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Joel O Johnson

Publications and source records attributed to Joel O Johnson.

9 recordsLinked to original sources
PubMed2005

Measurement of central venous pressure from a peripheral intravenous catheter in the lower extremity.

OBJECTIVES: The measurement of central venous pressure (CVP) is used to assess intravascular status. Although this is usually accomplished by placement of a central venous catheter (CVC), there are circumstances when placement of a CVC may be technically difficult or impossible. The current study investigates the feasibility of measuring CVP from a peripheral intravenous catheter. METHODS: CVP was simultaneously measured from a CVC and from a peripheral intravenous site. The continuity of the peripheral intravenous catheter with the central venous system was evaluated by noting the change in the pressure measured from the peripheral catheter during a sustained inspiratory effort and during occlusion of the extremity (arm or leg) above the catheter. RESULTS: The cohort for the study included 37 adult patients. In 8 of the 37 patients (22%), there was no increase in the peripheral venous pressure (PVP) in response to a Valsalva maneuver or occlusion of the extremity above the intravenous site. For the upper extremity intravenous sites without a PVP increase, the PVP-CVP difference was 11.2 +/- 6.2 mm Hg versus 2.7 +/- 2.2 mm Hg in the patients in whom the PVP increased with these maneuvers (P < 0.0001). For the lower extremity intravenous sites without a PVP increase, the PVP-CVP difference was 7.6 +/- 4.0 mm Hg versus 2.6 +/- 1.9 mm Hg in the patients in whom the PVP increased (P < 0.0001). No variation in the accuracy of the technique was noted, depending on the size of the intravenous cannula, its location (upper versus lower extremity), CVP value, or patient positioning (supine, prone, lateral). CONCLUSIONS: Provided that the PVP increases to a sustained inspiratory breath and occlusion above the intravenous site, there is a clinically useful correlation between the PVP and the CVP.

Adolescent↗
PubMed2003

Methods for decreasing postoperative gut dysmotility.

Postoperative disturbances of gastrointestinal function (postoperative ileus) are among the most significant side-effects of abdominal surgery for cancer. Without specific treatment, major abdominal surgery causes a predictable gastrointestinal dysfunction which endures for 4-5 days and results in an average hospital stay of 7-8 days. Ileus occurs because of initially absent and subsequently abnormal motor function of the stomach, small bowel, and colon. This disruption results in delayed transit of gastrointestinal content, intolerance of food, and gas retention. The aetiology of ileus is multifactorial, and includes autonomic neural dysfunction, inflammatory mediators, narcotics, gastrointestinal hormone disruptions, and anaesthetics. In the past, treatment has consisted of nasogastric suction, intravenous fluids, correction of electrolyte abnormalities, and observation. Currently, the most effective treatment is a multimodal approach. Median stays of 2-3 days after removal of all or part of the colon (colectomy) are now achievable. Recent discoveries have the potential to significantly reduce postoperative ileus in patients with cancer who have had abdominal surgery.

Abdomen↗
PubMed2003

Measurement of central venous pressure from a peripheral vein in infants and children.

BACKGROUND: Previous studies in adults have demonstrated a clinically useful correlation between central venous pressure (CVP) measured from a peripheral intravenous catheter and that measured from a central venous catheter. The current study prospectively compares CVP measurements from a central catheter and a peripheral catheter in infants and children. METHODS: The study cohort included patients younger than 12 years presenting for a surgical procedure for which central venous access was necessary. CVP was measured simultaneously every 15 minutes for a total of 10 measurements from the central venous catheter and the peripheral IV catheter using standard pressure transducers, which were zeroed at the phlebostatic axis. RESULTS: The cohort for the study included 30 infants and children ranging in age from 1 to 12 years. The peripheral IV catheter from which the CVP was measured ranged from a 24 to an 18 gauge. In 5 of the patients, there was no increase in the CVP value from the peripheral IV catheter in response to a sustained inspiratory breath or occlusion of the extremity above the catheter. In these 5 cases, the difference between the CVP measured from the central and peripheral catheter was 16 +/- 5 mm Hg versus 5 +/- 3 mm Hg in the other 25 patients (P < 0.0001). In the remaining 25 patients, the difference between the CVP measured from the peripheral and the central site was 5 +/- 3 mm Hg. There was no difference in the central versus peripheral CVP measurement depending on the size of the IV cannula, its location (upper versus lower extremity), or the patient's position. CONCLUSION: CVP can be measured from a peripheral IV catheter in infants and children provided that there is continuity with the central venous compartment demonstrated by showing an increase in the CVP from the peripheral IV catheter in response to a sustained inspiratory effort and by occlusion of the extremity above the site of the catheter.

