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W S Howland

Publications and source records attributed to W S Howland.

At least 37 records · Page 2Linked to original sources
PubMed1982

High-frequency jet ventilation: theoretical considerations and clinical observations.

High-frequency jet ventilation (HFJV) described a technique of mechanical respiratory support based on the delivery of gases under conditions of constant flow and low pressure. Among the benefits ascribed to HFJV are lessened interference with hemodynamic function and reduced danger of barotrauma. The theoretical and technical aspects of HFJV are discussed and the clinical experience with 39 patients in respiratory failure reported. Synchronization of HFMV with heart rate was attempted in three patients. Cardiac output and ejection fraction increased in all of them. At present, results suggest that HFJV may be the ideal form of support for patients with major airway disruption. The available data also indicated that extensive clinical trials are warranted to define advantages and limits of this form of ventilation.

Bronchial Fistula↗
PubMed1981

The seventies evolution in liver surgery for cancer.

During the past decade, one of the major changes in the field of oncology has been in the surgical approach to primary and secondary cancer of the liver. As a result of data and experience gained in liver transplantation programs and with the application of vascular surgical principles, resectability rates have been increased. The present rate of 32% has been achieved with an overall 30-day operative mortality rate of 9%. More sophisticated intraoperative and postoperative supports have been essential in achieving these results. The median operating time is now 4 3/4 hours in length. Complications are minimal. The median postoperative hospital stay is now 13 days. During the past decade, 436 patients with liver tumors were treated by the authors. It has become apparent in this experience and in that reported by others that an increasing number of patients with primary liver cancer or metastatic cancer in the liver can be cured by surgery with minimal operative risk. Adjuvant chemotherapy may increase the salvage rate. Current therapeutic results are best evaluated after staging of the liver disease: Stage I (no involvement of margins of resection, hepatic vascular structures or bile ducts; all gross disease removed): 85% three-year survival estimate, using the Kaplan-Meier method, for individuals with primary liver cancer; 71% for those with metastatic colorectal cancer. Stages II and III (regional or extrahepatic spread): 22% three-year survival for individuals with primary liver cancer but no survivors at two years with metastatic colorectal cancer. These data permit better selection of patients who are most likely to benefit from surgery.

Adolescent↗
PubMed1981

High-frequency jet ventilation in major airway or pulmonary disruption.

High-frequency jet ventilation is an experimental method of mechanical support, which achieves satisfactory alveolar ventilation and oxygenation at low peak-inspiratory pressures of 5 to 8 cm H2O and low end-expiratory pressures of 3 to 5 cm H2O. This characteristic was used to advantage in 23 patients with cancer, 12 of whom had tracheal or bronchial disruption complicated by pneumonia. Eight patients who could not be supported by conventional means were salvaged. Barotrauma complicated the very high peak airway pressures required to ventilate 8 of 11 patients with respiratory failure associated with diffuse interstitial pneumonia or pulmonary fibrosis. There were only 2 survivors despite temporary normalization of arterial blood gas values in 7 patients. Earlier use of high-frequency jet ventilation in patients with poor compliance may prevent pulmonary disruption in addition to deleterious hemodynamic and systemic effects of conventional high-pressure ventilation. Other applications under study include the role of jet ventilation in resection of the trachea or carina, and in major airway trauma.

Acute Disease↗
PubMed1981

Clinical experience with high frequency jet ventilation.

High frequency jet ventilation (HFJV) has been used in recent years in some forms of respiratory failure, where the presence of barotrauma limited the application of high peak inspiratory pressure. In the present report, the authors describe the clinical experience with 17 patients, who could not be supported with conventional mechanical support and were placed on HFJV. Rates of 100 breath/min, inspiratory/expiratory ratio of 1:2 and cannula size of 1.06--1.62 mm (18--14) gauge were used. Driving pressure required to maintain a PaCO2 of 40--45 torr was 14--45 psig; however, except in 2 patients who developed hemorrhagic tracheitis with subtotal obstruction of both mainstem bronchi, a driving pressure higher than 27 psig was never required, even when PEEP up to 32 cm H2O was used. Of 17 patients treated, 8 survived. In all cases, alveolar ventilation could be maintained within the desired range with high frequency ventilation, even in those patients who eventually died; mechanical support never provided better oxygenation or alveolar ventilation than high frequency ventilation. Hemodynamic function was essentially unchanged with high frequency ventilation; indeed, in three cases, inotropic support with dopamine could be discontinued after initiation of high frequency ventilation.

Carbon Dioxide↗
PubMed1981

Dopamine administration in oliguria and oliguric renal failure.

