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Biomedical subjects

E Ruiz

Publications and source records attributed to E Ruiz.

At least 145 records · Page 8Linked to original sources

Aortic compressor for aortic occlusion in hemorrhagic shock.

The aortic compressor is a device that allows rapid, simple, immediately reversible occlusion of the thoracic aorta, without the aortic dissection required to use an aortic cross-clamp. We evaluated the aortic compressor in a controlled study using a canine hemorrhagic shock model. Twelve mongrel dogs were exsanguinated to a mean arterial pressure (MAP) of 47 mm Hg and maintained at that level for 20 minutes. At that point, all animals had a left lateral thoracotomy. Six study animals had the thoracic aorta occluded at the diaphragm using the compressor. Five minutes after thoracotomy, with or without occlusion, the shed blood was reinfused. Application of the aortic compressor was the only variable. Use of the aortic compressor led to an immediate and statistically significant doubling of the study animals' MAP. The increased afterload of aortic occlusion did not impair cardiac output. The cardiac index of the study animals rose slightly, while that of the control animals fell. At the same time the compressor prevented blood flow to the abdominal aorta. If the canine model can be extrapolated to human application, then the aortic compressor would be expected to enhance perfusion of the heart and brain during hemorrhagic shock, prevent further arterial blood loss from intra-abdominal injury or ruptured abdominal aortic aneurysm, and preserve already diminished cardiac output. Because the aorta does not need to be dissected out to use the compressor, there is no risk of injury to nearby vascular structures.

Animals↗

Central venous pH as a predictor of arterial pH in prolonged cardiac arrest.

Sixty-five patients who arrived in the emergency department in cardiac arrest were studied prospectively to determine whether central venous pH could be used as an accurate predictor of arterial pH in prolonged cardiac arrest. Central venous and arterial access were obtained as soon as possible after arrival in the emergency department. Simultaneous arterial and venous samples were drawn and sent for blood gas analysis. Under normal conditions, central venous pH (pHcv) approximates arterial pH (pHa). In prolonged cardiac arrest, however, our data reveal a mean pHa of 7.31 +/- 0.25 and a mean pHcv of 7.08 +/- 0.19. There was moderate correlation between pHa and pHcv when all patients were considered (r = .69, P less than .01). The correlation was excellent, however, in the subgroup of 15 patients who had a pulse at some point during resuscitation (r = .95, P less than .01). In 13 of these 15 patients the acid base status would have been managed correctly based on the predicted pHa (pHcv + 0.12 correction factor). The pHcv was also valuable in identifying a second subgroup of patients who required no further bicarbonate therapy; all patients who had a pHcv greater than or equal to 7.15 had a pHa greater than 7.30 (21 patients). The central venous pH was found to be a useful index of arterial pH when applied to a definable subset of patients, which in this study constituted 45% of all patients in prolonged cardiac arrest.

Acidosis↗

Effects of sulpiride on levels of FSH, LH and steroid hormones.

In order to study the effects of prolactin upon the gonadotrophins and steroid hormones, hyperprolactinaemia was induced by the administration of sulpiride. 12 men between the ages of 18 and 20 were given 3 capsules of 50 mg of sulpiride daily for a period of 15 days, and the following parameters being measured before and after the treatment: (prolactine, FSH, LH, testosterone, estradiol, ACTH and DHEA-S) by RIA, (cortisol) by fluorimetry and (etiocholanone, androsterone, pregnandiol, pregnantriol, pregnantriolone, 11-keto etiocholanone and 11-OH androsterone) by gas chromatography. Our results show that on termination of the treatment there was a significant rise in the prolactin and DHEA-S serum levels and a drop in the FSH serum levels but not of LH. In addition there was a marked increase in all the androgen levels studied, (etiocholanone, androsterone and 11-keto etiocholanone) with the exception of testosterone.

Adolescent↗

LHRH test in ovariectomized women with and without treatment of sex hormones.

The modulatory effect of sex hormones on the LHRH test, has been studied on ovariectomized women, randomly divided into groups which received estrogen (E2), progesterone (P) and E2 + P respectively. One group was left untreated. Menstruating women in follicular phase were also studied. The LHRH test was performed on all women and FSH, LH levels were measured in the blood. The LH levels in the blood following the LHRH test showed an increase in all the groups under investigation, including the ovariectomized untreated one. This suggests that, after ovariectomy, the hypophysis does not reach its maximum capacity for gonadotrophin release. The FSH response to the LHRH test was very low in all the groups studied, including the ovariectomized without treatment. It thus could be suggested that FSH needs other stimuli besides LHRH for its physiological release.

