Outcome of patients with traumatic brain injury managed on a standardised head injury protocol.

A standardised protocol in the management of severe head injury in our hospital enables pre-determined critical care-paths and consistent treatment regimes to be instituted. In Singapore there has been no previously reported data on the outcome of severely head injured patients. Over a 6-month period, 48 consecutive patients who were enrolled in our severe head injury protocol were prospectively studied. In addition to demographic and outcome data, physiologic measurements obtained from a computerised patient information system (Carevue Hewlett-Packard 9000) were analysed to determine the mean cerebral perfusion pressure (CPP) and intracranial pressure (ICP) achieved throughout the protocol period. Median Glasgow Coma Score for all patients on admission to the protocol was 6 (range 4 to 8). The mean age was 34.46 +/- 15.03 years with a male to female ratio of 43:5. The average duration of treatment on the protocol was 110.73 hours. Initial ICP measured was 25.5 +/- 19.68 mmHg. Outcome was measured at 6 months post-injury using the Glasgow Outcome Score. Favourable outcome (GOS 4-5) was seen in 29 of 48 patients (60.4%) while 12 out of 48 (25%) had an unfavourable outcome. There was a mortality of 14.6% (7 of 48 patients). Patients who survived had a higher mean CPP (P = 0.00005), a lower initial ICP and a mean ICP (P = 0.007 and 0.0009). The use of a protocol with standardised treatment goals in the management of traumatic brain injury allows for the optimal use of limited resources and provides consistency in treatment. Good outcome is related to early aggressive resuscitation to prevent hypotension and hypoxia, prompt evacuation of surgical mass lesions and the maintenance of an adequate cerebral perfusion pressure. Our results are comparable with that reported in other established neurotrauma systems.

Fasciculations, myalgia and biochemical changes following succinylcholine with atracurium and lidocaine pretreatment.

PURPOSE: To determine the attenuation in the incidence of myalgia, fasciculations and changes in serum potassium and creatinine kinase concentrations when atracurium and lidocaine were used in combination and separately as pretreatment before succinylcholine. METHODS: In a prospective, double blind randomized study, 80 ASA 1 patients 20-50 yr were assigned to one of four groups. Anaesthesia was induced with thiopentone and fentanyl. Group C received placebo pretreatment before 1.5 mg.kg-1 succinylcholine; Group A 0.05 mg.kg-1 atracurium three minutes before; Group L, 1.5 mg.kg-1 lidocaine 30 sec before; and group AL both atracurium and lidocaine. Serum potassium five minutes after succinylcholine, and creatinine kinase 24 hr after operation were measured and the increases from preinduction values were compared. Fasciculations and postoperative myalgia at 24 and 48 hr were recorded. Patients received iv meperidine or po paracetamol for postoperative analgesia. RESULTS: The increase in serum potassium concentration (0.36 +/- 0.23 mEq.l-1) was not attenuated by any regimen (P < 0.05). The incidence of fasciculations (P < 0.05) and the increase in creatinine kinase (P < 0.01) was less in the atracurium (40%; 20.93 IU.l-1) and atracurium-lidocaine (30%; 22.85 IU.l-1) than in the lidocaine (85%; 45.01 IU.l-1) and control (100%; 56.5 IU.l-1) groups. Postoperative myalgia on Days 1 and 2 was lowest (P < 0.05) in the atracurium-lidocaine group (5%; 0%) followed by the atracurium (35%; 25%) and lidocaine (30%; 35%) groups and highest in the control (75%; 65%). CONCLUSION: Atracurium and lidocaine individually reduce postoperative myalgia, with further decrease occurring when used together.

Delivery of constant air-oxygen mixtures using a closed circle absorber system.

The aim of this study was to devise and validate a technique to deliver constant air-oxygen mixtures from a standard anaesthetic machine using only oxygen as the compressed gas source. The common gas outlet was modified to allow measured quantities of ambient air to be insufflated via a three-way attachment into a closed circle absorber system with a double-circuit collapsible bellows ventilator. During positive pressure ventilation, leakages of between 50-150 ml.min-1 occur from the circuit and nomograms of the minimal air and oxygen flow rates needed to maintain constant oxygen concentrations in the presence of the leaks were then mathematically derived. The accuracy of the nomograms was tested on three different anaesthetic machines using test lung models. There were no differences observed among the mean oxygen concentrations using the three machines. Pooled mean values (SD) of 30.65% (0.77), 51.07% (1.04) and 70.4% (0.73) were obtained for predicted inspired concentrations of 30, 50 and 70% respectively. Next, the technique was studied on 18 patients who underwent isoflurane or propofol anaesthesia (duration 40-210 min) for various surgical procedures. Pooled mean values (SD) obtained were 29.3% (1.86), 40.95% (1.65) and 50.06% (1.41) respectively for predicted oxygen concentrations of 30, 40 and 50% respectively. We conclude that this technique can be used to deliver constant air-oxygen mixtures accurately during inhalational or total intravenous anaesthesia when N2O is contraindicated but a source of compressed air is not readily available.