Ketamine-Associated Pediatric Laryngospasm
Clinical variables fail to predict pediatric ketamine-associated laryngospasm.
結論：
(1) Ketamine引起的喉頭痙攣很罕見。
(2) Ketamine引起的喉頭痙攣是無法預測的。
(3) Ketamine引起的喉頭痙攣是無法以BZD併用來預防的。
In a 2009 meta-analysis of 8282 children undergoing ketamine sedation in the emergency department, investigators identified risk factors for airway and respiratory adverse events, including 22 occurrences (0.3%) of laryngospasm, defined as "stridor or other evidence of airway obstruction that did not improve with airway alignment maneuvers" (Ann Emerg Med 2009; 54:158). Now, the investigators performed a case-control analysis on the same dataset to assess predictors of ketamine-associated laryngospasm.
Each of the 22 case patients (median age, 3.7 years) was matched to 4 controls by American Society of Anesthesiologists (ASA) physical status ≥3 vs. <3, oropharyngeal procedure, ketamine dose, route of ketamine administration (intravenous vs. intramuscular), coadministration of anticholinergic agents, and coadministration of benzodiazepines (individual variables were excluded from matching when the variable was tested as a predictor). In univariate and multivariate analysis, the investigators evaluated the association between laryngospasm and each of seven variables: age, dose, oropharyngeal procedure, underlying physical illness, route of ketamine administration, coadministration of anticholinergics, and coadministration of benzodiazepines.
Benzodiazepine coadministration was the only variable that was significantly associated with laryngospasm and only in the multivariate analysis (odds ratio, 13.7). The number needed to treat with ketamine plus benzodiazepines to result in 1 occurrence of laryngospasm was 26. The authors question the validity of an association between benzodiazepine coadministration and laryngospasm, given the lack of statistical significance in the univariate analysis or in their previous regression analyses.
Comment: This study shows that ketamine-associated laryngospasm is rare and unpredictable. Although data on the association between benzodiazepine coadministration and laryngospasm are mixed, given the potential risk and the absence of evidence of benefit, routine coadministration should be avoided.
—
Katherine Bakes, MD
Published in Journal Watch Emergency Medicine November 24, 2010
Citation(s): Green SM et al. Laryngospasm during emergency department ketamine sedation: A case-control study. Pediatr Emerg Care 2010 Nov; 26:798.
2010年11月27日 星期六
2010年11月11日 星期四
補充維他命B可以防呆嗎？
Vitamin B Supplementation and Cognition
In older men, supplementation did not affect cognition.
Because high plasma homocysteine levels are associated with cognitive impairment in epidemiologic studies, in multiple clinical trials researchers have examined whether vitamin B supplementation — which lowers homocysteine levels — improves cognition or delays onset of cognitive impairment in older adults; results have been mostly negative. In a new study, Australian researchers randomized 299 community-dwelling hypertensive men (age, above 75) without dementia to receive either placebo or a combination of vitamin B6, vitamin B12, and folic acid.
During 2 years of treatment, no differences between groups were noted on several measures of cognition. Even in subgroups in which benefit seemed likely — men with high baseline homocysteine levels (above 15 mcmol/L) and men with mild cognitive impairment at baseline — the investigators found no benefit from vitamin B supplementation.
Comment: This study adds to a growing body of evidence that vitamin B supplementation does not favorably affect cognition in older adults. One possible inference is that homocysteine is a marker — not a cause — of cognitive impairment in older adults.
—
Allan S. Brett, MD
Published in Journal Watch General Medicine November 10, 2010
Citation(s): Ford AH et al. Vitamins B12, B6, and folic acid for cognition in older men. Neurology 2010 Oct 26; 75:1540. (http://dx.doi.org/10.1212/WNL.0b013e3181f962c4)
In older men, supplementation did not affect cognition.
Because high plasma homocysteine levels are associated with cognitive impairment in epidemiologic studies, in multiple clinical trials researchers have examined whether vitamin B supplementation — which lowers homocysteine levels — improves cognition or delays onset of cognitive impairment in older adults; results have been mostly negative. In a new study, Australian researchers randomized 299 community-dwelling hypertensive men (age, above 75) without dementia to receive either placebo or a combination of vitamin B6, vitamin B12, and folic acid.