Arm↗
PubMed2002

Anesthesia for minimally invasive neurosurgery.

Neurosurgerical techniques utilizing minimally invasive approaches will continue to emerge. For some of these future possibilities, anesthesia may not be required. Other types of neurosurgery, whether performed by humans or a machine, will require entry through the cranium and an absolute lack of movement. Anesthesia will keep pace with these innovations by accurately controlling the delivery of anesthetic to achieve optimal conditions. This control will allow for a safer, more comfortable surgical procedure while decreasing blood loss and morbidity associated with neurosurgery.

Anesthesia↗
PubMed2002

Noninvasive intraoperative monitoring of carbon dioxide in children: endtidal versus transcutaneous techniques.

BACKGROUND: The current study prospectively compares the accuracy of the intraoperative use of transcutaneous (Tc) and endtidal (PE) CO2 monitoring during surgical procedures in 30 paediatric patients, ranging in age from 6 months to 15 years (6.15 +/- 4.35 years) and in weight from 4.7 to 73 kg (24.9 +/- 18.2 kg). METHODS: Following calibration and an equilibration time for the TcCO2 monitor, arterial blood gas samples were obtained as clinically indicated. A total of 64 sample sets (PaCO2, PECO2 and TcCO2) were obtained from the 30 patients. RESULTS: The PECO2 to PaCO2 difference was 0.6-0.9 kPa (4.4 +/- 7.1 mmHg) while the TcCO2 to PaCO2 difference was 0.36-0.38 kPa (2.8 +/- 2.9 mmHg) (P=NS). The difference between the PaCO2 and PECO2 was 0.4 kPa (3 mmHg) or less in 37 of 64 sample sets while the difference between the PaCO2 and TcCO2 was 0.4 kPa (3 mmHg) or less in 49 of 64 sample sets (P=0.038). Linear regression analysis of PECO2 vs. PaCO2 revealed a slope of 0.434, r=0.8761, r2=0.7676. Linear regression analysis of TcCO2 vs. PaCO2 revealed a slope of 0.914, r=0.9472, r2=0.8972. CONCLUSIONS: Although in most circumstances, both noninvasive monitors of PCO2 provided a clinically acceptable estimate of PaCO2, TCCO2 provided a slightly more accurate estimate of PaCO2 during intraoperative anaesthetic care in children.

Anesthesia, General↗
PubMed2002

Anaesthetic implications of Nager syndrome.

Nager acrofacial dysostosis is an oromandibular hypogenesis syndrome with associated limb abnormalities. Although it shares some phenotypic features with Treacher-Collins syndrome, it is recognized as a separate disorder. The physical features of Nager syndrome include down slanted palpebral fissures, malar hypoplasia, a high nasal bridge, atretic external auditory canals, cleft palate and micrognathia. Preaxial limb malformations include absent or hypoplastic thumbs, hypoplasia of the radius and shortened humeral bones. Of primary concern to the anaesthetist are the midface and mandibular manifestations which may complicate perioperative airway management. These problems may also manifest in the postoperative period with airway obstruction. Associated defects have included vertebral malformations with reports of cervical spine involvement, congenital cardiac defects and upper limb defects affecting the preaxial or radial side. We describe a 7-year-old boy with Nager syndrome who required anaesthetic care during placement of a syringopleural shunt for drainage of a spinal cord syrinx. The perioperative implications of this disorder are reviewed.

Anesthesia, General↗
PubMed2002

Noninvasive carbon dioxide monitoring during neurosurgical procedures in adults: end-tidal versus transcutaneous techniques.

BACKGROUND: We prospectively compared transcutaneous (TC) versus end-tidal (ET) carbon dioxide monitoring during neurosurgical procedures in adults. METHODS: After calibration and an equilibration time for the TC-CO2 monitor, arterial blood gas (ABG) values were obtained as clinically indicated. The PaCO2 values were compared with the values recorded by the noninvasive monitors (TC and ET). RESULTS: The ET-CO2 to PaCO2 difference was 6.1 +/- 5.6 mm Hg, and the TC-CO2 to PaCO2 difference was 3.7 +/- 2.9 mm Hg. The difference between the PaCO2 and ET-CO2 was 3 mm Hg or less in 17 of 57 values, while the difference between the PaCO2 and TC-CO2 was 3 mm Hg or less in 35 of 57 values. Linear regression analysis of ET-CO2 versus PaCO2 revealed a slope of 0.381 +/- 0.007. Linear regression analysis of TC-CO2 versus PaCO2 revealed a slope of 1.17 +/- 0.008. CONCLUSION: Transcutaneous CO2 monitoring provides a more accurate estimate of PaCO2 than ET-CO2 monitoring during neurosurgical procedures.

Adolescent↗