Guidelines for safe transfer of the brain-injured patient: trauma and stroke, 2019: Guidelines from the Association of Anaesthetists and the Neuro Anaesthesia and Critical Care Society.

The location of care for many brain-injured patients has changed since 2012 following the development of major trauma centres. Advances in management of ischaemic stroke have led to the urgent transfer of many more patients. The basis of care has remained largely unchanged, however, with emphasis on maintaining adequate cerebral perfusion as the key to preventing secondary injury. Organisational aspects and training for transfers are highlighted, and we have included an expanded section on paediatric transfers. We have also provided a table with suggested blood pressure parameters for the common types of brain injury but acknowledge that there is little evidence for many of our recommendations. These guidelines remain a mix of evidence-based and consensus-based statements. We have received assistance from many organisations representing clinicians who care for these patients, and we believe our views represent the best of current thinking and opinion. We encourage departments to review their own practice using our suggestions for audit and quality improvement.

Decompressive craniectomy for acute disseminated encephalomyelitis.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is a rare, acute demyelinating condition. Although it usually presents in an acute or subacute manner over days, its clinical course may be rapid with symptoms and signs of severe intracerebral mass effect secondary to cerebral oedema. METHODS: Case report and literature review. RESULTS: We report a case of a patient presenting with a hyperacute course manifested by rapid loss of consciousness and focal neurological signs. Management with emergency hemicraniectomy and steroids resulted in rapid neurological improvement and minimal long-term deficit. CONCLUSIONS: We believe that only surgical decompression is likely to be life saving in similar cases of hyperacute cerebral oedema due to ADEM. The wide decompression performed was concordant with that indicated for traumatic brain swelling. Such aggressive management is vindicated by the rapid recovery shown by our patient within days of surgery and the finding of minimal neurological sequelae at 3 months.

Erroneous intracranial pressure measurements from simultaneous pressure monitoring and ventricular drainage catheters.

The objective of this report is to highlight the potential for false pressure measurements from systems that combine intracranial pressure (ICP) measurement and ventricular drainage. If the ports of the drain become blocked to the extent that they present a high resistance to cerebrospinal fluid flow, then a significant pressure gradient between the inside and outside of the catheter may be established. Thus, any intracatheter transducer will faithfully record a pressure much lower than true ICP. This holds true for catheter-tip transducers when the transducer lies inside the catheter. In the absence of flow, however, pressures will equalize; therefore, accurate measurements may be taken if the drain is temporarily closed. We model this situation and provide simulations of expected measurements in such situations; these compare well to observed clinical readings.

High dose methylprednisolone in the immediate management of acute, blunt spinal cord injury: what is the current practice in emergency departments, spinal units, and neurosurgical units in the UK?

BACKGROUND: The National Acute Spinal Cord Injuries Studies and the Cochrane Review advocate the administration of high dose methylprednisolone following acute traumatic spinal cord injury. However, controversy surrounds its use and approaches between different units are often inconsistent. METHODS: A questionnaire was sent to all emergency departments receiving major trauma and all specialist neurosurgical and spinal units in the UK to determine the current practice regarding the use of high dose methylprednisolone in the immediate management of acute, blunt spinal cord injuries. RESULTS: Of 250 emergency departments, 187 replied to the questionnaire. Twelve of the 26 departments with a neurosurgical or spinal service on site stated they received consistent advice from specialist teams. Sixty four departments had a written policy regarding the treatment of spinal injuries, which in 51 departments contained advice about the administration of methylprednisolone. Of the 128 departments who gave methylprednisolone, 88 did so only on the advice of a specialist team, with the remaining 40 giving steroids immediately on identification of the injury. Ten out of 11 spinal units replied, of whom only two advised the used of steroids. Of the 34 neurosurgical units approached, seven out of 17 responders had a policy recommending the use of steroids. Of the 10 units who did not consistently recommend the use of steroids, seven had practise that varied between consultants. CONCLUSION: Currently practice varies in the UK regarding the immediate use of methylprednisolone after spinal injury. Clear guidelines need to be established to achieve a more consistent approach.

Traumatic atlantoaxial rotatory subluxation.

Atlantoaxial rotatory subluxation should be considered in the presentation of traumatic torticollis. This case report discusses the characteristic radiographic findings and appropriate management.

Prediction of hyperkalemia in dogs from electrocardiographic parameters using an artificial neural network.

