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Biomedical subjects

C E Lucas

Publications and source records attributed to C E Lucas.

At least 55 records · Page 3Linked to original sources

The vascular-interstitial pH gradient during and after hemorrhagic shock.

The interstitial fluid space (IFS) response to hemorrhagic shock (HS)-induced metabolic acidosis is reported. Prenodal skin lymph was used as a mirror of IFS changes. Twenty-three conditioned dogs had a reservoir HS insult followed by resuscitation with shed blood, crystalloid solution containing a total of 6.5 milliequivalents of sodium per kilogram of body weight and 250 milliliters of autologous banked blood. Prenodal skin lymph pH, oxygen tension (pO2), carbon dioxide tension (pCO2), bicarbonate level (HCO3) and flow rate measured before shock, during HS and in postresuscitation in 17 dogs in group 1 were compared with simultaneous samples of central venous blood. Peripheral venous values were not measured in dogs in group 1 to preclude any effects that local dissection might have on prenodal skin lymph. Six dogs in group 2 underwent the same HS and resuscitation model; the sequential changes in central mixed venous pH and lymphatic pH were compared with peripheral venous pH. HS caused metabolic acidosis; in group 1, the mixed venous pH decreased to 7.16 and in group 2, the peripheral venous pH decreased to 7.03. In contrast, the prenodal skin lymph pH in both groups was maintained at PS levels (7.51). Mixed venous pO2 decreased sharply with HS, whereas skin lymph pO2 was maintained. Maintained prenodal skin lymph pH and pO2 during HS-induced metabolic acidosis implies that the IFS undergoes stoichiometric changes. This facilitates the preferential adherence of highly charged proteins, like albumin, to the matrix to maintain cellular homeostasis.

Acidosis↗

Delayed pneumothorax after central venous access: a potential hazard.

Percutaneous central venous catheter access is common-place in surgical patients. Though several major complications of this procedure have been described, pneumothorax is the most common. Pneumothorax is routinely assessed by a chest X-ray within 2 hours after catheter placement. During a recent 6-month interval, the authors identified five patients with delayed onset and diagnosis of pneumothorax following percutaneous central venous access. All immediate post-insertion chest X-rays were normal; however, subsequent chest X-ray showed evidence of pneumothoraxes. The pneumothorax contributed to the death of one patient on positive pressure ventilation. A review of the literature revealed a total of 18 patients in the English literature with this complication. Although the incidence of delayed pneumothorax is low, it is, in some instances, life threatening, particularly in patients on positive pressure ventilation. A high index of suspicion is required to diagnosis and treat this reversible condition.

Adult↗

A comparison of the gastric bypass and the gastric wrap for morbid obesity.

The standard for surgical treatment of morbid obesity is gastric reservoir reduction (GRR). The two popular techniques for GRR are the gastric bypass (GBP) and vertical banded gastroplasty. In 1981, a new approach to GRR, namely, the gastric wrap (GW) was introduced. The GW envelops the stomach in a customized Teflon (polytetrafluoroethylene) mesh. The current study compares, for the first time, the long term efficacy of GW and GBP. One hundred and five morbidly obese patients were studied. Fifty-two patients had GBP and 53 had GW. Preoperative and ideal weights averaged 301 and 129 pounds in the GW patients versus 278 and 123 pounds in the GBP patients. The two groups had similar age, height and co-morbid conditions. All patients survived the operation. After discharge, the patients had follow-up examinations at two weeks, two months, six months and then yearly. The GW was significantly more effective than the GBP in attaining and maintaining weight loss. The increased percent excess weight loss (percent EWL) was statistically significant at 12 months when the GW patients achieved 67 percent EWL compared with 57 percent EWL in the GBP patients. After the third year, the percent of EWL declined in the GBP patients, averaging 48 percent at four years and 47 percent at five years. In contrast, the GW patients maintained a 72 percent EWL at four years and a 66 percent EWL at five years. This weight loss was accomplished without nutritional embarrassment in both groups. The superiority of the GW in achieving and maintaining weight loss is reflected by the opinions of the patients regarding the attainment of preoperative objectives and their willingness to recommend GW to others. The downside of the GW is the higher incidence of reversal and the increased technical difficulties with reversal or revision compared with the GBP.

