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Biomedical subjects

C J Harvey

Publications and source records attributed to C J Harvey.

51 records · Page 3Linked to original sources

Effect of a spacer on pulmonary aerosol deposition from a jet nebuliser during mechanical ventilation.

BACKGROUND: Several factors have been identified which improve nebulised aerosol delivery in vitro. One of these is the addition of a spacer to the ventilator circuit which improves aerosol delivery from a jet nebuliser to a model lung by approximately 30%. The current study was designed to demonstrate whether similar improvements could be demonstrated in vivo. METHODS: Ten patients (seven men) were studied during mechanical ventilation (Siemens Servo 900C) after open heart surgery. Aerosol was delivered using a Siemens Servo 945 nebuliser system (high setting) driving a System 22 Acorn jet nebuliser (Medic-Aid) containing 3 ml technetium-99m labelled human serum albumin (99mTc-HSA (50 micrograms); activity in the first nebulisation, 90 MBq; in the second nebulisation, 185 MBq). Central and peripheral lung aerosol deposition and the time to complete deposition were measured using a gamma camera and compared when the nebuliser was connected to the inspiratory limb using a simple T-piece or a 600 ml spacer. RESULTS: The addition of the spacer increased total lung deposition (mean (SD) percentage initial nebuliser activity) from 2.2 (0.7)% to 3 (0.8)%. There was no difference in the time required to complete nebulisation (18.2 min v 18.3 min respectively for T-piece and spacer) or in the retention of activity in the nebuliser (46.2% v 47.1% respectively). CONCLUSIONS: The combination of a spacer with a jet nebuliser increased lung deposition by 36% in mechanically ventilated patients and is a simple way of increasing drug deposition or reducing the amount of an expensive drug required for nebulisation.

Aerosols↗

Critical care obstetrics: experts' round table discussion.

A panel of leading experts in critical care obstetric (CCOB) nursing met to discuss the specialty and its future, the impact of changes in the health care system, educational opportunities to learn and update CCOB nursing, formation and use of standards for the specialty, patient placement (dedicated obstetric intensive care units [OB ICU], labor and delivery intensive care units [L & D ICU], regular intensive care units [ICU]), patient populations, and interactions and working relationships with the physicians who care for CCOB patients (perinatologists, obstetricians, internists, obstetric medicine specialists, anesthesiologists, other subspecialists). The topics for discussion were chosen by Carol J. Harvey, RNC, MS, who acted as moderator and Mary Ellen Burke, RN, MS, coordinated the publication of the discussion.

Critical Care↗

Are there indications for partial rib resection in patients with adolescent idiopathic scoliosis treated with Cotrel-Dubousset instrumentation?

In adolescent idiopathic scoliosis the cosmetically unacceptable rib prominence is one of the main reasons patients seek treatment. Ninety-eight patients were reviewed with Cotrel-Dubousset (CD) instrumentation (average follow-up, 27 months; average preoperative curve, 53 degrees) and 27 patients with Harrington instrumentation and rib resection (average follow-up, 43 months; average preoperative curve, 52 degrees). Of the 98 patients who had CD instrumentation, 15 underwent concomitant rib resection. Of the 83 patients without rib resection, 71 (72%) were rated satisfactory and 12 unsatisfactory by cosmetic criteria based on residual rib deformity. These results were compared to those of 27 patients receiving Harrington rod instrumentation and rib resection, of whom 23 (85%) were rated as satisfactory. All 15 patients with CD and rib resection were rated satisfactory. The CD patients were then redivided into two groups (rib resection indicated or rib resection not indicated) as follows: the 12 unsatisfactory CD patients without rib resection (in whom a rib resection should have been done) were grouped with the 15 CD patients who underwent rib resection, for a total of 27 rib resections indicated, or 28%. This group was compared to the 71 satisfactory CD patients without rib resection (rib resection not indicated). Patients with a rib prominence of > 15 degrees preoperatively had or should have had a rib resection. Patients with a higher chance of needing rib resection included those with a curve severity greater than 60 degrees, curve flexibility less than 20%, a preoperative rib prominence > 10 degrees, or intraoperative curve correction of less than 50%.

