T. Randell

Effects of alfentanil on the responses to awake fiberoptic nasotracheal intubation

Intubation conditions and pressor response were assessed in 30 healthy patients undergoing awake nasotracheal intubation. The patients were premedicated with peroral diazepam. All the patients were sedated with intravenous diazepam 0.1 mg/kg. Alfentanil 20 μg/kg or saline was administered in a double‐blind fashion. Alfentanil caused moderate respiratory depression but significantly improved conditions for fiberoscopy. In the control group, arterial pressures and heart rate increased significantly immediately after tracheal intubation. These responses were attenuated by alfentanil.

Massive blood transfusion exceeding 50 units of plasma poor red cells or whole blood: the survival rate and the occurrence of leukopenia and acidosis

The survival rate after bleeding requiring massive blood transfusions exceeding 50 units has been reported to be low or zero. There seems to be no reports of leukopenia in connection with massive blood transfusion. This retrospective study was carried out to investigate the survival rate and the occurrence of leukopenia and acidosis in patients who were transfused with more than 50 units of plasma poor red cells or whole blood. The survival rate was 16 of 23. Three of the five patients with a blood transfusion of over 100 units survived. Pure component therapy was used on 18 occasions. All patients had a leukopenia, which lasted up to five days. All patients had an acidosis. The range of the lowest pH values in patients who did not survive was from 6.77 to 7.27 and in survivors from 6.87 to 7.28. The survival rate was considerably higher than reported in previous studies. Pure component therapy appeared to be particularly suited to massive transfusion. Leukopenia was a regular phenomenon. Severe acidosis did not predict a poor outcome.

Medical and legal considerations of brain death

Brain death was first defined in 1968, and since then laws on determining death have been implemented in all countries with active organ transplantation programs. As a prerequisite, the aetiology of brain death has to be known, and all reversible causes of coma have to be excluded. The regulations for the diagnosis of brain death are most commonly given by the national medical associations, and they vary between countries. Thus, the guidelines given in the medical textbooks are not universally applicable. The diagnosis is based on clinical examination, but confirmatory tests, such as angiography or EEG, are allowed on most occasions. Brain death is followed by cardiovascular and hormonal changes, which have implications in the management of a potential organ donor. Spinal reflexes are preserved, and motor and haemodynamic responses are frequently observed in brain dead patients.

Intubation difficulties in patients with rheumatoid arthritis: A retrospective analysis

Background: Fibreoptic intubation has been suggested to be the best method to manage a compromised airway. This retrospective study was designed to compare endotracheal intubation with the help of a rigid laryngoscope or a fibrescope in patients with rheumatoid arthritis.

Haemodynamic responses to intubation: what more do we have to know?

THE influence of airway manipulation on heart rate and blood pressure was recognized more than 50years ago, and the magnitude of the changes was observed to depend on the depth of anaesthesia (1, 2). In 1951, King and co-workers described in detail what we now know as the haemodynamic response to laryngoscopy and intubation. In patients anaesthetized with thiopental, a mean rise of 53mmHg in systolic arterial pressure and of 23 beats per minute in heart rate were recorded after tracheal intubation. The changes appeared during laryngoscopy, and levelled off within 5min of intubation (2). The results of these early studies have not been challenged. However, in the decades that followed, hundreds of studies aiming tomodify the cardiovascular response have been published in the anaesthesia literature. Among the first ones, Wycoff (3) showed attenuation of the haemodynamic response to laryngoscopy and intubation with topical anaesthesia of the airway, and similarly, Kautto and Heinonen demonstrated attenuation but not inhibition of the pressor response by aerosol spray or gargling with viscous lidocaine before the induction of anaesthesia (4). Since the earliest studies, the favourable effect of topical anaesthesia has been questioned, until in 2001 when Takita and others suggested that it is effective only if applied at least 2min before the laryngoscopy (5). Laryngoscopy and tracheal intubation contribute to the responses separately as shown by King et al. and Shribman and others (1, 6). Also, the duration of laryngosopy has a significant effect on the magnitude of the pressor response, during a 60-s laryngoscopy, mean arterial pressure increased until 45 s; thereafter, no further increase was seen until tracheal intubation (7). It is generally accepted that the increases in blood pressure and heart rate occur within 30 s of the stimuli, and can last up to 5min. Consequently, when the attenuation of these responses is studied, direct arterial blood pressure measurement should be a standard practice. On the other hand, inserting an arterial cannula in healthy patients undergoing minor surgery for research purposes has been considered unethical by some institutional committees, which limits the selection of patients for these studies. Furthermore, to obtain reliable results, only patients without anticipated difficulties in airway management should be included, and the duration of laryngoscopy and intubation needs to be recorded. The anaesthetic agents may be considered to be the most appropriate choice in controlling the changes in haemodynamic parameters at induction of anesthesia. In a double-blind and placebo-controlled trial, Kautto demonstrated that fentanyl 2mg/kg attenuated and fentanyl 6mg/kg inhibited the pressor response (8). The relatively high doses of fentanyl can delay recovery, but the more short-acting opioids, alfentanil 15—45mg/kg (9) or remifentanil 0.5—1mg/kg followed by an infusion, are also effective in this respect (10). Also, the laryngoscopy and intubation-related increases in the concentrations of catecholamines (11—13) can be attenuated by opioids (9, 14). On the other hand, inhalation anaesthetics blunt the increase in arterial pressure, but at the same time may result in elevated concentrations of plasma catecholamines (15). Of the intravenous induction agents, thiopentone and propofol modulate the haemodynamic response, but do not abolish it at commonly used doses (16, 17). Either one of them with a muscle relaxant has been given to patients in control groups in studies evaluating the effectiveness of other drugs in the attenuation of cardiovascular responses to airway manipulation. Beyond these approaches, intravenous lidocaine, beta blocking drugs, alpha-2 agonists, and vasodilators among others have been studied in this context. The results on the efficacy are highly variable even within the specific drug groups, and most of the studied agents have blunted either the tachycardic or the hypertensive component of the haemodynamic Acta Anaesthesiol Scand 2004; 48: 393—395 Copyright # Acta Anaesthesiol Scand 2004 Printed in Denmark. All rights reserved ACTA ANAESTHESIOLOGICA SCANDINAVICA

