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During a survey conducted for the cytodiagnosis of early bronchogenic carcinoma, cytoplasmic viral inclusion bodies were found sporadically in tracheobronchial smears of asymtomatic patients of both sexes (ages ranging from 18 to 80 years) undergoing general endotracheal anesthesia for surgery. A review of 3,049 cases performed to assess the frequency of occurrence of this phenomenon showed a 1.1 percent incidence in all smears studied. There was no relationship between smoking habit, age, or sex and the presence of inclusion bodies; however, there was a marked seasonal incidence, with 60 percent of inclusion-bearing smears being found during the months of January through March.

In order to assess the uptake of halothane by the goldfish, the respiratory rate of six fish was studied when water temperature was varied with and without changes in oxygen or carbon dioxide tension. The effective dose 50 of halothane (ED-50-H) and the time taken to reach it (T-ED-50-H) at an FIO2 of 0.35 in nitrogen, were studied when temperature and CO2 tension were varied. Nomograms were drawn to predict respiratory rate as a function of water CO2 tension, when CO2 was bubbled in air or in oxygen, and with changes in water temperature. At low temperatures (5 degrees C to 7.5 degrees C), respiratory rate remained below 10 per min, irrespective of CO2 partial pressure. At 28 degrees C, a CO2 partial pressure of 8 +/- 0.2 kPa produced a respiratory rate of 125 +/- 3/min in air, and in oxygen unexpectedly 140 +/- 3/min. Halothane ED-50 varied with temperature (0.8% at 10 degrees C and 1.6% at 23 degrees C). Time to reach ED-50-H decreased with increases in respiratory rate, but increased as water temperature was elevated.

The suction-biopsy channel (SBC) of a flexible bronchofiberscope was used to deliver gas into the trachea during high-frequency jet ventilation (HFJV) at a rate of 95 cycle/min and a tidal volume (VT) of 95 ml. A Portex epidural catheter inserted into the SBC was used to entrain water for humidification by the injector principle. Inspired humidity (IH) was regulated by adjusting the distance (D) between the injector and jet portals. Airway pressures, pulmonary gas exchange and IH levels were measured in 11 dogs. In addition, tracheal cytology scores (TCS, a sensitive index of tracheal epithelial damage caused by breathing dry gases) were assessed in 12 patients. The system maintained adequate pulmonary gas exchange in both dogs and humans. In dogs the mean tracheal pressure was 2.8 +/- 0.5 (SD) torr with a peak pressure of 3.8 +/- 0.5 torr. The upper-airway pressure was subatmospheric (-2 +/- 0.2 torr) during the first half of jet inspiration, but peaked synchronously with tracheal pressures during the second half. Both the upper airway and the trachea had a positive end-expiratory pressure (PEEP) of 1.8 +/- 0.2 torr. When D was 0.3 cm, the system delivered gas with an IH of 44 mg H2O/L (almost saturated at 37 degrees C). Human TCS did not change significantly after 2 h of humidified HFJV, suggesting efficient humidification.

Les auteurs ont decrit les differentes definitions concernant ľhumidite des gaz ďanesthesie et ont etudie les facteurs capables ďinfluencer sa regulation. Ils ont de plus demontre les effets nefastes de ľemploi des gaz secs qui dessechent les muqueuses respiratoires et elevent le pourcentage des complications pulmonaires qui suivent ľanesthesie. Une revue du debit de vapeur ďeau des systemes en usage courant a ete suivie par une description des mesures prises pour elever ľhumidite des gaz respires par les malades durant ľanesthesie. Ils ont aussi recommande la reduction de ľhumidite durant les periodes ďhyperthermie et les precautions a prendre pour eviter la contamination microbienne des equipements ďanesthesie, un risque augmente durant ľhydratation des gaz aspires par les malades.

