SUPERIOR MESENTERIC VEIN OCCLUSION PRESENTING WITH A MASSIVE VASCULAR MALFORMATION OF THE COLON

Superior mesenteric vein occlusion is a rare condition which has protean clinical manifestations. It frequently occurs secondary to an underlying coagulation defect. We present the case of a young female who presented uniquely with a massive colonic vascular malformation and who had various predisposing factors, the most serious being a protein C deficiency.     

Significance of diastolic pulmonary artery pressure peaks

We describe a patient undergoing elective surgery for treatment of an abdominal aortic aneurysm in whom an abrupt change in the contour of the pulmonary artery pressure (PAP) trace indicated the development of an intermediate (20 mm Hg) V wave in the pulmonary artery wedge pressure (PAWP) trace. As the PAP trace is displayed continuously, attention to its contour may allow for early detection of changes to the underlying PAWP trace.FC Anaesth     

Use of Vasopressin in a Canine Model of Severe Verapamil Poisoning: A Preliminary Descriptive Study

OBJECTIVES: The purpose of this preliminary study was to evaluate the effect of arginine vasopressin (AVP) administration in a model of shock induced by calcium channel antagonist overdose and to determine endogenous serum AVP concentrations in calcium channel antagonist-induced shock. METHODS: This was a controlled, randomized laboratory investigation based on a previously described canine model of verapamil toxicity. After induction of verapamil toxicity, animals in both the control and the experimental groups (n = 6 each) received a continuous infusion of verapamil. Experimental animals received an escalating dose of AVP, while control animals received an equal volume of 0.9% saline infusion. The hemodynamic end point was return of mean arterial pressure (MAP) to within 20% of baseline. Surviving animals were killed after 60 minutes. RESULTS: In the treatment group, administration of low-dose AVP (4 mU/kg/min) resulted in further declines in cardiac index and heart rate. No significant change was noted in MAP with low-dose AVP. A slight increase in MAP was noted with both escalating doses of AVP and equivalent volumes of normal saline. By the end of the 60-minute antidote/saline phase, the MAPs of the saline control group and the AVP experimental group were similar. The primary hemodynamic end point was not achieved in either the AVP or the saline control arm. Mean baseline serum AVP concentration in control animals was 5.8 pg/mL, increasing to 225 pg/mL during the toxicity phase. CONCLUSIONS: In an animal model of verapamil-induced shock, endogenous AVP levels increased nearly 40-fold compared with baseline levels. Escalating doses of exogenous AVP worsened cardiac index and failed to return MAP to within 20% of baseline.     

Outcomes in patients requiring repeat extracorporeal membrane oxygenation

Background

As the number of patients requiring extracorporeal membrane oxygenation (ECMO) increases nationwide, many patients may require ECMO more than once. We review our experience and outcomes in patients requiring repeat ECMO support.

Methods

The Nebraska ECMO Research Database was utilized for data analysis, and repeat ECMO patients (REPs) were compared to the overall ECMO population.

Results

Of 246 patients, 2.4% (6/246) were REPs. There was no statistical difference between the median days of initial support run (P = 0.670) and second support run (P = 0.813) for REPs when comparing to the non‐REP population. Median hospital length of stay for REPs was 53 days (16‐124) compared to the non‐REPs, who had a median hospital length of stay of 22 days (1‐270); P = 0.043. In‐hospital mortality rate for REPs was 50% (3/6) and 50% for non‐REPs (120/240). Survival 30 days postdischarge for REPs was 50% (3/6) compared to non‐REPs at 48.3% (116/240); P = NS.

Conclusions

Outcomes for repeat ECMO patients compare favorably to the overall ECMO population and suggest a need to explore and broaden the clinical indications for repeat ECMO.     

The PB3300 intraarterial blood gas monitoring system

Continuous intraarterial blood gas (IABG) monitoring is in clinical use both in the operating room and intensive care unit. This technology uses miniature, optically-based sensors that can be placed into a patient's artery. The arterial blood gas values are transduced into an optical signal that is measured by a bedside monitor on which the values are displayed. In this paper, we describe the operating principles of the PB3300 Intra-Arterial Blood Gas Monitoring System (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Topics include the principles of fluorescent determinations of pH,PCo ₂, andPO ₂; the optical path of the PB3300; system calibration; dye layer geometry; and clinical operation. The accuracy, precision, and drift of the system measuring tonometered aqueous standards are reported. The following values were noted for eight sensors sending data to eight monitors: system bias and precisions of 0.00±0.02 pH at a pH of 7.40, –2.5±1.5 mm HgPCo ₂ at aPCo ₂ of 40 mm Hg, and 3.3±1.3 mm HgPO ₂ at aPO ₂ of 80 mm Hg.

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Abstrakt Die kontinuierliche intraarterielle Blutgasüberwachung (IABG) wird klinisch sowohl im OP als auch auf der Intensivstation eingesetzt. Hierbei werden miniaturisierte, optische Sensoren angewandt, die sich direkt in der Arterie des Patienten plazieren lassen. Die Blutgaswerte werden in optische Signale umgesetzt und von einem bettseitigen Monitor gemessen und angezeigt. In dieser Arbeit beschreiben wir das Funktionsprinzip des Intra-Arteriellen Blutgasanalysesystems PB3300 (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Themen sind die Grundlagen der Bestimmung von pH, PCO2 und PO2 mittels Fluoreszenz; die optische Übertragung des PB3300; die Kalibrierung des Systems; die Geometrie der Farbschichten und der Einsatz in der Klinik. Die Genauigkeit, Auflösung und Drift des Systems bei der Messung von tonometrischen wässrigen Standards wird beschrieben. Die folgenden Werte ergaben sich aus einer Meßreihe mit 8 Sensoren, die an 8 Monitore angeschlossen waren (jeweils Bias, Streuung und Sollwert): 0.00±0.02 pH bei 7.40 pH, –2.5±1.5 mmHg PCO2 bei 40 mmHg PCO2 und 3.3±1.3 mmHg PO2 bei 80 mmHg PO2.

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Resumen La monitorizaciòn continua de gases intraarteriales tiene uso clinico, tanto en el pabellòn de operaciones como en la unidad de cuidados intensivos. Esta tecnologia utiliza sensores miniatura de tipo òptico que pueden ser introducidos en una arteria del paciente. Los valores de gases arteriales son transducidos en forma de señal òptica que es medida al lado de la cama del paciente por un monitor que presenta los valores numéricos. En este trabajo, describimos los principios de operaciòn del PB3300 Intra-Arterial Blood Gas Monitoring System (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Los temas incluyen los principios de determinaciones fluorescentes de pH, PCO₂, and PO₂; la via òptica del PB3300; calibraciòn del sistema; geometria de la capa de colorante; y la operaciòn clinica. Se presentan la exactitud, precisiòn, y deriva (drift) del sistema, midiendo soluciones acuosas de tonometrìa estàndar. Los siguientes valores fueron registrados para ocho sensores enviando informaciòn a ocho monitores: los sesgos del sistema y las precisiones fueron de 0.00±0.02 pH a pH 7.40, –2.5±1.5 mmHg PCO₂ a PCO₂ 40 mmHg, y 3.3±1.3 mmHg PO₂ a PO₂ 80 mmHg.