Adult↗

Acute resuscitation of the patient with head and spinal cord injuries.

The major immediate goal in the treatment of a patient with central nervous system injuries is to prevent secondary injuries resulting from hypotension, hypoxemia, hypercapnia, intracranial hypertension, infection, and unnecessary motion of an unstable spinal column. This combined with application of the fundamentals of trauma resuscitation should achieve optimal results.

Adrenal Cortex Hormones↗

Another aspect of acute urinary retention in young patients.

Four homosexual men and one heterosexual woman presented with acute urinary retention secondary to intense anal intercourse. All had normal urologic histories. Their residual urine volumes ranged from 475 ml to 1,400 ml. Urinalyses and urine cultures were negative. All were treated with an indwelling Foley catheter and then with bethanechol and dibenzyline. Normal micturition was restored. To evaluate the influence of anal dilatation on detrusor function, five control patients with urge incontinence were studied. A cystometrogram (CMG) displayed a hyperreflexic bladder pattern in all five patients. Average bladder capacity was 86 ml. Calibrated anal dilatation increased bladder capacity to the average value of 406 ml on CMG. The diameter of anal dilatation ranged from 3.5 cm to 5 cm. Intense anal intercourse producing severe anal dilatation triggers reflex bladder inhibition leading to acute urinary retention. The sensory input travels from the dilated anus to the sacral spinal micturition center, which sends inhibitory stimuli to the urinary bladder.

Acute Disease↗

Cricothyrotomy in the emergency department.

Thirty-eight emergency cricothyrotomies were performed over a 3-year period. This was the first airway control maneuver attempted in 5 patients, 3 of whom had facial and/or neck injury, one apneic with upper airway hemorrhage, and one with aortobronchial fistula. The remaining 33 procedures were performed only after other airway management failed. Five indications were identified among these cases: 1) excessive emesis or hemorrhage (11), 2) possible cervical spine injury with airway compromise (9), 3) technical failure (7), 4) clenched teeth (5), and 5) masseter spasm following succinylcholine administration (1). Fourteen immediate complications occurred in 12 patients (32%). The most frequent was incorrect site of tracheostomy tube placement (5), with 4 of 5 misplaced through the thyrohyoid membrane. Others included execution time greater than 3 minutes (4), unsuccessful tracheostomy tube placement (3), and significant hemorrhage (2). Twelve of the 38 patients were long-term survivors. There was one long-term complication, a longitudinal fracture of the thyroid cartilage during forceful placement of an oversized tube (8 mm inner diameter) through the cricothyroid membrane. This required operative repair and left the patient with severe dysphonia.

Airway Obstruction↗

Succinylcholine for endotracheal intubation.

In the emergency department at Hennepin County Medical Center, succinylcholine has been used to assist difficult intubations since March 1, 1979. In this report, the first 48 cases are reviewed. In these 48 patients, complete relaxation allowing endotracheal intubation was achieved in 42. Forty of the 42 patients intubated suffered no adverse effects. One patient vomited, delaying intubation, and another developed transient asystole. Six of 48 patients were not successfully intubated after succinylcholine; five of these six subsequently required cricothyrotomy. Inadequate dose, improper technique of administration, foreign material obscuring airway, and idiosyncratic reactions were thought to be reasons for failure. When properly administered, succinylcholine can be used to facilitate difficult intubations in the emergency department with an acceptable incidence of adverse effects or failures.

Adult↗

Effect of pneumatic trousers on intracranial pressure in hypovolemic dogs with an intracranial mass.

Thirty-six dogs under chloralose anesthesia were studied in groups of six. Arterial pressure (BP), central venous pressure (CVP), intracranial pressure (ICP), and arterial blood gases were monitored. The group underwent: 1) anesthesia only; 2) phlebotomy (P) (40% of blood volume) and reinfusion (RI) of half the shed blood plus Ringer's lactate solution; 3) P followed by pneumatic trousers (PT), and then RI; 4) inflation of an epidural 2-cc Foley catheter (EFC); 5) P followed by EFC and then RI; and 6) P followed by EFC and then by PT and RI. Group 1 was stable. In Group 2, P lowered BP (49 torr systolic +/- 6 SEM), CVP, and ICP. RI restored these. In Group 3, the PT improved BP (P less than .05) without increasing ICP. In Group 4, EFC increased ICP (P less than .05) to 15 +/- 4 torr. In Groups 5 and 6, ICP was not significantly increased by EFC or PT and RI.

Animals↗

Augmentation of systolic blood pressure during external cardiac compression by use of the MAST suit.