OBJECTIVE: To predict severe hyperkalemia from single electrocardiogram (ECG) tracings. METHODS: Ten conditioned dogs each underwent this protocol three times: Under isoflurane anesthesia, 2 mEq/kg/hr of potassium chloride was given intravenously until P-waves were absent from the ECG and ventricular rates decreased > or =20% in < or =5 minutes. Serum potassium levels (K(+)) were measured at regular intervals with concurrent digital storage of lead II of the surface ECG. A three-layer artificial neural network with four hidden nodes was trained to predict K(+) from 15 separate elements of corresponding ECG data. Data were divided into a training set and a test set. Sensitivity, specificity, and diagnostic accuracy for recognizing hyperkalemia were calculated for the test set based on a prospectively defined K(+) = 7.5. RESULTS: The model produced data for 189 events; 139 were placed in the training set and 50 in the test set. The test set had 37 potassium levels at or above 7.5 mmol/L. The neural network had a sensitivity of 89% (95% CI = 75% to 97%) and a specificity of 77% (95% CI = 46% to 95%) in recognizing these. The positive likelihood ratio was 3.87. Overall accuracy of this model was 86% (95% CI = 73% to 94%). Mean (+/-SD) difference between predicted and actual K(+) values was 0.4 +/- 2.0 (95% CI = -0.2 to 1.0). CONCLUSIONS: An artificial neural network can accurately diagnose experimental hyperkalemia using ECG parameters. Further work could potentially demonstrate its usefulness in bedside diagnosis of human subjects.

Minimally invasive direct cardiac massage and defibrillation.

Direct massage of the heart may be performed using a specifically designed device inserted via a limited thoracic incision. The technique is simple to perform and has been shown in experimental studies to be physiologically similar to formal open-chest cardiac massage. Preliminary human studies have been encouraging and pre-hospital and in-hospital studies are in progress. Modification of the device allows combined epicardial-transthoracic defibrillation. Energy requirements for successful defibrillation using this method are considerably lower than standard external defibrillation.

Hypertonic saline treatment of severe hyperkalemia in nonnephrectomized dogs.

OBJECTIVES: To determine whether a hypertonic saline bolus improves cardiac conduction or plasma potassium levels more than normal saline infusion within 15 minutes of treatment for severe hyperkalemia. Previously with this model, 8.4% sodium chloride (NaCl) and 8.4% sodium bicarbonate (NaHCO(3)) lowered plasma potassium equally effectively. METHODS: This was a crossover study using ten conditioned dogs (14-20 kg) that received, in random order, each of three intravenous (IV) treatments in separate experiments at least one week apart: 1) 2 mmol/kg of 8.4% NaCl over 5 minutes (bolus); 2) 2 mmol/kg of 0.9% NaCl over one hour (infusion); or 3) no treatment (control). Using isoflurane anesthesia and ventilation (pCO(2) = 35-40 torr), 2 mmol/kg/hr of IV potassium chloride (KCl) was infused until conduction delays (both absent p-waves and >/=20% decrease in ventricular rate in

Use of tube condensation as an indicator of endotracheal tube placement.

STUDY OBJECTIVE: To determine whether condensation on the inner surface of the endotracheal tube (vapor trail) is a reliable indicator of intratracheal placement. METHODS: Twenty-seven separate experiments were conducted on 10 conditioned, mongrel dogs weighing 15 to 20 kg each. After induction of anesthesia, an endotracheal tube was placed in the trachea under direct visualization. A second, identical endotracheal tube was then placed in the esophagus. An attending emergency physician, blinded to tube placement, then used a bag-valve apparatus to manually ventilate each endotracheal tube in turn. Five ventilations were performed on each tube, and the presence or absence of condensation on the inner surface of the tube was recorded. A second physician, blinded both to tube placement and to the actions of the first assessor, then repeated the ventilation and assessment of both tubes. RESULTS: Vapor trail was observed in 27 (100%) of 27 endotracheal tubes correctly placed in the trachea (95% confidence interval [CI], 90% to 100%) and in 23 (83%) of 27 tubes placed in the esophagus (95% CI, 66% to 96%). Physicians concurred in all cases. Absence of vapor trail was 15% sensitive (95% CI, 4% to 34%) for indicating incorrect (esophageal) tube placement. CONCLUSION: In this model, condensation on the inner surface of the endotracheal tube was common after placement within the esophagus. If these results are confirmed in human studies, the presence of a vapor trial should not be used as a clinical indicator of correct endotracheal tube placement.