Adult↗

Triiodothyronine (T3) improves cardiovascular function during hemorrhagic shock.

Prior work showed that an intact thyroid axis augments survival from hemorrhagic shock (HS); this study assesses the effects of specific thyroid-related hormones on cardiovascular (CV) function during HS. Following thyroidectomy, 32 conditioned male dogs were subjected to HS to a mean arterial pressure (MAP) of 60 mm Hg for 90 min then to 40 mm Hg for 30 min. Postshock (PS), the dogs received thyroid-releasing hormone (TRH; 2 mg/kg), thyroid-stimulating hormone [control (TSH; 10 IU)], T3 (12 micrograms/kg), or T4 (40 micrograms/kg). Thirty minutes following treatment (PTX), they were resuscitated with shed blood and 50 ml/kg saline. CV and hormonal parameters were measured PS, PTX, postresuscitation (PR), and on day 2 (D2). There were no PS differences in CV parameters between groups. Following treatment, T3 significantly increased MAP (59.0 +/- 13 vs, 39.9 +/- 2.2 mm Hg) and cardiac output (CO; 0.92 +/- 0.1 vs. 0.80 +/- 0.1 liter/min; P < 0.05 by ANOVA). TRH treatment significantly improved PTX MAP (62.7 +/- 10 vs. 40.8 +/- 2.1; P < 0.05 by ANOVA). TSH and T4 did not significantly change PTX MAP or CO. There were no significant CV differences in the four groups following resuscitation or on D2. In conclusion, T3 improves MAP and CO during hemorrhagic shock. TRH transiently improved PTX blood pressure. Further study of the mechanism of this beneficial response afforded by T3 administration is warranted.

Animals↗

A comparison of gastrostomy techniques in patients with advanced head and neck cancer.

Patients with advanced head and neck carcinomas often suffer from impaired deglutition and require prolonged enteral feedings during therapy. This retrospective study analyzed 75 patients managed with three different gastrostomy techniques. Thirty patients received a percutaneous endoscopic gastrostomy; 28 patients had an open tube gastrostomy using a Foley or Malecot catheter through a purse-string stay suture; and 17 patients received an open-tube gastrostomy with a 1-cm Dacron-cuffed Silastic catheter enclosed in a 3-cm Witzel tunnel with the cuff buried in the subperitoneal pocket. The complication rate for 100 days of tube use was 0.21 for cuffed Silastic gastrostomy, 0.35 for open tube gastrostomy, and 1.41 for the percutaneous endoscopic gastrostomy group. We conclude that the cuffed Silastic gastrostomy technique is superior in this patient population.

Enteral Nutrition↗

Splenic abscess associated with endocarditis.

BACKGROUND: Refractory or recurrent sepsis in patients with endocarditis may be from splenic abscess. The purpose of this review is to assess this relationship. METHODS: Of 564 patients treated for documented endocarditis between 1970 and 1990, splenic abscesses developed in 27 patients. The mean age of the 18 men and nine women was 37 years. Etiologic factors included street drugs, dental abscess, and rheumatic fever. Symptoms included fever, myalgia, chills, and dyspnea; the prodrome averaged 2 weeks. Typical signs were heart murmur, left lower-lobe infiltrate, and leukocytosis. Splenomegaly was found in three patients. All patients had valve lesions, which involved the aortic valve alone in 10 patients, the mitral valve alone in eight patients, and multiple valves in nine patients. RESULTS: A splenic defect on computed axial tomographic scan was diagnosed correctly as an abscess in 10 patients, was indeterminant in three patients, and was incorrectly called an infarct in four patients. Thirteen patients died. All 10 patients treated without splenectomy died, including five patients who underwent valvular replacement. In contrast, only three of 17 patients treated by splenectomy with (11 patients) or without (six patients) valvular surgery died. CONCLUSIONS: Splenic abscess often accompanies endocarditis. The diagnosis is suspected by refractory fever and confirmed by abdominal computed axial tomography scan. Splenectomy is warranted before or after valvular surgery, depending on the patient's clinical response to antibiotics.

Abscess↗

The influence of an anesthetic regimen on patient care, outcome, and hospital charges.