We previously reported (1) that tracheobronchial secretions of patients in hemorrhagic shock contained significantly more iron laden histiocytes than secretions of matched controls and demonstrated by histiologic studies in rats bled to hemorrhagic shock that these animals' lungs contained significantly more iron laden histiocytes than those of a control group. Two explanations appeared plausible: 1) abnormal hemoglobin breakdown products of systemic hypoperfusion during shock (2, 3, 5) may have accumulated in the pulmonary circulation where they were phagocytozed by pulmonary histiocytes, or 2) circulating iron laden histiocytes may have been arrested in the lung, which is well known to act as a filter during low-flow states (4). The present study reports on assay of bronchial secretions of 12 open-heart surgery patients under cardiopulmonary bypass from specimens obtained 1) immediately after onset of anesthesia; 2) during; and 3) after termination of cardiopulmonary bypass. The percentage of iron laden histiocytes rose from 15.6+/-6.0 after intubation, to 49.6+/-6.8 after 1 hour on bypass with occluded pulmonary arteries (p less than 0.0025), remaining close to the latter value after pulmonary circulation was restored. Hypoperfusion, accumulation of metabolites, or falling pH at the tissue level are probable explanations for these findings.

The humidity output of a circle system was raised to 28 mg H2O/l by the use of a modified rotating wick vaporizer placed in the center of the soda lime canister and coaxial inspiratory and expiratory limbs. Both the fresh gas inflow and the expired gases passed through the lime and reached a compartment below it. The bag/ventilator connector, bearing a pressure relief valve, opened on the lateral wall of that compartment. Gases returning to the inspiratory valve passed: (1) through a tube in the canister connecting the inferior compartment to the vaporizer above water level, (2) through the upper portion of the vaporizer and around the rotating wick, and (3) through a tube emerging from the top of the vaporizer to reach the inspiratory valve. Thus inspired gases were humidified by the rotating wick constantly replenishing its water content warmed by the reaction of neutralization. The use of coaxial inspiratory and expiratory limbs reduced water condensation outside the canister.

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.

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.

One of the disadvantages of conventional circle absorber breathing circuits is that twisting between tile inspiratory and expiratory limbs sometimes occurs. In situations where access to the patient's airway is limited, such as during neurosurgical and head and neck operations, this disadvantage may lead to accidental disconnection or extubation. Another is that the temperature and humidity of inspired gas are usually less than desirable, predisposing to heal loss.1 and drying of tracheal mucusa.2 We have constructed a circuit that houses the inspiratory limb entirely within the lumen of a slightly larger expiratory limb. This makes it easy to handle and allows heat exchange between the cold inspired and warmer expired streams. Heat of condensation liberated by condensation of water on the outer surface of the inspiratory limb enhances vaporization of water droplets normally deposited on the inner surface of that limb, thereby increasing inspired humidity.

A scaled-down version of a modified adult circle system capable of increasing normal humidity output 300% was constructed for pediatric use. The moisture content of the gases leaving the system was tested and found to be superior to that of any pediatric circle system commercially available that does not incorporate an electrically heated water vaporizer.

Significantly elevated numbers of iron laden histiocytes have been shown to appear in the tracheobronchial secretions of subjects in hemorrhagic shock and in patients undergoing open heart-surgery during cardiopulmonary bypass (3,4). Abnormal heme pigments have also been demonstrated in the serum of dogs bled to hemorrhagic shock (6) and have been felt to be toxic. Because the ingestion of abnormal heme pigments by histiocytes may be part of a defense mechanism, we have attempted to correlate the percentage of iron laden histiocytes found in the tracheobronchial secretions of patients in hemorrhagic shock (Prussian blue method) with the presence of degradation of products of hemoglobin found in their serum by scanning spectrophotometry. There were, generally speaking, few iron laden histiocytes when hemoglobin degradation was advanced, and always numerous iron laden histiocytes when abnormal heme pigments were absent or spectrophotometric findings revealed minor degrees of degradation. Our findings probably reflect the process in the reticuloendothelial systems which eliminates toxic products accumulating in the circulation in low-flow states.

