Shinji Akada

The efficacy of dexmedetomidine in patients with noninvasive ventilation: a preliminary study.

BACKGROUND: Agitation is associated with failure of noninvasive ventilation (NIV). We investigated the effect of dexmedetomidine in patients with NIV. METHODS: This was a prospective clinical investigation in an intensive care unit. Dexmedetomidine was infused in 10 patients in whom NIV was difficult because of agitation. RESULTS: Ramsay and Richmond Agitation-Sedation Scale scores were maintained at 2.94 ± 0.94 and −1.23 ± 1.30, respectively. All patients were successfully weaned from NIV, and the respiratory state was not worsened. CONCLUSION: This study shows that dexmedetomidine is an effective sedative drug for patients with NIV.

Clinical role and efficacy of landiolol in the intensive care unit

Beta-adrenergic receptor blockers have proved to be effective for the management of various cardiovascular diseases and the prevention of perioperative cardiac events and cerebrovascular accidents. Landiolol is a short-acting beta-blocker, with high beta 1-selectivity and a short duration of action. We thought landiolol was valuable and suitable for intensive care unit (ICU) patients, and conducted a retrospective study. The records of 80 patients (58 post-surgical patients; group S and 22 internal medicine patients; group IM) were reviewed. Thirty-seven (64%) of the group S patients were post-coronary artery bypass graft surgery, and the IM group consisted mostly of patients with acute myocardial infarction. The most common indication for landiolol in group S was the prevention of myocardial ischemia (50%), and in group IM, it was atrial fibrillation (45%). The median infusion rate of landiolol was 5 μg·kg−1·min−1 and the median infusion time was 2 days. Twenty-six patients were continued on oral beta-adrenergic receptor blockers. Landiolol reduced heart rate significantly without reducing blood pressure, and stabilized hemodynamics. We confirmed that landiolol is valuable as a bridge to starting oral beta-adrenergic receptor blockers and as an anti-arrhythmic agent, and that it is suitable for ICU patients due to its high beta 1-selectivity and rapid onset and offset of action.

Factors predicting successful noninvasive ventilation in acute lung injury

PurposeNoninvasive ventilation (NIV) has been successfully used to treat various forms of acute respiratory failure. It remains unclear whether NIV has potential as an effective therapeutic method in patients with acute lung injury (ALI). The aims of this study were to determine factors predicting the need for endotracheal intubation in ALI patients treated with NIV, and to promote the selection of patients suitable for NIV.MethodsWe conducted a retrospective study of all patients admitted to the intensive care unit (ICU) of the Nippon Medical School Hospital from 2000 to 2006 with a diagnosis of ALI, in whom NIV was initiated.ResultsA total of 47 patients with ALI received NIV, and 33 patients (70%) successfully avoided endotracheal intubation. Patients who required endotracheal intubation had a significantly higher Acute Physiology and Chronic Health Evaluation (APACHE) II score and a significantly higher Simplified Acute Physiology Score (SAPS) II, and a significantly lower arterial pH. The respiratory rate decreased significantly within 1 h of starting NIV only in patients successfully treated with NIV. An APACHE II score of more than 17 (P = 0.022) and a respiratory rate of more than 25 breaths·min−1 after 1 h of NIV (P = 0.024) were independent factors associated with the need for endotracheal intubation. Patients who avoided endotracheal intubation had a significantly lower ICU mortality rate and in-hospital mortality rate than patients who required endotracheal intubation.ConclusionWe determined an APACHE II score of more than 17 and a respiratory rate of more than 25 breaths·min−1 after 1 h of NIV as factors predicting the need for endotracheal intubation in ALI patients treated with NIV.

A case of cardiac tamponade following esophageal resection.

We report a rare case of cardiac tamponade after esophageal resection for esophageal cancer. A 69-year-old man underwent subtotal esophagectomy and reconstruction of the gastric tube with cervical anastomosis via the poststernal route and three-field lymphadectomy via a median sternotomy. On postoperative day 4, the patient developed dyspnea, chest oppression, and hemodynamic instability due to cardiac tamponade. Emergency percutaneous catheter drainage was performed to manage the cardiac tamponade. Acute pericarditis due to the original surgical procedure was suspected to be the cause of the tamponade. Although rare, cardiac tamponade should be considered as a cause of hemodynamic instability after esophageal resection.

Postoperative intensive care unit drug fever caused by dexmedetomidine.

Dexmedetomidine hydrochloride is a potent, highly selective alpha-2 adrenergic receptor agonist, broadly used as a sedative drug in intensive care units. We describe the case of a 59-yr-old patient who experienced drug fever caused by dexmedetomidine hydrochloride. The patient was transferred to the intensive care unit with an abdominal aortic aneurysm rupture. After initiation of sedation with dexmedetomidine hydrochloride, he developed pyrexia of more than 39 degrees C. This symptom improved rapidly 7 h after stopping dexmedetomidine hydrochloride. Other possible causes (such as infection) were sequentially eliminated.

Salicylate action on medullary inspiratory neuron activity in a brainstem-spinal cord preparation from newborn rats.

Salicylate affects central respiratory control. The inspiratory neurons are the most important component of the medullary respiratory control center because they modulate the final motor output via the phrenic nerve. We investigated changes in burst rate, intraburst firing frequency, and membrane properties of inspiratory neurons in the isolated brainstem after the administration of salicylate. Newborn rat brainstem-spinal cord preparations were superfused with salicylate. Whole-cell recordings were performed from inspiratory neurons. Application of 1 mM salicylate caused an increase in the inspiratory neuronal burst rate from 6.9 +/- 1.6 bursts/min to 8.2 +/- 1.9 bursts/min (P < 0.05). The inspiratory neuron burst rate decreased from 8.3 +/- 0.7 bursts/min to 4.5 +/- 1.1 bursts/min after the application of 10 mM salicylate (P < 0.01). The depressant effect of 10 mM salicylate was antagonized by the gamma-aminobutyric acid (GABA) receptor antagonist bicuculline (1 microM). Resting membrane potential and intraburst firing frequency did not change with the application of salicylate and bicuculline even when the burst rate did change. We conclude that the effects of salicylate on the medullary inspiratory neurons are mainly due to a presynaptic action. GABAergic mechanisms are probably involved in the salicylate-induced central respiratory depression.

Use of Dexmedetomidine in Patients with Noninvasive Ventilation

Agitation and delirium are relative contraindications for noninvasive ventilation (NIV) in acute care [1]. These cause serious complications, and even if indicated, NIV sometimes fails with these complications. Although sedation therapy can play an important role in NIV success, it is also potentially dangerous because respiratory depression is a concern when using potent analgesics or sedatives. Routine use of sedatives such as opioids and benzodiazepines can lead to a fatal outcome when overdosed.