Oliguric renal failure significanlty worsens the prognosis of many critical illnesses, particularly in patients with respiratory failure. In 52 patients, a continuous infusion of dopamine, 1.5-2.5 micrograms/kg . min, was administered when creatine clearance (Ccr) fell below 40 ml/min and urinary output was less than 1 ml/kg . h despite normal intravascular volume. In 18 patients, a continuous infusion of furosemide (3-5 mg/kg . day) was also administered. Daily, two 3-h collections of urine and blood specimens were obtained to determine Ccr, osmolar clearance (Cosm), free water clearance (CH2O) and excreted fraction of filtered sodium (FENa); one collection was made during dopamine infusion and one while the infusion was suspended. Cardiac output and pulmonary venous admixture were also measured. The authors obtained 199 urine collections in 52 patients; considering the aggregate patient pouplation, urinary output increased by 42.3% (30.2 +/- 3.45 (SEM) ml/h), on dopamine infusion. Cosm, FENa, and Ccr were also higher on dopamine. CH2O and hemodynamic variables were not altered by dopamine infusion. When patients were startified on the basis of mechanical ventilatory support, Ccr and furosemide administration, dopamine infusion essentially caused the same changes in the variables studied as described for the aggregate patient population. Diuresis and sodium excretion increased significantly on dopamine even in those patients receiving furosemide infusion. The authors conclude that fluid and osmolar load can be eliminated more effectively in critically ill patients with continuous infusion of 1.5-2.5 micrograms/kg . min of dopamine.

Anuria↗
PubMed1980

Calcium chloride administration in normocalcemic critically ill patients.

Ten normocalcemic critically ill patients who had experienced a decrease in cardiac index greater than or equal to 0.5 liter/min/m2 after incremental changes of PEEP received 7 mg/kg of CaCl2 as a slow iv bolus, followed by an infusion of 20 mg/kg CaCl2 over 60 min. Hemodynamic pressures and flow, oxygen uptake and transport, and blood chemistry variables were determined over a 120-min period. The results indicated that: (1) hemodynamic variables were not affected except for left ventricular stroke work index and mean blood pressure, which increased slightly; (2) both serum calcium and ionized calcium concentrations increased significantly, sometimes to dangerous levels; (3) colloid osmotic pressure and hemoglobin levels decreased slightly but consistently. In conclusion, CaCl2 administration failed to improve hemodynamic function depressed by PEEP. If CaCl2 can play a relevant role in the management of cardiovascular depression, further identification of appropriate doses and patients is necessary.

Aged↗
PubMed1980

Evaluation of an "in vivo" PaO2 and PaCO2 monitor in the management of respiratory failure.

A commercially available gas-chromatograph (Sentorr Gas Analyzer, Ohio Medical Products, Madison, WI) was tested, featuring continuous measurement of in vivo PaO2 and PaCO2 by means of a thin, heparin-coated catheter, inserted through an indwelling arterial line. Gas tensions are displayed every 4 min. The probes had a tendency to break rather easily, and a considerable proportion of them was faulty. We measured 105 paired determinations of blood gases obtained from patients in respiratory failure requiring mechanical ventilation with a Corning IL 175 Analyzer and displayed by the Sentorr Gas Analyzer. A high correlation (p < 0.01) existed between the two sets of values, but an estimated error of 10-20% was found in the Sentorr data. After modifications of the respirator, changes of displayed values were already notable after 4 min and 90% completed by 8-12 min. The use of this device enabled us to considerably accelerate decision-making in the management of respiratory failure. Although techology still necessitates improvements, before widespread use of in vivo monitoring of PaO2 and PaCO2 is advisable, the concept has significant clinical potential and may represent a major advance in the management of respiratory failure.

Carbon Dioxide↗
PubMed1980

Pulmonary venous admixture during mechanical ventilation with varying FIO2 and PEEP.

Many authors have indicated that high FIO2 (0.75-1.0) ventilation may increase pulmonary venous admixture. Reabsorption atelectasis is supposedly responsible for this adverse effect. The authors attempted to determine if increasing PEEP during high FIO2 ventilation could eliminate the detrimental influence of the latter. In 17 patients in respiratory failure, hemodynamic and respiratory variables were measured during ventilation with FIO2 0.50, 0.75, and 1.0 and PEEP varying from -3 to +5 cm H2O from baseline. Before exposure to FIO2 > 0.75, addition of PEEP resulted in a decrease of Qs/Qt from a mean of 26.6-21.9%. After exposure to FIO2 0.75-1.0, Qs/Qt remained at levels not different from baseline, even when PEEP 8 cm H2O above baseline was added. The authors conclude that ventilation with high FIO2 is not useful in determining Qs/Qt, and may prevent the improvement in pulmonary venous admixture associated with PEEP therapy.

Blood Gas Analysis↗
PubMed1979

Unexpected giant "V" waves during pulmonary artery catheterization.

Two cases of catheterization of the pulmonary artery, in which the hemodynamic findings were very different from the initial clinical diagnosis, are presented. The importance of verifying the adequate position and motion of the pulomonary artery catheters with two consecutive chest x-rays is discussed. In particular, attention is brought to the possible misinterpretation that occurs in patients with very elevated pulmonary artery mean pressure.

Blood Pressure↗
PubMed1979

Nephrotoxic antibiotics in patients with renal failures: guidelines for debilitated patients.