Sixty-three white Swiss Webster mice were divided into seven equal groups. Their tolerance to pain (heat applied to the tail by a test tube containing hot water at a temperature measured by telethermometry) was assessed before and after intraperitoneal injection of (1) physiologic saline; (2) meperidine 14 micrograms X g-1; (3) amitriptyline 6 micrograms X g-1 (4) amitriptyline 12 micrograms X g-1; (5) phenelzine 1.5 micrograms X g-1; (6) phenelzine 3 micrograms X g-1; and (7) amitriptyline 6 micrograms X g-1 plus phenelzine 1.5 micrograms X g-1. All post-injection tests were conducted 45 and 90 minutes after administration, and repeated 24 hours later. No significant difference in pain threshold was noted in any pre-injection test or in any test conducted with physiologic saline. By 90 minutes post-injection, all groups receiving drugs developed increased tolerance to pain. Mice which had received phenelzine plus amitriptyline, or either dose of phenelzine were more tolerant to pain for up to 24 hours than mice which had received physiologic saline. The most marked increases in tolerance to pain were seen with 1.5 micrograms X g-1 and 3 micrograms X g-1 of phenelzine and phenelzine plus amitriptyline. However, phenelzine was more effective and had a longer-lasting effect than either dose of amitriptyline, or meperidine. The combination of phenelzine plus amitriptyline was no more effective than phenelzine alone.

The minimum alveolar anesthetic concentration of halothane (MACh) was tested by the tail clamping method in 12 male white albino mice and found to be 1.1 %. A further 24 mice were given 15% alcohol to drink for 60 days, after which they were divided into four groups of six mice each. One group was tested for MACh immediately after withdrawal from alcohol and the remaining groups were tested 4, 10, and 18 days later. In the first group MACh was 0.6%. It rose to 1.1% 4 days later and gradually reached 1.6% after an additional 14 days. Before receiving alcohol the mice were starved for 24 hours and placed in a maze containing food. The time taken to reach the food was recorded. The mice completed their way through the maze in 147 ± 21 seconds on the first run and in 73 ± 10 seconds on a second run, after which they made no further significant progress. During the first 9 days on alcohol mice made their way through the maze in an average of 178 ± 17 seconds (no memory). On the 10th day they went through the maze in 160 ± 17 seconds on the first run (still no memory) but in 59 ± 8 seconds on a second run (regained learning function) (p

A computer program was developed to calculate intrapulmonary venous admixture on a Texas Instruments TI 59 programmable calculator. The program incorporates the following characteristics: 1) a correction for saturated water vapor pressure which varies with body temperature; 2) a mathematical model of the standard oxyhemoglobin dissociation curve; and 3) correction factors for shifts of the dissociation curve due to variations in pH and carbon dioxide tension. It also corrects oxygen tensions obtained at electrode temperature to those at patient temperature, and calculates variations of the Bunsen solubility coefficient of oxygen in blood with body temperature.

A pediatric anesthesia system was constructed by connecting the machine end of a modified Mapleson D system to a soda lime canister containing a water vaporizer heated through the reaction of neutralization of the lime by the CO2 emerging from the breathing tube. The vaporizer was placed in line with the fresh-gas delivery tube of the circuit. The humidity output of the system varied from 15 +/- 1 mg H2O/L with a CO2 output of 15 ml/L to 27 +/- 1.5 mg H2O/L with a CO2 output of 60 ml/min. Rebreathing of CO2 was within acceptable limits as long as fresh-gas inflow remained at 5 L/min. The system compares favorably in respect to its humidity output with all other circuits availabe on the market for pediatric anesthesia.

