An unusual cause for collapse in a patient with arthritis.

We present the clinical case of a patient who was admitted to the intensive care ward with severe central nervous system symptoms and cardiovascular collapse within a week of starting sulphasalazine; in the absence of any other diagnosis, these symptoms were felt to be due to a previously unreported adverse effect of sulphasalazine.

Hypertonic saline: A review of the literature and evaluation of its role in resuscitation of traumatic hypovolaemic shock.

Hypertonic saline solutions have properties that may be advantageous for resuscitation. In both animal and human studies rapid improvements in cardiovascular status occur when hypertonic saline is administered to hypovolaemic subjects and the possible side effects of hypertonic solutions have not been shown to be of clinical importance. Hypertonic saline certainly has a potential role in resuscitation of hypovolaemic casulaties in the modern military setting.

Quadraplegia in a patient with an undiagnosed odontoid peg fracture. The importance of cervical spine immobilisation in patients with head injuries.

A 59 year old man was found collapsed and unconscious, tracheal intubation was performed without immobilisation of the cervical spine. Examination revealed signs of spinal cord transection with quadraplegia and a lateral cervical spine radiograph showed a displaced fracture of the odontoid peg. This case reinforces the importance of appropriate cervical spine management in all victims of trauma especially those with head injuries and is particularly relevant to the military situation.

Acute respiratory distress syndrome following autotransfusion with the Biosurge autotransfuser.

A case of acute respiratory distress syndrome in a 79-year-old man is presented in which the use of a BioSurge synchronous autotransfuser may be implicated. This has not been reported before.

The effect of laryngoscopy of different cervical spine immobilisation techniques.

Fifty patients underwent laryngoscopy with two different cervical spine immobilisation techniques. First the cervical spine was immobilised in a rigid collar with tape across the forehead and sandbags on either side of the neck, then with an assistant providing manual in-line immobilisation. Finally, patients underwent laryngoscopy in the routine intubating position. In 56% of patients the view of the larynx improved by one grade and in 10% the view improved by two grades when manual immobilisation was substituted for the collar, tape and sandbags (p < 0.0001). There was a poor view on laryngoscopy (grade 3 or 4) in 64% of patients when immobilised in a collar, tape and sandbags compared to 22% of patients undergoing in-line manual immobilisation (p < 0.001). Mouth opening was significantly reduced when patients were wearing cervical collars and this was the main factor contributing to the increased difficulty of laryngoscopy in this particular form of cervical spine immobilisation. It is recommended that manual in-line immobilisation should be the method of choice for cervical spine stabilisation during tracheal intubation.

Experiences and attitudes of consultant and nontraining grade anaesthetists to continuing medical education (CME).

A questionnaire survey was sent to 164 consultant anaesthetists with the aim of investigating their experiences and attitudes to continuing medical education. The response rate was 79%. Most anaesthetists were motivated to achieve the required number of credits and for the majority of anaesthetists, regional, national and internal departmental discussion meetings were the mainstay of educational activities. The educational standard of available activities could be improved to include more workshop-style learning opportunities and to make journal reading a creditable continuing medical education activity. The place of research is questioned. There was doubt as to whether sanctions such as withdrawing recognition for training should be imposed on departments where some anaesthetists fail to achieve the required number of credits and whether this would motivate anaesthetists to achieve the set standards. Continuing medical education was felt to be effective and the main barriers to attending educational activities are discussed.

The effects of sevoflurane on cerebral hemodynamics during propofol anesthesia.

UNLABELLED: We investigated the cerebral hemodynamic effects of 0.5 and 1.5 minimum alveolar anesthetic concentration (MAC) sevoflurane during propofol anesthesia in 10 patients undergoing supratentorial tumor resection. All patients received a standardized anesthetic, and their lungs were ventilated with a mixture of air and oxygen to produce mild hypocapnia. Anesthesia was then maintained with a propofol infusion. Muscle relaxation was obtained by infusion of atracurium. A transcranial Doppler probe was used to measure red cell flow velocity in the right middle cerebral artery (Vmca). A right-sided jugular bulb catheter was inserted for sampling of jugular bulb blood. After a 30-min period of stabilization and before the start of surgery, baseline arterial and jugular bulb blood samples were drawn to define the arterial-venous oxygen content difference (AVDO2). Mean arterial pressure and Vmca were recorded. Sevoflurane (0.5 and 1.5 MAC) in oxygen/air was then administered, and all measurements were repeated. Administration of sevoflurane at 0.5 MAC did not change Vmca or AVDO2. Sevoflurane (1.5 MAC) did not change Vmca. There was an approximately 25% reduction in AVDO2 (P < 0.05). This suggests that during propofol anesthesia, although 1.5 MAC sevoflurane does not increase red blood cell velocity, there is a relative increase in flow with respect to metabolism. Administration of large-dose sevoflurane may be associated with a degree of luxury perfusion. IMPLICATIONS: We investigated the cerebral hemodynamic effects of sevoflurane in patients undergoing neurosurgery. Small-dose sevoflurane (1%) did not change brain blood flow or oxygen consumption. Large-dose sevoflurane (3%) did not change flow velocity but reduced brain oxygen consumption by 25%. Sevoflurane may provide a degree of luxury perfusion.

Establishing the timing of implantation in the Harlan Porcellus Dutch and New Zealand White rabbit and the Han Wistar rat.

The purpose of this study was to establish the timing of the onset of implantation in both the Harlan Porcellus Dutch and New Zealand White rabbit and the Han Wistar rat. Implantation was initiated on Day 5 (rat) and 7 (rabbit) and established by Day 7 and 8 of gestation in the rat and rabbit, respectively. Recent guidelines on toxicity testing during embryo-fetal development studies require that maternal exposure to pharmaceutical compounds does not occur until after implantation has taken place. In order to ensure that this is the case, female Harlan Porcellus Dutch and New Zealand White rabbits and Han Wistar rats were sacrificed on different days of gestation, over the expected periods of implantation. The presence of preimplantation blastocysts in the uterus was investigated, and evidence of established implantation sites was assessed.