Adolescent↗

Spinal cord injury and pregnancy.

Spinal cord injuries occur more frequently in women than in the past because of the societal and cultural changes in this country. Female survivors of spinal cord injuries have an improved prognosis for return to independence and societal contribution over their counterparts of 15 to 20 years ago. Because fertility is not affected, it is reasonable to predict that perinatal centers will continue to see an increase in spinal cord-injured patients. The unique nature of the injury makes pregnancy in these women a challenging event. The objectives of care are to prevent the complications associated with pregnancy while supporting independence. A multidisciplinary team approach best serves these patients and provides the best possible outcome for both mother and baby.

Adult↗

The effect of cesarean section on intraventricular hemorrhage in the preterm infant.

OBJECTIVE: The null hypothesis is that active labor is a more important factor with regard to both timing and progression of periventricular-intraventricular hemorrhage than is route of delivery. Infants delivered by cesarean section after entering the active phase of labor will behave in a manner similar to that of previously studied infants delivered vaginally as to when periventricular-intraventricular hemorrhage occurs and frequency of progression. STUDY DESIGN: The 106 infants of 85 women delivered by cesarean section were the subjects of this study. Forty-six infants were in the no-labor group, 33 in the latent-phase labor group, and 27 in the active-phase labor group. Head ultrasonographic examinations were performed at delivery, at 1, 6, 12, and 24 hours, and then daily for the first 7 days of life. Continuous variables were compared by one-way analysis of variance among those infants with no hemorrhage or with periventricular-intraventricular hemorrhage. Categoric variables were compared by chi 2 analysis and Fisher's exact test when appropriate. A p value of less than 0.05 was considered significant. RESULTS: There was no difference in the frequency of early hemorrhage (less than or equal to 1 hour of age), late hemorrhage (greater than 1 hour of age), or overall periventricular-intraventricular hemorrhage in the infants not in labor, in latent-phase labor, or in active-phase labor at the time of cesarean section. However, the frequency of grade 3 or 4 hemorrhage and the progression of hemorrhage were significantly higher in the infants whose mothers had an active phase of labor compared with infants whose mothers had no labor or did not progress beyond the latent phase. Infants who had early periventricular-intraventricular hemorrhage (less than or equal to 1 hour of age) also had a higher frequency of progression of hemorrhage. CONCLUSIONS: Cesarean section before the active phase of labor does not change the overall frequency of hemorrhage but results in a lower frequency of progression to grade 3 or 4 hemorrhage. We do not feel that these data support performing more cesarean sections for preterm delivery as a method of preventing progression of periventricular-intraventricular hemorrhage in the preterm infant.

Birth Weight↗

Management of the intrapartum patient in the intensive care unit: preparing for delivery.

Caring for a critically ill obstetric patient requires a thorough understanding of both the pathophysiology of the disease and the physiologic changes that accompany pregnancy and childbirth. This article addresses the care of an intrapartum patient in an intensive care unit. Physiologic aspects of the labor and delivery process are reviewed with emphasis on nursing assessments and interventions. Additionally, techniques for delivery of the neonate are presented.

Critical Care↗

Pregnancy-induced hypertension: understanding severe preeclampsia and the HELLP syndrome.

Pregnancy-induced hypertension (PIH) is a multisystem disease with life-threatening complications requiring expert nursing and medical management. Nurses caring for critically ill patients with this disease must be knowledgeable about the pathophysiologic occurrences of PIH as well as the protocols for anticonvulsant and antihypertensive therapy. This article presents the hemodynamic alterations of preeclampsia, the pathophysiology of the disease, and principles of acute management.

Critical Care↗

Principles of oxygen transport in the critically ill obstetric patient.

Invasive hemodynamic monitoring is commonly used in critically ill patients in whom cardiorespiratory compromise is evident. The information acquired assists the clinician in the assessment of cardiac and intravascular status. However, many patients have complex pathophysiologic conditions that dictate the evaluation of their oxygen transport system. This article provides a discussion of the principles of oxygen transport, including the concepts of oxygen content, oxygen affinity, oxygen delivery, and oxygen consumption. Clinicians providing care for critically ill pregnant women should have a thorough understanding of the physiology of oxygen transport, its alterations in specific disease process, and interventions necessary to improve the individual components of oxygen transport.