Thoracic impedance of 18 patients undergoing transurethral resection of the prostate was measured 15 minutes preoperatively, and 30 and 60 minutes after the start of the operation. Impedance variations were compared to variation in 1) cardiac output, 2) serum sodium osmolality and 3) alveolar-arterial oxygen tension difference. Thoracic impedance, initially 24.6 plus or minus 0.3, decreased to 23.8 plus or minus 0.5, 30 minutes after the onset of the operation (p less than 0.0005) and 22.9 plus or minus 0.5, 30 minutes later (p less than 0.01 from previous reading and 0.0005 from control). Patients in whom impedance had decreased 10 per cent or more from control values received 10 mg. furosemide intravenously 60 minutes after the onset of the operation. This therapy permitted the restoration of impedance values, cardiac output, alveolar-arterial oxygen tension difference and serum sodium osmolality to values statistically similar to those found in the 10 patients who had not sustained such precipitous decreases in impedance within 60 minutes. We believe that the measurement of thoracic impedance during transurethral prostatic surgery offers the most sensitive index of early water intoxication. Measurements can be obtained without delay in the operating room and, thus, permit immediate correction of the condition.

The transition from the scientific system of measurements used in the United States to the Systeme International creates difficulties for Americans who consult European or Canadian journals. Similar difficulties occur when they want to publish abroad. We have developed a program for the portable microcalculator, which may be coupled selectively to a recorder. Two types of programs are used on 7.5×1.5-cm electromagnetic cards. Program P 1 is used with the recorder and program P 2 with the calculator only. ( JAMA 244:165-166, 1980)

Smears were made from tracheobronchial washings of patients undergoing general endotracheal anesthesia for surgery. Morphologically abnormal histiocytes were noticed in specimens obtained from subjects during hemorrhagic shock. These cells were overloaded with Papanicolaou stain (a greenish orange compound) which compressed the nucleus against the cell membrane. Cytochemical staining methods were undertaken to discover the composition of this substance. In secretions suctioned from ten patients in shock, large numbers of histiocytes were found to have ingested inorganic iron detectable by the Prussian blue method. Only two patients from a matched control group had smears in which this phenomenon was discovered. The maximum proportion of histiocytes containing Prussian blue granules was 40% for patients in shock and only 2% in normal controls. Histologic studies conducted on rats submitted to hemorrhagic shock were carried out to investigate this phenomenon. Iron-laden histiocytes were found in the kidneys, spleen, and lungs of both shocked and control animals. However, substantially more histiocytes containing Prussian blue positive granules were discovered in the lungs of rats in shock than in controls. It may, therefore, be that iron is deposited in the lungs in low flow states.

Allegedly toxic heme pigments have been described in the serum of animals bled to hemorrhagic shock (5,7). In addition, Sears et al. (9), and Braun et al. (1) have shown that the products derived from the degradation of hemoglobin following intravascular hemolysis were toxic (heme carried by hemopexin and albumin). The accumulation of metabolites, caused by the impeded circulation, degrades free hemoglobin into heme pigments and their concentration then reaches a level which exceeds the normal heme-carrying capacity of serum proteins. We have already demonstrated the presence of abnormal heme pigments in clinical cases of shock using scanning spectrophotometry (3). We have endeavored to identify these pigments by serum electrophoresis, and to relate the appearance of some of these compounds to mortality rates. There were no deaths associated with the presence of haptoglobin-hemoglobin alone in serum. As shock deepened and mortality rose, hemopexin-heme and methemalbumin appeared. The highest mortality rate (4 out of 5 cases) was found when both hemopexin-heme and methemalbumin were present. It appears, therefore, that the administration of serum proteins in shock may reduce the toxicity of the products of degradation formed in low-flow states.

Twenty mice aged three to four months and trained to find food in a six compartment maze after a 24 hour fast, were divided into two equal groups. For just over one month the group which had received intraperitoneal meperidine 3 microgram.g-1 and promethazine 1.66 microgram.g-1 performed significantly slower than the group which had received intraperitoneal physiological saline. Because of this marked effect, it was decided to investigate the action of the drug combination on brain development and to assess whether it produced permanent retardation in learning function. The dams of a second group of 12 mice were, therefore, given either the same dose of drug combination or saline. At the age of seven weeks, the six pups born to dams which had received intramuscular saline and the six born to dams which were given intramuscular promethazine with meperidine performed equally well in a series of tests conducted in a T maze and in the six compartment maze after a 24 hour fast. In the T maze they had to distinguish between the presence of food provided in diminishing amounts or no food. In the six compartment maze they were tested with multiple maze pattern sequences. Meperidine and promethazine given during early labor does not permanently affect the learning function of the progeny of mice.

