Criteria of air flow and negative pressure for high volume dental suction

BDJ ◽  
1971 ◽  
Vol 130 (11) ◽  
pp. 483-487 ◽  
Author(s):  
M H Davies ◽  
M Rosen ◽  
J D Eccles ◽  
R J Marshal
1974 ◽  
Vol 2 (2) ◽  
pp. 131-141 ◽  
Author(s):  
John L. Poole ◽  
N. Abrahams ◽  
G. C. Fisk

Catheters for paediatric endotracheal suction were studied using an artificial lung with compliances in the range encountered in paediatric practice. With various combinations of “lung” compliance, size of endotracheal tube, endotracheal connector and catheter,” tracheal” pressure and air flow between endotracheal tube and catheter were measured. Recommendations for combinations of endotracheal tube, connector and catheter size are made. The maximum negative pressure applied to the catheter should be limited.


1980 ◽  
Vol 9 (2) ◽  
pp. 87-92 ◽  
Author(s):  
F H Howorth

Bacteria-carrying particles and exhaled anaesthetic gases are the two contaminants found in the air flow patterns of operating rooms. Their origin, direction and speed were illustrated by a motion picture using Schlieren photography and smoke tracers. Compared with a conventionally well air conditioned operating theatre, it was shown that a downward flow of clean air reduced the number of bacteria-carrying particles at the wound site by sixty times. The Exflow method of achieving this without the restriction of any side panels or floor obstruction was described. The total body exhaust worn by the surgical team was shown to reduce the bacteria count by a further eleven times. Clinical results show that when both these systems are used together, patient infection was reduced from 9 per cent to between 0.3 per cent and 0.5 per cent, even when no pre-operative antibiotics were used. Anaesthetic gas pollution was measured and shown to be generally 1000 p.p.m. at the head of the patient, in induction, operating and recovery rooms, also in dental and labour rooms. A high volume low pressure active scavenging system was described together with its various attachments including one specially for paediatric scavenging. Results showed a reduction of nitrous oxide pollution to between zero and 3 p.p.m. The economy and cost effectiveness of both these pollution control systems was shown to be good due to the removal of health hazards from patients and theatre staff.


2020 ◽  
Vol 10 (21) ◽  
pp. 52-74
Author(s):  
Tamás Molnár F.

Insufflation and arteficial aeration of the lungs are referenced in biblical times. Pneuma in its double meaning as air(oxygen) and soul have been inseparable since then. Induced and obstacle-free positive and negative intrapulmonary air flow challenged generations of surgeons from the late 19th century. Following a transient dominance of the extrathoracic negative pressure approach (Sauerbruch’s negative pressure concept) the transtracheal intrapulmonary alternating positive pressure concept won. Medical engineering played a decisive role in developing positive pressure machines. Till the 1950s ventilation and anaesthesia machines were combined and longterm arteficial ventilation was unavailable. The volume regulated Engström ventilator introduced in the 1952-3 polio epidemic was the game changer followed by other concepts, pressure ventilation included. Negative pressure chamber ventilation (iron lung and cuirass) saw a renaissance in the 1950s only to be replaced by intratratcheal ventilation by the end of the decade. Invasive ventilation became the norm till just recently when noninvasive breath support saw the second renaissance. COVID-19, a medico-political pandemic 2019-20 posed a new challenge to the intensive therapist, necessitating the review and maybe resuscitation of bygone philosophies and methods.


2021 ◽  
Vol 8 ◽  
Author(s):  
H. C. Albrecht ◽  
C. Amling ◽  
C. Menenakos ◽  
S. Gretschel

Background: Postoperative pancreatic fistula (POPF) is a major cause of morbidity after pancreaticoduodenectomy. There is no consensus on the best technique to protect the pancreato-enteric anastomosis and reduce the rate of POPF. This study investigated the feasibility and efficiency of external suction drainage of the pancreatic duct to improve the healing of pancreaticogastrostomy.Methods: Between July 2019 and June 2021, 21 consecutive patients undergoing elective pancreaticoduodenectomy were included. In all patients we performed a pancreaticogastrostomy and inserted a negative pressure drainage into the pancreatic duct. The length and diameter of the pancreatic duct were measured and the texture of the pancreas was evaluated. The daily secretion volume and the lipase value via pancreatic duct drainage were documented. The occurrence of POPF was evaluated.Results: None of the patients had drainage-related complications. In 4 patients we registered a dislocation of the drainage from the pancreas duct into the stomach. 17/21 Patients showed no signs of POPF. A biochemical leak was measured in one patient. Furthermore, 2 patients had a POPF grade B. In one patient, POPF grade C required reoperation and resection of the remnant pancreas. All 4 cases of POPF met the risk criteria soft pancreas, high volume and high lipase value in the duct drainage.Conclusion: The insertion of the pancreatic duct drainage was feasible and caused no drainage-related morbidity. POPF-rate was moderate in the risk population of soft pancreas and small duct.


2019 ◽  
Vol 12 (9) ◽  
pp. 4725-4731
Author(s):  
Richard Hann ◽  
Mark Hermanson

Abstract. Sampling the atmosphere to analyze contaminants is different from other environmental matrices because measuring the volume of air collected requires a mechanical flow-through device to draw the air and measure its flow rate. The device used must have the capability of concentrating the analytes of interest onto a different substrate because the volumes of air needed are often on the order of hundreds of cubic meters. The use of high-volume air samplers has grown since 1967, when recommended limits of a large number of organic contaminants in air were developed. Equations used for calculating the air flow through the device over time have similarly been developed. However, the complete derivation of those equations has never appeared in the scientific literature. Here a thorough derivation of those equations is provided with definitions of the mechanical systems that are used in the process, along with the method of calibrating and calculating air flow.


1965 ◽  
Vol 3 (1-2) ◽  
pp. 64-71
Author(s):  
Kosuke NOZAKI
Keyword(s):  
Air Flow ◽  

2019 ◽  
Vol 128 (6) ◽  
pp. 569-574 ◽  
Author(s):  
Ashley Dorneden ◽  
Garth Olson ◽  
Nathan Boyd

Objectives: Cervical chylous fistula is an uncommon but potentially severe occurrence associated with neck surgery. Methods for treating this problem have inconsistent efficacy and may result in lengthy hospital stays. Negative pressure wound therapy (NPWT) is a highly effective tool in the management of complex wounds. We report 3 cases where NPWT was successfully used to treat chylous fistulas following neck dissection. Methods: This is a retrospective chart review of 3 patients who developed chylous fistulas after neck dissection and were successfully treated with NPWT. Results: Chylous ouput ceased within 2 to 8 days of proper wound VAC placement. Hospital stays ranged from 6 to 47 days. Patients received altered diets, including TPN for 1 patient with high-flow output and nil-per-os (NPO) or clear liquids for the others. Patients received octreotide throughout their hospitalization. Conclusion: NPWT shows potential as a treatment option for both high-volume and low-volume chylous fistulas following neck dissection.


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