Critical Care↗

Systemic lupus erythematosus: obstetric and neonatal implications.

Systemic lupus erythematosus (SLE) is a collagen vascular disease that may have a tremendous impact on pregnancy. The pregnant patient with SLE is at increased risk for fetal wastage, intrauterine growth retardation (IUGR), intrauterine fetal demise (IUFD), pregnancy-induced hypertension (PIH), and exacerbations of the lupus process. SLE is an autoimmune disease with tremendous implications for pregnancy. The diagnosis of SLE is based on criteria developed by The American Rheumatism Association. The recent identification of circulating antibodies associated with women who have lupus has led to some confusion. The circulating antibodies are associated with an increased risk of fetal wastage. However, those antibodies have been documented in women who do not have lupus. The diagnosis of SLE and pregnancy requires intensive obstetrical care. SLE may also affect the neonate, from skin lesions to complete heart block. This article describes the effects of SLE on the mother, pregnancy, and the neonate.

Adrenal Cortex Hormones↗

Pulmonary edema in severe preeclampsia-eclampsia: analysis of thirty-seven consecutive cases.

During approximately a 9-year period, 37 severe preeclamptic-eclamptic patients had pulmonary edema for an incidence of 2.9%. The incidence was significantly higher in older patients (p less than 0.0001) and in multigravid patients (p less than 0.05). Eleven (30%) had antepartum edema with 10 (90%) of the 11 having preexisting chronic hypertension. Twenty-six (70%) had postpartum edema with an average onset of 71 hours post partum. The majority of these patients had excessive colloid and crystalloid infusions for various medical, surgical, and obstetric complications. There were four maternal deaths and morbidity was significant. Eighteen patients had disseminated intravascular coagulopathy, 17 had sepsis, 12 had abruptio placentae, 10 had acute renal failure, six had hypertensive crisis, five had cardiopulmonary arrest, two had rupture of the liver, and two had ischemic cerebral damage. The overall perinatal mortality was 530/1000 and neonatal morbidity was significant. Pulmonary edema is infrequent in severe preeclampsia-eclampsia without associated medical, surgical and obstetric complications. The occurrence of pulmonary edema in such patients is associated with high maternal and perinatal mortality and morbidity.

Adult↗

Interpreting the electronic fetal monitor. Strategies for management.

Electronic fetal monitoring offers the practitioner involved in the intrapartum care of women a mechanism to validate the fetus' physiologic adaptation to the labor and delivery experience. Utilizing a predetermined framework for constant assessment of fetal well-being will assist the clinician in the bedside management of these patients. This pathway of reassurance for fetal evaluation is an effective tool in the intrapartum observations of the fetus. If the fetus can demonstrate his physiologic well-being, labor may continue. However, if there are no signs of reassurance, immediate delivery of the fetus should be considered.

Acidosis↗

Functional CT imaging of the acute hyperemic response to radiation therapy of the prostate gland: early experience.

PURPOSE: Functional CT can measure perfusion and permeability. We hypothesized that acute changes could be measured in these indexes following radiation therapy (RT) to the prostate gland. METHOD: Twenty-two patients with prostatic cancer were studied before and 1-2 and 6-12 weeks after RT. A single section through the prostate was repeatedly scanned after contrast medium bolus injection. Contrast agent clearance per unit volume (alpha/V) and fractional vascular volume (fvv) were calculated using Patlak graphical analysis. Perfusion was calculated as the ratio between maximal rate of tissue enhancement and peak arterial enhancement. RESULTS: Significant increases in all indexes occurred after RT. Mean perfusion rose from 0.122 to 0.263 ml/min/ml at 1-2 weeks, mean alpha/V increased from 0.0012 to 0.0016 ml/min/ml at 1-2 weeks, and mean fvv increased from 13.7 to 21% at 1-2 weeks. All three indexes remained elevated at 6-12 weeks after the start of RT. CONCLUSION: Functional CT demonstrated an acute hyperemic response following RT to the prostate gland.

Acute Disease↗