A study of 111 patients undergoing elective surgery under general endotracheal anesthesia has shown that the pulmonary complication rate after operation is minimal in nonsmokers (7.9 percent) and that it rises steadily as smoking habit increases, reaching 43 percent in very heavy smokers. Peak expiratory flow rate and timed vital capacity (FEV1) were unaffected before operation except in very heavy smokers. The morphologic integrity of the ciliated tracheobronchial epithelial cells seen in smears obtained within ten minutes of the onset of anesthesia and quantitated by a scoring system, deteriorates progressively with increasing smoking habit and constitutes the most sensitive index for the prediction of diminished resistance to the stress of anesthesia and operation and of incipient chronic obstructive lung disease in smokers.

Auto-tolerance and cross-tolerance to halothane, isoflurane and enflurane were tested on 36 mice divided into three equal groups. Each group was first exposed to increasing concentrations of either of the three anesthetics on 13 occasions. The concentration at which each mouse lost its righting reflex during successive exposures in a rotating cage was noted. Cross-tolerance was assessed by comparing the number of mice which had lost their righting reflexes during their first exposure to a given anaesthetic agent to the number which lost it after having been exposed to another anaesthetic. All animals developed auto-tolerance to halothane, isoflurane and enflurane. Cross-tolerance was noted only between mice exposed to isoflurane and enflurane and between mice exposed to halothane and subsequently anaesthetized with isoflurane, but not vice versa.

This study was conducted to assess the learning function of murine progeny born of mothers that had received either 1% or 2% halothane or 2% or 4% enflurane, on days 6 and 10 or days 14 and 17 or gestation. Their timed performance at the age of 6 to 7 weeks was compared in a maze with that of control mice of similar ages that had not been exposed to anesthetics prenatally. All mice exposed to halothane in utero performed poorly at first, especially the group with mothers exposed to 2% halothane on days 14 and 17 of pregnancy. By the 10th training period, the performance of all mice improved but remained significantly slower than control mice. The offsprings of mice exposed to enflurane also performed poorly on the first training period, but between the fifth and seventh training periods, made statistically significant progress. However, they too remained slower in maze performance than control mice. Although blood pressure and arterial blood gas studies were only performed on two pregnant mice, data obtained suggest that the anesthetics did not have sufficient effect on respiration to affect our results. Second generation offspring, born to dams exposed to 2% halothane in utero late in pregnancy and sired by normal unexposed males, were also consistently slower than control mice, indicating a possible genetic effect induced by the anesthetic.

The Pall bacterial filter was tested as a potential heat and moisture exchanger on a model patient, placed on a circle absorber system, and clinically. The laboratory study was conducted during mechanical ventilation at a V of 6 L/min with fresh gas inflows of 1, 3 and 6 L/min. The model patient introduced carbon dioxide into the circuitry at a rate of 200 ml/min. The resistance of the filter was tested before and after each experiment. With all fresh gas inflows , absolute humidity increased from around 19 mg H2O/L at the start of experimentation to about 27 mg H2O/L within 30 min. Maximum humidities reached were 28 +/- 0.7 mg H2O/L, 27.6 +/- 0.5 mg H2O/L, and 27.7 +/- 0.5 mg H2O/L within 3 hr, with fresh gas inflows of 1, 3, and 6 L/min, respectively. Variations in inspired humidity were also assessed at minute volumes of 4 and 5 L/min with fresh gas inflows of 6 and 3 L/min. Increases in percent dead space were negligible when the filter was inserted between the model patients (assumed to weigh between 70-40 kg) and the circuit. There was no statistically significant increase in pressure with gas flows of 50 L/min when the instrument was dry (0.02 +/- 0.001 cm H2O/L X min-1) or when it was wet (0.02 +/- 0.002 cm H2O/L X min-1). The clinical study was conducted on ten adult anesthetized patients breathing through the bacterial filter and ten controls. The loss of body temperature was 0.2 degrees C when the filter was used and 1.5 degrees C when the filter was not used. Arterial blood gas tensions were within normal limits when the bacterial filter was used as a humidifier.