Fifty-seven cancer patients, who had had an 8--15% loss of body weight in the previous 6 months, were studied to establish the reliabity in wasted individuals of presently available nomograms correlating serum creatinine with creatinine clearance. Other predictors of renal function, such as osmolar clearance, free water clearance, and excreted fraction of filtered sodium, were also considered. In all patients, and especially in those with a measured creatinine clearance 10--50 ml/min, the use of standard nomograms based on serum creatinine resulted in gross overestimation of renal function. None of the other tests of renal function proved reliable for clinical purposes. It is concluded that in wasted patients administration of nephrotoxic drugs that are renally excreted should be adjusted to measured creatine clearance. Using other common predictors of renal function may result in overdosage.

Aminoglycosides↗
PubMed1978

Factors influencing postoperative morbidity and mortality in patients treated with bleomycin.

Patients treated with bleomycin are at risk of developing the acute adult respiratory distress syndrome post-operatively. In a prospective study of 12 patients who had received bleomycin preoperatively and were undergoing removal of retroperitoneal lymph nodes or pulmonary metastases several preventive factors were established. These were the use of low concentrations of inspired oxygen during operation and in the immediate postoperative period, careful monitoring of fluid replacement, and restriction of crystalloids in favour of colloids.

Adolescent↗
PubMed1978

Adverse effects of calcium administration. Report of two cases.

Calcium chloride, 7 mg/kg, and calcium gluconate, 20 mg/kg, were administered to patients with low or low-normal levels of serum ionized calcium. Both patients had low blood pressure and cardiac index, and did not respond to digitalis, volume expansion, and beta-adrenergic stimulation with dopamine. Administration of calcium rapid increase of serum ionized calcium levels, decrease of serum potassium levels, and development of severe cardiac arrhythmias. Atrioventricular dissociation and further fall of cardiac index and blood pressure were common features of both cases. Administration of exogenous calcium can cause severe complications, even when theoretically indicated.

Adult↗
PubMed1978

Major hepatic resection for neoplasia: personal experience in 108 patients.

One hundred eight patients have undergone major hepatic resection by the senior author during the eight year period April 1970 to April 1978. Primary liver cancer was present in 36; metastatic colorectal cancer in 25, miscellaneous metastatic cancers in 15, hepatoblastoma in 5, gallbladder cancer in 4, and bile duct cancer in 3. Benign tumors, principally giant hemangioma, were resected in 20 additional patients. The 30 day operative mortality rate was 9% overall. Prior to 1975, 41 of the resections were done using the vascular isolation perfusion technique. The operative mortality rate of 17% for this technique is a reflection of early experience and the advanced stage of disease of many patients. The operative mortality for the standard resection has been only 4%. Subphrenic abscess has developed in only 13% of patients during the past three years. Postoperative hospitalization has been shortened, being a median of 13 days. The resectability rate for malignant disease was 33%. Forty-six percent of the resections were performed with curative intent. Fifty-four per cent were palliative, performed in individuals with regional spread or distant metastasis. After curative surgery, three year survival was 88% for individuals with primary liver cancer and 72% with metastatic colorectal cancer. After palliative resection, the rates were 31 and 0%, respectively. The three year survival rate is 46% overall, being 81% for the curative resection group and 18% for the palliative group. Tumor markers proved useful in monitoring patients after hepatic resection.

Bile Duct Neoplasms↗
PubMed1978

Surgical mortality among the elderly. An analysis of 4,050 operations (1970-1974).

The overall surgical mortality rate of 3.4 percent in 32,308 operations (22,288 patients) between 1970 and 1974 was essentially the same as the 3.7 percent recorded for 30,241 operations (22,967 patients) during the preceding 5 years. The surgical mortality rate among patients 70 years or older fell significantly (p less than 0.005) from 6.8 percent of 3,754 procedures (2,766 patients) during the 1965--1969 period to 4.8 percent of 4,050 procedures (2, 783 patients) between 1970 and 1974. There was a 50 percent increase in operative mortality from all causes among the elderly when compared to the rates of 4.7 percent of patients and 3.2 percent of procedures observed in patients under the age of 70. If the patients in whom the surgical procedure seemed incidental to their death from other causes are excluded, the mortality rate among the elderly was a more realistic 2.8 percent of procedures (114 patients) between 1970 and 1974. The 30-day mortality rate from all causes noted in this group was 3.7 percent of procedures, or 5.4 percent of patients. These results appear to justify the philosophy that age alone is no contraindication to potentially curative cancer surgery, and demonstrate that such surgery can be performed with acceptable mortality rates.

Age Factors↗
PubMed1977

Serratia marcescens pneumonia.

Though rare, Serratia marcescens pneumonia is being reported with increasing frequency, especially in patients in intensive care units. We report three cases of S. marcescens pneumonia that presented striking similarities for age, group, type of surgical procedure, and microbiological, hemodynamic, and respiratory patterns. All patients survived after prolonged ventilatory support.

Aged↗