External cardiac compression has been shown to circulate blood effectively, but the systolic pressures obtained are less than normal cardiac functioning. This study was undertaken to determine whether applying the military anti-shock trouser (MAST) suit resulted in improving systolic blood pressure while using external cardiac compression during cardiac resuscitation. Individuals admitted to the emergency department in cardiac arrest had external cardiac massage applied at a constant rate and force. Intra-arterial blood pressure monitoring was established and baseline systolic blood pressure obtained. In eight patients, the average increase in systolic blood pressure utilizing the MAST suit was 15 mm Hg. The implications of these findings, as well as other means to increase cardiac output in the cardiac arrest patient, are discussed. These findings will be related to both prehospital and emergency department care of patients in cardiac arrest.

Aged↗

Use of atropine for brady-asystolic prehospital cardiac arrest.

The efficacy of atropine in treating prehospital cardiac arrest patients developing asystole slow pulseless idioventricular rhythms (PIVR) was evaluated in a controlled, prospective study. Twenty-one prehospital cardiac-arrested patients developing asystole or PIVR (less than 40) were divided into atropine-treated or non-atropine (control) groups. Control group patients received treatment including bicarbonate, epinephrine, calcium, isoproterenol, dexamethasone, and transthoracic pacing. Atropine-treated patients received 1 mg atropine intravenously with a repeat dose at one minute if no rhythm change occurred. These patients then received the same therapy as the control group. In both groups, rhythm changes were treated as appropriate for the specific circumstances. No differences in mortality or effected rhythm changes were observed. Ten of the 11 controls and eight of 10 atropine patients developed rhythms other than asystole or PIVR less than 40. However, only two patients in each group were successfully resuscitated in the emergency department and only one control group patient was discharged alive. Our findings are not in agreement with those of previous authors who have advocated the use of atropine in cardiac arrest patients with these arrhythmias. We question the usefulness of atropine in this setting. More study is necessary in order to clearly define its role in the resuscitation of patients who have sustained brady-asystolic arrests.

Adolescent↗

Emergency twist drill trephination.

We have used the rapid progression of post-traumatic uncal herniation in spite of intensive medical therapy as the indication for twist drill trephination in the emergency department. During a 54-month period, 51 trephinations were performed on 41 patients. The trephine was placed through the temporal bone ipsilateral to the dilated pupil, and the dura mater was opened to allow partial evacuation of the hematoma. All patients subsequently underwent craniotomy, autopsy, and/or cerebral computed tomography (CT). The trephination was diagnostically accurate for the absence or presence of an extracerebral hematoma in 42 of 51 trephinations (82%). In 6 of these cases the dilated pupil responded to partial hematoma evacuation by decreasing in size. In 3 of the 6 there was a marked overall improvement in neurological status subsequent to trephination. These 3 patients later recovered to an independent functional state. Only 23 of these 41 patients (56%) with herniation profiles actually had significant extracerebral hematomas. This fact emphasizes the inadvisability of taking this type of patient directly to the operating room without a diagnostic study. A rapidly performed CT scan is the obvious first choice. However, if there is any delay in obtaining this study or when uncal herniation occurs rapidly, a twist drill trephination can be of value in diagnosing the absence or presence of a treatable extracerebral hematoma. There were no complications related to this procedure in this group.

Adult↗

Toxicity of alkaline solutions.

We examined the question of what determines the toxicity of alkaline solutions--pH, viscosity, or other factors. Our experiments have identified pH measurement as the simplest and most easily measured parameter for determining initial management of caustic ingestions. Viscosity is not a clinically useful measurement. The closer to 14 the pH measures, the more destructive the caustic. Non-lye solutions known to cause esophageal ulceration have a pH of 12.5 to 13.5. Most cases of deep ulceration going on to stricture formation involve lye solutions of pH 14. The critical pH that causes esophageal ulceration is 12.5, and thus a patient ingesting a substance with a pH greater than 12 should be followed closely for the possibility of esophageal ulceration.

Alkalies↗

Critical care in an emergency department.

A one year review of resuscitation in an emergency department (ED) was conducted. In the stabilization room (SR) within the ED at Hennepin County Medical Center, 852 cases were treated in the year ending July 31, 1978. There were 166 deaths in the SR (19.5%) overall, and 141 (47.9%) and 16 (5.3%) for cardiac and trauma cases, respectively. The 32 fatal cases of blunt trauma (six in the SR, 10 within 24 hours, and 16 late deaths) were reviewed and assigned an injury severity score (ISS). Of these, 12 deaths were unrelated to central nervous system causes. These had an average ISS of 42.8.

Adolescent↗