The humidity output and CO2 elimination of the Bain circuit were tested on a simulated adult patient. The moisture content of inspired gases was found to be adequate when the circuit was used with a minute volume of 8.4 L/min and a fresh gas inflow of 4.9 L/min (65 percent relative humidity at room temperature at the onset of experimentation, rising to 100 percent after 80 minutes). However, the mean inspired CO2 concentration increased from 0.8 percent to 5.5 percent when the fresh gas inflow was decreased from 8 L/min to 3.5 L/min. It is recommended, therefore, that the circuit should not be used for long periods of time without measuring arterial CO2 tension or in situations where intentional hypocarbia is desired.

Four 11-week-old white Swiss Webster male mice were exposed to 2% enflurane in oxygen for 4 hr/day on 5 alternate days. Eight days later each male was mated with 2 females. There was a 20% loss of offspring due to stillbirths. A total of 24 pups survived (group E). At the age of 7 weeks the learning function of group E mice was tested in a Rosensweig maze and compared to that of 24 pups born to sires similarly exposed to oxygen alone (group C). Pups from group E performed statistically significantly slower than group C pups. After animals had been tested for 10 alternate days, there was no further change in performance in either group over the next 10 weeks. Thus changes of the reproductive cells of male mice caused by exposure to enflurane adversely affect the learning function of their offspring.

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.

The possibility of damage to the ciliated epithelium of the tracheobronchial tree by dry anesthetic gases was investigated in six patients receiving general anesthesia via endotracheal tube for three hours or more. Controls included 12 patients exposed to 60 per cent relative humidity at room temper

The patency of palmar arches must be ascertained before radial-artery cannulation is performed. A simple test in which digital pulsation is felt after proximal occlusion of the radial artery has been devised for that purpose. The method is reliable, does not require active patient cooperation, and can be carried out in all clinical situations where the radial artery can be felt.

Local anesthetics injected into the epidural space during a uterine contraction are commonly believed to produce a higher than usual level of anesthesia. This was evaluated in 34 parturients undergoing continuous lumbar epidural labor analgesia. The patients were divided into two equal groups. In group A, the inducing dose (2% chloroprocaine, 8 ml) was injected during an active uterine contraction and the top-up dose was injected between contractions. In group B, the injection sequence was reversed. Irrespective of the time of injection, in relation to uterine contractions, approximately 16 dermatomal segments were blocked in both groups. It is concluded that uterine contractions do not affect spread of local anesthetic solution in the epidural space.

A thermometer reaching the center of an experimental thermally-insulated lime container, placed in the exhalation limb of a Foregger circle system, was used to measure the carbon dioxide (C02) output of a paralyzed anesthetized patient. Fresh gas inflow, ventilatory rate, and tidal volume were standard. Temperature rise in the canister was found closely related to CO2 output, which was calculated, after a period of stabilization, with the help of a nomogram. The results with this simple instrument coincided with those of more complex procedures.

Commonly used disposable anesthesia circuits were studied for leak and gas spillage. Trace anesthetic gas concentrations produced by these circuits in the anesthesiologist's breathing zone were analyzed by a Hewlett-Packard Gas Chromatograph. These measurements demonstrated ambient halothane (3.29 +/- 0.1 ppm) and N2O (333.5 +/- 2.31 ppm) concentrations well above target levels, when swivel-type disposable anesthesia circuits were used, despite the presence of standard gas-scavenging devices and appropriate operating room fresh air exchange rates. Lower ambient concentration levels (0.38 +/- 0.03 ppm halothane and 31.3 +/- 1.49 ppm N2O) were measured when Y-type disposable anesthesia circuits were used.