pre-operative otolaryngological assessment failed to identify those patients who subsequently proved difficult or impossible to intubate nasally and incorrectly predicted difficulty in 11 patients who had pre-existing deviation of the nasal septum. In conclusion, short-term nasotracheal intubation was not associated with significant nasal morbidity, and pre-operative anatomical assessment failed to identify those in whom nasal intubation proved difficult or impossible.

Adolescent↗
PubMed1996

Routine suxamethonium in children. A regional survey of current usage.

This survey aimed to assess the extent and pattern of use of suxamethonium for elective tracheal intubation in children and the occurrence of major complications. A postal questionnaire was sent to 280 consultant anaesthetists and senior registrars in the West Midlands Region. Of the 180 replies received, 84% of respondents use suxamethonium routinely. Usage was more common amongst those more recently trained (all anaesthetists with less than 10 years experience reported using suxamethonium for routine intubation compared with 81% of those with over 20 years experience). Reported side effects directly attributable to suxamethonium were common, the most frequent being cardiac arrhythmias (especially bradycardia) following the first dose (24% respondents) or the second dose (43%), and prolonged apnoea (36% of respondents). There were 13 reported cardiac arrests (requiring external cardiac massage), three of which were associated with repeat dosing and one with undiagnosed Duchenne muscular dystrophy. Three cases of documented hyperkalaemia did not lead to cardiac arrest. There were two deaths, neither of which could be solely attributed to the use of suxamethonium. We conclude that suxamethonium remains popular in paediatric practice and that minor side effects are common and usually preventable. Life-threatening reactions are rare and until a truly comparable alternative is produced this drug will continue to be used in children.

Adolescent↗
PubMed1995

Cardiorespiratory effects of laparoscopy with and without gas insufflation.

BACKGROUND: Patients who are undergoing laparoscopic procedures can present with a number of ventilatory and circulatory problems. The use of a gasless technique for performing a laparoscopy by using a mechanical lifting device may potentially avoid such problems. OBJECTIVE: To compare the cardiorespiratory effects of laparoscopy with and without gas insufflation. METHODS: Twelve adult pigs were randomized to undergo a laparoscopy by using either carbon dioxide insufflation or mechanical elevation. Full invasive monitoring was performed preoperatively and at 10-minute intervals throughout the operative period. Parameters that were measured included blood gas determinations, mean arterial pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac output, stroke volume, and total peripheral resistance. RESULTS: Carbon dioxide insufflation unlike mechanical elevation led to a fall in PO2 and absorption of a significant quantity of CO2, resulting in hypercapnia, acidosis, and a consequent hyperdynamic circulation. CONCLUSION: These findings have significant implications for the use of CO2 insufflation for laparoscopy in patients with a compromised respiratory or cardiac status.

Animals↗
PubMed1995

Anesthesia for stereotactic radiosurgery in children.

The development of stereotactic radiosurgery has been a major advance in the treatment of intracranial lesions. By using a stereotactic head frame attached to the skull, large doses of radiation can be delivered precisely to the lesion while sparing surrounding tissues. Although adults can usually undergo this procedure with local anesthesia or conscious sedation alone, children frequently require general anesthesia. This report describes our experience with the anesthetic management of all children who have received this therapy at our institution since the inception of our stereotactic radiosurgery program in 1986 through June 1993. Sixty-eight radiosurgery procedures were performed in 65 patients. Anesthesia time averaged 9.2 h (range, 7-15). Twenty-two patients (ages 11-17; mean 14.3) received local anesthesia alone, two patients (ages 11 and 15) received local anesthesia plus i.v. sedation, and 44 patients (ages 2-14; mean, 7.3) received general anesthesia. Four potentially serious anesthesia-related events occurred; in one child (age 7) receiving general anesthesia, an endotracheal tube obstruction developed during radiosurgery requiring rapid reintubation while the child was still in the head frame; another (age 7) who was undergoing chemotherapy and had neutropenia and rhinitis had a lobar collapse while intubated, requiring mechanical ventilation and endotracheal tube suctioning for lung expansion. Another (age 5) with a recent upper respiratory tract infection had copious endotracheal secretions and sinusitis (ethmoid and maxillary) noted on initial computed tomography scanning and was given antibiotics and decongestants (following nasotracheal extubation), and another (age 15) receiving sedation without endotracheal intubation vomited an undigested meal midway through the procedure while her head was partially immobilized in the head frame.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Nitric oxide in the management of persistent pulmonary hypertension of the newborn--an unusual cause of failure.

A diagnosis of persistent pulmonary hypertension of the newborn should be reviewed if there is a failure to respond to appropriate treatment. We report a case in which both conventional therapy and inhaled nitric oxide failed to break the cycle of right-to-left shunting. Reassessment revealed a massive pulmonary arteriovenous malformation for which surgery was successfully performed in the neonatal period.

Administration, Inhalation↗
PubMed1994

A season of football injuries.

All rugby and soccer players presenting to the Accident & Emergency department during the football season 1992-1993 (a total of 871) were prospectively studied to compare the injuries sustained in the two sports. The nature and site of injury, treatment required, age, fitness, experience and position of the player, situation giving rise to injury, and medical attention at the grounds were all analysed. The results show that rugby and soccer players had the same number of injuries, and while there were some differences in the nature of the injuries, there was no difference in overall severity. Rugby flankers and soccer goalkeepers are particularly at risk. Competitive matches produce more injuries than training sessions. Experience or fitness did not appear to be a factor and 45% of rugby injuries and 15% of soccer injuries were from school matches. Law changes (e.g. the rugby scrum and the use of gum-shields) have reduced some injuries, but other areas (e.g. jumping for the ball in soccer, rucks and mauls in rugby) also warrant consideration. There was one death, but no spinal cord injuries. Medical attention at the grounds was limited. Rugby injuries, therefore, do not appear to be more numerous or severe than soccer injuries. Law changes have been of benefit but they need to be enforced and perhaps more should be considered. Medical attention at sports grounds could be improved and Registers of injuries kept by the sporting bodies would be of benefit.

Adolescent↗