The effects of the anesthetic regimen on patient care, outcome, and hospital charges were studied in 86 morbidly obese patients who underwent gastric reservoir reduction at two hospitals (A and B) in the Detroit Medical Center. At Hospital A, postoperative ventilation was routinely planned in 36 patients who received two intravenous lines, an arterial ine, and a Foley catheter. At Hospital B, postoperative ventilation was not routinely planned for in 50 patients who received one intravenous line and no Foley catheter or arterial line. For anesthesia, Hospital A routinely used isoflurane (0.98%) and N2O (53.0%) with little fentanyl (0.7 mg in 26 patients). Muscle relaxation with pancuronium (13.2 mg) was reversed in only five patients. In contrast, Hospital B patients used little isoflurane (0.4% in 14 patients),* more N2O (64.0%),* more fentanyl (1.3 mg),* and less pancuronium (9.7 mg)*; reversal with naloxone and pyridostigmine was routine. The operating room time was longer in Hospital A patients (5.0 vs 4.6 hours),* and they received significantly more intravenous fluids (6.2L vs 3.2L).* Routine postoperative ventilation in Hospital A patients led to a 46.5 hour intensive care unit stay and a 9.7 day postoperative stay. In contrast, routine anesthetic reversal allowed operating room extubation, patient self-transfer to the stretcher, and ambulation on the day of surgery in Hospital B where patients had a 1.7 hour recovery room stay and a 9.6 day postoperative stay. Total hospital charges in Hospital A patients averaged $14,524.00 due to the increased cost of the intensive care unit ($2,094.00) and support services versus $7,580.00* in Hospital B patients. All 86 patients survived.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Recurrent spontaneous intrahepatic hemorrhage from peliosis hepatis.

Peliosis hepatis is a rare and highly lethal liver lesion in which numerous blood-filled cavities or cystic spaces are dispersed throughout the hepatic parenchyma. The cause is unknown, although the condition is associated with several disease states and medications. Patients may present with hemorrhage, liver failure, the hepatorenal syndrome, cholestasis, or portal hypertension. We treated a patient who survived two separate hemorrhages from peliosis hepatis. The surgical intervention used, hepatic dearterialization, has allowed this patient to remain asymptomatic for 5 years.

Female↗

Splenic trauma. Choice of management.

The modern era for splenic surgery for injury began in 1892 when Riegner reported a splenectomy in a 14-year-old construction worker who fell from a height and presented with abdominal pain, distension, tachycardia, and oliguria. This report set the stage for routine splenectomy, which was performed for all splenic injury in the next two generations. Despite early reports by Pearce and by Morris and Bullock that splenectomy in animals caused impaired defenses against infection, little challenge to routine splenectomy was made until King and Schumacker in 1952 reported a syndrome of "overwhelming postsplenectomy infection" (OPSI). Many studies have since demonstrated the importance of the spleen in preventing infections, particularly from the encapsulated organisms. Overwhelming postsplenectomy infection occurs in about 0.6% of children and 0.3% of adults. Intraoperative splenic salvage has become more popular and can be achieved safely in most patients by delivering the spleen with the pancreas to the incision, carefully repairing the spleen under direct vision, and using the many adjuncts to suture repair, including hemostatic agents and splenic wrapping. Intraoperative splenic salvage is not indicated in patients actively bleeding from other organs or in the presence of alcoholic cirrhosis. The role of splenic replantation in those patients requiring operative splenectomy needs further study but may provide significant long-term splenic function. Although nonoperative splenic salvage was first suggested more than 100 years ago by Billroth, this modality did not become popular in children until the 1960s or in adults until the latter 1980s. Patients with intrasplenic hematomas or with splenic fractures that do not extend to the hilum as judged by computed tomography usually can be observed successfully without operative intervention and without blood transfusion. Nonoperative splenic salvage is less likely with fractures that involve the splenic hilum and with the severely shattered spleen; these patients usually are treated best by early operative intervention. Following splenectomy for injury, polyvalent pneumococcal vaccine decreases the likelihood of OPSI and should be used routinely. The role of prophylactic penicillin is uncertain but the use of antibiotics for minor infectious problems is indicated after splenectomy.

Adult↗

Colloid oncotic pressure and body water dynamics in septic and injured patients.

