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Biomedical subjects

H Turndorf

Publications and source records attributed to H Turndorf.

At least 145 records · Page 8Linked to original sources
PubMed1980

Effects of minute volume increases on the rebreathing characteristics of the Bain anaesthesia circuit during controlled ventilation.

In the course of a study on the carbon dioxide rebreathing characteristics of the Bain anaesthesia circuit, it was noted that raising the minute volume without changing the fresh gas inflow invariably led to increased rebreathing of expired gases. Altering tidal volume and rate in order to reproduce a given minute volume had the same effect on rebreathing. A nomogram constructed to quantitate increases in rebreathing in function of carbon dioxide production per minute, fresh gas flow from the anaesthesia machine, and minute volume is produced. It can be used to assess the amount of fresh gas flow necessary to mantain a steady and inspired gas composition.

Anesthesiology↗
PubMed1980

Intracranial pressure during nitroglycerin-induced hypotension.

Nitroglycerin was given intravenously to five anesthetized, hyperventilated (PaCO2 25 to 30 torr) patients during craniotomy, to facilitate surgery by creating a relatively bloodless field, and to decrease the potential need to blood transfusion. A subarachnoid screw and an indwelling radial artery catheter were inserted to monitor intracranial pressure (ICP) and mean arterial pressure (MAP). As MAP decreased from 10.4 +/- 4.0 (SE) to 69.0 +/- 1.8 torr, ICP increased from 14.2 +/- 0.7 (SEM) to 30.8 +/- 1.1 torr. Cerebral perfusion pressure decreased from 90.2 +/- 3.6 (SEM) to 38.2 +/- 2.3 torr (p < 0.0005). We attribute this nitroglycerin-induced ICP increase to capacitance vessel dilation within the relatively noncompliant cranial cavity, with subsequent cerebral blood volume increase.

Adult↗
PubMed1980

Bronchofiberscopic jet ventilation.

The suction-biopsy channel of a flexible bronchofiberscope was used to provide subglottic jet ventilation in six dogs and eight adult human subjects. In dogs, after 75 minutes of ventilation at a driving pressure of 2580 torr/cm2 (50 lb/in2) the PaO2 was 412 +/- 18 torr and the PaCO2 32 +/- 3 torr with a peak airway pressure of 6 torr. In patients, after 30 minutes of jet ventilation, the PaO2 varied from 347 to 480 torr, the PaCO2 from 17 to 36 torr, and peak tracheal pressure from 6 to 8 torr. The method is convenient, simple and applicable in a variety of clinical situations.

Adult↗
PubMed1980

Furosemide facilitates recovery of evoked twitch response after pancuronium.

Two groups consisting of 10 A.S.A. class I-II neurosurgical patients each were studied to determine whether patients require greater quantities of pancuronium to maintain paralysis after having been given furosemide, 1 mg/kg. After a standardized barbiturate, narcotic and nitrous oxide induction of anesthesia, pancuronium was given intravenously until twitch response was suppressed by 95%. The study group received in addition furosemide, 1 mg/kg, 10 minutes prior to induction of anesthesia. Mean recovery time from 95% to 50% twitch suppression was 21.8 minutes in the control group and 14.7 minutes in the study group. Urinary output was significantly greater (13.5 vs 674 ml) and serum potassium levels lower (4.05 vs 3.85 meq/L) in the study group during recovery of twitch response. Furosemide, 1 mg/kg, facilitates recovery of evoked twitch response after pancuronium.

Furosemide↗
PubMed1980

Tracheobronchial cytologic changes during prolonged cannulation.

The tracheobronchial cytology of eighteen patients undergoing prolonged mechanical ventilation were examined for the type of cell population present, together with the morphologic integrity of the ciliated epithelial cells 1, 3, 5,10, and 20 days after tracheal cannulation. Smears obtained from patients recovering from cardiac surgery were different from all others in that: (1) they contained fewer epithelial cells (ciliated and squamous) which disappeared earlier; (2) they initially had more pus cells which appeared earlier; (3) they originally contained more histocytes but these were not found after the 5th day after cannulation; and (4) their ciliated epithelial cells displayed more cytomorphologic changes. Differences in cytology were attributed to impaired cardiac output in these patients. The reduced perfusion pressure of the vasculature of their tracheobronchial tree was presumably unable to sustain the lateral wall pressure of tube cuffs pressure, which further impaired tracheal perfusion. Less reparative processes (squamous metaplasia and early appearance of histiocytes) were also found in patients following cardiac surgery, together with early invasion of smears by pus cells indicating premature lowered resistance to bacterial infection.

Adolescent↗
PubMed1979

The pattern of memory loss resulting from intravenously administered diazepam.

A word recognition task was designed to determine the stage in memory affected by a single 10-mg intravenous injection of diazepam and the duration of the effect. Injection in three experimental subjects produced an anterograde amnesia for the 14 to 24-minute period immediately after injection. Memory loss resulted from impaired storage, the stage during which information is entered into memory. Retention and retrieval stages of memory were unaffected. This temporary amnesia may result from increased inhibition in the hippocampal system produced by diazepam, which shares many properties with the inhibitory neurotransmitter gamma-aminobutyric acid.

Amnesia↗
PubMed1979

Hand-held toy squeaker during carotid endarterectomy in the awake patient.

A toy squeaker held by the patient in the contralateral hand is used to monitor cerebral circulation during carotid endarterectomy. Regional anesthesia--cervical plexus block--allowed the patient to cooperate and give useful information, especially during the crucial period of test clamping. In a series of 300 cases, during a period of five years, it was instrumental in avoiding brain damage in 6% of the cases.

Anesthesia, Conduction↗
PubMed1979

Humidity and the anesthetized patient.

Damage to the ciliated cells of the tracheobronchial tree and incidence of postoperative pulmonary complications were measured by point-scoring systems in 202 patients who breathed dry and humidified anesthetic gases for 225 +/- 78 min. The incidence of postoperative pulmonary complications decreased as the humidity of administered anesthetic gases increased from 0 to 32.5 mg H2O/l. A similar relationship was found between the amount of inhaled moisture and the damage to the ciliated epithelium of the tracheobronchial tree. These results appear to indicate that a high inspired humidity is beneficial for operations on normothermic patients, and that cellular damage caused by dryness is a possible contributory factor in the production of the pulmonary atelectasis that follows stoppage of the mucociliary transport system in the immmediate postoperative period.

Adolescent↗
PubMed1979

Impact of cardiopulmonary resuscitation training on resuscitation.

Restoration of adequate spontaneous circulation after "arrest" and cardiopulmonary resuscitation (CPR) of 546 patients before and 460 patients after initiation of a CPR training course in a 500-bed city hospital is reported. Between January 1972 and June 1976, adequate circulation after CPR was present in 38.6% of patients before and 50.4% after training ICU nurses and house physicians in modern resuscitation techniques. Factors crucial to resumption of adequate circulation are: (1) CPR training of all hospital personnel so that effective CPR can be started immediately after recognition of an arrest situation, (2) production of a palpable pulse with closed chest cardiac massage, and (3) prompt effective therapy so that the time interval between arrest and resumption of adequate spontaneous circulation is short.

Blood Circulation↗