Pre-hospital severe traumatic brain injury – comparison of outcome in paramedic versus physician staffed emergency medical services

BackgroundTraumatic brain injury (TBI) is one of the leading causes of death and permanent disability. Emergency Medical Services (EMS) personnel are often the first healthcare providers attending patients with TBI. The level of available care varies, which may have an impact on the patient’s outcome. The aim of this study was to evaluate mortality and neurological outcome of TBI patients in two regions with differently structured EMS systems.MethodsA 6-year period (2005 – 2010) observational data on pre-hospital TBI management in paramedic-staffed EMS and physician-staffed EMS systems were retrospectively analysed. Inclusion criteria for the study were severe isolated TBI presenting with unconsciousness defined as Glasgow coma scale (GCS) scoreu2009≤u20098 occurring either on-scene, during transportation or verified by an on-call neurosurgeon at admission to the hospital. For assessment of one-year neurological outcome, a modified Glasgow Outcome Score (GOS) was used.ResultsDuring the 6-year study period a total of 458 patients met the inclusion criteria. One-year mortality was higher in the paramedic-staffed EMS group: 57xa0% vs. 42xa0%. Also good neurological outcome was less common in patients treated in the paramedic-staffed EMS group.DiscussionWe found no significant difference between the study groups when considering the secondary brain injury associated vital signs on-scene. Also on arrival to ED, the proportion of hypotensive patients was similar in both groups. However, hypoxia was common in the patients treated by the paramedic-staffed EMS on arrival to the ED, while in the physician-staffed EMS almost none of the patients were hypoxic. Pre-hospital intubation by EMS physicians probably explains this finding.ConclusionThe results suggest to an outcome benefit from physician-staffed EMS treating TBI patients.Trial registrationClinicalTrials.gov ID NCT01454648

Orotracheal fibreoptic intubation in children under general anaesthesia

Orotracheal fibreoptic intubation under general anaesthesia in children was studied in eleven consecutive patients of three months to eight‐years‐of‐age without anticipated intubation difficulties. One case report is also included. Three fibrescopes with a different diameter were used in the study. The fibrescope used was chosen so that it fitted snugly in the tracheal tube. The fibreoscopy was prolonged in one patient due to mucus and two tries were needed. Resistance to the tracheal tube upon intubation was encountered in five patients, only one of these patients was older than two years. Fibreoptic intubation succeeded in nine patients. Two patients were intubated with the Macintosh laryngoscope. The problems encountered in children during orotracheal fibreoptic intubation under general anaesthesia are the same as with adults: easy fibreoscopy is not always followed by easy tracheal intubation, there may be prolonged fibreoscopy and failed intubations. Manipulation of the tracheal tube can lead to successful tracheal intubation and resistance to the tube is more common in smaller children.