Colloid oncotic pressure (COP) and fluid shifts were studied in 43 septic (SS) patients and 33 injured (HS) patients (ISS = 48.2). During maximal postresuscitation fluid retention, plasma volume (PV/RISA), red cell volume (RBC/51Cr), inulin space (ECF), and COP were measured. Interstitial space (IFS), PV/IFS ratio, and correlation coefficients (r) were calculated. A subgroup of 22 SS patients and 22 HS patients of equal study weight were also compared. Septic patients had greater IFS expansion (17.6 L vs. 11.5 L) than HS patients who, by inference, had more intracellular expansion. Expansion of IFS in SS patients correlated (r = -0.76, p less than 0.02) with reduced plasma COP; this was not seen in HS patients (r = -0.09, p less than 0.35). In contrast, plasma COP correlated (r = 0.72, p less than 0.001) with PV/RISA in HS patients but not in SS patients (r = 0.09, p greater than 0.35). We conclude: (1) SS patients with greater IFS expansion that correlates with reduced plasma COP likely have increased capillary permeability; and (2) HS patients with less IFS expansion that does not correlate with reduced plasma COP likely have maintained capillary permeability with altered IFS matrix configuration causing reduced protein exclusion.

Blood Proteins↗

Antrectomy with gastrojejunostomy for unresectable pancreatic cancer-causing duodenal obstruction.

The traditional approach to gastric outlet obstruction caused by unresectable pancreatic cancer is gastrojejunostomy performed during or after biliary bypass surgery. Previous work showed that gastrojejunostomy failed in 95% of patients with preoperative outlet obstruction, which was evidenced by nausea and vomiting. This study defines a better bypass procedure, namely, antrectomy with gastrojejunostomy, which was performed in 19 such patients. The cancer was primary pancreatic in 17 patients and metastatic to the pancreas in two patients with a renal and urinary bladder primary. All patients had duodenal extension with impaired alimentation. Fourteen patients underwent simultaneous biliary bypass surgery and antrectomy with gastrojejunostomy; the antrectomy with gastrojejunostomy procedure was performed in five patients 3 weeks to 6 months after biliary bypass surgery when duodenal obstruction supervened. Visible cancer extended to the duodenal stump in five patients, including two patients whose partial closure was buttressed with omentum. All 19 patients tolerated regular diet at the time of discharge 1 to 4 weeks after the antrectomy with gastrojejunostomy procedure. All patients, who died at 4 to 21 months after surgery tolerated solid food until immediately before death. All nine surviving patients have taken solid foods 9 to 29 months since the antrectomy with gastrojejunostomy procedure. We conclude that the antrectomy with gastrojejunostomy procedure, whether performed simultaneously with or subsequently to biliary bypass surgery, is the best palliative procedure for duodenal obstruction in patients with unresectable pancreatic cancer.

Aged↗

Sclerotherapy of bleeding esophageal varices using a thrombogenic cocktail.

The short- and long-term efficacy of a thrombogenic sclerosant (1% tetradecyl sulfate, thrombin, and cefazolin) was studied in 101 patients. The majority of patients had alcoholic cirrhosis with Child's C classification (84/101). Bleeding was controlled in 94 per cent of patients with the first sclerotherapy. In-hospital and early (within 6 weeks) mortality were 14 per cent and 19 per cent, respectively. There was a strong correlation with hospital mortality and the severity of hepatic disease. Long-term follow-up in 70 patients (mean of 16 months) showed that survival correlated with compliance to follow-up sclerotherapy and abstention from further alcohol intake. Mortality in patients compliant with follow-up was 5 per cent (1/19), as compared with 24 per cent (12/51) in patients who were not compliant with follow-up sclerotherapy. The mortality in alcoholic cirrhotic patients who abstained from further alcoholic intake was 6 per cent (1/17), as compared with 23 per cent (10/44) in those who continued to abuse alcohol. No systemic thrombotic or allergic events related to the use of bovine thrombin were noted during a total of 349 sclerotherapy sessions.

Adolescent↗

Postoperative complications of abdominal trauma.

Postoperative complications following laparotomy for patients with abdominal trauma may be difficult to detect, particularly in those patients with multiple injuries. Such complications may lead to multiple organ system failure and death. Consequently, techniques for prevention of these postoperative complications, from resuscitation through operation, are emphasized. These techniques include means for detecting all abdominal injuries, management of the complicated wound, and evaluation and treatment of abdominal abscesses.