Blunt duodenal rupture: a 6-year statewide experience.

OBJECTIVES: To characterize the incidence, presentation, diagnostic features, injury pattern, and mortality of blunt duodenal rupture. METHODS: The records of 103,864 patients entered into a state-wide trauma registry during a 6-year period were screened for the diagnosis of blunt duodenal injury. The hospital records of all patients meeting diagnostic criteria of blunt duodenal rupture from 28 trauma centers were reviewed. RESULTS: Blunt duodenal injury was identified in 206 (0.2%) patients. Thirty (14.5%) of these had full-thickness rupture of the duodenum. Of these 30 patients, 21 had been involved in motor vehicle crashes. Twenty-five presented with either abdominal pain, tenderness, or guarding on physical examination. Diagnostic peritoneal lavage was performed on 12 patients. Three patients were found to have isolated rupture of the duodenum. Computerized tomography was the primary diagnostic investigation in eighteen cases. Extravasation of contrast was noted in only two cases. Four studies were interpreted as normal. The second portion of the duodenum was most commonly injured, and there was a high incidence of associated intra-abdominal injuries. Seven patients underwent operation >12 hours after admission. Twenty-six patients survived to hospital discharge. Two deaths were caused by duodenal injury-related sepsis. CONCLUSION: Blunt rupture of the duodenum is rare. Most blunt duodenal injuries do not result in full-thickness injury. The majority of patients with duodenal rupture presented with either a history or a physical examination suggestive of intra-abdominal injury. Computerized tomography results were often negative or nonspecific. Delay in diagnosis of duodenal rupture remains common but does not appear to affect mortality. Overall mortality was lower than previously reported.

Open-chest cardiac massage without major thoracotomy: metabolic indicators of coronary and cerebral perfusion.

OBJECTIVE: To compare the coronary and cerebral perfusion achieved using a novel method of minimally-invasive, direct cardiac massage to that obtained using bimanual, open-chest cardiac massage. DESIGN: Prospective, controlled animal study with repeated measures. SETTING: University research laboratory. SUBJECTS: Large domestic swine. INTERVENTIONS: Aortic, coronary sinus, jugular venous and pulmonary artery catheters were placed. Following an equilibration period, ventricular fibrillation was induced. After 4 min of untreated ventricular fibrillation, animals underwent bimanual, open-chest cardiac massage (N = 6) or minimally-invasive, direct cardiac massage using a novel device for direct cardiac compression (N = 6). Adrenaline was administered at a dose of 1 mg intravenously every 5 min. MEASUREMENTS: Systemic metabolic parameters, (arterial PO2, PCO2 and lactate concentration) and coronary sinus and jugular venous metabolic parameters (pH, PVO2, SVO2, PVCO2 and lactate concentration) were measured and calculated (coronary sinus/jugular-arterial SVO2, coronary sinus/jugular-arterial PCO2 and lactate differences) at baseline and at 10, 20 and 30 min following induction of ventricular fibrillation. Animals were euthanised after 30 min with no attempt at defibrillation. MAIN RESULTS: Oxygen tension and oxygen saturation of coronary sinus blood declined significantly during the experimental period, but no differences were noted between treatment groups. The coronary sinus-arterial oxygen saturation difference increased during the study with no significant differences between groups. Coronary sinus PCO2 and the coronary sinus-arterial PCO2 difference increased significantly in both experimental groups during cardiac massage. No inter-group differences were noted. A similar relationship was noted in coronary sinus lactate values. The coronary sinus-arterial lactate difference displayed a positive balance at all intervals with no differences noted between group values. The oxygen tension and oxygen saturation of jugular venous blood, were reduced from baseline levels with both treatments. The jugular-arterial oxygen saturation difference increased in both groups compared to baseline values. Between group values were significantly different only at the 20 min interval. Both the jugular venous PCO2 and the jugular-arterial PCO2 gradient were elevated at all intervals, but no inter-group differences were noted. Jugular venous lactate concentration rose steadily with time in both groups. No significant increase in the jugular-arterial lactate gradient was noted at any time point. CONCLUSIONS: Minimally-invasive, direct cardiac massage provides coronary and cerebral perfusion similar to that achieved using standard open-chest cardiac massage. This method may provide a more effective substitute for standard, closed-chest cardiac massage in cases of refractory cardiac arrest.