Fracture of the cricoid cartilage after Sellick's manoeuvre.

We report a case of fracture of the cricoid cartilage associated with cricoid pressure during rapid sequence tracheal intubation in a patient with status asthmaticus. This patient had a history of laryngeal trauma 48 yr previously. Fracture of the cricoid cartilage has not been reported previously after cricoid pressure.

A study of laryngeal mask inflation. Pressures exerted on the pharynx.

Laryngeal mask airway cuff inflation pressures were measured when inflated with the same volume of gas firstly in free space and then in position in the pharynx. A large difference in these pressures was observed and this was related to pharyngeal mucosal perfusion pressure. This study shows that it may be easy to produce pressures on the pharyngeal mucosa in excess of the critical perfusion pressure and thus potentiate mucosal trauma. Furthermore, laryngeal mask cuff pressures were measured at intervals during anaesthesia and were found to rise by a significant amount if room air was used as the cuff inflating gas. This effect could, however, be reversed if inspired gas was used to inflate the mask cuff. We conclude that care must be taken when inflating the laryngeal mask cuff if postoperative morbidity is to be avoided and also that it may not be necessary to use as high a volume of inflating gas as has been recommended during spontaneous respiration.

Nitrous oxide reduces the cost of intravenous anaesthesia.

One hundred and one women (ASA grades I and II) were anaesthetized for routine gynaecological surgery using an intravenous (i.v.) anaesthetic technique combining propofol and alfentanil. The patients were allocated randomly into groups. Group one received 33% oxygen in nitrous oxide and group two received 33% oxygen in air (total i.v. anaesthesia). The group receiving nitrous oxide required significantly less (P < 0.05) of the propofol and alfentanil mixture to maintain anaesthesia and this was found to reduce the mean cost of anaesthesia by 1.70 pounds, (P < 0.05). There was no significant difference in the incidence of postoperative complications between the two groups. We suggest that nitrous oxide may be used to reduce the cost of total i.v. anesthesia with propofol and alfentanil without causing any increase in post-operative morbidity in patients undergoing routine gynaecological surgery.

Direct cerebral vasodilatory effects of sevoflurane and isoflurane.

BACKGROUND: The effect of volatile anesthetics on cerebral blood flow depends on the balance between the indirect vasoconstrictive action secondary to flow-metabolism coupling and the agent's intrinsic vasodilatory action. This study compared the direct cerebral vasodilatory actions of 0.5 and 1.5 minimum alveolar concentration (MAC) sevoflurane and isoflurane during an propofol-induced isoelectric electroencephalogram. METHODS: Twenty patients aged 20-62 yr with American Society of Anesthesiologists physical status I or II requiring general anesthesia for routine spinal surgery were recruited. In addition to routine monitoring, a transcranial Doppler ultrasound was used to measure blood flow velocity in the middle cerebral artery, and an electroencephalograph to measure brain electrical activity. Anesthesia was induced with propofol 2.5 mg/kg, fentanyl 2 micro/g/kg, and atracurium 0.5 mg/kg, and a propofol infusion was used to achieve electroencephalographic isoelectricity. End-tidal carbon dioxide, blood pressure, and temperature were maintained constant throughout the study period. Cerebral blood flow velocity, mean blood pressure, and heart rate were recorded after 20 min of isoelectric encephalogram. Patients were then assigned to receive either age-adjusted 0.5 MAC (0.8-1%) or 1.5 MAC (2.4-3%) end-tidal sevoflurane; or age-adjusted 0.5 MAC (0.5-0.7%) or 1.5 MAC (1.5-2%) end-tidal isoflurane. After 15 min of unchanged end-tidal concentration, the variables were measured again. The concentration of the inhalational agent was increased or decreased as appropriate, and all measurements were repeated again. All measurements were performed before the start of surgery. An infusion of 0.01% phenylephrine was used as necessary to maintain mean arterial pressure at baseline levels. RESULTS: Although both agents increased blood flow velocity in the middle cerebral artery at 0.5 and 1.5 MAC, this increase was significantly less during sevoflurane anesthesia (4+/-3 and 17+/-3% at 0.5 and 1.5 MAC sevoflurane; 19+/-3 and 72+/-9% at 0.5 and 1.5 MAC isoflurane [mean +/- SD]; P<0.05). All patients required phenylephrine (100-300 microg) to maintain mean arterial pressure within 20% of baseline during 1.5 MAC anesthesia. CONCLUSIONS: In common with other volatile anesthetic agents, sevoflurane has an intrinsic dose-dependent cerebral vasodilatory effect. However, this effect is less than that of isoflurane.

Blood pressure changes in head-injury patients during pre-hospital anaesthesia with propofol.

Intubation at the site of accident is often necessary for patients who have sustained significant head injuries. Propofol can attenuate the hypertensive response to intubation, and cause hypotension in anaesthetic doses which can be greatly exaggerated in hypovolaemic patients. We studied nine patients with isolated head injuries and 11 multiply injured patients with associated head injuries. Patients were resuscitated and then intubated with a small dose of propofol, titrated to ensure unconciousness, and then suxamethonium. In neither group was there a statistically significant fall in blood pressure afterwards although the multiply injured patients tended have greater falls. We conclude that propofol used thus does not cause clinically important hypotension in these potentially unstable patients, but only doctors with suitable anaesthetic and pre-hospital experience should attempt it.