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Biomedical subjects

J L Nates

Publications and source records attributed to J L Nates.

7 recordsLinked to original sources
PubMed2000

Percutaneous tracheostomy in critically ill patients: a prospective, randomized comparison of two techniques.

OBJECTIVE: To prospectively compare two commonly used methods for percutaneous dilational tracheostomy (PDT) in critically ill patients. DESIGN: Prospective, randomized, clinical trial. SETTING: Trauma and general intensive care units of a university tertiary teaching hospital, which is also a level 1 trauma center. PATIENTS: One hundred critically ill patients with an indication for PDT. INTERVENTIONS: PDT with the Ciaglia technique using the Ciaglia PDT introducer set and the Griggs technique using a Griggs PDT kit and guidewire dilating forceps. MEASUREMENTS AND MAIN RESULTS: Surgical time, difficulties, and surgical and anesthesia complications were measured at 0-2 hrs, 24 hrs, and 7 days postprocedure. Groups were well matched, and there were no differences between the two methods in surgical time or in anesthesia complications. Major bleeding complications were 4.4 times more frequent with the Griggs PDT kit. With the Ciaglia PDT kit, both intraoperative and at 2 and 24 hrs, surgical complications were less common (p = .023) and the procedure was more often completed without expert assistance (p = .013). Tracheostomy bleeding was not associated with either anticoagulant therapy or an abnormal clotting profile. Multivariate analysis identified the predictors of PDT complications as the Griggs PDT kit (p = .027) and the Acute Physiology and Chronic Health Evaluation (APACHE) II score (p = .041). The significant predictors of time required to complete PDT were the APACHE II score (p = .041), a less experienced operator (p = .0001), and a female patient (p = .013). CONCLUSIONS: Patients experiencing PDT with the Ciaglia PDT kit had a lower surgical complication rate (2% vs. 25%), less operative and postoperative bleeding, and less overall technical difficulties than did patients undergoing PDT with the Griggs PDT kit. Ciaglia PDT is, therefore, the preferred technique for percutaneous tracheostomy in critically ill patients.

APACHE↗
PubMed1997

Acute weakness syndromes in critically ill patients--a reappraisal.

Over the last twenty years, increasing numbers of critically ill, mechanically ventilated patients who develop acute profound muscle weakness have been described. These acute weakness syndromes have not been well understood and they have been given many names including: acute steroid myopathy, acute quadriplegic myopathy, the floppy person syndrome, critical illness polyneuropathy, critical illness polyneuromyopathy, and prolonged neurogenic weakness. Many of these "syndromes" either overlap or represent the same disease process in different patients. Many have been incompletely diagnosed. During this review it became evident that the acute weakness syndromes currently recognized in critically ill patients could be categorized into four major groups: myopathy, neuromuscular junction abnormalities, neuropathy and polyneuromyopathy. Each had different possible aetiologies. "Myopathy" includes acute necrotizing myopathy and disuse atrophy. Neuromuscular junction abnormalities are subdivided into myasthenia-like syndromes and prolonged neuromuscular blockade. Neuropathies are divided into critical illness polyneuropathy and acute motor neuropathy. The anterior horn cell injury in Hopkins syndrome should also be considered in this group. Polyneuromyopathies include various combinations of neuropathy and myopathy in the same patients.

Acute Disease↗
PubMed1996

Polyamines induce blood-brain barrier disruption and edema formation in the rat.

Polyamines (PA) are derived from ornithine by the enzyme ornithine decarboxylase (ODC), which is activated very rapidly as acute and delayed responses to brain ischemia and trauma. Polyamines play a role in the disruption of the blood-brain barrier (BBB) in different pathological states. This study examined the effect of exogenous polyamines, administered intracerebrally (i.c.v.) or intracarotidly on BBB function. Putrescine, spermidine and spermine, given individually, were found to disrupt BBB integrity within 15 min of i.c.v. administration (p = 0.03; p = 0.0013; p = 0.042 vs saline treated rats, respectively). The effect was still evident after 1 h; however, since the saline treated rats also showed increased permeability of Evans blue at this time, there was no statistical difference between polyamines or saline treated rats 1 h post injection. When injected into the carotid artery, rapid increase in BBB permeability was found 1 min after putrescine and spermidine (p < 0.01 vs saline), with a slight decline at 15 min. A slower effect was noticed after spermine administration which reached significance only at 15 min. These results suggest a role for PA as mediators of vasogenic edema formation in the brain soon after brain injuries which induce increased production of these compounds.

Analysis of Variance↗
PubMed1992

Changes in brain polyamine levels following head injury.

The changes in polyamines levels in the brain after closed head injury were studied in rats. At 1 and 15 min, 24 and 48 h after closed head injury cortical tissue from the site of injury, from the contralateral region, and from remote areas were taken. The levels of the diamine putrescine and the polyamines spermine and spermidine were assayed by thin layer liquid chromatography of their dansyl derivatives. Head injury induced a significant increase in putrescine at 48 h at the site of injury and in the frontal lobe of the injured hemisphere, respectively. In the contralateral hemisphere only minor changes in putrescine were found. Spermine and spermidine showed minor changes at that time course. We have previously shown that at 24-48 h after injury, severe edema is found at the site injury. In order to study the role of putrescine in edema formation in this model we treated the traumatized rats with alpha-difluoromethyl-ornithine (DFMO), an inhibitor of ornithine-decarboxylase, the rate limiting enzyme in putrescine biosynthesis. This drug did not affect the level of edema 4 or 48 h after injury although it abolished the increase in putrescine. The effect of DFMO on blood-brain barrier function was studied, using Evans blue extravasation, at the early post-traumatic period (15 min-4 h), where a massive amount of dye is taken up by traumatized brain. No changes in the amount of dye extracted was found after DFMO treatment. On the other hand, DFMO had a beneficial effect on the neurological outcome, as evaluated by a set of clinical criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