Detection of pulmonary aspiration of gastric contents in an animal model by assay of peptic activity in bronchoalveolar fluid.

OBJECTIVE: To determine whether peptic activity in bronchoalveolar fluid, due to the presence of the gastric proteolytic enzyme pepsin, could serve as a biochemical marker for pulmonary aspiration of gastric contents. DESIGN: Prospective, experimental trial. SETTING: A university animal research laboratory. SUBJECTS: Thirty-six New Zealand rabbits, weighing 2 to 4 kg. INTERVENTIONS: New Zealand rabbits were anesthetized, intubated via tracheostomy, and mechanically ventilated. Pulmonary aspiration was induced by the intratracheal instillation of 2 mL/kg human gastric juice (pH 1.2 +/- 0.2; pepsin activity 0.02 +/- 0.006 microgram/mL; human gastric juice group, n = 24) or normal saline solution (pH 5.2 +/- 0.2; normal saline solution group; n = 12). Mechanical ventilation was continued. Bronchoalveolar lavage was performed at 15 mins (human gastric juice group, n = 8; normal saline solution group, n = 4), 30 mins (human gastric juice group, n = 8; normal saline solution group, n = 4), or 60 mins (human gastric juice group, n = 8; normal saline solution group, n = 4) postaspiration. MEASUREMENTS AND MAIN RESULTS: Peak airway pressure and PaO2 values were measured at baseline and 15 and 30 mins after aspiration. The pH of retrieved bronchoalveolar lavage fluid was measured and pepsin activity in sample fluid was determined. Changes from baseline in peak airway pressure and PaO2 were significant in human gastric juice animals at 15 and 30 mins when compared with normal saline solution animals (PaO2 -4% vs. -44%, peak airway pressure 20% vs. 36% at 15 mins; PaO2 -16% vs. -79%, peak airway pressure 28% vs. 69% at 30 mins; normal saline solution group vs. human gastric juice group, p < .02). Bronchoalveolar lavage fluid pH was not significantly different between groups at any time postaspiration (6.6 +/- 0.7 vs. 6.0 +/- 0.4 at 15 mins; 7.4 +/- 0.9 vs. 6.5 +/- 0.4 at 30 mins; 7.2 +/- 0.5 vs. 6.4 +/- 0.4 at 60 mins, normal saline solution group vs. human gastric juice group, p = NS). No peptic activity was present in bronchoalveolar lavage fluid from normal saline solution animals at any time. In the human gastric juice group, peptic activity was detected in postaspiration bronchoalveolar lavage fluid in eight of eight animals at 15 mins, six of eight animals at 30 mins, and five of eight animals at 60 mins (normal saline solution group vs. human gastric juice group; p < .001 at 15 mins, p < .01 at 30 mins, p = NS at 60 mins). Peptic activity of bronchoalveolar lavage fluid varied; mean values were greater at 15 mins than at 30 or 60 mins (pepsin activity: 0.004 +/- 0.002 microgram/mL vs. 0.002 +/- 0.001 microgram/mL vs. 0.0006 +/- 0.0001 microgram/mL, respectively, p < .05). CONCLUSIONS: The results of this study suggest that peptic activity in bronchoalveolar lavage fluid can be detected up to 60 mins after induced, experimental gastric juice aspiration and may prove a clinically useful biochemical marker for episodes of occult pulmonary aspiration of gastric contents.

Insertion of Hickman central venous catheters by using angiographic techniques in patients with hematologic disorders.

During a 9-month period, 69 Hickman catheters were successfully inserted by using angiographic techniques in 59 patients with hematologic disorders. A pneumothorax, which did not require drainage, developed in one patient. No other significant complications occurred at the time of insertion. Eighteen catheters were removed electively, 15 are still in situ, six were removed for thrombosis, and five were accidentally removed. Infection precipitated removal in six subjects. Ten patients died with the catheter in place. Five catheters were removed in patients with refractory septicemia of unknown origin. One catheter burst during an injection and had to be removed. Three patients were lost to follow-up. There were 3.24 infectious episodes per 1000 days of catheterization, more than twice the rate found in some other series. The results of this study are compatible with the growing body of evidence in favor of the angiographic insertion of Hickman catheters. The apparently high rate of infection is ascribed to factors other than insertion in the angiography suite, including the high proportion of bone marrow transplantation patients.