Continuous EEG Monitoring in a Consecutive Patient Cohort with Sepsis and Delirium.

BACKGROUND: Delirium is common during sepsis, although under-recognized. We aimed to assess the value of continuous electroencephalography (cEEG) to aid in the diagnosis of delirium in septic patients. METHODS: We prospectively evaluated 102 consecutive patients in a medical intensive care unit (ICU), who had sepsis or septic shock, without evidence of acute primary central nervous system disease. We initiated cEEG recording immediately after identification. The median cEEG time per patient was 44 h (interquartile range 21-99 h). A total of 6723 h of cEEG recordings were examined. The Confusion Assessment Method for the ICU (CAM-ICU) was administered six times daily to identify delirium. We analyzed the correlation between cEEG and delirium using 1252 two-minute EEG sequences recorded simultaneously with the CAM-ICU scorings. RESULTS: Of the 102 included patients, 66 (65%) had at least one delirium episode during their ICU stay, 30 (29%) remained delirium-free, and 6 (6%) were not assessable due to deep sedation or coma. The absence of delirium was independently associated with preserved high-frequency beta activity (> 13 Hz) (P < 10-7) and cEEG reactivity (P < 0.001). Delirium was associated with preponderance of low-frequency cEEG activity and absence of high-frequency cEEG activity. Sporadic periodic cEEG discharges occurred in 15 patients, 13 of whom were delirious. No patient showed clinical or electrographic evidence of non-convulsive status epilepticus. CONCLUSIONS: Our findings indicate that cEEG can help distinguish septic patients with delirium from non-delirious patients.

Effect of hypoxia on BOLD fMRI response and total cerebral blood flow in migraine with aura patients.

Experimentally induced hypoxia triggers migraine and aura attacks in patients suffering from migraine with aura (MA). We investigated the blood oxygenation level-dependent (BOLD) signal response to visual stimulation during hypoxia in MA patients and healthy volunteers. In a randomized double-blind crossover study design, 15 MA patients were allocated to 180 min of normobaric poikilocapnic hypoxia (capillary oxygen saturation 70-75%) or sham (normoxia) on two separate days and 14 healthy volunteers were exposed to hypoxia. The BOLD functional MRI (fMRI) signal response to visual stimulation was measured in the visual cortex ROIs V1-V5. Total cerebral blood flow (CBF) was calculated by measuring the blood velocity in the internal carotid arteries and the basilar artery using phase-contrast mapping (PCM) MRI. Hypoxia induced a greater decrease in BOLD response to visual stimulation in V1-V4 in MA patients compared to controls. There was no group difference in hypoxia-induced total CBF increase. In conclusion, the study demonstrated a greater hypoxia-induced decrease in BOLD response to visual stimulation in MA patients. We suggest this may represent a hypoxia-induced change in neuronal excitability or abnormal vascular response to visual stimulation, which may explain the increased sensibility to hypoxia in these patients leading to migraine attacks.

Migraine induced by hypoxia: an MRI spectroscopy and angiography study.

Migraine with aura is prevalent in high-altitude populations suggesting an association between migraine aura and hypoxia. We investigated whether experimental hypoxia triggers migraine and aura attacks in patients suffering from migraine with aura. We also investigated the metabolic and vascular response to hypoxia. In a randomized double-blind crossover study design, 15 migraine with aura patients were exposed to 180 min of normobaric hypoxia (capillary oxygen saturation 70-75%) or sham on two separate days and 14 healthy controls were exposed to hypoxia. Glutamate and lactate concentrations in the visual cortex were measured by proton magnetic resonance spectroscopy. The circumference of cranial arteries was measured by 3 T high-resolution magnetic resonance angiography. Hypoxia induced migraine-like attacks in eight patients compared to one patient after sham (P = 0.039), aura in three and possible aura in 4 of 15 patients. Hypoxia did not change glutamate concentration in the visual cortex compared to sham, but increased lactate concentration (P = 0.028) and circumference of the cranial arteries (P < 0.05). We found no difference in the metabolic or vascular responses to hypoxia between migraine patients and controls. In conclusion, hypoxia induced migraine-like attacks with and without aura and dilated the cranial arteries in patients with migraine with aura. Hypoxia-induced attacks were not associated with altered concentration of glutamate or other metabolites. The present study suggests that hypoxia may provoke migraine headache and aura symptoms in some patients. The mechanisms behind the migraine-inducing effect of hypoxia should be further investigated.