During 2 years of treatment, no differences between groups were noted on several measures of cognition. Even in subgroups in which benefit seemed likely — men with high baseline homocysteine levels (above 15 mcmol/L) and men with mild cognitive impairment at baseline — the investigators found no benefit from vitamin B supplementation.
Comment: This study adds to a growing body of evidence that vitamin B supplementation does not favorably affect cognition in older adults. One possible inference is that homocysteine is a marker — not a cause — of cognitive impairment in older adults.
—
Allan S. Brett, MD
Published in Journal Watch General Medicine November 10, 2010
Citation(s): Ford AH et al. Vitamins B12, B6, and folic acid for cognition in older men. Neurology 2010 Oct 26; 75:1540. (http://dx.doi.org/10.1212/WNL.0b013e3181f962c4)
2010年11月9日 星期二
SAH 的重要臨床特徵
Clinical Decision Rules to Identify Patients at High Risk for Subarachnoid Hemorrhage
One of three rules might eliminate unnecessary evaluation of patients with acute headache.
Because subarachnoid hemorrhage (SAH) is a potentially devastating cause of acute headache, many patients with acute headache undergo extensive testing (e.g., computed tomography [CT], lumbar puncture) to rule it out. In this 5-year multicenter prospective Canadian study that involved nearly 2000 neurologically intact adults who presented with acute (peaking within 1 hour) nontraumatic headache, investigators sought to identify clinical characteristics that predicted SAH.
Overall, 130 patients had SAH. Sixteen clinical characteristics were associated significantly with SAH and were used to create three possible clinical decision rules:
Comment:
Although these decision rules are promising, they must be validated in other populations before they are used routinely; indeed, the authors note that a prospective validation study is under way. But, in the meantime, the findings provide guidance: Patients who present with nontraumatic headaches that peak within 1 hour and who have any of the clinical characteristics mentioned in the rules above should be assessed carefully for SAH. As the authors note, validated rules "could allow clinicians to be more selective and accurate when investigating patients with headache" and lower use of CT and lumbar puncture.
—
Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine November 9, 2010
Citation(s): Perry JJ et al. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: Prospective cohort study. BMJ 2010 Oct 28; 341:c5204. (http://dx.doi.org/10.1136/bmj.c5204)
One of three rules might eliminate unnecessary evaluation of patients with acute headache.
Because subarachnoid hemorrhage (SAH) is a potentially devastating cause of acute headache, many patients with acute headache undergo extensive testing (e.g., computed tomography [CT], lumbar puncture) to rule it out. In this 5-year multicenter prospective Canadian study that involved nearly 2000 neurologically intact adults who presented with acute (peaking within 1 hour) nontraumatic headache, investigators sought to identify clinical characteristics that predicted SAH.
Overall, 130 patients had SAH. Sixteen clinical characteristics were associated significantly with SAH and were used to create three possible clinical decision rules:
- Rule 1: age >40, complaint of neck pain or stiffness, witnessed loss of consciousness, onset of headache with exertion.
- Rule 2: arrival by ambulance, age >45, vomiting at least once, diastolic blood pressure >100 mm Hg.
- Rule 3: arrival by ambulance, systolic blood pressure >160 mm Hg, complaint of neck pain or stiffness, age 45–55.
Comment:
Although these decision rules are promising, they must be validated in other populations before they are used routinely; indeed, the authors note that a prospective validation study is under way. But, in the meantime, the findings provide guidance: Patients who present with nontraumatic headaches that peak within 1 hour and who have any of the clinical characteristics mentioned in the rules above should be assessed carefully for SAH. As the authors note, validated rules "could allow clinicians to be more selective and accurate when investigating patients with headache" and lower use of CT and lumbar puncture.
