Devising negative pressure within intercuff space reduces microaspiration.

BACKGROUND: Microaspiration past the tracheal tube cuffs causes ventilator-associated pneumonia. The objective of the current study was to evaluate whether creating negative pressure between the tracheal double cuffs could block the fluid passage past the tracheal tube cuffs. METHODS: A new negative pressure system was devised between the double cuffs through a suction hole in the intercuff space. Blue-dyed water was instilled above the cuff at negative suction pressures of - 54, - 68, - 82, - 95, - 109, - 122, and - 136 cmH2O, and the volume leaked was measured in an underlying water trap after 10 min. Leakage tests were also performed during positive pressure ventilation, and using higher-viscosity materials. The actual negative pressures delivered at the hole of double cuffs were obtained by placing microcatheter tip between the intercuff space and the artificial trachea. RESULTS: No leakage occurred past the double cuff at - 136 cmH2O suction pressure at all tracheal tube cuff pressures. The volume leaked decreased significantly as suction pressure increased. When connected to a mechanical ventilator, no leakage was found at - 54 cmH2suction pressure. Volume of the higher-viscosity materials (dynamic viscosity of 63-108 cP and 370-430 cP) leaked was small compared to that of normal saline (0.9-1.1 cP). The pressures measured in the intercuff space corresponded to 3.8-5.9% of those applied. CONCLUSIONS: A new prototype double cuff with negative pressure in the intercuff space completely prevented water leakage. The negative pressure transmitted to the tracheal inner wall was a small percentage of that applied.

Ultrasound-guided oblique subcostal transversus abdominis plane block for analgesia after laparoscopic cholecystectomy: a randomized, controlled, observer-blinded study.

BACKGROUND: The oblique subcostal transversus abdominis plane (OSTAP) block has been described as an effective analgesic method for upper abdominal surgery. We evaluated the postoperative analgesia of the OSTAP block and compared it with that of the transversus abdominis plane (TAP) block in patients undergoing laparoscopic cholecystectomy (LC). METHODS: Patients scheduled for elective LC were randomized to receive either standard care or to undergo an OSTAP or TAP block. All blocks were performed with ultrasound guidance, and 20 mL of 0.375% ropivacaine was injected bilaterally. The postoperative pain score and consumption of rescue analgesics were evaluated. RESULTS: The OSTAP block reduced postoperative verbal numerical rating scale pain scores (median [Interquartile range, IQR]) compared to standard care at 10 min (2 [1-4] vs. 7 [5-8]), 30 min (2 [1-5] vs. 6 [5-8]), 1 h (2 [1-3] vs. 5 [4-6]), and 3 h (2 [2-3] vs. 4 [3-5]). Pain scores were also lower in the OSTAP group than in the TAP group at 10 min (2 [1-4] vs. 4 [2-6]), 1 h (2 [1-3] vs. 3 [3-4]), 3 h (2 [2-3] vs. 3 [3-4]), 6 h (2 [2-3] vs. 3 [3-5]), and 24 h (1 [1-2] vs. 2 [2-3]) postoperatively. The total fentanyl requirement was reduced in the OSTAP group (p = 0.005). CONCLUSION: The OSTAP block can provide better analgesia than the TAP block or standard care during the postoperative 24 h period in patients undergoing LC.

Arterial pulsatility as an index of cerebral microangiopathy in diabetes.

BACKGROUND AND PURPOSE: This study was designed to evaluate cerebral hemodynamic changes related to diabetes mellitus (DM) with transcranial Doppler ultrasonography (TCD). METHODS: We measured the flow velocities and the Gosling pulsatility index (PI) of the middle cerebral artery (MCA), extracranial internal carotid artery (ICA), and basilar artery (BA) in 56 stroke-free, normotensive patients with type 2 DM and 70 age- and gender-matched healthy volunteers. Patients were divided into 2 groups according to the presence of microvascular complications such as retinopathy, nephropathy, and neuropathy. RESULTS: Patients showed slightly lower hematocrit and higher serum fibrinogen levels than control subjects, but other clinical profiles, including stroke risk factors except for diabetes, were comparable between patients and controls. The flow velocity of the ICA but not the MCA and BA in patients regardless of the complication was significantly higher than that in controls. The PIs of the MCA and ICA were significantly higher in patients with complication than those without complication, as well as in controls. The PI of the BA was also significantly higher, even in patients without complication, than in controls. The PIs of the MCA and ICA but not the BA were closely correlated with the duration of DM (r(2)=0.46 and 0.34, respectively). CONCLUSIONS: This study defines TCD findings of diabetes-related cerebral hemodynamic changes and suggests that the PI reflects microangiopathic changes of cerebral vessels.

Recurrent herpes zoster myelitis.

Recurrent zoster myelitis is quite rare. We present a previously healthy 27-year-old woman who developed recurrent attacks of myelopathy shortly after the characteristic skin rashes of herpes zoster. Magnetic resonance imaging studies demonstrated each lesion in the spinal cord at the same segments as the skin lesions. She had two attacks at opposite sites at the same spinal cord level and complete recovery after being treated with intravenous acyclovir. We suspect that direct invasion of varicella zoster virus was the cause of recurrent myelopathy in our patient.