[The fasting regime prior to anaesthesia]. / Fasteregler i forbindelse med anæstesi.

In modern anaesthesiology fasting preoperatively has been introduced in order to minimise the incidence of aspiration to the lungs. Since the 1990's studies have confirmed the safety of the current fasting regime of six hours for solids and two hours for fluids. By allowing the intake of carbohydrate-rich fluids until two hours before induction of anaesthesia, it has been shown that the negative effects of fasting such as thirst, starvation and anxiety are minimised. In the future, ultrasound technology might be used to assess the gastric volume prior to induction of anaesthesia.

The number of in-out catheterisations is reduced by mobilising the postoperative patient with bladder needs to the toilet in the recovery room: A randomised clinical trial.

BACKGROUND: Many patients are diagnosed with postoperative urine retention in the recovery room and treated with in-out catheterisation (IOC). OBJECTIVES: We hypothesised that the use of IOC could be reduced by mobilising patients to the toilet to pass urine instead of offering a bedpan or urinal. DESIGN: A randomised, controlled, nonblinded study with two groups. SETTING: University Hospital, October 2009 to June 2012. PATIENTS: One hundred and fifty-two patients scheduled for surgery for cervical or lumbar disc herniation. Inclusion criteria were a bladder volume more than 350 ml and/or the need to pass urine in the recovery room. INTERVENTIONS: Participants were randomised in the recovery room for mobilisation to the toilet (Group I) or use of a bedpan or urinal in the bed (Group C). MAIN OUTCOME MEASURES: The number of IOC cases in the recovery room (primary outcome) and the duration of stay in the recovery room. RESULTS: Thirteen of 67 patients (19%) in Group I and 38 of 71 patients in Group C (54%) required IOC (P < 0.001). The median (IQR) durations of stay in the RR were 125 (97 to 125) min in Group I and 157 (115 to 214) min in Group C (P = 0.006). The median times from arrival to first general ward mobilisation were 85 (37 to 139) min in Group I and 180 (118 to 245) min in Group C (P < 0.001). CONCLUSION: Patients were mobilised early after disc herniation intervention to permit toilet visits in the recovery room. This strategy decreased the number of IOCs, duration of stay in the recovery room and time from arrival to first mobilisation in the general ward.

Self-positioning followed by induction of anaesthesia and insertion of a laryngeal mask airway versus endotracheal intubation and subsequent positioning for spinal surgery in the prone position: a randomised clinical trial.

BACKGROUND: Anaesthesia followed by positioning in the prone position takes time and may have complications. OBJECTIVE: The hypothesis was that self-positioning in the prone position followed by anaesthesia and introduction of a laryngeal mask airway (LM method) would be faster with fewer complications than positioning after tracheal intubation (ET method). DESIGN: Randomised, controlled trial. SETTING: University Hospital, March 2009 to March 2011. PATIENTS: One hundred forty patients scheduled for spinal surgery were allocated to the LM or the ET method. Exclusion criteria were surgery expected to last more than 2 h, American Society of Anesthesiologists status more than II, age more than 70 years, abnormal neck, throat, and mouth anatomy and function, Mallampati score III-IV, BMI more than 35 kg m, anticipated difficult airway/mask ventilation and decreased neck mobility. INTERVENTIONS: Patients in the LM group placed themselves in the prone position, anaesthesia was induced and a laryngeal mask was introduced. Patients in the ET group were anaesthetised, intubated and then placed in the prone position. MAIN OUTCOME MEASURES: Time taken from identification of the patient at the outset to readiness for radiographic examination following anaesthesia and positioning. Airway problems, sore throat, hoarseness and pain from muscles and joints were also noted. RESULTS: One hundred and forty patients were randomised to LM (n = 70) and ET (n = 70). Data from 64 and 67 patients were analysed. Values are expressed as median (interquartiles) [range]. The primary outcome time was 25 min (23 to 29) [16 to 44] in the LM group and 30 min (26 to 33) [17 to 47] in the ET group (P <0.001). In two patients in group LM, a complete seal could not be obtained; one was intubated, and the other had surgery cancelled due to arterial hypotension. There were fewer cases with sore throat, hoarseness and pain from muscles and joints in the LM group at 3 h, but not at 24 h postoperatively. CONCLUSION: Self-positioning and induction of anaesthesia in the prone position saves time. More patients should be studied to confirm safety and examine whether the method reduces the number of severe complications associated with the prone position. TRIAL REGISTRATION: www.clinicaltrials.gov identifier: NCT01041352.