—
Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine November 9, 2010
Citation(s): Perry JJ et al. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: Prospective cohort study. BMJ 2010 Oct 28; 341:c5204. (http://dx.doi.org/10.1136/bmj.c5204)
2010年11月5日 星期五
Head trauma: 到院前不給高張溶液
Prehospital Hypertonic Fluid Fails to Improve Outcomes in Patients with Blunt Head Trauma
In the largest randomized controlled trial to date, prehospital hypertonic fluid therapy did not improve neurological outcomes in patients with severe blunt head trauma without hypovolemic shock.
Hypertonic fluid therapy diminishes cerebral edema and enhances systemic perfusion pressure in patients with severe blunt head injury, but its effect on neurological outcome is unknown. In a multicenter, double-blind, randomized, placebo-controlled trial, researchers evaluated the effect of hypertonic fluid in patients >15 years who had sustained severe blunt closed head injury (prehospital Glasgow Coma Scale score <8) and did not have hypovolemic shock (systolic blood pressure ≤70 mm Hg or 71–90 mm Hg with a pulse ≥108 beats per minute). Patients were randomized to receive an initial fluid bolus of 250 mL of 7.5% saline, 7.5% saline/6% dextran 70, or 0.9% saline within 4 hours of the dispatch call.
Six-month outcome data were available for 1087 of 1282 patients (85%) who were enrolled from 2006 to 2009. At 6 months, there were no significant differences between the hypertonic-fluid groups and the normal-saline group in neurological outcome (as measured by the Extended Glasgow Outcome Scale and Disability Rating Scale), survival at 28 days, survival at hospital discharge, development of organ failure, or length of stay in an intensive care unit or hospital. No increase in progression of intracranial hemorrhage was noted in the hypertonic-fluid groups.
Comment:
Although this study is the largest of its kind, the authors did not control for postintervention neurosurgical management or fluid administration (including additional hypertonic saline or mannitol), and 15% of patients were lost to follow-up. Currently, hypertonic saline is not recommended for prehospital treatment of patients with severe head injury. This trial should not lead to a change in practice.
—
John A. Marx, MD, FAAEM
Published in Journal Watch Emergency Medicine November 5, 2010
Citation(s): Bulger EM et al. Out-of-hospital hypertonic resuscitation following severe traumatic brain injury: A randomized controlled trial. JAMA 2010 Oct 6; 304:1455.
In the largest randomized controlled trial to date, prehospital hypertonic fluid therapy did not improve neurological outcomes in patients with severe blunt head trauma without hypovolemic shock.
Hypertonic fluid therapy diminishes cerebral edema and enhances systemic perfusion pressure in patients with severe blunt head injury, but its effect on neurological outcome is unknown. In a multicenter, double-blind, randomized, placebo-controlled trial, researchers evaluated the effect of hypertonic fluid in patients >15 years who had sustained severe blunt closed head injury (prehospital Glasgow Coma Scale score <8) and did not have hypovolemic shock (systolic blood pressure ≤70 mm Hg or 71–90 mm Hg with a pulse ≥108 beats per minute). Patients were randomized to receive an initial fluid bolus of 250 mL of 7.5% saline, 7.5% saline/6% dextran 70, or 0.9% saline within 4 hours of the dispatch call.
Six-month outcome data were available for 1087 of 1282 patients (85%) who were enrolled from 2006 to 2009. At 6 months, there were no significant differences between the hypertonic-fluid groups and the normal-saline group in neurological outcome (as measured by the Extended Glasgow Outcome Scale and Disability Rating Scale), survival at 28 days, survival at hospital discharge, development of organ failure, or length of stay in an intensive care unit or hospital. No increase in progression of intracranial hemorrhage was noted in the hypertonic-fluid groups.
Comment:
Although this study is the largest of its kind, the authors did not control for postintervention neurosurgical management or fluid administration (including additional hypertonic saline or mannitol), and 15% of patients were lost to follow-up. Currently, hypertonic saline is not recommended for prehospital treatment of patients with severe head injury. This trial should not lead to a change in practice.
—
John A. Marx, MD, FAAEM
Published in Journal Watch Emergency Medicine November 5, 2010
Citation(s): Bulger EM et al. Out-of-hospital hypertonic resuscitation following severe traumatic brain injury: A randomized controlled trial. JAMA 2010 Oct 6; 304:1455.
訂閱：
文章 (Atom)