Prone Versus Sitting Position in Neurosurgery—Differences in Patients' Hemodynamic Management

OBJECTIVEnNeurosurgery in general anesthesia exposes patients to hemodynamic alterations in both the prone and the sitting position. We aimed to evaluate the hemodynamic profile during stroke volume-directed fluid administration in patients undergoing neurosurgery either in the sitting or the prone position.nnnMETHODSnIn 2 separate prospective trials, 30 patients in prone and 28 patients in sitting position were randomly assigned to receive either Ringer acetate (RAC) or hydroxyethyl starch (HES; 130 kDa/0.4) for optimization of stroke volume. After combining data from these 2 trials, 2-way analysis of variance was performed to compare patients hemodynamic profile between the 2 positions and to evaluate differences between RAC and HES consumption.nnnRESULTSnTo achieve comparable hemodynamics during surgery, a higher mean cumulative dose of RAC than HES was needed (679 mL ± 390 vs. 455 mL ± 253; P < 0.05). When fluid consumption was adjusted with weight, statistical difference was lost. Fluid administration did not differ between the prone and sitting position. Mean arterial pressure was lower and cardiac index and stroke volume index were higher over time in patients in the sitting position.nnnCONCLUSIONSnThe sitting position does not require excess fluid treatment compared with the prone position. HES is slightly more effective than RAC in achieving comparable hemodynamics, but the difference might be explained by patient weight. With goal-directed fluid administration and moderate use of vasoactive drugs, it is possible to achieve stable hemodynamics in both positions.

Transfusion Frequency of Red Blood Cells, Fresh Frozen Plasma, and Platelets During Ruptured Cerebral Aneurysm Surgery

BACKGROUNDnThe use of blood products after subarachnoid hemorrhage (SAH) is common, but not without controversy. The optimal hemoglobin level in patients with SAH is unknown, and data on perioperative need for red blood cell (RBC), fresh frozen plasma (FFP), or platelet transfusions are limited. We studied perioperative administration of RBCs, FFP, and platelets and the impact of red blood cell transfusions (RBCTs) on outcome in patients undergoing surgery for ruptured a cerebral arterial aneurysm.nnnMETHODSnA retrospective analysis was performed of 488 patients with aneurysmal SAH during the years 2006-2009 at Helsinki University Central Hospital. Patients who received RBC, FFP, or platelet concentrates perioperatively were compared with a cohort of patients from the Helsinki database of aneurysmal SAH who did not receive transfusions. A multiple regression model was created to identify factors related to transfusion and outcome.nnnRESULTSnRBC, FFP, or platelet concentrates were given in 7.6% (37 of 488), 3.1% (15 of 488), and 1.2% (6 of 488) of patients intraoperatively and in 3.5% (17 of 486), 1.6% (8 of 488), and 0.9% (4 of 488) of patients postoperatively. Of 37 intraoperative RBCTs, 26 were related to intraoperative rupture of the aneurysm. Intraoperative RBCTs were associated with lower preoperative hemoglobin concentration, higher World Federation of Neurosurgical Societies classification, and intraoperative rupture of an aneurysm. In multivariate analysis, intraoperative RBCT (odds ratio = 5.13, 95% confidence interval = 1.53-17.15), worse World Federation of Neurosurgical Societies classification and Fisher grade (odds ratio = 1.97, confidence interval = 1.64-2.36 and odds ratio = 1.89, confidence interval = 1.23-2.92, respectively), and increasing age (odds ratio = 1.07, confidence interval = 1.04-1.10) independently increased the risk of poor neurologic outcome at 3 months.nnnCONCLUSIONSnTransfusion frequencies of RBCs, FFP, and platelets were relatively low. Intraoperative RBCT was strongly related to intraoperative rupture of the aneurysm in patients with poor-grade SAH. The observed association between poor outcome and RBCT in patients with SAH warrants further study.

Isoflurane inhibits muscle fasciculations caused by succinylcholine in children

The incidence and intensity of muscle fasciculations as well as the occurrence of cardiac arrhythmias following succinylcholine were evaluated in 36 premedicated children (1.0–5.7 years) after intravenous induction with thiopentone or after inhalation induction with isoflurane (3.75 vol‐% in 70% nitrous oxide in oxygen). The study was randomized. In the thiopentone group, fasciculations were seen in all children and in the isotlurane group in 5 of 18 children (P<0.001). The median of the duration of fasciculations was 15 s with a minimum of 5 s and maximum of 36 s (1st quartile 9 s and 3rd quartile 20 s) in the thiopentone group and 0 (0–15) s with a 1st quartile of 0 and a 3rd quartile of 3 s in the isoflurane group (P<0.001). No cardiac arrhythmias were noted in either group. In conclusion, isoflurane in nitrous oxide inhibits succinylcholine‐induced muscle fasciculations in children.