Abdominal Injuries↗

Ostomy prolapse in paraplegic patients: etiology, prevention, and treatment.

Colostomies are sometimes used to manage those SCI patients who have large pressure sores that are frequently soiled by stool. Seventeen such patients in an Acute Spinal Cord Injury Unit were reviewed to define the problem of ostomy prolapse in paraplegic patients. It was concluded that prolapse is more likely in those patients with an injury at or above the T-10 level. The two patients who had loop colostomies developed prolapse. Those ostomies that were end-sigmoid and exteriorized into an area where there was sensation and abdominal wall muscular integrity were the most successful.

Acute Disease↗

Efficacy of liver wound healing by secondary intent.

Nonoperative treatment of liver injury raises questions about liver wound healing (LWH) when the edges are not approximated by primary intent. The efficacy of LWH was studied in 18 dogs and 18 pigs with a total of 108 standard 6-cm injuries. The 36 injuries in six dogs and six pigs were compressed for hemostasis and then allowed to heal by second intent. LWH in these animals was compared to 36 liver wounds in six dogs and six pigs following primary closure (hepatorrhaphy) and 36 liver wounds after omental buttress plus hepatorrhaphy in six dogs and six pigs. Average wound breaking strength (WBS) of liver wounds was studied at 3 weeks (54 wounds) and 6 weeks (54 wounds) with a Chatillon tensiometer and microscopic analysis. The WBS of liver wounds was also compared to normal uninjured liver WBS. The porcine WBS at 3 weeks after healing by second intent (0.31 kg/cm2) was similar to the WBS at 3 weeks after healing by hepatorrhaphy (0.30 kg/cm2) and omental buttress (0.25 kg/cm2). Porcine WBS at 6 weeks after healing by second intent was significantly greater than WBS at 6 weeks after hepatorrhaphy or omental buttress. The canine WBS at 3 weeks after healing by second intent exceeded WBS at 3 weeks after hepatorrhaphy or omental buttress. Canine WBS at 6 weeks after healing by second intent exceeded WBS at 6 weeks after omental buttress and was similar to WBS at 6 weeks after hepatorrhaphy. WBS in all groups paralleled the extent of fibrosis seen on microscopic analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Management of close-range shotgun injuries to the chest by diaphragmatic transposition: case reports.

A method of reconstructing the chest wall following close-range shotgun injuries is described. This technique requires detaching the diaphragm peripherally and suturing it above the chest wall defect, resulting in an intact chest cavity and an abdominal wall defect. This latter problem can then be addressed by a variety of standard methods. Two patients are presented with excellent long-term results of diaphragmatic transposition, which should be in the armamentarium of all surgeons who deal with trunk trauma.

Adult↗

Update on trauma care in Canada. 4. Resuscitation through the three phases of hemorrhagic shock after trauma.

There are three phases of acute hemorrhagic shock after trauma. In phase I (from injury to operation for control of bleeding) the patient suffers from low cardiac output, tachycardia, reduced organ perfusion, oliguria and decreased capillary hydrostatic pressure, which in turn reduces extravascular fluid loss. Contraction of the interstitial space matrix replenishes plasma volume. Optimal therapy includes blood and crystalloid replacement to restore plasma volume, red cell mass and interstitial fluid. Three litres of crystalloid are usually required for each litre of blood lost. After operation, a period of obligatory extravascular fluid sequestration occurs as the intracellular and interstitial spaces expand (phase II). Optimal replacement therapy during this phase maintains plasma volume. Replacement is provided according to the patient's vital signs, because extravascular fluid expansion cannot be influenced by therapeutic manipulation. Phase III is a mobilization and diuretic phase. During this phase systolic hypertension may occur, and the patient must be treated with restriction of fluid, diuresis and careful monitoring of the heart and lungs. Attempts to alter these physiologic responses with supplemental albumin have proved detrimental. The albumin causes salt and water retention in the nephron, leading to weight gain, higher central filing pressures and worsening pulmonary function, and a greater need for diuretic and inotropic therapy. Albumin therapy also induces relocation of non-albumin proteins into the interstitial space, leading to impaired immunocompetence and coagulation. Successful resuscitation is facilitated by adaptation to these physiologic responses of hemorrhagic shock rather than manipulation of them.

Albumins↗