There is room for improvement in the prevention and treatment of headache after lumbar puncture.

INTRODUCTION: The incidence of post dural puncture headache (PDPH) after lumbar puncture (LP) can be reduced from 36% to 0-9% by use of an atraumatic needle size 24 gauge (G)/0.56 mm rather than a traumatic needle size 22 G/0.7 mm. The evidence supporting some of the prophylactic and therapeutically treatments of PDPH is sparse. The objective of this study was to clarify which needles doctors at neurological departments in Denmark use for LP and how they treat and prevent PDPH. MATERIAL AND METHODS: The present study is a questionnaire survey among doctors employed at the 13 neurological departments in Denmark. RESULTS: A total of 161 (51%) returned the questionnaire. As for needle size, 78% stated that they used needle size 22 G, 5% used 21 G, 13% used 20 G and 3% used 18 G. Overall, 74% used traumatic needles, while 18% were unaware of the needle type used. Prophylactic bed rest was prescribed by 44%. Prescribed treatments of PDPH were caffeine, analgesics/fluid therapy and epidural blood patch (EBP). Surprisingly many of the doctors used relatively thick and/or traumatic needles although PDPH is significantly reduced when smaller atraumatic needles are used. 90% prescribed fluid therapy, but the role of fluid therapy as well as that of analgesics in the treatment of PDPH remains uncertain. There was no difference in the incidence of PDPH using prophylactic bed rest versus early mobilization. Caffeine can reduce the number of patients with persisting PDPH, while EBP is the most effective treatment for PDPH. CONCLUSION: Atraumatic needles for LP have not become standard in Danish neurological departments. Knowledge about the treatment and prevention of PDPH seems insufficient.

Vasoactive modulators during and after craniotomy: relation to postoperative hypertension.

Hypertension after craniotomy is frequent. To establish an association between vasoactive modulators and postoperative hypertension, we followed the arterial blood pressure and plasma concentrations of selected substances in patients undergoing craniotomy. Twelve consecutive patients scheduled for operation of a supratentorial brain tumor were anesthetized with thiopental, fentanyl, isoflurane, and pancuronium. None of the patients had a history of arterial hypertension or were hypertensive before the operation. Arterial blood pressure and heart rate measurements were obtained preoperatively, after incision, during closure, and four times in the 50-minute interval after stopping isoflurane. At the same time, plasma concentrations of norepinephrine, epinephrine, renin, aldosterone, atrial natriuretic peptide, endothelin, and cortisol were measured. Data are given as mean +/- SD (range). The postoperative concentrations of these substances were significantly higher than the baseline concentrations measured preoperatively. Six of the patients developed postoperative hypertension defined as a mean arterial pressure (MAP) > 20% more than the baseline MAP (group H), and six had normal blood pressure postoperatively (group N). The mean value of the maximal postoperative MAPs measured in groups H and N, respectively, was 118 +/- 16 mm Hg (range: 96-132) and 103 +/- 9 mm Hg (range: 92-115) (P =.01). Only renin levels were higher intraoperatively in group H when compared to group N. However, postoperative levels of catecholamines, aldosterone, renin, and endothelin levels were higher in group H patients. The results suggest that in addition to an increased discharge of the sympathetic system, activation of the renin-angiotensin aldosterone system may also play an important role in the development of postoperative hypertension after craniotomy.